Depression
Posted: Sat May 10, 2008 3:51 pm
Causes of Depression
Depression has no single cause; often, it results from a combination of things. You may have no idea why depression has struck you.
Whatever its cause, depression is not just a state of mind. It is related to physical changes in the brain, and connected to an imbalance of a type of chemical that carries signals in your brain and nerves. These chemicals are called neurotransmitters.
Some of the more common factors involved in depression are:
• Family history. Genetics play an important part in depression. It can run in families for generations.
• Trauma and stress. Things like financial problems, the breakup of a relationship, or the death of a loved one can bring on depression. You can become depressed after changes in your life, like starting a new job, graduating from school, or getting married.
• Pessimistic personality. People who have low self-esteem and a negative outlook are at higher risk of becoming depressed. These traits may actually be caused by low-level depression (called dysthymia).
• Physical conditions. Serious medical conditions like heart disease, cancer, and HIV can contribute to depression, partly because of the physical weakness and stress they bring on. Depression can make medical conditions worse, since it weakens the immune system and can make pain harder to bear. In some cases, depression can be caused by medications used to treat medical conditions.
• Other psychological disorders. Anxiety disorders, eating disorders, schizophrenia, and (especially) substance abuse often appear along with depression.
Depression-Related Mood Disorders
Major depressive disorder, commonly referred to as "depression," can severely disrupt your life, affecting your appetite, sleep, work, and relationships.
The symptoms that help a doctor identify depression include:
• constant feelings of sadness, irritability, or tension
• decreased interest or pleasure in usual activities or hobbies
• loss of energy, feeling tired despite lack of activity
• a change in appetite, with significant weight loss or weight gain
• a change in sleeping patterns, such as difficulty sleeping, early morning awakening, or sleeping too much
• restlessness or feeling slowed down
• decreased ability to make decisions or concentrate
• feelings of worthlessness, hopelessness, or guilt
• thoughts of suicide or death
If you are experiencing any or several of these symptoms, you should talk to your doctor about whether you are suffering from depression.
If you are in an immediate serious crisis please contact your doctor or go to your local hospital or emergency room.
Dysthymia is another mood disorder. People who have it may feel mildly depressed on most days over a period of at least two years. They have many symptoms resembling major depression, but with less severity.
Symptoms of depression may surface with other mood disorders. They include seasonal major depression (also known as seasonal affective disorder), postpartum depression, and bipolar disorder.
Seasonal Affective Disorder has symptoms that are seen with any major depressive episode. It is the recurrence of the symptoms during certain seasons that is the hallmark of this type of depression.
Postpartum Depression is a type of depression that can occur in women who have recently given birth. It typically occurs in the first few months after delivery, but can happen within the first year after giving birth. The symptoms are those seen with any major depressive episode. Often, postpartum depression interferes with the mother's ability to bond with her newborn. It is very important to seek help if you are experiencing postpartum depression. Postpartum depression is different from the "Baby Blues", which tend to occur the first few days after delivery and resolve spontaneously.
What are the symptoms of depression?
People with depressive illnesses do not all experience the same symptoms. The severity, frequency and duration of symptoms will vary depending on the individual and his or her particular illness.
Symptoms include:
Persistent sad, anxious or "empty" feelings
Feelings of hopelessness and/or pessimism
Feelings of guilt, worthlessness and/or helplessness
Irritability, restlessness
Loss of interest in activities or hobbies once pleasurable, including sex
Fatigue and decreased energy
Difficulty concentrating, remembering details and making decisions
Insomnia, early–morning wakefulness, or excessive sleeping
Overeating, or appetite loss
Thoughts of suicide, suicide attempts
Persistent aches or pains, headaches, cramps or digestive problems that do not ease even with treatment
What illnesses often co-exist with depression?
Depression often co–exists with other illnesses. Such illnesses may precede the depression, cause it, and/or be a consequence of it. It is likely that the mechanics behind the intersection of depression and other illnesses differ for every person and situation. Regardless, these other co–occurring illnesses need to be diagnosed and treated.
Anxiety disorders, such as post–traumatic stress disorder (PTSD), obsessive–compulsive disorder, panic disorder, social phobia and generalized anxiety disorder, often accompany depression.3,4 People experiencing PTSD are especially prone to having co-occurring depression. PTSD is a debilitating condition that can result after a person experiences a terrifying event or ordeal, such as a violent assault, a natural disaster, an accident, terrorism or military combat.
People with PTSD often re–live the traumatic event in flashbacks, memories or nightmares. Other symptoms include irritability, anger outbursts, intense guilt, and avoidance of thinking or talking about the traumatic ordeal. In a National Institute of Mental Health (NIMH)–funded study, researchers found that more than 40 percent of people with PTSD also had depression at one-month and four-month intervals after the traumatic event.5
Alcohol and other substance abuse or dependence may also co–occur with depression. In fact, research has indicated that the co–existence of mood disorders and substance abuse is pervasive among the U.S. population. 6
Depression also often co–exists with other serious medical illnesses such as heart disease, stroke, cancer, hiv/aids, diabetes, and Parkinson's disease. Studies have shown that people who have depression in addition to another serious medical illness tend to have more severe symptoms of both depression and the medical illness, more difficulty adapting to their medical condition, and more medical costs than those who do not have co–existing depression.7 Research has yielded increasing evidence that treating the depression can also help improve the outcome of treating the co–occurring illness.8
What causes depression?
There is no single known cause of depression. Rather, it likely results from a combination of genetic, biochemical, environmental, and psychological factors.
Research indicates that depressive illnesses are disorders of the brain. Brain-imaging technologies, such as magnetic resonance imaging (MRI), have shown that the brains of people who have depression look different than those of people without depression. The parts of the brain responsible for regulating mood, thinking, sleep, appetite and behavior appear to function abnormally. In addition, important neurotransmitters–chemicals that brain cells use to communicate–appear to be out of balance. But these images do not reveal why the depression has occurred.
Some types of depression tend to run in families, suggesting a genetic link. However, depression can occur in people without family histories of depression as well.9 Genetics research indicates that risk for depression results from the influence of multiple genes acting together with environmental or other factors.10
In addition, trauma, loss of a loved one, a difficult relationship, or any stressful situation may trigger a depressive episode. Subsequent depressive episodes may occur with or without an obvious trigger.
How do women experience depression?
Depression is more common among women than among men. Biological, life cycle, hormonal and psychosocial factors unique to women may be linked to women's higher depression rate. Researchers have shown that hormones directly affect brain chemistry that controls emotions and mood. For example, women are particularly vulnerable to depression after giving birth, when hormonal and physical changes, along with the new responsibility of caring for a newborn, can be overwhelming. Many new mothers experience a brief episode of the "baby blues," but some will develop postpartum depression, a much more serious condition that requires active treatment and emotional support for the new mother. Some studies suggest that women who experience postpartum depression often have had prior depressive episodes.
Some women may also be susceptible to a severe form of premenstrual syndrome (PMS), sometimes called premenstrual dysphoric disorder (PMDD), a condition resulting from the hormonal changes that typically occur around ovulation and before menstruation begins. During the transition into menopause, some women experience an increased risk for depression. Scientists are exploring how the cyclical rise and fall of estrogen and other hormones may affect the brain chemistry that is associated with depressive illness.11
Finally, many women face the additional stresses of work and home responsibilities, caring for children and aging parents, abuse, poverty, and relationship strains. It remains unclear why some women faced with enormous challenges develop depression, while others with similar challenges do not.
How do men experience depression?
Men often experience depression differently than women and may have different ways of coping with the symptoms. Men are more likely to acknowledge having fatigue, irritability, loss of interest in once–pleasurable activities, and sleep disturbances, whereas women are more likely to admit to feelings of sadness, worthlessness and/or excessive guilt.12,13
Men are more likely than women to turn to alcohol or drugs when they are depressed, or become frustrated, discouraged, irritable, angry and sometimes abusive. Some men throw themselves into their work to avoid talking about their depression with family or friends, or engage in reckless, risky behavior. And even though more women attempt suicide, many more men die by suicide in the United States.14
How do older adults experience depression?
Depression is not a normal part of aging, and studies show that most seniors feel satisfied with their lives, despite increased physical ailments. However, when older adults do have depression, it may be overlooked because seniors may show different, less obvious symptoms, and may be less inclined to experience or acknowledge feelings of sadness or grief.15
In addition, older adults may have more medical conditions such as heart disease, stroke or cancer, which may cause depressive symptoms, or they may be taking medications with side effects that contribute to depression. Some older adults may experience what some doctors call vascular depression, also called arteriosclerotic depression or subcortical ischemic depression. Vascular depression may result when blood vessels become less flexible and harden over time, becoming constricted. Such hardening of vessels prevents normal blood flow to the body's organs, including the brain. Those with vascular depression may have, or be at risk for, a co–existing cardiovascular illness or stroke.16
Although many people assume that the highest rates of suicide are among the young, older white males age 85 and older actually have the highest suicide rate. Many have a depressive illness that their doctors may not detect, despite the fact that these suicide victims often visit their doctors within one month of their deaths.17
The majority of older adults with depression improve when they receive treatment with an antidepressant, psychotherapy, or a combination of both.18 Research has shown that medication alone and combination treatment are both effective in reducing the rate of depressive recurrences in older adults.19 Psychotherapy alone also can be effective in prolonging periods free of depression, especially for older adults with minor depression, and it is particularly useful for those who are unable or unwilling to take antidepressant medication.20, 21
How do children and adolescents experience depression?
Scientists and doctors have begun to take seriously the risk of depression in children. Research has shown that childhood depression often persists, recurs and continues into adulthood, especially if it goes untreated. The presence of childhood depression also tends to be a predictor of more severe illnesses in adulthood.22
A child with depression may pretend to be sick, refuse to go to school, cling to a parent, or worry that a parent may die. Older children may sulk, get into trouble at school, be negative and irritable, and feel misunderstood. Because these signs may be viewed as normal mood swings typical of children as they move through developmental stages, it may be difficult to accurately diagnose a young person with depression.
Before puberty, boys and girls are equally likely to develop depressive disorders. By age 15, however, girls are twice as likely as boys to have experienced a major depressive episode.23
Depression in adolescence comes at a time of great personal change–when boys and girls are forming an identity distinct from their parents, grappling with gender issues and emerging sexuality, and making decisions for the first time in their lives. Depression in adolescence frequently co–occurs with other disorders such as anxiety, disruptive behavior, eating disorders or substance abuse. It can also lead to increased risk for suicide. 22, 24
An NIMH–funded clinical trial of 439 adolescents with major depression found that a combination of medication and psychotherapy was the most effective treatment option.25 Other NIMH–funded researchers are developing and testing ways to prevent suicide in children and adolescents, including early diagnosis and treatment, and a better understanding of suicidal thinking.
How is depression detected and treated?
Depression, even the most severe cases, is a highly treatable disorder. As with many illnesses, the earlier that treatment can begin, the more effective it is and the greater the likelihood that recurrence can be prevented.
The first step to getting appropriate treatment is to visit a doctor. Certain medications, and some medical conditions such as viruses or a thyroid disorder, can cause the same symptoms as depression. A doctor can rule out these possibilities by conducting a physical examination, interview and lab tests. If the doctor can eliminate a medical condition as a cause, he or she should conduct a psychological evaluation or refer the patient to a mental health professional.
The doctor or mental health professional will conduct a complete diagnostic evaluation. He or she should discuss any family history of depression, and get a complete history of symptoms, e.g., when they started, how long they have lasted, their severity, and whether they have occurred before and if so, how they were treated. He or she should also ask if the patient is using alcohol or drugs, and whether the patient is thinking about death or suicide.
Once diagnosed, a person with depression can be treated with a number of methods. The most common treatments are medication and psychotherapy.
Medication
Antidepressants work to normalize naturally occurring brain chemicals called neurotransmitters, notably serotonin and norepinephrine. Other antidepressants work on the neurotransmitter dopamine. Scientists studying depression have found that these particular chemicals are involved in regulating mood, but they are unsure of the exact ways in which they work.
The newest and most popular types of antidepressant medications are called selective serotonin reuptake inhibitors (SSRIs). SSRIs include fluoxetine (Prozac), citalopram (Celexa), sertraline (Zoloft) and several others. Serotonin and norepinephrine reuptake inhibitors (SNRIs) are similar to SSRIs and include venlafaxine (Effexor) and duloxetine (Cymbalta). SSRIs and SNRIs are more popular than the older classes of antidepressants, such as tricyclics–named for their chemical structure–and monoamine oxidase inhibitors (MAOIs) because they tend to have fewer side effects. However, medications affect everyone differently–no one–size–fits–all approach to medication exists. Therefore, for some people, tricyclics or MAOIs may be the best choice.
People taking MAOIs must adhere to significant food and medicinal restrictions to avoid potentially serious interactions. They must avoid certain foods that contain high levels of the chemical tyramine, which is found in many cheeses, wines and pickles, and some medications including decongestants. MAOIs interact with tyramine in such a way that may cause a sharp increase in blood pressure, which could lead to a stroke. A doctor should give a patient taking an MAOI a complete list of prohibited foods, medicines and substances.
For all classes of antidepressants, patients must take regular doses for at least three to four weeks before they are likely to experience a full therapeutic effect. They should continue taking the medication for the time specified by their doctor, even if they are feeling better, in order to prevent a relapse of the depression. Medication should be stopped only under a doctor's supervision. Some medications need to be gradually stopped to give the body time to adjust. Although antidepressants are not habit–forming or addictive, abruptly ending an antidepressant can cause withdrawal symptoms or lead to a relapse. Some individuals, such as those with chronic or recurrent depression, may need to stay on the medication indefinitely.
In addition, if one medication does not work, patients should be open to trying another. NIMH–funded research has shown that patients who did not get well after taking a first medication increased their chances of becoming symptom–free after they switched to a different medication or added another medication to their existing one. 26,27
Sometimes stimulants, anti–anxiety medications, or other medications are used in conjunction with an antidepressant, especially if the patient has a co–existing mental or physical disorder. However, neither anti–anxiety medications nor stimulants are effective against depression when taken alone, and both should be taken only under a doctor's close supervision.
What are the side effects of antidepressants?
Antidepressants may cause mild and often temporary side effects in some people, but they are usually not long–term. However, any unusual reactions or side effects that interfere with normal functioning should be reported to a doctor immediately.
The most common side effects associated with SSRIs and SNRIs include:
Headache–usually temporary and will subside.
Nausea–temporary and usually short–lived.
Insomnia and nervousness (trouble falling asleep or waking often during the night)–may occur during the first few weeks but often subside over time or if the dose is reduced.
Agitation (feeling jittery).
Sexual problems–both men and women can experience sexual problems including reduced sex drive, erectile dysfunction, delayed ejaculation, or inability to have an orgasm.
Tricyclic antidepressants also can cause side effects including:
Dry mouth-it is helpful to drink plenty of water, chew gum, and clean teeth daily.
Constipation-it is helpful to eat more bran cereals, prunes, fruits, and vegetables.
Bladder problems–emptying the bladder may be difficult, and the urine stream may not be as strong as usual. Older men with enlarged prostate conditions may be more affected. The doctor should be notified if it is painful to urinate.
Sexual problems–sexual functioning may change, and side effects are similar to those from SSRIs.
Blurred vision–often passes soon and usually will not require a new corrective lenses prescription.
Drowsiness during the day–usually passes soon, but driving or operating heavy machinery should be avoided while drowsiness occurs. The more sedating antidepressants are generally taken at bedtime to help sleep and minimize daytime drowsiness.
FDA Warning on antidepressants
Despite the relative safety and popularity of SSRIs and other antidepressants, some studies have suggested that they may have unintentional effects on some people, especially adolescents and young adults. In 2004, the Food and Drug Administration (FDA) conducted a thorough review of published and unpublished controlled clinical trials of antidepressants that involved nearly 4,400 children and adolescents. The review revealed that 4% of those taking antidepressants thought about or attempted suicide (although no suicides occurred), compared to 2% of those receiving placebos.
To help a friend or relative:
Offer emotional support, understanding, patience and encouragement.
Engage your friend or relative in conversation, and listen carefully.
Never disparage feelings your friend or relative expresses, but point out realities and offer hope.
Never ignore comments about suicide, and report them to your friend's or relative's therapist or doctor.
Invite your friend or relative out for walks, outings and other activities. Keep trying if he or she declines, but don't push him or her to take on too much too soon. Although diversions and company are needed, too many demands may increase feelings of failure.
Remind your friend or relative that with time and treatment, the depression will lift.
How can I help myself if I am depressed?
If you have depression, you may feel exhausted, helpless and hopeless. It may be extremely difficult to take any action to help yourself. But it is important to realize that these feelings are part of the depression and do not accurately reflect actual circumstances. As you begin to recognize your depression and begin treatment, negative thinking will fade.
To help yourself:
Engage in mild activity or exercise. Go to a movie, a ballgame, or another event or activity that you once enjoyed. Participate in religious, social or other activities.
Set realistic goals for yourself.
Break up large tasks into small ones, set some priorities and do what you can as you can.
Try to spend time with other people and confide in a trusted friend or relative. Try not to isolate yourself, and let others help you.
Expect your mood to improve gradually, not immediately. Do not expect to suddenly "snap out of" your depression. Often during treatment for depression, sleep and appetite will begin to improve before your depressed mood lifts.
Postpone important decisions, such as getting married or divorced or changing jobs, until you feel better. Discuss decisions with others who know you well and have a more objective view of your situation.
Remember that positive thinking will replace negative thoughts as your depression responds to treatment.
Where can I go for help?
If you are unsure where to go for help, ask your family doctor. Others who can help are listed below.
Mental Health Resources:
Mental health specialists, such as psychiatrists, psychologists, social workers, or mental health counselors
Health maintenance organizations
Community mental health centers
Hospital psychiatry departments and outpatient clinics
Mental health programs at universities or medical schools
State hospital outpatient clinics
Family services, social agencies or clergy
Peer support groups
Private clinics and facilities
Employee assistance programs
Local medical and/or psychiatric societies
You can also check the phone book under "mental health," "health," "social services," "hotlines," or "physicians" for phone numbers and addresses. An emergency room doctor also can provide temporary help and can tell you where and how to get further help.
What if I or someone I know is in crisis?
If you are thinking about harming yourself, or know someone who is, tell someone who can help immediately.
Call your doctor.
Call 911 or go to a hospital emergency room to get immediate help or ask a friend or family member to help you do these things.
Call the toll-free, 24-hour hotline of the National Suicide Prevention Lifeline at 1-800-273-TALK (1-800-273-8255); TTY: 1-800-799-4TTY (4889) to talk to a trained counselor.
Make sure you or the suicidal person is not left alone.
For More Information
Visit the National Library of Medicine's MedlinePlus and En Español
For information on clinical trials for depression
National Library of Medicine Clinical Trials Database
Information from NIMH is available in multiple formats. You can browse online, download documents in PDF, and order paper brochures through the mail. If you would like to have NIMH publications, you can order them online at www.nimh.nih.gov. If you do not have Internet access and wish to have information that supplements this publication, please contact the NIMH Information Center at the numbers listed below.
Please check the NIMH Web site for the most up-to-date information on this topic.
National Institute of Mental Health
Science Writing, Press & Dissemination Branch
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Room 8184, MSC 9663
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Phone: 301-443-4513 or
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Depression has no single cause; often, it results from a combination of things. You may have no idea why depression has struck you.
Whatever its cause, depression is not just a state of mind. It is related to physical changes in the brain, and connected to an imbalance of a type of chemical that carries signals in your brain and nerves. These chemicals are called neurotransmitters.
Some of the more common factors involved in depression are:
• Family history. Genetics play an important part in depression. It can run in families for generations.
• Trauma and stress. Things like financial problems, the breakup of a relationship, or the death of a loved one can bring on depression. You can become depressed after changes in your life, like starting a new job, graduating from school, or getting married.
• Pessimistic personality. People who have low self-esteem and a negative outlook are at higher risk of becoming depressed. These traits may actually be caused by low-level depression (called dysthymia).
• Physical conditions. Serious medical conditions like heart disease, cancer, and HIV can contribute to depression, partly because of the physical weakness and stress they bring on. Depression can make medical conditions worse, since it weakens the immune system and can make pain harder to bear. In some cases, depression can be caused by medications used to treat medical conditions.
• Other psychological disorders. Anxiety disorders, eating disorders, schizophrenia, and (especially) substance abuse often appear along with depression.
Depression-Related Mood Disorders
Major depressive disorder, commonly referred to as "depression," can severely disrupt your life, affecting your appetite, sleep, work, and relationships.
The symptoms that help a doctor identify depression include:
• constant feelings of sadness, irritability, or tension
• decreased interest or pleasure in usual activities or hobbies
• loss of energy, feeling tired despite lack of activity
• a change in appetite, with significant weight loss or weight gain
• a change in sleeping patterns, such as difficulty sleeping, early morning awakening, or sleeping too much
• restlessness or feeling slowed down
• decreased ability to make decisions or concentrate
• feelings of worthlessness, hopelessness, or guilt
• thoughts of suicide or death
If you are experiencing any or several of these symptoms, you should talk to your doctor about whether you are suffering from depression.
If you are in an immediate serious crisis please contact your doctor or go to your local hospital or emergency room.
Dysthymia is another mood disorder. People who have it may feel mildly depressed on most days over a period of at least two years. They have many symptoms resembling major depression, but with less severity.
Symptoms of depression may surface with other mood disorders. They include seasonal major depression (also known as seasonal affective disorder), postpartum depression, and bipolar disorder.
Seasonal Affective Disorder has symptoms that are seen with any major depressive episode. It is the recurrence of the symptoms during certain seasons that is the hallmark of this type of depression.
Postpartum Depression is a type of depression that can occur in women who have recently given birth. It typically occurs in the first few months after delivery, but can happen within the first year after giving birth. The symptoms are those seen with any major depressive episode. Often, postpartum depression interferes with the mother's ability to bond with her newborn. It is very important to seek help if you are experiencing postpartum depression. Postpartum depression is different from the "Baby Blues", which tend to occur the first few days after delivery and resolve spontaneously.
What are the symptoms of depression?
People with depressive illnesses do not all experience the same symptoms. The severity, frequency and duration of symptoms will vary depending on the individual and his or her particular illness.
Symptoms include:
Persistent sad, anxious or "empty" feelings
Feelings of hopelessness and/or pessimism
Feelings of guilt, worthlessness and/or helplessness
Irritability, restlessness
Loss of interest in activities or hobbies once pleasurable, including sex
Fatigue and decreased energy
Difficulty concentrating, remembering details and making decisions
Insomnia, early–morning wakefulness, or excessive sleeping
Overeating, or appetite loss
Thoughts of suicide, suicide attempts
Persistent aches or pains, headaches, cramps or digestive problems that do not ease even with treatment
What illnesses often co-exist with depression?
Depression often co–exists with other illnesses. Such illnesses may precede the depression, cause it, and/or be a consequence of it. It is likely that the mechanics behind the intersection of depression and other illnesses differ for every person and situation. Regardless, these other co–occurring illnesses need to be diagnosed and treated.
Anxiety disorders, such as post–traumatic stress disorder (PTSD), obsessive–compulsive disorder, panic disorder, social phobia and generalized anxiety disorder, often accompany depression.3,4 People experiencing PTSD are especially prone to having co-occurring depression. PTSD is a debilitating condition that can result after a person experiences a terrifying event or ordeal, such as a violent assault, a natural disaster, an accident, terrorism or military combat.
People with PTSD often re–live the traumatic event in flashbacks, memories or nightmares. Other symptoms include irritability, anger outbursts, intense guilt, and avoidance of thinking or talking about the traumatic ordeal. In a National Institute of Mental Health (NIMH)–funded study, researchers found that more than 40 percent of people with PTSD also had depression at one-month and four-month intervals after the traumatic event.5
Alcohol and other substance abuse or dependence may also co–occur with depression. In fact, research has indicated that the co–existence of mood disorders and substance abuse is pervasive among the U.S. population. 6
Depression also often co–exists with other serious medical illnesses such as heart disease, stroke, cancer, hiv/aids, diabetes, and Parkinson's disease. Studies have shown that people who have depression in addition to another serious medical illness tend to have more severe symptoms of both depression and the medical illness, more difficulty adapting to their medical condition, and more medical costs than those who do not have co–existing depression.7 Research has yielded increasing evidence that treating the depression can also help improve the outcome of treating the co–occurring illness.8
What causes depression?
There is no single known cause of depression. Rather, it likely results from a combination of genetic, biochemical, environmental, and psychological factors.
Research indicates that depressive illnesses are disorders of the brain. Brain-imaging technologies, such as magnetic resonance imaging (MRI), have shown that the brains of people who have depression look different than those of people without depression. The parts of the brain responsible for regulating mood, thinking, sleep, appetite and behavior appear to function abnormally. In addition, important neurotransmitters–chemicals that brain cells use to communicate–appear to be out of balance. But these images do not reveal why the depression has occurred.
Some types of depression tend to run in families, suggesting a genetic link. However, depression can occur in people without family histories of depression as well.9 Genetics research indicates that risk for depression results from the influence of multiple genes acting together with environmental or other factors.10
In addition, trauma, loss of a loved one, a difficult relationship, or any stressful situation may trigger a depressive episode. Subsequent depressive episodes may occur with or without an obvious trigger.
How do women experience depression?
Depression is more common among women than among men. Biological, life cycle, hormonal and psychosocial factors unique to women may be linked to women's higher depression rate. Researchers have shown that hormones directly affect brain chemistry that controls emotions and mood. For example, women are particularly vulnerable to depression after giving birth, when hormonal and physical changes, along with the new responsibility of caring for a newborn, can be overwhelming. Many new mothers experience a brief episode of the "baby blues," but some will develop postpartum depression, a much more serious condition that requires active treatment and emotional support for the new mother. Some studies suggest that women who experience postpartum depression often have had prior depressive episodes.
Some women may also be susceptible to a severe form of premenstrual syndrome (PMS), sometimes called premenstrual dysphoric disorder (PMDD), a condition resulting from the hormonal changes that typically occur around ovulation and before menstruation begins. During the transition into menopause, some women experience an increased risk for depression. Scientists are exploring how the cyclical rise and fall of estrogen and other hormones may affect the brain chemistry that is associated with depressive illness.11
Finally, many women face the additional stresses of work and home responsibilities, caring for children and aging parents, abuse, poverty, and relationship strains. It remains unclear why some women faced with enormous challenges develop depression, while others with similar challenges do not.
How do men experience depression?
Men often experience depression differently than women and may have different ways of coping with the symptoms. Men are more likely to acknowledge having fatigue, irritability, loss of interest in once–pleasurable activities, and sleep disturbances, whereas women are more likely to admit to feelings of sadness, worthlessness and/or excessive guilt.12,13
Men are more likely than women to turn to alcohol or drugs when they are depressed, or become frustrated, discouraged, irritable, angry and sometimes abusive. Some men throw themselves into their work to avoid talking about their depression with family or friends, or engage in reckless, risky behavior. And even though more women attempt suicide, many more men die by suicide in the United States.14
How do older adults experience depression?
Depression is not a normal part of aging, and studies show that most seniors feel satisfied with their lives, despite increased physical ailments. However, when older adults do have depression, it may be overlooked because seniors may show different, less obvious symptoms, and may be less inclined to experience or acknowledge feelings of sadness or grief.15
In addition, older adults may have more medical conditions such as heart disease, stroke or cancer, which may cause depressive symptoms, or they may be taking medications with side effects that contribute to depression. Some older adults may experience what some doctors call vascular depression, also called arteriosclerotic depression or subcortical ischemic depression. Vascular depression may result when blood vessels become less flexible and harden over time, becoming constricted. Such hardening of vessels prevents normal blood flow to the body's organs, including the brain. Those with vascular depression may have, or be at risk for, a co–existing cardiovascular illness or stroke.16
Although many people assume that the highest rates of suicide are among the young, older white males age 85 and older actually have the highest suicide rate. Many have a depressive illness that their doctors may not detect, despite the fact that these suicide victims often visit their doctors within one month of their deaths.17
The majority of older adults with depression improve when they receive treatment with an antidepressant, psychotherapy, or a combination of both.18 Research has shown that medication alone and combination treatment are both effective in reducing the rate of depressive recurrences in older adults.19 Psychotherapy alone also can be effective in prolonging periods free of depression, especially for older adults with minor depression, and it is particularly useful for those who are unable or unwilling to take antidepressant medication.20, 21
How do children and adolescents experience depression?
Scientists and doctors have begun to take seriously the risk of depression in children. Research has shown that childhood depression often persists, recurs and continues into adulthood, especially if it goes untreated. The presence of childhood depression also tends to be a predictor of more severe illnesses in adulthood.22
A child with depression may pretend to be sick, refuse to go to school, cling to a parent, or worry that a parent may die. Older children may sulk, get into trouble at school, be negative and irritable, and feel misunderstood. Because these signs may be viewed as normal mood swings typical of children as they move through developmental stages, it may be difficult to accurately diagnose a young person with depression.
Before puberty, boys and girls are equally likely to develop depressive disorders. By age 15, however, girls are twice as likely as boys to have experienced a major depressive episode.23
Depression in adolescence comes at a time of great personal change–when boys and girls are forming an identity distinct from their parents, grappling with gender issues and emerging sexuality, and making decisions for the first time in their lives. Depression in adolescence frequently co–occurs with other disorders such as anxiety, disruptive behavior, eating disorders or substance abuse. It can also lead to increased risk for suicide. 22, 24
An NIMH–funded clinical trial of 439 adolescents with major depression found that a combination of medication and psychotherapy was the most effective treatment option.25 Other NIMH–funded researchers are developing and testing ways to prevent suicide in children and adolescents, including early diagnosis and treatment, and a better understanding of suicidal thinking.
How is depression detected and treated?
Depression, even the most severe cases, is a highly treatable disorder. As with many illnesses, the earlier that treatment can begin, the more effective it is and the greater the likelihood that recurrence can be prevented.
The first step to getting appropriate treatment is to visit a doctor. Certain medications, and some medical conditions such as viruses or a thyroid disorder, can cause the same symptoms as depression. A doctor can rule out these possibilities by conducting a physical examination, interview and lab tests. If the doctor can eliminate a medical condition as a cause, he or she should conduct a psychological evaluation or refer the patient to a mental health professional.
The doctor or mental health professional will conduct a complete diagnostic evaluation. He or she should discuss any family history of depression, and get a complete history of symptoms, e.g., when they started, how long they have lasted, their severity, and whether they have occurred before and if so, how they were treated. He or she should also ask if the patient is using alcohol or drugs, and whether the patient is thinking about death or suicide.
Once diagnosed, a person with depression can be treated with a number of methods. The most common treatments are medication and psychotherapy.
Medication
Antidepressants work to normalize naturally occurring brain chemicals called neurotransmitters, notably serotonin and norepinephrine. Other antidepressants work on the neurotransmitter dopamine. Scientists studying depression have found that these particular chemicals are involved in regulating mood, but they are unsure of the exact ways in which they work.
The newest and most popular types of antidepressant medications are called selective serotonin reuptake inhibitors (SSRIs). SSRIs include fluoxetine (Prozac), citalopram (Celexa), sertraline (Zoloft) and several others. Serotonin and norepinephrine reuptake inhibitors (SNRIs) are similar to SSRIs and include venlafaxine (Effexor) and duloxetine (Cymbalta). SSRIs and SNRIs are more popular than the older classes of antidepressants, such as tricyclics–named for their chemical structure–and monoamine oxidase inhibitors (MAOIs) because they tend to have fewer side effects. However, medications affect everyone differently–no one–size–fits–all approach to medication exists. Therefore, for some people, tricyclics or MAOIs may be the best choice.
People taking MAOIs must adhere to significant food and medicinal restrictions to avoid potentially serious interactions. They must avoid certain foods that contain high levels of the chemical tyramine, which is found in many cheeses, wines and pickles, and some medications including decongestants. MAOIs interact with tyramine in such a way that may cause a sharp increase in blood pressure, which could lead to a stroke. A doctor should give a patient taking an MAOI a complete list of prohibited foods, medicines and substances.
For all classes of antidepressants, patients must take regular doses for at least three to four weeks before they are likely to experience a full therapeutic effect. They should continue taking the medication for the time specified by their doctor, even if they are feeling better, in order to prevent a relapse of the depression. Medication should be stopped only under a doctor's supervision. Some medications need to be gradually stopped to give the body time to adjust. Although antidepressants are not habit–forming or addictive, abruptly ending an antidepressant can cause withdrawal symptoms or lead to a relapse. Some individuals, such as those with chronic or recurrent depression, may need to stay on the medication indefinitely.
In addition, if one medication does not work, patients should be open to trying another. NIMH–funded research has shown that patients who did not get well after taking a first medication increased their chances of becoming symptom–free after they switched to a different medication or added another medication to their existing one. 26,27
Sometimes stimulants, anti–anxiety medications, or other medications are used in conjunction with an antidepressant, especially if the patient has a co–existing mental or physical disorder. However, neither anti–anxiety medications nor stimulants are effective against depression when taken alone, and both should be taken only under a doctor's close supervision.
What are the side effects of antidepressants?
Antidepressants may cause mild and often temporary side effects in some people, but they are usually not long–term. However, any unusual reactions or side effects that interfere with normal functioning should be reported to a doctor immediately.
The most common side effects associated with SSRIs and SNRIs include:
Headache–usually temporary and will subside.
Nausea–temporary and usually short–lived.
Insomnia and nervousness (trouble falling asleep or waking often during the night)–may occur during the first few weeks but often subside over time or if the dose is reduced.
Agitation (feeling jittery).
Sexual problems–both men and women can experience sexual problems including reduced sex drive, erectile dysfunction, delayed ejaculation, or inability to have an orgasm.
Tricyclic antidepressants also can cause side effects including:
Dry mouth-it is helpful to drink plenty of water, chew gum, and clean teeth daily.
Constipation-it is helpful to eat more bran cereals, prunes, fruits, and vegetables.
Bladder problems–emptying the bladder may be difficult, and the urine stream may not be as strong as usual. Older men with enlarged prostate conditions may be more affected. The doctor should be notified if it is painful to urinate.
Sexual problems–sexual functioning may change, and side effects are similar to those from SSRIs.
Blurred vision–often passes soon and usually will not require a new corrective lenses prescription.
Drowsiness during the day–usually passes soon, but driving or operating heavy machinery should be avoided while drowsiness occurs. The more sedating antidepressants are generally taken at bedtime to help sleep and minimize daytime drowsiness.
FDA Warning on antidepressants
Despite the relative safety and popularity of SSRIs and other antidepressants, some studies have suggested that they may have unintentional effects on some people, especially adolescents and young adults. In 2004, the Food and Drug Administration (FDA) conducted a thorough review of published and unpublished controlled clinical trials of antidepressants that involved nearly 4,400 children and adolescents. The review revealed that 4% of those taking antidepressants thought about or attempted suicide (although no suicides occurred), compared to 2% of those receiving placebos.
To help a friend or relative:
Offer emotional support, understanding, patience and encouragement.
Engage your friend or relative in conversation, and listen carefully.
Never disparage feelings your friend or relative expresses, but point out realities and offer hope.
Never ignore comments about suicide, and report them to your friend's or relative's therapist or doctor.
Invite your friend or relative out for walks, outings and other activities. Keep trying if he or she declines, but don't push him or her to take on too much too soon. Although diversions and company are needed, too many demands may increase feelings of failure.
Remind your friend or relative that with time and treatment, the depression will lift.
How can I help myself if I am depressed?
If you have depression, you may feel exhausted, helpless and hopeless. It may be extremely difficult to take any action to help yourself. But it is important to realize that these feelings are part of the depression and do not accurately reflect actual circumstances. As you begin to recognize your depression and begin treatment, negative thinking will fade.
To help yourself:
Engage in mild activity or exercise. Go to a movie, a ballgame, or another event or activity that you once enjoyed. Participate in religious, social or other activities.
Set realistic goals for yourself.
Break up large tasks into small ones, set some priorities and do what you can as you can.
Try to spend time with other people and confide in a trusted friend or relative. Try not to isolate yourself, and let others help you.
Expect your mood to improve gradually, not immediately. Do not expect to suddenly "snap out of" your depression. Often during treatment for depression, sleep and appetite will begin to improve before your depressed mood lifts.
Postpone important decisions, such as getting married or divorced or changing jobs, until you feel better. Discuss decisions with others who know you well and have a more objective view of your situation.
Remember that positive thinking will replace negative thoughts as your depression responds to treatment.
Where can I go for help?
If you are unsure where to go for help, ask your family doctor. Others who can help are listed below.
Mental Health Resources:
Mental health specialists, such as psychiatrists, psychologists, social workers, or mental health counselors
Health maintenance organizations
Community mental health centers
Hospital psychiatry departments and outpatient clinics
Mental health programs at universities or medical schools
State hospital outpatient clinics
Family services, social agencies or clergy
Peer support groups
Private clinics and facilities
Employee assistance programs
Local medical and/or psychiatric societies
You can also check the phone book under "mental health," "health," "social services," "hotlines," or "physicians" for phone numbers and addresses. An emergency room doctor also can provide temporary help and can tell you where and how to get further help.
What if I or someone I know is in crisis?
If you are thinking about harming yourself, or know someone who is, tell someone who can help immediately.
Call your doctor.
Call 911 or go to a hospital emergency room to get immediate help or ask a friend or family member to help you do these things.
Call the toll-free, 24-hour hotline of the National Suicide Prevention Lifeline at 1-800-273-TALK (1-800-273-8255); TTY: 1-800-799-4TTY (4889) to talk to a trained counselor.
Make sure you or the suicidal person is not left alone.
For More Information
Visit the National Library of Medicine's MedlinePlus and En Español
For information on clinical trials for depression
National Library of Medicine Clinical Trials Database
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Please check the NIMH Web site for the most up-to-date information on this topic.
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