Each year, almost 44 million Americans experience a mental disorder (U.S. Department of Health and Human Services, 2002). In fact, mental illnesses are among the most common conditions affecting health today. Researchers believe most serious mental illnesses are caused by complex imbalances in the brain’s chemical activity. They also believe environmental factors can play a part in triggering, or protecting against, the onset of mental illness.

Mood disorders are one form of serious mental illness. This fact sheet is intended to be a starting point for gaining an understanding about two of the most common mood disorders: depression and bipolar disorder, also known as manic-depressive illness. It is by no means exhaustive, nor does it include the full range of symptoms and treatments. Keep in mind that new research can yield rapid and dramatic changes in our understanding of, and approaches to, mental disorders.

Like other diseases, mental illnesses can be treated. The good news is that most people who have mental illnesses, even serious ones, can lead productive lives with proper treatment. If you believe you or a loved one has a mood disorder, seek advice from a competent professional.

Bipolar Disorder

Extreme mood swings punctuated by periods of generally even-keeled behavior characterize bipolar disorder. For example, a person with this disorder may soar with happiness and feel capable of “taking on the world” for a while, only to be immobilized by crushing sadness and a sense of worthlessness some time later.

Bipolar disorder tends to run in families. This disorder typically begins in the midtwenties and continues throughout life. It affects approximately 1.2 percent of the adult population, or almost 2.3 million individuals (National Alliance for the Mentally Ill, 2001). Without treatment, people with bipolar disorder often encounter devastating life events such as marital breakups, job loss, substance abuse, and suicide.


  • Mania – expansive or irritable mood, inflated self-esteem, decreased need for sleep; increased energy; racing thoughts; feelings of invulnerability; poor judgment; heightened sex drive; and denial that anything is wrong.
  • Depression – feelings of hopelessness, guilt, worthlessness, or melancholy; fatigue; loss of appetite for food or sex; sleep disturbances, thoughts of death or suicide; and suicide attempts.

Mania and depression may vary in both duration and degree of intensity.

Formal Diagnosis: Although scientific evidence indicates that bipolar disorder is caused by chemical imbalances in the brain, there is no existing lab test to diagnose the disorder. In fact, this mental illness often goes unrecognized by the person who has it, as well as relatives, friends, and even physicians.

If you suspect someone you know or love has bipolar disorder, you may actively have to help that person find appropriate treatment. It may also help to realize that this is a long-term illness: people who have it usually require treatment for the rest of their lives.

The first step of diagnosis is to receive a complete medical evaluation to rule out any other mental or physical disorders. Anyone who has this mental illness should be under the care of a psychiatrist skilled in the diagnosis and treatment of bipolar disorder.

Treatment: Eighty to 90 percent of people who have bipolar disorder can be treated effectively with medication and psychotherapy (National Alliance for the Mentally Ill, 2001). Self-help groups can offer emotional support and assistance in recognizing signs of relapse in order to avert a full-blown episode of bipolar disorder. The three most commonly prescribed medications to treat bipolar disorder are: lithium carbonate, carbamazepine, and valproate.


Everyone feels down in the dumps sometimes, especially when life’s unavoidable pitfalls make just getting through the day a challenge. But when a person’s feelings of sadness persist beyond a few weeks, he or she may have depression. Three to four million men are affected by depression; it affects twice as many women (National Institute for Mental Health, 2002).

To a lesser extent than with bipolar disorder, depression appears to run in families. However, researchers do not know the exact mechanisms that trigger depression. Two neurotransmitters (natural substances that allow brain cells to communicate with one another) are implicated in depression: serotonin and norepinephrine.


  • Changes in appetite and sleeping patterns;
  • feelings of worthlessness, hopelessness, and inappropriate guilt;
  • loss of interest or pleasure in formerly important activities;
  • fatigue;
  • inability to concentrate;
  • overwhelming sadness;
  • disturbed thinking;
  • physical symptoms such as headaches or stomachaches;
  • and suicidal thoughts or behaviors.

Formal Diagnosis: Four or more of the above symptoms have been present continually, or most of the time, for more than 2 weeks. The term clinical depression merely means the episode of depression is serious enough to require treatment. Major depression is marked by far more severe symptoms, such as literally being unable to drag oneself out of bed. Another form of depression, known as seasonal affective disorder, is associated with seasonal changes in the amount of available daylight.

Treatment: More than 80 percent of individuals affected by depressive disorders will improve with proper treatment (National Institute for Mental Health, 2001). Some types of cognitive/behavioral therapy and interpersonal therapy may be as effective as medications for some people. In general, psychiatrists agree that people with severe depression do better with medication or with a combination of medication and psychotherapy. Special therapy with a bright light helps many people who have seasonal affective disorder.

Three major types of medication are used to treat depression: tricyclics, the newer selective serotonin re-uptake inhibitors (SSRIs), and monoamine oxidase inhibitors (MAO inhibitors). The tricyclics and the SSRIs are most often prescribed for people with depression that is characterized by fatigue; feelings of hopelessness, helplessness and excessive guilt; inability to feel pleasure; and loss of appetite with resulting weight loss. Although MAO inhibitors are not usually prescribed as a first-line medication, they may be prescribed for people whose depression has not been lifted by other drugs or therapies. These and other medications often have side effects. In addition, it may not be appropriate to prescribe antidepressants for certain individuals with other medical conditions.

Electroconvulsive therapy uses small amounts of electricity applied to the scalp to affect neurotransmitters in the brain. Usually referred to as ECT, this highly controversial and potentially life-saving technique is considered only when other therapies have failed, when a person is seriously medically ill and/or unable to take medication, or when a person is bordering on suicide. Substantial improvements in the equipment, dosing guidelines and anesthesia have significantly reduced the possibility of side effects.

For more information about mood disorders and referrals to specialists and self-help groups in your State, contact:

National Foundation for Depressive Illness
P.O. Box 2257
New York, NY 10016
Telephone: 800-239-1265
NIMH Depression Page

Depression and Bipolar Support Alliance (DBSA)
(formerly the National Depressive and Manic-Depressive Association)
730 N. Franklin Street, Suite 501
Telephone: 800-826-3632
Fax: 312-642-7243

Note: These are suggested resources. It is not meant to be a complete list.