The disorder usually appears around the age of 25 and affects men and women equally. Children are rarely affected. The cause is unknown, but genetics do seem to be involved. Relatives of people with bipolar affective disorder and depression are more likely to be affected.

There are different types of bipolar affective disorder. Bipolar I is the classic form of the condition, with discrete periods of mania alternating with depression. In a person with bipolar II, the depressive phase predominates and there is no true mania. There may be periods of elevated mood and energy in which the person doesn't completely lose touch with reality (hypomania).

People with bipolar II may appear to have depression rather than bipolar affective disorder (especially since few people complain about periods of good mood and energy that don't cause problems), but mood stabilizers seem to help more than antidepressants.

Bipolar affective disorder results in pathological mood swings from mania to depression, which have a tendency to recur and subside spontaneously. Either the manic or the depressive episodes can predominate and produce few mood swings, or the patterns of mood swings may be cyclic, often starting with mania that ends in a crash into deep depression.

Some people are known as rapid cyclers because their mood may change several times a day. Others have what are called "mixed states," where depressed thoughts can intrude on an episode of mania, or vice versa. When bipolar affective disorder occurs in children, it usually appears as mixed states.

In the depressive phase:

• loss of self-esteem
• withdrawal
• feelings of helplessness or worthlessness
• excessive or inappropriate guilt
• fatigue (tiredness or weariness) lasting for weeks to months
• overwhelming sluggishness (inertia)
• persistent daytime sleepiness
• insomnia
• difficulty concentrating, easily distracted by inconsequential event(s)
• difficulty making decisions
• loss of appetite
• weight loss (unintentional)
• abnormal thoughts about death
• thoughts about suicide, plans to commit suicide, or suicide attempt(s)
• diminished interest in daily activities
• diminished pleasure in activities that a person once enjoyed

In the manic phase:

• elevated mood
• increase in goal-directed activities
• flight of ideas or racing thoughts
• inflated self-esteem
• decreased need for sleep
• agitation
• more talkative than usual or feeling pressure to keep talking
• increased purposeless activity (pacing, hand wringing)
• extreme restlessness
• weight gain (unintentional)
• poor temper control
• excessively irresponsible behavior pattern
• increased goal-directed social or sexual activity
• excessive involvement in pleasurable activities with high potential for painful consequences (spending sprees, unsafe sex with multiple partners, alcohol and other drug binges)
• false beliefs (delusions)
• hallucinations

Note: Manic and depressive symptoms may occur simultaneously or in quick succession in what is called a mixed state.

A psychiatric history of mood swings and observation of current behavior and mood are critical in diagnosing this disorder. Obtaining information from family members regarding the patient's behavior is also helpful. It is important to inquire about family history.

A physical examination as well as some laboratory tests (thyroid and drug screen) may be performed to rule out other causes for the symptoms, though use of recreational drugs does not rule out bipolar affective disorder, as it may be a symptom. People with this condition are at increased risk of substance misuse disorders.

Hospitalization may be required during an acute phase to control the symptoms and for the safety of the patient.

The mainstay of treatment are mood-stabilizing medications (such as valproic acid, lithium, and carbamazepine) which are effective for both the manic and the depressive phases as well as in preventing recurrence.

Antidepressant drugs may be given during the depressive phase, while neuroleptic (antipsychotic) drugs and benzodiazepines are often used to control mania in the acute phase.

Patients usually must take a mood stabilizer before antidepressants are given, since giving an antidepressant without a mood stabilizer may result in the patient becoming manic.

In severe cases, electroconvulsive therapy (ECT) may be used to treat persistent depression. ECT is a psychiatric treatment that causes a seizure of the central nervous system by means of an electrical current. It is used to treat severe depression and can be effective in manic disorders.

Psychotherapy may also be needed for emotional support during the depressive and manic phases.

Treatment with mood-stabilizing medication can prevent recurrence of symptoms. However, many people with this condition stop taking the medication as soon as they feel better, or because they want to experience the period preceding mania that can be productive and creative.

Some people are almost "addicted" to the experience of this state, and it takes many negative consequences before they recognize the need to stay on medication.

Proper medication use is also difficult to sustain because of side effects. People with this condition and their families need support to encourage proper medication use and to ensure that any episodes of mania and depression that do occur are treated as early as possible.

Suicide in both phases is a very real risk and suicidal thoughts, ideas, and gestures in people with bipolar affective disorder require emergency attention.

Disruption of relationships, work, and finances is common. Alcohol and other drug problems are another common complication.

Call your health care provider or mental health professional if you experience symptoms of bipolar affective disorder.

There is no known way to prevent this condition, but maintaining good and regular sleep habits may prevent switches into mania.