Bipolar disorder, formerly known as manic-depressive disorder,
is a very severe and relatively common mental illness characterized by extreme mood swings
between episodes of emotional highs and lows, that is, between mania or hypomania and depression.
The episodes can last anywhere from several weeks to several months. Depressive episodes typically
last longer than manic or hypomanic episodes. Some patients only have a
few episodes during their lifetime, while others experience multiple episodes a year.
In between episodes, patients may have residual symptoms, or no symptoms at all.
Bipolar disorder can occur at any age, but it is most often diagnosed in teens and young adults.
The cause likely involves complex interactions of biological and psychological factors. Bipolar
disorder is perhaps the most heritable psychiatric disorder. It has a significant genetic component
that implicates multiple genes. The condition is associated with neurodegeneration in some brain
areas, dysregulation of several neurotransmitters, and hormone imbalances. Stressful life events, as
well as substance abuse and certain medications, can trigger episodes or exacerbate symptoms.
There are several types of bipolar disorder: Bipolar I disorder is defined as having at least
one full-blown manic episode, with or without depressive episodes.
Bipolar II disorder is when patients have at least one major depressive episode
and at least one hypomanic episode, but never had a full-blown manic episode.
Cyclothymic disorder is when patients have at least two years of both hypomanic and
depressive episodes, but never had a major depressive or a full-blown manic episode.
Other types include disorders with clear bipolar pattern but the episodes
do not meet the criteria for any specific type. A manic episode is defined as at least one week
of a persistently elevated or irritable mood with at least 3 of the following symptoms:
- Increased energy or irritability - Decreased need for sleep
- Inflated sense of self-worth or confidence - Unusual talkativeness, rapid flow of speech
- Racing of thoughts - Increased distractibility
- and participating in high-risk activities without regard for consequences
Lack of judgement, increased energy and exaggerated self-confidence may lead to
dangerous behaviors that can harm both the patient and people around them. In some cases,
mania may trigger a complete break from reality, known as psychosis.
Hypomania is a milder form of mania. A hypomanic episode is defined as having at least
4 days of at least 3 manic symptoms as listed, but with lower severity. Normal function is not
markedly impaired, and for some patients, it may be perceived as a welcomed development.
A major depressive episode is defined as at least 2 weeks of at least 5 of the following symptoms:
- Depressed mood, feeling sad or hopeless - Loss of interest in all or almost all activities
- Significant weight gain or loss; or increased or decreased appetite
- Difficulty sleeping or sleeping too much - Increased restlessness or unusual sluggishness
- Fatigue - Feeling worthless or guilty,
fixating on past failures or mistakes - Difficulty thinking,
concentrating or making decisions - Having suicidal thoughts or attempts
A small number of patients may have mixed episodes with alternate manic and depressive symptoms.
Mixed episodes are considered most severe, as risk of suicide is high, and prognosis is poor.
Diagnosis is based on criteria for bipolar disorders published by the
American Psychiatric Association. Physical conditions, such as hyperthyroidism,
and substance use, must be ruled out. Medications typically include mood stabilizers
such as lithium, and antipsychotics. Because antidepressants may trigger manic episodes,
they are usually prescribed in combination with a mood stabilizer or antipsychotic,
and only for severe depression. It may take some time to establish
the right medications and dosage. Patients must be monitored for adverse effects.
Electroconvulsive therapy, in which electrical currents induce a brief seizure,
may be a good option for people who do not respond to, or cannot take medications.
Psychotherapy is generally more effective for depressive episodes because manic patients tend
to believe they are in their best mental state. Psychoeducation, together with support systems,
are an important part of long-term treatment plan to prevent future episodes.