What is bipolar disorder?

Bipolar disorder¹ (BD), previously referred to as manic depressive illness or manic depression, is a mental disorder characterized by emotional shifts called “mood swings” that range from high (manic) to low (depressed).

These changes in mood² are different from typical mood swings because of their severity. They can be so intense that they may interfere with your job or school performance, damage your relationships, or disrupt your ability to function normally in your daily life. Mood swings³ generally affect a person’s mood, energy, activity levels, concentration, and the ability to carry out routine tasks.

Manic episodes are characterized by energized or irritable behaviors, while depressive episodes involve sad, hopeless, or indifferent behavior. These episodes may occur rarely or as frequently as several times a year⁴.

Bipolar disorder is separated into three subtypes: bipolar 1 disorder, bipolar 2 disorder, and cyclothymic disorder⁵. All three subtypes involve distinct mood changes and alterations in activity or energy levels.

The two most successful treatments for bipolar disorder, which may be used individually or together, are medication and psychotherapy. While bipolar disorder is a lifelong condition and cannot be cured, these treatments can help manage the disorder with the help of a mental healthcare provider, such as a psychiatrist.

Bipolar 1 and bipolar 2

The first two subtypes of bipolar disorder are bipolar 1 and bipolar 2.

Both of these subtypes are characterized as featuring depressive episodes (bipolar depression). Bipolar depression⁶ was previously categorized as general depression. However, research suggests that there are integral differences between the two disorders, specifically in terms of effective treatment options.

Bipolar disorder in general is noted as featuring distinct “highs” and “lows.” Bipolar depression is different from unipolar (or “regular”) depression, such as major depressive disorder, because of these “highs.” Some symptoms are more common in bipolar depression than in regular depression, such as irritability, guilt, unpredictable mood swings, and feelings of restlessness. People with bipolar depression may also move or speak slowly, sleep more than is normal, and experience weight gain.

Where bipolar 1 and 2 differ is in the severity and duration of the “highs,” or mania, experienced.

Bipolar 1 disorder is the form of BD in which a person flips between depressive symptoms and at least one instance of full-blown mania (called a manic episode) that lasts for at least 7 days. A manic episode⁷ is defined as a distinct period of abnormally and persistently elevated, expansive, or irritable mood that lasts at least seven days and/or occurs with such severity that immediate hospital care is needed. Manic episodes may occur before or after a hypomanic episode (just under manic) or major depressive episode⁴. In some cases, severe mania may trigger a break from reality (called psychosis).

Bipolar 2 disorder⁸ also features a pattern of depressive episodes and elevated states. However, the depressive episodes seen in people with bipolar 2 commonly last longer than those in bipolar 1 (diagnostically, each episode must last for at least two weeks). Additionally, the agitation or elevated mood seen in bipolar 2 is milder than in bipolar 1. This is called hypomania. Hypomanic episodes⁹, or instances of hypomania, are characterized by feelings of euphoria, high energy, and high productivity that do not turn into full-blown mania. Hypomania¹⁰ is defined by milder manic symptoms that are present for at least 4 days (rather than 7 days, which is characteristic of the mania in bipolar 1).

Bipolar 2 disorder is not a mild form of bipolar 1—it is an entirely separate diagnosis. As bipolar 2 does not present with full-blown manic episodes, it can be harder to diagnose than bipolar 1. Because of this, patients with bipolar 2 disorder are more likely to receive an incorrect diagnosis¹¹ than those with bipolar 1.

Cyclothymic disorder

Cyclothymia¹², or cyclothymic disorder, is the third subset of bipolar disorder. It is a rare mood disorder that causes ups and downs that are similar to—but not as severe as—those seen in bipolar 1 and 2.

Patients with cyclothymic disorder experience emotional shifts that are higher and lower than their baseline (average) mood. Like bipolar 2 disorder, cyclothymia’s “highs” consist of periods of mild, shorter-lasting manic symptoms known as hypomanic episodes. The “lows” of the disorder feature periods of mild to moderate depressive symptoms. Between these ups and downs, patients may feel stable and remain at their baseline mood.

Diagnostically, cyclothymia features hypomanic symptoms and periods of depressive symptoms that last for at least 2 years (or at least 1 year, in children and adolescents). Cyclothymia is diagnosed when a patient’s symptoms are not severe or long-lasting enough to meet the criteria for diagnosing bipolar 1 or 2. However, these symptoms often interfere with day-to-day life.

How common is bipolar disorder?

Bipolar disorder affects¹³ about 45 million people worldwide, and approximately 2.3 million¹⁴ people in the United States (nearly 1% of the population). Both men and women are equally likely¹⁵ to develop the disorder.

Bipolar disorder can occur at any age, but usually develops in adolescence or early adulthood. Bipolar disorder rarely develops in people older than age 40.

Bipolar disorder causes

Researchers are not fully certain what causes¹⁶ bipolar disorder. It is believed that a number of factors can contribute to a person developing the disorder, including:

• Biological differences: Some studies¹⁷ indicate that people with BD may have slightly different brain structures than those without the condition.

• Genetics: Researchers believe there may be a combination of genes associated with having bipolar disorder, as the disorder is more common in those with a first-degree relative with the condition.

In addition to underlying causes (such as a genetic predisposition to developing bipolar disorder), researchers believe external environmental and psychological factors can “trigger” new manic or depressive episodes in some cases. Examples of potential triggers¹⁸ include:

• Stress: Drastic changes to a person’s life (negative or positive), such as the death of a loved one, moving, getting married, or losing one’s job, can all act as triggers to someone who is predisposed to bipolar disorder.
• Substance abuse: Certain drugs, such as cocaine, ecstasy, and amphetamines, can trigger manic episodes, while alcohol and tranquilizers can trigger depression.
• Medication: Certain medications, including antidepressants, cold medicines, appetite suppressants, caffeine, corticosteroids, and thyroid medications, have been known to trigger manic episodes.
• Seasonal changes: Some people find their episodes of mania or depression follow a seasonal pattern, with manic episodes occurring more frequently in the summer and depressive episodes more frequently in the fall, winter, and spring.
• Sleep deprivation: Persistent loss of sleep, even if it is just a few hours per night, can trigger a manic episode.

Risk factors for bipolar disorder

Some factors¹⁹ may increase your risk of developing bipolar disorder, including:

• Having a first degree relative (such as a parent or sibling) who has bipolar disorder
• Periods of high stress or traumatic events, such as the death of a loved one
• Drug or alcohol abuse

Bipolar disorder symptoms

The symptoms of bipolar disorder vary depending on whether a person is experiencing a manic or depressive episode. The severity and duration of symptoms also depend upon the subset of bipolar disorder (1, 2, or cyclothymic disorder) a patient has.

Bipolar 1 includes major depressive episodes paired with at least one full manic episode. Mania and hypomania are similar, but mania is more severe and can be more dangerous. A manic or hypomanic episode will include at least three of the symptoms listed below.

The symptoms of bipolar 2 disorder are similar to those of bipolar 1. The difference in diagnosis between the two subtypes is based on the severity and duration of the mania. Bipolar 2 disorder is characterized by long periods of depression and hypomania (a milder form of mania). It is also typical for people with bipolar 2 disorder to experience longer periods of depression than those with bipolar 1 disorder.

The symptoms of cyclothymia are also similar to those of bipolar 1 and 2, but are characteristically less severe. Depressive episodes, however, must last for at least 2 years in adults and 1 year in children and adolescents for the condition to be characterized as cyclothymic disorder.

The signs and symptoms of a depressive²⁰ period in bipolar disorder may include:

• Distinctly low mood
• Irritability (commonly seen in children and teens)
• Loss of interest or pleasure
• Fatigue
• Changes in appetite
• Significant weight fluctuations
• Sleeping more or less than usual
• Appearing agitated
• Fatigue or loss of energy
• Feelings of guilt or worthlessness
• Paranoia or suspicion
• Poor concentration or memory
• Indecisiveness
• Thoughts of death or suicide

While they differ slightly, the symptoms of bipolar disorder often overlap with those of major depression²¹, which include:

• Noticeable loss of interest or inability to feel pleasure in activities that once brought joy
• Significant weight loss or gain
• Sleeping too much or too little
• Feeling worthless or unduly guilty
• Decreased ability to concentrate
• Fatigue
• Restlessness
• Slowed behavior
• Thoughts or intentions of suicide

In order to be classified as experiencing a depressive episode²², an individual must show a change from their normal mood that negatively impacts socializing, work, school, or other important daily functions. A healthcare provider will take measures to determine whether depressive symptoms are caused by bipolar disorder or by other factors, such as drug/alcohol abuse or other trauma, such as grieving the loss of a loved one.

Bipolar disorder also characteristically features periods of abnormally agitated or elevated mood, called manic symptoms. These symptoms are milder in patients with bipolar 2 and cyclothymia, who experience hypomania rather than full-blown mania. Generally, patients with hypomania do not experience delusions or hallucinations; rather, they tend to be extremely productive at work with little sleep and can continue to function in their day-to-day lives (until flipping into a depressive episode).

Common signs and symptoms of both mania and hypomania17 include:

• Being abnormally upbeat or jumpy
• Increased energy or agitation
• Decreased need for sleep
• Exaggerated sense of self-confidence
• Unusual talkativeness
• Racing thoughts
• Poor decision-making

In periods of full-blown mania²³, patients may experience:

• Unusually high levels of activity and energy
• Feeling unusually optimistic
• Irritable mood
• Decreased need for sleep
• Exaggerated or inflated sense of self-esteem
• Rapid or “pressured” speech
• Rapid thoughts
• High distractibility
• Increased recklessness (i.e., engaging in risky financial or sexual behavior)
• Delusions (false beliefs) or hallucinations (false perceptions)

In order to be classified as a full-blown manic episode, a patient’s symptoms²⁴ must be severe enough that they cause significant impairment in daily functioning, affect social activities or relationships with others, necessitate hospitalization to prevent harm to oneself or others, or display characteristics of psychosis.

It is also important to note that certain factors—such as substance use or pre-existing health conditions—may cause some of the symptoms seen in bipolar disorder. For this reason, your healthcare provider will rule out the use of behavior-altering substances (drugs/alcohol) or a genetic medical condition (such as an overactive thyroid gland) as the cause of your symptoms.

Complications from bipolar disorder

If left untreated, bipolar disorder can have serious effects on a person’s quality of life. These problems can include²⁵:

• Drug and alcohol abuse
• Suicidal thoughts or attempts
• Legal or financial issues
• Damaged relationships
• Poor work or school performance

Symptoms from a depressive period of bipolar disorder can be very severe and pose a real danger if a person’s thoughts turn to self-harm or suicide. The risk of suicide is higher in people with bipolar disorder who have more frequent depressive episodes, a history of abusing drugs or alcohol, a family history of suicidal thoughts/actions, or an early onset of the disorder.

Warning signs16 of suicide include:

• Feeling hopeless or helpless
• Talking about self-harm, death, or suicide
• Feeling like a burden to others
• Feeling worthless
• Acting recklessly without concern for one’s safety
• Saying “goodbye” to loved ones or setting affairs in order
• Giving away valuable or treasured possessions to others
• Seeking out methods of committing suicide

If you or someone you know is exhibiting the warning signs above, please call the National Suicide Prevention Lifeline at 1-800-273-TALK. You can also visit suicide.org to find a phone number to call in your country.