Bipolar disorder (formerly called manic-depressive illness or manic depression) is a mental illness that causes unusual shifts in a person's mood, energy, activity levels, and concentration. These shifts can make it difficult to carry out day-to-day tasks. There are three types of bipolar disorder.

Types of Bipolar Disorder

There are several types of bipolar and related disorders. They may include mania or hypomania and depression. Symptoms can cause unpredictable changes in mood and behavior, resulting in significant distress and difficulty in life.

• Bipolar I disorder. You've had at least one manic episode that may be preceded or followed by hypomanic or major depressive episodes. In some cases, mania may trigger a break from reality (psychosis).

• Bipolar II disorder. You've had at least one major depressive episode and at least one hypomanic episode, but you've never had a manic episode.

• Cyclothymic disorder. You've had at least two years — or one year in children and teenagers — of many periods of hypomania symptoms and periods of depressive symptoms (though less severe than major depression).

• Other types. These include, for example, bipolar and related disorders induced by certain drugs or alcohol or due to a medical condition, such as Cushing's disease, multiple sclerosis or stroke.

Bipolar II disorder is not a milder form of bipolar I disorder, but a separate diagnosis. While the manic episodes of bipolar I disorder can be severe and dangerous, individuals with bipolar II disorder can be depressed for longer periods, which can cause significant impairment.

Although bipolar disorder can occur at any age, typically it's diagnosed in the teenage years or early 20s. Symptoms can vary from person to person, and symptoms may vary over time.

Symptoms of Bipolar Disorder

Manic and Hypomanic Episodes

• Euphoria or Irritability: Feeling overly happy or extremely irritable.

• Increased Activity: Overly active, either mentally or physically.

• Racing Thoughts: Thoughts are too fast, skipping from one idea to another.

• Decreased Need for Sleep: Feeling rested after only a few hours of sleep.

• Grandiosity: Inflated self-esteem or feeling invincible.

• Poor Judgment: Making impulsive decisions that can have serious consequences, such as spending sprees or risky behaviors.

• Rapid Speech: Talking very quickly, often without making sense to others.

Depressive Episodes

• Persistent Sadness: Feeling down, hopeless, or empty for most of the day.

• Loss of Interest: Losing interest in most activities once enjoyed

• Changes in Appetite: Significant weight loss or gain

• Sleep Disturbances: Sleeping too much or too little.

• Fatigue: Constant tiredness or lack of energy.

• Feelings of Worthlessness or Guilt: Feeling useless or excessively guilty.

• Cognitive Impairments: Difficulty concentrating, remembering, or making decisions.