What is bipolar disorder? Symptoms, Causes, Types and Treatment 

Bipolar disorder, also known as manic-depressive illness, is a mental health condition characterized by extreme mood swings from depressive lows to manic highs. Bipolar disorder affects about 2.8% of the population worldwide, making it more common than people may realize. People with bipolar disorder experience periods of heightened mood and energy known as mania or hypomania alternating with lows of depression.  

Symptoms of Bipolar Disorder

The main symptoms of bipolar disorder relate to dramatic shifts in an individual's mood, energy, behaviour and thinking patterns:

Manic or hypomanic episodes: Symptoms include an elevated or irritable mood, racing thoughts, pressured speech, distractibility, decreased need for sleep, increase in goal-directed activity, poor judgment, and inflated self-esteem. Mania tends to be more severe with psychotic features.    

Depressive episodes: Symptoms include feelings of sadness, hopelessness, guilt, irritability, loss of interest in activities, changes in sleep and appetite, fatigue, trouble concentrating and recurrent thoughts of death and suicide.      

Mixed episodes: Some people experience both manic and depressive symptoms at the same time, known as mixed episodes. This can involve elevated mood along with negative thoughts, anxiety and insomnia.

Types of Bipolar Disorder

Several types of bipolar disorder are distinguished based on the pattern of manic, hypomanic and depressive episodes:

Bipolar I: Characterized by at least one manic episode, often with major depressive episodes. Episodes tend to be more severe and last longer.  

Bipolar II: Includes major depressive episodes with hypomanic episodes, but no full-blown manic episodes. Episodes may be briefer and less severe.

Cyclothymia: A milder form marked by many periods of hypomania and depression that don't meet the full bipolar criteria. The symptoms are present for at least two years.       

Other types include bipolar disorder due to another medical condition, Substance-induced bipolar disorder and Other specified or unspecified bipolar disorder.

Causes of Bipolar Disorder 

The exact causes of bipolar disorder are complex and not fully understood. Risk factors likely involve a combination of biological, genetic and environmental triggers:

 Biological factors: Studies have identified abnormalities that may occur in the brains of people with bipolar disorder, especially in areas responsible for regulating mood.

Genetic factors: bipolar disorder tends to run in families, indicating that genes play an important role. However, no single "bipolar gene" has been identified.

Environmental triggers:  Stressful life events, disruptions to sleep patterns and substance use may trigger initial onset or subsequent episodes in genetically predisposed individuals. 

Chemical imbalance: Research suggests that neurotransmitter dysfunctions involving serotonin, norepinephrine and dopamine may underlie the mood instability of bipolar disorder.

Treatment of Bipolar Disorder

No cure exists for bipolar disorder, but effective treatment options aim to reduce the frequency and severity of mood episodes:

Medications: The mainstay of treatment involves using mood stabilizers such as lithium and anticonvulsants along with antipsychotics and antidepressants in some cases. 

Psychotherapy: Talk therapies such as cognitive behavioural therapy (CBT) help individuals develop strategies to identify and modify negative thought patterns that contribute to mood swings.  

Lifestyle changes: Practicing good sleep habits, engaging in regular exercise, avoiding substance abuse and maintaining a structured daily routine can help stabilize moods.   

Social support: Family, friends and support groups offer encouragement and accountability that improves treatment adherence and symptom management.  

Hospitalization: In severe bipolar cases, a brief hospital stay may be needed to safely manage acute manic or depressive episodes not controlled through outpatient means.

Medication Side Effects

While medications can effectively control bipolar symptoms for many people, they also come with side effect risks:

Lithium - Common side effects include nausea, vomiting, hand tremors, frequent urination and weight gain. High doses can damage the kidneys and thyroid. Regular blood testing is required.    

Anticonvulsants - Side effects may include headaches, dizziness, memory problems, weight gain and skin reactions. Blood monitoring is often needed.

Antipsychotics - Weight gain, drowsiness, movement disorders and high blood sugar/cholesterol levels are common with both typical and atypical antipsychotics.    

Antidepressants - Side effects can include insomnia, nausea, agitation, sexual dysfunction and weight gain. They may also trigger mania in those with bipolar disorder.   

Though unpleasant, many side effects can be managed through adjustments to the treatment plan. The benefits of stabilization often outweigh the risks when medications are properly monitored.

Course and Prognosis

Bipolar disorder tends to follow a chronic, fluctuating course over the lifespan:

• Episodes may appear as early as childhood but often arise for the first time in the late teens and 20s.
• Without proper treatment, episodes tend to worsen over time, become more frequent and last longer.   
• Most individuals experience a pattern of recurrences interspersed with symptom-free periods of remission.
• Bipolar disorder has a relatively high relapse and recurrence rate compared to other mental illnesses.

However, with well-managed treatment including medications and psychotherapy, many people with bipolar disorder are able to achieve long stretches of remission and lead fulfilling lives. Early diagnosis and intervention yield the best outcomes.