The Marriage Plot

Content Warning: This section of the guide includes discussion of mental illness.

Bipolar disorder is a neurological condition considered a mental illness that involves extreme mood differences. Individuals with this condition experience bouts of serious depression followed by periods of euphoria, elatedness, and bursts of physical and mental energy. Initially termed “manic depression” or “manic disorder,” bipolar can be a dangerous condition it not treated. Its depressive periods can lead to substance use, suicide, or other self-harm. By the same token, the patient can suffer hallucinations or delusions. Both depressed and manic states can have physical symptoms and can interfere with daily tasks or social functioning (“Bipolar Disorder.” National Institute of Mental Health, Dec. 2024).

There is no single, exact cause of bipolar disorder, but scientists have identified several factors that are at play in a person’s development of the condition. These include genetic factors—a person is more likely to have bipolar disorder if they have a parent with the diagnosis. Certain brain features have also been identified as being unique in people with bipolar disorder, such as differences in brain size and brain function. Finally, some scientists point to evidence that severe trauma or a traumatic event may contribute to bipolar disorder manifesting itself.