Caution: This fact sheet provides a general overview of Bipolar I and Bipolar II disorders based on the DSM-5 (Fifth Edition of the Diagnostic and Statistical Manual of Mental Disorders). It is not intended for diagnostic purposes. Only a licensed mental health professional can diagnose or provide personalized treatment.
Bipolar I Disorder
Brief Description
Bipolar I disorder is a mood disorder defined by the occurrence of at least one manic episode, which is the core diagnostic feature. A manic episode involves an abnormally elevated, expansive, or irritable mood, along with increased energy or activity, lasting at least one week (or requiring hospitalization).
Symptoms may include inflated self-esteem, decreased need for sleep, pressured speech, racing thoughts, distractibility, impulsive or risky behaviors, and impaired judgment. While major depressive episodes are common in Bipolar I, they are not required for the diagnosis.
This distinguishes Bipolar I from Bipolar II disorder, where individuals experience recurrent major depressive episodes and at least one hypomanic episode, but never a full manic episode.
Thus, the presence of mania—rather than hypomania—is the defining difference.
Epidemiological studies estimate the lifetime prevalence of Bipolar I disorder at approximately 0.6% to 1% of the global population. The condition typically emerges in late adolescence or early adulthood and is associated with significant functional impairment, high rates of recurrence, and an increased risk of comorbid conditions, including substance use disorders and anxiety disorders.
Core Symptoms
- Manic episodes: elevated, irritable, or expansive mood lasting at least 7 days
- Depressive episodes: sadness, loss of interest, low energy
- Periods of normal mood between episodes
Common Onset & Course
Often begins in late teens to early 20s; tends to be lifelong with recurring episodes.
Diagnosis Criteria
At least one manic episode and one major depressive episode
Treatment Options
- Mood stabilizers
- Antidepressants (often combined with mood stabilizers)
- Psychotherapy (CBT, interpersonal therapy)
- Routine, sleep hygiene, stress reduction
What It Feels Like
- People often describe mania as intense, overwhelming, or euphoric, sometimes feeling invincible or out of control
- Depressive episodes can be deeply painful, draining, and may last longer than the manic periods
- Mood swings can be sudden and severe, sometimes requiring hospitalization during mania
Resources & Support
- Depression and Bipolar Support Alliance (DBSA) – org
- Mental Health America – org
- National Institute of Mental Health (NIMH) – nih.gov
- National Alliance on Mental Illness (NAMI) – org
- SAMHSA Helpline – 1-800-662-HELP (4357)
- World Health Organization (WHO) – int/mental_health
