What Is Bipolar Disorder? Types, Symptoms, and Treatment
Reviewed byDaniel Montville, MD, Psychiatrist
SiggyMD Clinical Team · Last updated June 19, 2026
Key Takeaways
- Bipolar disorder involves distinct episodes of mania or hypomania alternating with depression. Bipolar I requires at least one manic episode lasting 7 days or severe enough to require hospitalization. A depressive episode is not required for the Bipolar I diagnosis.
- Bipolar II requires at least one hypomanic episode and one major depressive episode, but no full manic episode. Despite being labeled milder, Bipolar II carries comparable suicide risk to Bipolar I.
- Cyclothymia involves at least 2 years of cycling between hypomanic and depressive symptoms that do not reach the full diagnostic threshold for either episode type.
- People with bipolar disorder are 10 to 30 times more likely to die by suicide than the general population. Lithium has specific, documented anti-suicide properties beyond its mood-stabilizing effects.
- The average diagnostic delay for bipolar disorder is approximately 10 years. Antidepressant monotherapy in bipolar disorder can trigger manic switching and worsen the disorder's course.
Bipolar disorder is one of the most frequently misdiagnosed conditions in psychiatry. Most people with it spend years, sometimes a decade, being treated for the wrong thing before the correct diagnosis is made. That diagnostic delay carries real clinical costs: wrong medications, worsening course, and missed windows for effective treatment.
This page explains what bipolar disorder actually is, what distinguishes the three main subtypes, and what the clinical evidence says about recognition and treatment.
What This Page Covers
- The clinical definition of bipolar disorder and DSM-5 criteria
- Bipolar I, Bipolar II, and cyclothymia: what distinguishes them
- Why bipolar disorder is so commonly missed or misdiagnosed
- Suicide risk: the numbers and what they mean for treatment urgency
- Why antidepressants require extreme caution in bipolar disorder
- First-line medications and psychotherapy
- Why continuous monitoring matters
What Is Bipolar Disorder?
Bipolar disorder, formerly called manic-depressive illness, represents a group of disorders that cause extreme fluctuation in a person’s mood, energy, and ability to function, in which symptoms of mania and depression alternate. It is not simply having mood swings. It is a specific clinical syndrome with defined episode types, severity thresholds, and duration requirements.
In 2021, an estimated 37 million people worldwide were living with bipolar disorder, approximately 0.5% of the global population. In the United States, bipolar spectrum disorders affect approximately 2.6% of adults in any given year. On average, people with bipolar disorder die 13 years earlier than the general population, primarily due to medical comorbidities and suicide.
Bipolar I: The Defining Feature Is Mania
Bipolar I disorder requires at least one manic episode lasting at least 7 days, or of any duration if hospitalization is required. A manic episode involves a distinct period of abnormally elevated, expansive, or irritable mood with increased activity or energy, plus at least three of the following: grandiosity or inflated self-esteem, decreased need for sleep, pressured speech, racing thoughts, distractibility, increased goal-directed activity, and excessive involvement in risky activities.
A major depressive episode is not required for a Bipolar I diagnosis. Many patients present first with depression, which is why the diagnosis is so often delayed. Clinicians must inquire about past manic, hypomanic, and depressive episodes in patients presenting with depression, particularly for those with early onset (under 25), high number of lifetime depressive episodes (5 or more), or family history of bipolar disorder.
Bipolar II: Hypomania and Depression Without Full Mania
Bipolar II requires at least one hypomanic episode and at least one major depressive episode, with no history of a full manic episode. Once a full manic episode occurs, the diagnosis becomes Bipolar I.
Hypomania involves the same symptom types as mania but at a level that does not cause marked functional impairment, does not require hospitalization, and does not include psychotic features. Hypomanic episodes last at least 4 days. The elevated mood of hypomania can feel productive and positive, which is one reason people with Bipolar II often seek treatment for the depressive episodes while the hypomanic periods go unreported.
Despite being described as the milder subtype, Bipolar II is not mild in its clinical impact. A systematic review and meta-analysis found similar risk of completed suicide in Bipolar I and Bipolar II, contradicting the common clinical assumption that Bipolar II carries lower suicide risk. The predominantly depressive burden in Bipolar II, combined with frequent rapid cycling and comorbidities, makes it a serious condition.
Cyclothymia: Two Years of Subclinical Cycling
Cyclothymic disorder involves at least 2 years (1 year in adolescents) of numerous periods of hypomanic symptoms that do not meet full hypomanic criteria and depressive symptoms that do not meet full major depressive episode criteria. During the 2-year period, the person has not been without these symptoms for more than 2 consecutive months.
Cyclothymia is not simply mild bipolar. It involves chronic mood instability that impairs daily functioning, often significantly. Research suggests 35% of cyclothymia cases progress to higher-threshold bipolar presentations over time.
Why Bipolar Disorder Gets Missed
Bipolar disorder is the most frequently misdiagnosed of the mood disorders. People most often seek treatment during depressive episodes, not manic or hypomanic episodes. The hypomanic or manic history that would clarify the diagnosis may not be reported because it felt positive, or may not have been asked about.
The average diagnostic delay is approximately 10 years, and just 1 in 4 individuals receives an accurate diagnosis within the first 3 years of symptom onset. In that decade of delay, many people receive antidepressant monotherapy for apparent unipolar depression, which can destabilize bipolar disorder by triggering manic episodes.
Suicide Risk: The Numbers That Matter
Bipolar disorder carries substantially elevated suicide risk. Individuals with bipolar disorder are 10 to 30 times more likely to die by suicide compared to the general population. Bipolar disorder accounts for an estimated 3 to 14% of all suicide deaths in the United States each year.
Suicide risk is not limited to depressive episodes. Mixed features, transitions between episodes, and the aftermath of a manic episode when insight returns and consequences become clear all carry significant risk.
If you or someone you know is in crisis, call or text 988 or go to the nearest emergency room.
Meta-analyses of observational studies have found that bipolar patients on lithium have significantly lower risk of suicidal behavior, with the time to self-harm longest for patients on lithium compared to other mood stabilizers and antipsychotics. This is one of the strongest arguments for lithium as a first-line mood stabilizer in bipolar disorder.
Why Antidepressants Require Extreme Caution
The most clinically important prescribing principle in bipolar disorder: antidepressant monotherapy is contraindicated.
Current guidelines do not endorse adjunctive antidepressants as a first-line treatment for acute bipolar depression and explicitly recommend avoiding antidepressant monotherapy in Bipolar I disorder. The concern is treatment-emergent mania: the switch from a depressive episode into a manic or hypomanic one triggered by the antidepressant.
When antidepressants are used in bipolar disorder, they must be combined with a mood stabilizer or atypical antipsychotic. They are more commonly appropriate for Bipolar II than Bipolar I and require careful monitoring for signs of switching.
First-Line Medication Treatment
Mood Stabilizers
Lithium remains the most studied mood stabilizer with the strongest evidence base for preventing both manic and depressive episodes, and the only agent with documented anti-suicide effects. It requires regular blood monitoring due to its narrow therapeutic window.
Valproate (Depakote) is effective for acute mania and rapid cycling. It carries significant teratogenic risk in pregnancy. Women of childbearing age must be counseled explicitly before starting.
Lamotrigine (Lamictal) is the most effective mood stabilizer specifically for bipolar depression but provides limited protection against mania. Titration must be slow to minimize the risk of Stevens-Johnson syndrome.
Atypical Antipsychotics
Several atypical antipsychotics have FDA approval for bipolar disorder: quetiapine (for mania, bipolar depression, and maintenance), lurasidone (for bipolar depression), cariprazine (for mania and bipolar depression), and aripiprazole (for mania and maintenance). They may be used as monotherapy or combined with mood stabilizers.
Psychotherapy
Medication is the cornerstone of bipolar treatment, but psychotherapy significantly improves outcomes. Cognitive behavioral therapy, family-focused therapy, and interpersonal and social rhythm therapy all have evidence for reducing relapse rates, improving medication adherence, and enhancing daily functioning. Psychoeducation about the disorder’s biology, course, and early warning signs is an independent predictor of treatment adherence.
Why Continuous Monitoring Matters
Manic episodes typically have a prodrome of days to weeks with progressive sleep reduction, energy elevation, and subtle behavioral changes that precede the full episode. Catching this prodrome is where treatment has the most leverage.
“What I need to catch a manic episode early is a window into what’s happening day by day, not a summary of the last three months,” says Daniel Montville, MD, Psychiatrist, of the SiggyMD clinical team. “The person in early mania often doesn’t know they’re in early mania. They feel great. But the pattern in their sleep and activity data tells me something different is happening.”
SiggyMD’s daily check-in model captures the longitudinal data that makes early intervention possible: sleep trajectory, mood elevation, medication adherence, and early signs of episode onset before they become crises.
About SiggyMD
SiggyMD provides clinician-reviewed psychiatric care for anxiety and depression, with daily check-ins and licensed prescriber oversight. For patients managing bipolar disorder or complex mood disorders and wanting a clinical relationship that tracks their symptoms continuously, start your anonymous intake with SiggyMD. You can also read: What a Manic Episode Feels Like and Bipolar Medication Guide: Mood Stabilizers, Antipsychotics, and Antidepressant Cautions.
What Members Are Saying
KS
K.S., 36
Bipolar I Disorder
“I was treated for depression for seven years before anyone asked me about elevated periods. When I finally described the periods of no sleep and racing ideas, my prescriber said: that’s mania, not just anxiety. The correct diagnosis completely changed what we were treating and how.”
AM
A.M., 29
Bipolar II Disorder
“I kept stopping my mood stabilizer because I felt fine. The third time I relapsed, I finally understood: I feel fine because of the medication, not in spite of it. Having someone check in with me daily helps me remember that stability isn’t the same as not needing the medication anymore.”
Member stories reflect real experiences. Names and identifying details have been changed to protect privacy. Results vary. SiggyMD is currently invite-only.
Sources
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American Psychiatric Association. What Are Bipolar Disorders? Accessed June 2026.
-
World Health Organization. Bipolar disorder. Updated 2024.
-
StatPearls. Bipolar Disorder. NCBI Bookshelf. Updated 2024.
-
Cleveland Clinic. Bipolar Disorder. Accessed June 2026.
-
Viktorin A, et al. The Risk of Switch to Mania in Patients With Bipolar Disorder During Treatment With an Antidepressant Alone and in Combination With a Mood Stabilizer. American Journal of Psychiatry. 2014;171(10):1067-1073.
-
Shuy YK, et al. International Trends in Lithium Use and Clinical Correlates in Bipolar Disorder. Brain Sciences. 2024;14(1):102.
-
Suicide risk comparison in Bipolar I vs Bipolar II. Systematic review and meta-analysis. Journal of Affective Disorders. 2024.
-
American Journal of Psychiatry. Antidepressants and Bipolar Disorder. Editorial. 2024.
Reviewed by Daniel Montville, MD, Psychiatrist | Last updated June 2026
Frequently Asked Questions
What is the difference between Bipolar I and Bipolar II?
Bipolar I is defined by at least one manic episode lasting 7 days or requiring hospitalization, with significant functional impairment and possible psychotic features. Depressive episodes are common but not required. Bipolar II is characterized by hypomanic episodes (less severe mania, at least 4 days, no psychosis or significant impairment) alternating with major depressive episodes. A person who has had even one full manic episode has Bipolar I, not Bipolar II. The two diagnoses are mutually exclusive.
What does a manic episode feel like?
The early phase often feels positive: elevated energy, decreased need for sleep without fatigue, increased confidence, and rapid ideas. As an episode intensifies, thoughts race, decisions become risky, irritability emerges, and insight decreases. Many people with Bipolar I describe not recognizing themselves during a manic episode, especially in retrospect. Mixed features, where mania and depression occur simultaneously, are particularly distressing and carry elevated suicide risk.
Can bipolar disorder go undiagnosed for years?
Yes, and it frequently does. Research suggests many people deal with symptoms for up to 10 years before receiving the correct diagnosis. Bipolar disorder is most commonly misdiagnosed as unipolar depression, particularly when the patient presents between manic or hypomanic episodes. Antidepressant monotherapy prescribed for misdiagnosed unipolar depression can trigger manic switching and destabilize bipolar disorder.
Can bipolar disorder be treated without medication?
Not effectively for most people. Pharmacotherapy is the cornerstone of bipolar treatment and must typically be continued indefinitely due to the high risk of relapse when discontinued. Psychotherapy, particularly CBT and psychoeducation, significantly improves medication adherence and reduces relapse rates, but therapy alone is not sufficient to prevent mood episodes in most people with Bipolar I or II disorder.
What are the first-line medications for bipolar disorder?
Lithium is the most studied mood stabilizer and the only pharmacological treatment with documented anti-suicide effects in bipolar disorder. Valproate (Depakote) is effective for acute mania and rapid cycling. Lamotrigine (Lamictal) is preferred for bipolar depression specifically. Atypical antipsychotics including quetiapine, lurasidone, cariprazine, and aripiprazole are FDA-approved for bipolar mania, bipolar depression, or both.
Is bipolar disorder more common in men or women?
The lifetime prevalence of bipolar disorder is approximately equal between men and women. However, Bipolar II disorder is more common in women. Women with bipolar disorder tend to have more depressive episodes relative to manic ones and are more likely to experience rapid cycling. Both sexes face comparable overall suicide risk.
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