What Are the Differences Between Bipolar I and Bipolar II Disorder?

Bipolar disorder is a mental health condition characterized by fluctuations in mood and energy levels. Each person with the condition is affected differently. However, the length and intensity of manic, hypomanic, or depressive episodes will determine the type of bipolar disorder a person is diagnosed with.

Read more to learn about the types of bipolar disorder and the differences between bipolar I and bipolar II.  

Bipolar vs. Bipolar II - Illustration by Laura Porter

Verywell / Laura Porter

Types of Bipolar Disorder

Types of bipolar disorder are differentiated by their symptoms and the duration of those symptoms. There are a few types of bipolar disorder, including:

  • Bipolar I disorder: One episode of mania must occur and last for at least one week. Mania is characterized by an extreme elevation of mood and energy. An episode of hypomania or depression may precede or occur after the manic episode.
  • Bipolar II disorder: At least one episode in which symptoms of hypomania (a less-intense form of mania) persist for at least four days, as well as the occurrence of one major depressive episode.
  • Cyclothymic disorder: Over the course of two years, symptoms of hypomania and depression persist, but do not meet the criteria for a full-blown episode.

Regardless of the type, bipolar disorder can significantly impact a person's daily life.

Differences Between Bipolar I and Bipolar II

Bipolar I and II are similar in that periods of elevated mood and symptoms of depression can occur in both types of the condition.

The main difference between the two types is the degree to which mania presents.

In bipolar I disorder, a person experiences a full manic episode, which causes extreme changes in mood and energy. Symptoms are severe enough that they may interfere with a person's functioning at home, school, or work.

Less severe symptoms occur during a hypomanic episode, which are present in bipolar II disorder. In hypomania, a person experiences an elevated mood, but it isn't as intense and doesn't last as long as a manic episode.

Ultimately, these types share similar symptoms, but the way in which they are experienced can be different.


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This video has been medically reviewed by Michael MacIntyre, MD


During a manic episode, a person can experience the following symptoms for at least a week:

  • Euphoria/elevated mood or irritability
  • Decreased need for sleep
  • Distractibility (e.g., poor focus and multitasking)
  • Excessive talking 
  • Participation in risky activities (e.g., excessive spending, sexual encounters, and substance use)
  • Racing thoughts
  • Inflated sense of self
  • Psychosis (hallucinations, delusions,and disorganized thinking)

Symptoms of hypomania mirror those of mania, except they last for a shorter period, at least four days, and are less severe. 

Depression in bipolar disorder might look like:

  • Sadness or low mood
  • Low energy
  • Feelings of hopelessness, powerlessness, and worthlessness
  • Changes in sleeping patterns (typically a need for more sleep)
  • Lack of interest or joy in daily activities
  • Decreased appetite
  • Isolation and withdrawal
  • Feelings of guilt
  • Psychomotor agitation
  • Thoughts of death or suicidal thoughts

Help Is Available

If you or someone you know are having suicidal thoughts, dial 988 to contact the 988 Suicide & Crisis Lifeline and connect with a trained counselor. If you or a loved one is in immediate danger, call 911. For more mental health resources, see our National Helpline Database.


While the cause of bipolar disorder is not entirely understood, genetics and environmental factors may contribute to the onset of the condition.

The risk of developing bipolar disorder is higher in people with a first-degree relative (a parent or sibling).

Environmental factors such as maltreatment during childhood, trauma, or experiencing significant life events may also influence the onset of the disorder, as stress may be a trigger. For those who have bipolar disorder, lack of sleep can trigger a manic or hypomanic episode.

Further research is needed to enhance understanding and expand on the potential causes of bipolar disorder.


There is no definitive test a person can take to determine if they have bipolar disorder. However, getting a mental health evaluation with a psychiatrist or licensed psychologist is the first step toward getting a diagnosis.

During an assessment, a licensed mental health professional gathers information about a patient’s psychological health, including the intensity and severity of symptoms. This process allows them to get a complete picture of a patient’s history and current concerns to make an accurate diagnosis.

To specifically diagnose bipolar I vs. bipolar II, a mental health professional will need to review any manic, hypomanic, and depressive episodes that have occurred.

They may also recommend that patients seek a physical evaluation so a healthcare provider can rule out potential medical conditions that could be causing symptoms.

Upon diagnosing a patient with bipolar disorder, conversations about treatment will begin. 


Though they are different types, treatments for bipolar I and bipolar II are very similar.

Medications are used to help stabilize the mood of patients with bipolar disorder. These can include:

  • Mood stabilizers, such as lithium, valproic acid, and lamotrigine, may be used to combat mania and depression.
  • Antipsychotics can treat mania and psychosis.
  • Alpha-2 adrenergic agonists, such as Igalmi (dexmedetomidine) may be used to treat agitation associated with bipolar I or II. 
  • Antidepressants are an option, but they may not be prescribed to treat bipolar I disorder, as they can trigger episodes of mania.

Working closely with a psychiatrist can help with finding the right medication combination for you. It also creates an opportunity for patients to consistently monitor their symptoms, discuss any changes, or get questions about medication answered. 

Talk therapy is also effective for treating bipolar disorder, especially in conjunction with medication. Patients can learn more about a diagnosis, identify triggers and patterns, and establish coping and safety plans as needed.

Various therapy methods can be used in the treatment of bipolar disorder, including cognitive behavioral therapy and family-focused therapy. A cognitive approach helps clients to develop healthy thoughts and behaviors, and cope with difficult feelings. Family-focused strategies can provide education and understanding for family members and a person’s support system.

Additionally, treatment interventions that focus on creating a routine and healthy habits can benefit people with the condition.


Being diagnosed with bipolar disorder can be overwhelming.

On one hand, it may be a relief for some to have a diagnosis, which can help patients learn more about the condition and provide context for their experiences. On the other hand, a diagnosis can stir up feelings of anxiety or fear about their prognosis.

Part of living with and receiving treatment for bipolar disorder is learning to accept the condition and take care of yourself. Helpful coping strategies might include:

  • Working consistently with a mental health care team (psychiatrist and therapist)
  • Establishing a support system
  • Getting consistent sleep (sleep disruption is the most common trigger for a manic episode)
  • Identifying and engaging in self-care activities like exercising, which can help alleviate depressive symptoms
  • Being compassionate toward yourself
  • Joining a mental health support group


Bipolar disorder is a mood disorder characterized by extreme changes in a person's mood and energy. There are various types of bipolar disorder, including bipolar I and bipolar II. In bipolar I, a person must experience at least one manic episode (heightened, elevated mood). In bipolar II, a person may experience a hypomanic episode.

A Word From Verywell

The symptoms of bipolar disorder can vary from mild to extreme. The best way to determine if you have bipolar I or bipolar II is to speak with a psychiatrist or licensed mental health professional. Understanding which type of the disorder you have can help you live with the condition. Your provider can create an individualized treatment plan to manage your symptoms and improve your quality of life. Finding ways to cope with the diagnosis or symptoms can improve well-being.

Frequently Asked Questions

  • Is bipolar I or II worse?

    The symptoms of bipolar I disorder can be more severe than bipolar II due to the mania associated with bipolar I disorder. Mania is characterized by an elevated mood, inflated sense of self, agitation, impulsiveness, and a decreased need for sleep. In extreme cases, mania can lead to psychosis, including delusions and hallucinations. With bipolar II, hypomania (a less intense and shorter duration of symptoms) occurs.

  • Which is more common, bipolar I or II?

    Bipolar disorder prevalence is low, with only 2.8% of U.S. adults having the condition. A review of the literature on the prevalence of bipolar I and II determined there needs to be further study on this topic. For that reason, it is difficult to identify which is more common. The study noted the prevalence of each type of the condition as being slightly over 1%.

8 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  3. Rowland TA, Marwaha S. Epidemiology and risk factors for bipolar disorderTher Adv Psychopharmacol. 2018;8(9):251-269. doi:10.1177/2045125318769235

  4. Datto C, Pottorf WJ, Feeley L, LaPorte S, Liss C. Bipolar II compared with bipolar I disorder: baseline characteristics and treatment response to quetiapine in a pooled analysis of five placebo-controlled clinical trials of acute bipolar depressionAnn Gen Psychiatry. 2016;15:9. doi:10.1186/s12991-016-0096-0

  5. Food and Drug Administration. Igalmi label.

  6. Kato T. Current understanding of bipolar disorder: Toward integration of biological basis and treatment strategiesPsychiatry Clin Neurosci. 2019;73(9):526-540. doi:10.1111/pcn.12852 

  7. National Alliance on Mental Illness. Bipolar disorder.

  8. Clemente AS, Diniz BS, Nicolato R, et al. Bipolar disorder prevalence: a systematic review and meta-analysis of the literatureBraz J Psychiatry. 2015;37(2):155-161. doi:10.1590/1516-4446-2012-1693

By Geralyn Dexter, PhD
Geralyn is passionate about empathetic and evidence-based counseling and developing wellness-related content that empowers and equips others to live authentically and healthily.