What is Bipolar Disorder?

In general, bipolar disorder can be defined as a mood disorder with extreme and episodic shifts in a person’s mood and behavior. The mood shifts range from depression to hypomania and mania.

Bipolar disorder is defined by subtypes, which include bipolar I, II and mixed episode.

Understanding the differences between these subtypes, however, can sometimes be confusing as they tend to share similarities in symptoms.

Similarities of Bipolar I and Bipolar II

For instance, depressive episodes for type I and II both include symptoms of:

  • Weight gain or loss
  • Insomnia or hypersomnia
  • Restlessness or agitation or simply feeling very slowed down
  • Fatigue or loss of energy
  • Feelings of worthlessness or guilt
  • Trouble concentrating and making decisions
  • Thoughts of death and suicidal ideation

At the same, manic and hypomanic episodes both include symptoms such as:

  • Abnormally high self-esteem
  • A decreased need for sleep
  • Feeling more talkative than usual or pressure to keep talking
  • Racing thoughts or more ideas than usual
  • Distractibility
  • An increase in goal-directed behaviour
  • Involvement in pleasurable activities that have a high likelihood to have negative consequences

What Makes Bipolar I and Bipolar II Different?

So, what exactly makes these subtypes different? The key difference between type I and II is seen within the manic and hypomanic episodes.

Bipolar I includes experiences with manic episodes, whereas bipolar II includes experiences with hypomanic episodes.


Although these two subtypes share very similar symptoms, it is mania that makes it very difficult for individuals to maintain functioning and to fulfil their daily responsibilities.

Manic episodes cause significant impairment, often leading to noticeable distress and deterioration in the areas of work, relationships, and personal health and stability. Put simply, mania makes it very difficult to interact with friends, family and even the self. For example, the person may not be able to go to work because they’re spending too much time on a new interest or creative task. Or their irritability and impulsivity during a manic episode may create friction and hurt with loved ones and relationships may be lost.

As mania becomes more severe, people may begin to experience psychotic symptoms, such as delusions and hallucinations. Delusions are strongly held beliefs even when there is no evidence to support the belief, such as the grandiose belief that a person was specifically chosen to complete a special task. Hallucinations are experiences of the sensations that do not exist, such as seeing, hearing, and feeling things that are not there. Often, when mania becomes severe, hospitalization is required.


Hypomania, on the other hand, is typically shorter, less severe, and does not always impair a person’s level of functioning. Hypomania episodes last at least four days, where mania can last up to a week. If left untreated, both can last for several months. Although hypomania is not as severe as mania, it is important to remember that the shift in high or irritable mood is still considered unusual compared to what the person would normally experience. Hypomania is not just a “good day” feeling. Further, hypomania does not usually require hospitalization and does not include any symptoms of psychosis.

What Is A Mixed Episode?

With the DSM5 now out, the term mixed episode has now been changed to “mixed features.” This is characterized when manic and depressive symptoms tend to occur at the same time or there is cycling between the two. They can sometimes take place during a manic or depressive episode, such as a mania episode with some symptoms of depression or vice versa; however, they more commonly take place with depressive episodes.

Consider a person who is currently experiencing a depressive episode, with symptoms of agitation and restlessness, but at the same time, they’re also experiencing a sudden jump in their energy, racing thoughts, and a lack of need for sleep. This is when mixed features occur simultaneously during a depressive episode.

A different example is a person who feels extremely happy and energized one moment only to have intense feelings of worthlessness and a sudden low mood the next minute. This captures the cycling between manic and depressive symptoms that can occur for some people.

People with bipolar can experience shifts between high moods and low moods, but with mixed features, there is usually no break between the cycles.

Wrapping up…

In short, mania and hypomania share similar symptoms, but the key differences are found with the severity or intensity of the symptoms. Although both mania and hypomania can last for several days or weeks, manic episodes interfere with a person’s daily functioning, making it challenging for them to interact with their friends, go to work, or maintain awareness of one’s self and behaviors.

Hypomanic episodes include unusual elevations in a person’s mood, but not to extent of interrupting their daily lives. Again, bipolar type I experiences mania, where bipolar II experiences hypomania.

Finally, mixed episodes or features are when individuals experience both high and low symptoms at the same time or directly after one another. Mixed episodes can be experienced in both types I and type II bipolar.

Muge Yavaser

Muge Yavaser

Graduate Psychology Student