Section Learning Objectives

• Identify the symptoms of bipolar disorders.
• Identify and distinguish between the three types of bipolar disorders.
• Identify the disorders that are commonly comorbid with bipolar disorders.
• Describe the epidemiology of bipolar disorders.
• Discuss the factors that contribute to the etiology of bipolar disorders.
• Describe treatment options for bipolar disorders.

6.2.1 Clinical Description

There are three primary bipolar disorders –  bipolar I disorder, bipolar II disorder, and cyclothymic disorder.

A diagnosis of bipolar I disorder is made when the individual has experienced at least one manic episode. This manic episode may be preceded by or followed by a hypomanic or major depressive episode but neither is required for a diagnosis of bipolar I disorder. In contrast, a diagnosis of bipolar II disorder is made when the individual has experienced both a hypomanic episode and a depressive episode. A manic episode (past or present) rules out a diagnosis of bipolar II disorder. In simpler words, if an individual has ever experienced a manic episode, they qualify for a bipolar I diagnosis. If the criteria have been met for both a hypomanic and depressive episode then the individual qualifies for a diagnosis of bipolar II disorder.

So, what defines a manic episode? The key feature of a manic episode is an abnormally euphoric or irritable mood that is experienced persistently for at least one week. In order to qualify as a manic episode, the individual must experience at least three other symptoms of a manic episode. These symptoms include inflated self-esteem, decreased need for sleep, pressured speech, racing thoughts, distractibility, psychomotor agitation, and involvement in pleasurable activities that are likely to result in negative consequences (e.g., risky sexual behavior, gambling, foolish business investments). These symptoms must cause distress, impairment in functioning, and/or necessitate hospitalization to be considered a true manic episode.

With regards to mood, an individual in a manic episode will appear excessively happy and full of energy. They may also display rapid shifts in mood, also known as mood lability, ranging from happy to irritable. Inflated self-esteem or grandiosity is also commonly present during a manic episode. Occasionally these inflated levels of self-esteem can appear delusional. Individuals may believe they are friends with a celebrity, do not need to abide by laws, or even at times think they are God or famous.

Despite their increased activity level, individuals experiencing a manic episode also typically experience a decreased need for sleep, sleeping as little as a few hours a night, and still feeling rested. In fact, decreased need for sleep may be an indicator that a manic episode is to begin imminently.

It is not uncommon for those in a manic episode to have rapid, pressured speech. It can be difficult to follow their conversation due to the fast nature of their talking, as well as the tangential storytelling (i.e., jumping from topic to topic). Additionally, they can be difficult to interrupt in conversation, often disregarding the reciprocal nature of communication. If the individual is more irritable than expansive, speech can become hostile or even pronounced by angry tirades, particularly if they are interrupted or not allowed to engage in an activity they are seeking out. Based on their speech pattern, it should not be a surprise that manic episodes are also marked by racing thoughts which are commonly referred to as a flight of ideas. Because of these rapid thoughts, speech may become disorganized or incoherent.

Hypomanic episodes are milder versions of manic episodes. While the symptoms of the two are the same, a diagnosis of a hypomanic episode requires only 4 days of symptoms rather than the full week required to diagnose a manic episode. Moreover, hypomanic episodes cannot cause impairment, distress, or the need for hospitalization. If any of these three features are present the episode is considered manic, rather than hypomanic.

It should be noted that there is a subclass of individuals who experience periods of hypomanic symptoms that do not meet the full DSM 5-TR criteria for a hypomanic episode and depressive symptoms that again do not meet the full DSM 5-TR criteria for a depressive episode. These individuals can be diagnosed with cyclothymic disorder (APA, 2022). Full criteria for a manic, hypomanic, or depressive episode must have never been met. Cyclothymic disorder is further distinguished from bipolar II disorder by its duration. Specifically, cyclothymic disorder requires that subthreshold depressive and hypomanic symptoms are present at least half the time for a full 2-year period before a diagnosis can be made. Further, as with most disorders, the symptoms must cause clinically significant distress or impairment in functioning.

6.2.2 Epidemiology

Compared to depression, epidemiological studies on the rates of bipolar disorder suggest a significantly lower one-year prevalence rate for both bipolar I and bipolar II disorder, with yearly rates reported as 1.5% for bipolar I disorder and 0.8% for bipolar II disorder in the U.S. (APA, 2022). There are no apparent differences in the frequency of men and women diagnosed with bipolar I or bipolar II disorder; however, rapid-cycling episodes (where four or more mood episodes are experienced in a one-year period) are more common in women (Bauer & Pfenning, 2005).

The risk of suicide is approximately 20-30 times greater in individuals with bipolar I disorder and than the general population and an estimated 5%-6% of people with bipolar disorders die by suicide (APA, 2022). As with depressive disorders, suicide attempts are higher in women while dying by suicide is higher in men. Further, past history of suicide attempts and length of time spent depressed are associated with greater risk of suicide in people with bipolar disorders (APA, 2022).

While only a small percentage of the population develops cyclothymic disorder (lifetime prevalence estimates range from 0.4 to 2.5%; APA, 2022), it can eventually progress into bipolar I or bipolar II disorder (Zeschel et al., 2015).

As stated previously, bipolar II disorder requires a past or present depressive episode and, while not required, depressive episodes are commonly experienced in bipolar I disorder. The depressive episode can occur before or after the manic/hypomanic episode, and the two types of episodes can alternate or “cycle” throughout one’s life.

6.2.3 Comorbidity

Bipolar disorders also have a high comorbidity rate with other mental disorders, particularly anxiety disorders, ADHD, and substance use disorders. The combination of bipolar disorder and substance use disorder places individuals at a greater risk of suicide attempts (APA, 2013). While these comorbidities are high across both bipolar I and bipolar II, bipolar II appears to have more comorbidities, with 60% of individuals with bipolar II disorder meeting the criteria for three or more co-occurring mental disorders (APA, 2013).

6.2.4 Etiology

6.2.4.1 Biological

As is typical with most mental disorders there is an elevated prevalence of bipolar disorders among first-degree biological relatives of people with bipolar I or bipolar II disorder. Specifically, first-degree biological relatives of individuals with bipolar I or II disorder have a 5-to-10-fold increased risk of developing bipolar disorder (APA, 2022). Twin studies within bipolar disorder yield concordance rates for identical twins at as high as 70% and as high as 20% for fraternal twins. Both of these percentages are significantly higher than that of the general population, suggesting a strong genetic component of bipolar disorder (Edvardsen et al., 2008). Indeed, as some of these statistics demonstrate, the genetic contribution to bipolar disorder is believed to be greater than the genetic contribution to depressive disorders. There also seems to be a shared genetic component between the bipolar disorders and major depressive disorder (MDD) as relatives of individuals with bipolar disorder have elevated rates of MDD. Similarly, MDD, bipolar I and bipolar II disorders are more common in relatives of individuals with cyclothymic disorder.

Due to the close nature of depression and bipolar disorder, researchers initially believed that norepinephrine, serotonin, and dopamine were all implicated in the development of bipolar disorder; however, the idea was that there was a drastic increase in serotonin during manic episodes. Unfortunately, research actually supports the opposite. It is believed that manic episodes may, in fact, be explained by low levels of serotonin and high levels of norepinephrine (Soreff & McInnes, 2014). Moreover, following evidence that drugs like cocaine which stimulate dopamine produce manic-like symptoms it is further believed that elevated dopamine may be implicated in bipolar I disorder. Additional research in this area is needed to conclusively determine exactly what is responsible for the manic episodes that characterize bipolar I disorder.

6.2.4.2 Psychological

Stressful life events are believed to trigger early episodes of mania and depression, but as the disorder progresses the cycling from mania to depression can take on a life of its own and become more removed from stressors. Nevertheless, stressful life events can always provoke a relapse. As we saw with the depressive disorders, separated and divorced people have higher rates of bipolar I disorder than do people who are married or who were never married. Once again, the direction of this relationship is not clear but it is likely bidirectional with the symptoms of bipolar disorder contributing to marital discord and the termination of a marriage representing a severe psychosocial stressor that can contribute to the onset of a bipolar disorder or trigger a relapse of the disorder. Finally, a lack of social support is associated with more depressive episodes in bipolar disorder, as it was for depressive disorders.

6.2.5 Treatment

6.2.5.1 Psychopharmacology

Unlike treatment for MDD, there is some controversy over the most effective treatment for bipolar disorder. One suggestion is to treat bipolar disorder aggressively with mood stabilizers such as Lithium or Depakote as these medications do not induce pharmacological mania/hypomania. These mood stabilizers are occasionally combined with antidepressant medications later in treatment only if necessary (Ghaemi, Hsu, Soldani & Goodwin, 2003). Research has shown that mood stabilizers are less powerful in treating depressive symptoms in those with bipolar disorder, and therefore, this combination approach is believed to help reduce the occurrence of both manic and depressive episodes (Nivoli et al., 2011).

The other treatment option is to forgo the mood stabilizer and treat symptoms with newer antidepressants early in treatment. Unfortunately, large-scale research studies have not shown great support for this method (Gijsman, Geddes, Rendell, Nolen, & Goodwin, 2004; Moller, Grunze & Broich, 2006). In fact, antidepressants can trigger a manic or hypomanic episode in people with bipolar disorder. Because of this, the first-line treatment option for bipolar disorder is mood stabilizers, particularly Lithium.

Lithium and other mood stabilizers are very effective in managing the symptoms of bipolar disorder. Unfortunately, adherence to the medication regimen can be problematic. The euphoric highs that are associated with manic and hypomanic episodes are often desired and can lead individuals with bipolar disorder to cease taking their medication. Combinations of psychopharmacology and psychotherapy that is aimed at increasing medication adherance rates may be the most effective treatment option for bipolar I and II disorder.

6.2.5.2 Psychological Treatment 

Although psychopharmacology is the first and most widely used treatment for bipolar disorders, occasionally psychological interventions are also paired with medication. However, psychotherapy alone is not a sufficient treatment option for the bipolar disorders. The majority of psychological interventions are aimed at medication adherence, as many people with bipolar disorder stop taking their mood stabilizers when they “feel better” (Advokat et al., 2014) or as described above to induce a manic or hypomanic episode. CBT can also be used to help treat and reduce the reoccurrence of depressive episodes. Social skills training and problem-solving skills can further be helpful techniques to address as individuals with bipolar disorder may struggle in these areas. Finally, individuals with bipolar disorder may be advised to stabilize their routines, especially their sleep routines, to reduce the risk of relapse.

Chapter Recap

That concludes our discussion of mood disorders. You should now have a good understanding of the two major types of mood disorders – depressive and bipolar disorders. Be sure you are clear on what makes them different from one another in terms of their clinical presentation, diagnostic criteria, epidemiology, comorbidity, etiology, and treatment. Also be sure to understand how the different depressive disorders (MDD and PDD) are distinguished as well as how the various bipolar disorders (bipolar I disorder, bipolar II disorder, and cyclothymic disorder) differ from one another.