Bipolar disorder carries the distinction of having some of the highest rates of comorbidity with other psychiatric illnesses, which means that someone diagnosed with bipolar disorder is likely to have at least one other psychiatric diagnosis. Some researchers suspect that because bipolar disorder may actually be closely related to some of these illnesses, in terms of underlying brain changes — they may not really be separate disorders at all.
Given how psychiatric illness is diagnosed at this point in time, the disorders are described as separate entities and call them comorbidities.
Anxiety disorders
Anxiety disorders occur very frequently with bipolar disorder. One study of a large community sample found that more than 90 percent of people with bipolar I disorder had a co-occurring anxiety disorder diagnosis. When all bipolar groups were considered, it was about 70 percent. Most studies have found rates of anxiety disorders to occur in somewhere between a third and slightly more than a half of people diagnosed with all types of bipolar disorder. Here are a few of the anxiety disorders commonly associated with bipolar:
Panic disorder occurs in about 21 percent of people with a bipolar diagnosis. That's more than 20 times the rate seen in the general population. Researchers suspect an underlying genetic relationship between the two disorders in some people and families.
Generalized anxiety disorder seems to occur in nearly a third of all individuals with bipolar.
Social anxiety seems to occur in about 50 percent of people with bipolar, in some studies.
Obsessive compulsive disorder (OCD) has been found in about 21 percent of people with all types of bipolar disorder — about ten times the rate seen in the general population.
Post-traumatic stress disorder (PTSD) has a high rate of occurrence in the general population, but an even higher rate in bipolar disorder. Women have higher rates than men with PTSD, both with and without bipolar disorder.
Treatment of anxiety disorders may complicate or complement the treatments of bipolar disorder, but reducing anxiety symptoms is an important part of managing bipolar disorder effectively.
Substance use disorder
Although the studies vary in exact numbers, studies overall suggest that about 60 percent of people with a bipolar diagnosis have had a substance abuse problem at least sometime in their lives, with more than 40 percent having current or past problems with alcohol abuse and similar but slightly lower numbers having had problems with drug abuse.
Psychiatric hospitalization rates are generally higher for people with both bipolar and substance use disorder. The course of the illnesses seems to be more severe when both are present. Males with bipolar disorder have more substance abuse than females, but the rates are high in both groups. The rates decline as people get older but are still higher than rates of substance abuse in older people without bipolar disorder.
Treatment of both substance abuse and bipolar disorder is challenging, and having both adds many layers of challenges to the treatment. Resolution of bipolar symptoms may be quite difficult to achieve in the context of active substance abuse, and substance abuse is particularly difficult to address during active mood episodes. Successfully managing both disorders is necessary for long-term recovery from both.
Attention deficit hyperactivity disorder
Research in this area has suggested that about 20 percent of adults with all types of bipolar disorder have ADHD. Researchers have suggested that bipolar disorder that overlaps with ADHD might be a particular subtype of bipolar. In children with bipolar disorder, the distinction between bipolar and ADHD and the levels of overlap remain difficult issues to resolve. Some researchers have suggested significantly high levels of comorbidity in children, but others have found the levels to be much lower. Stay tuned for more information as the research unfolds.
The general consensus is that those with ADHD and bipolar disorder have worse outcomes for their bipolar disorder. Treatment is complicated because use of stimulants such as Ritalin to treat ADHD can significantly exacerbate bipolar symptoms. And with the high rates of substance use disorder in bipolar disorder, potential misuse of these medications must also be considered.
Personality disorders
Personality disorders are conditions in which the development of emotional, social, and behavioral systems is disrupted, causing significant, lifelong problems with function. Personality disorders are divided into clusters and then further into specific types; for example Cluster B personality disorders include borderline, antisocial, histrionic, and narcissistic personality disorders. Studies suggest that about 30 to 40 percent of people with bipolar disorder also meet criteria for a personality disorder.
Personality disorders are difficult to treat and often don't respond to medications. Psychotherapies are becoming more and more effective; people with personality disorders often have difficulty gaining insight into how their problems affect their lives, because they've never known a more adaptive level of functioning. Without insight, trying to address the problems is quite difficult. Layering these challenges onto a bipolar disorder adds tremendously to the difficulties of achieving sustained recovery.
Childhood trauma may be closely related to the development of some personality disorders, including borderline personality disorder. Early trauma can have damaging effects on the development of emotional and interpersonal skills. Identifying and addressing trauma is an important part of managing these conditions.
Memory and thinking problems
Problems with cognitive skills such as memory and attention and the ability to think clearly are common in bipolar disorder, both during and between mood episodes. Compounding the cognitive issues inherent in bipolar is that fact that some medications used to treat bipolar can cloud thinking as a side effect. Addressing problems with thinking and memory is important in recovery from bipolar disorder to help people get back on their feet in terms of work, life management, and interpersonal and leisure time skills.
Certain medications used to treat bipolar disorder may have neuroprotective properties; that is, they may prevent damage and perhaps help the recovery or regeneration of brain cells. Some recent studies have suggested that lithium, while sometimes causing short-term mental cloudiness, may actually protect brain cells over time and may prevent or reduce cognitive decline.