Bipolar Disorder: Common Comorbidities Increase Burden

Prone to comorbidities, patients with bipolar disorder can benefit from collaborative care among health care providers.

A diagnosis of bipolar disorder is often accompanied by a constellation of other diagnoses. Patients with the disease, plagued with paralyzing depression at some times and perilous mania at others, are apt to engage in activities that not only elevate rates of medical comorbidity, but also increase mortality rates and worsen disease trajectories.

A new study that appears in the August 2014 issue of Bipolar Disorders examines common predictors associated with medical comorbidity. This study, conducted by psychiatry researchers at 10 prestigious medical schools across the United States, used the Clinical and Health Outcomes Initiative in Comparative Effectiveness for Bipolar Disorder study (Bipolar CHOICE, N = 482) to identify the features of bipolar disorder that may differ by type of bipolar illness, and how comorbidities vary with diagnosis length.

All study subjects had bipolar I or bipolar II disorder and were assessed for current and lifetime DSM-IV-TR diagnoses, demographics, psychiatric and medical history, symptom severity, and level of functioning at enrollment. The researchers followed study subjects for 6 months.

Almost all (96.3%) study subjects had at least 1 medical comorbidity. Older subjects were more likely to have cardiometabolic conditions and substance abuse issues (including smoking and use of illegal drugs), similar to people in the general population. Patients who had been diagnosed with bipolar symptoms early in life were less likely to have cardiometabolic conditions, but more likely to have other types of medical comorbidities.

Several other characteristics predicted other medical comorbidities: longer cumulative time depressed and longer duration from diagnosis. The researchers found that patients who experienced the most and the most severe manic symptoms were less likely to have cardiometabolic conditions; this was unexpected. They postulate that this could be related to less depression (a known risk factor for cardiometabolic disease), or lower body weight.

Many patients with bipolar illness take medications associated with weight gain; these patients were more likely to have lipid aberrations. The researchers reported, “Other parameters (e.g., hypertension, hyperlipidemia, and diabetes) were not associated with these medications.” They explain this unexpected finding by noting the study may not have been powered to detect these diagnoses.

The authors report that bipolar disorder’s medical burden creates a need for collaborative care among health care providers so patients’ psychiatric and medical needs are addressed concurrently.