Bipolar Research Update: Risks and More Risks

The risk of Parkinson disease is increased significantly in patients with BD compared with the general population. In a meta-analysis and systematic review, a previous bipolar diagnosis increased the likelihood of a subsequent diagnosis of idiopathic Parkinson disease, although preplanned subgroup analyses did not show a significant effect. The findings suggest an association of BD with a later development of Parkinson and support differential diagnosis of Parkinsonism features in persons with BD.

In the Longitudinal Assessment of Manic Symptoms (LAMS) study, baseline ADHD was not a significant prospective risk factor for bipolar spectrum disorders (BPSD), but persistence of ADHD may marginally mediate risk of BPSD. BPSD developed in 12.4% of participants with baseline ADHD but not BPSD, compared with 14.5% who did not have either baseline diagnosis. There was more nonmood comorbidity over the follow‐up in those in whom BPSD developed than in those in whom it did not. Those who started with both diagnoses had more severe symptoms/impairment than those who had later developed BPSD and reported having ADHD first.

The risk of rapid cycling in BD increases with hospitalization, prevalent polarity, and female sex. In the National Epidemiological Research on Bipolar Disorder (RENDiBi) study, the final multivariable regression analysis showed female sex (male vs female: odds ratio [OR] = 0.64), unidentifiable prevalent polarity (vs depressive polarity: OR = 1.76; vs manic polarity: OR = 2.86), and hospitalization in the last year (no vs yes: OR = 0.63) to be positively associated with rapid cycling. The authors suggested taking these factors into account in managing and monitoring patients who have rapid cycling versus those who do not.

A recent meta-analysis confirmed that suicide attempts are common in BD and identified risk factors. The lifetime prevalence (33.9%) was significantly higher than in the general population (0.8%) and in schizophrenia (14.6%) but only slightly higher than in major depression (31%). Factors positively associated with suicide attempts were female sex, bipolar I disorder, BD not otherwise specified, and rapid cycling subtypes. The authors suggested that further efforts are needed to facilitate identification and prevention.

Identifying minor differences in the symptom profile and the course of depressive symptomatology may help distinguish between major depressive disorder (MDD) and bipolar depression. Routine outcome monitoring for hospitalized patients with MDD or bipolar depression included a structured diagnostic interview at baseline (Mini-International Neuropsychiatric Interview Plus [MINI-Plus]). Patients with MDD scored higher on weight loss, and those with bipolar depression showed a higher long-term likelihood of response. The same association was seen for remission. Efficiency between the MINI-Plus and clinical diagnosis of bipolar depression was high.