Bipolar disorder may increase risk for developing Parkinson disease

(HealthDay)—Patients with bipolar disorder (BD) seem to have an increased risk for developing Parkinson disease (PD), according to a review published online Oct. 14 in JAMA Neurology.

Patricia R. Faustino, M.D., from the University of Lisbon in Portugal, and colleagues conducted a systematic literature review to examine the correlation of BP with a later diagnosis of idiopathic PD. Seven studies that included data on the likelihood of developing PD in a BD versus non-BD population were included, with 4,374,211 participants.

The researchers found that the likelihood of a subsequent diagnosis of idiopathic PD was increased with a previous diagnosis of BD (odds ratio, 3.35). In a sensitivity analysis with removal of studies that had a high risk for bias, an increased risk for PD was seen in people with BD (odds ratio, 3.21). There was no significant effect noted in preplanned subgroup analyses according to study design and diagnostic certainty.

"The main clinical implication of this review should be to underline that if patients with BD present with parkinsonism features, this may not be drug induced and may recommend the investigation of PD," the authors write. "There are implications for the care of patients with BD, namely with longitudinal motor assessments, monitoring for prodromal motor or nonmotor signs of PD, and eventually by parkinsonism risk mitigation via medication selections and nonpharmacological treatments."

Two authors disclosed financial ties to the biopharmaceutical industry.