To investigate hypomania and mania related to dopamine replacement therapy (DRT) in Parkinson's disease (PD).

We recruited 108 non-demented PD patients without deep brain stimulation from a movement disorders in and outpatient clinic. Forty-five age- and gender-matched controls were also included. Disease characteristics, cognitive functioning, comorbid psychiatric diseases, dopaminergic and psychiatric medication were evaluated. Diagnosis of DRT-related hypomania and mania was based on DSM-IV-TR criteria with supplementary assessment of two mania self-rating scales. First, patients and controls were compared. Patients with DRT-related hypomania or mania were then compared to the remaining patients. A binary logistic regression analysis was performed to identify correlates of DRT-related hypomania.

Patients scored significantly higher on mania self-rating scales than controls. Twelve patients (11.1%) had DRT-related hypomania and six patients (5.6%) had DRT-related mania. Both groups had significantly higher self-rating mania-scores than patients without these mood states. DRT-related hypomania was significantly related to younger age, younger age at PD onset, dyskinesias, higher levodopa equivalent daily dose, dopamine dysregulation, and amantadine treatment. In contrast, DRT-related mania was significantly associated with hallucinations and delusions, history of levodopa-induced psychosis, quetiapine treatment, higher depression and daily levodopa dose, and cognitive deficits. Regression analysis revealed dopamine dysregulation, dyskinesias, amantadine treatment, and younger age at PD onset as significant correlates of DRT-related hypomania.

DRT-related hypomania and mania are relevant comorbidities in PD. DRT-related hypomania may exist as a distinct psychiatric symptom complex in young patients with early disease onset. Different patient profiles likely underlie DRT-related hypomania and mania.