Bipolar affective disorder and Parkinson's disease: a rare, insidious and often unrecognized association.

Five patients (4 women) with Parkinson's disease (PD) and primary major psychiatric disorder (PMPD) meeting DSM-IV criteria for the diagnosis of bipolar affective disorder (BAD) were studied. Four patients had early onset PD. Four developed a severe psychiatric disorder a few years after starting dopaminergic therapy in presence of a mild motor disability and a mild cognitive impairment, with no evidence of cerebral atrophy at CT or MRI. Two patients developed a clear manic episode; the other three presented a severe depressive episode (in one case featuring a Cotard syndrome). None showed previous signs of long term L-dopa treatment syndrome (LTS), hallucinosis or other minor psychiatric disorders. The two manic episodes occurred shortly after an increase of dopaminergic therapy and in one case rapid cyclic mood fluctuations were observed. At the onset of psychiatric symptoms, all patients had an unspecific diagnosis of chronic delusional hallucinatory psychosis (CDHP).