Trazodone alleviates both dyskinesia and psychosis in the parkinsonian marmoset model of Parkinson's disease

Trazodone is a clinically available anti-depressant that exhibits affinity for serotonin 1A and 2A receptors, as well as for alpha-adrenoceptors, suggesting that it may be useful to treat l-3,4-dihydroxyphenylalanine (l-DOPA)-induced dyskinesia and psychosis that are encountered in advanced Parkinson’s disease (PD). Here, we investigated the anti-dyskinetic and anti-psychotic effects of trazodone in the parkinsonian non-human primate. 6 common marmosets were rendered parkinsonian by administration of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Following repeated administration of l-DOPA to induce stable dyskinesia and psychosis-like behaviours (PLBs), trazodone (0.1, 1 and 10 mg/kg) or vehicle was administered in combination with l-DOPA and its effects on dyskinesia, PLBs and parkinsonism were determined. The addition of trazodone 10 mg/kg to l-DOPA reduced peak dose dyskinesia by ≈ 39% (P