[Psychological and cognitive problems in Parkinson disease--therapeutic possibilities]

Depression, hallucinations, psychosis and cognitive deficits may often complicate advanced Parkinson's disease. Their detection and treatment have extraordinary importance, as they may cause significant invalidity and even an increase in mortality. Optimization of antiparkinsonian therapy may exert a positive influence on depressive symptoms, and should therefore be performed before antidepressant drugs are started. On the other hand, hallucinations and dementia do usually benefit from a discontinuation or dosage reduction of anticholinergic drugs, selegiline, DA-agonists and amantadine. When a levodopa monotherapy is indicated, slow-release formulations should be avoided. When a neuroleptic treatment is needed, clozapine and maybe quetiapine should be preferred. Preliminary evidence suggests that cholinesterase inhibitors might partially improve cognitive deficits in Parkinson's disease.