The prevalence of the Ideopathic Parkinson's Syndrome sums up to 2% and ranks second in the list of neurodegenerative diseases. Beside psychotic, cognitive and behavioural symptoms that go along with the IPS, the authors focus on epidemiology, pathogenesis as well as diagnosis and therapy of depressive symptoms seen in the context of IPS. Metaanalytic data on the prevalence of depressive symptoms sum up to 31%. As depression in IPS relies on a complex interaction of psychological and biological causes the clinical picture is difficult to assess because symptomatology differs from classical depression. Dopamine agonists as well as antidepressants present the mainstay in biological therapeutic interventions. A therapeutic algorithm based on theoretical considerations is presented.