Depression in Parkinson disease: a disabling but neglected factor

20 depressed and 20 non depressed patients with Parkinson disease were rated for disability on the Northwestern University Disability Scale and for severity of the "typical" motor symptoms on the Columbia University Rating Scale and were assessed for mental deterioration. The severity of the "typical" symptoms was practically equivalent in the two groups but the depressed patients not only presented mild mental deterioration but were significantly more disabled (less independent) than the patients without depression. A significant correlation was found between severity of depression and degree of disability but not between severity of depression and severity of "typical" motor symptoms. Depression was diagnosed much later than the "typical" symptoms. Only 25% of the depressed parkinsonians had received tricyclic antidepressants, about 20% had been treated with dopamine-antagonist psychotropic drugs and some 50% had received no treatment at all against depression. Timely diagnosis and appropriate treatment of depression in parkinsonian patients limits the effects of a major disabling factor.