Depression and Parkinson disease, two very different conditions at first sight, have much more intricate connections than is usually believed. Depression may be the patient's reaction to Parkinson disease, a condition that is anticipated with anxiety, with good reason as it is often very disabling and has not been significantly prolonged by dopamine therapy. Depression may precede the first signs of Parkinson disease. Pseudoparkinsonian melancholia may be difficult to distinguish from the akinetic form of Parkinson disease. Most of the symptoms of the latter have been encountered in the former. The following features do not occur in depression: astasia with trepidation, festination, monotonous tachyphemia and palilalia, sebaceous hypersecretion, and of course unilateral or frankly asymmetric signs. Parkinson syndrome secondary to depression can be classified with those parkinsonian syndromes that are different from parkinson disease and secondary to a clearcut etiology. In some instances, diagnosis is established by the response to therapy. In the present state of our knowledge, the treatment of depression relies on chemotherapy and sismotherapy and not on dopamine therapy. The management of Parkinson disease rests on dopamine which may be associated with tricylic antidepressants.