As part of our clinical and research activities in neurology and psychiatry, we had the chance to examine hundreds of patients with Parkinson's disease (PD). The Movement Disorders Unit kept us abreast of the new developments in the management of the clinical complications of PD, and made us aware of the emotional, behavioral, and cognitive complications of the disease. These problems have been specifically studied at the Departments of Neuropsychiatry of our Institutes, where we carry out most of our clinical and research activities in the interface between neurology and psychiatry.

Whereas emotional problems such as depression and anxiety are very prevalent in PD, they are rarely diagnosed and treated. One of the reasons for the low awareness of mood problems in PD is that some of the key symptoms of depression, such as psychomotor retardation, lack of energy, loss of libido, insomnia, and low energy, are also frequently found among PD patients. There may also be a tendency to “expect” PD patients to be somewhat depressed based on their physical limitations, and to consider depressed mood as an “understandable” consequence of the illness. On the other hand, behavioral problems such as delusions and hallucinations dramatically affect both patients' and caregivers' lives, and treatment is readily obtained. Cognitive disorders slowly develop in a high proportion of PD patients, and the familial and financial impact of this complication is comparable to that in other dementias.