Nuclear medicine in psychiatry.

From the second half of the twentieth century, advances in biological and psychopharmacological research seemed to promise a swift discovery of an organic basis of psychiatric diseases. Today we know that biological research in psychiatry is not a success story. This may be due to the complicated character of psychiatric disorders, where it is difficult to establish a unified model of the disease and thus in many cases difficult to fit into any categorical classification. This also affects the role of nuclear medicine (NM) in psychiatry.