2 The syndromal heterogeneity of the diagnostic constructs makes it impossible to demonstrate a potential

syndromal specificity of a drug. Historically, drugs have been developed empirically on the basis of clinical observations. The discovery of chlorpromazinc for the treatment of schizophrenia in the early fifties by Delay and Deniker,3 and of imipramine for depression a few years later by Kuhn4 are such examples. On the other hand, new psychopathological syndromes have been PD0332991 nmr identified by observant clinicians who recognized the unique actions of psychotropic drugs like clomipramine for the treatment of specific disorders such as obsessive-compulsive disorder (OCD)5 or imipramine for panic disorders.6,7 Unlike other medical Inhibitors,research,lifescience,medical conditions, the etiology and pathophysiology of psychiatric disorders

remain unknown. This is true despite the recent advances in the understanding of the function Inhibitors,research,lifescience,medical of the central nervous system (CNS) and in the field of biological psychiatry. Neurotransmitter imbalances in some areas of the CNS as well as neuroanatomical and neurophysiological abnormalities have been hypothesized to explain most of these psychiatric disorders, but this hypothesis has failed to be conclusively demonstrated. However, as no rational alternative explanation has been advanced for these disorders, the current pharmacological approach to Inhibitors,research,lifescience,medical the treatment of psychiatric disorders is based Inhibitors,research,lifescience,medical on trying to restore the observed dysfunction of central neurotransmitters. Since the ICD-10 and DSM-IV classifications are based on clinical descriptions, they neglect biochemical and physiological

abnormalities that are involved in the pathogenesis of disorders. The increasing knowledge of transmitter function in relation to behavioral pharmacology has suggested links to numerous psychiatric conditions. This “pathophysiological approach” to Inhibitors,research,lifescience,medical the development of new treatments is oriented more toward behavioral abnormalities than toward nosological syndromes. Pathophysiological approaches allow transnosological treatment because particular symptoms can occur in many different psychiatric disorders. Behavioral abnormalities can be attributed to increased or decreased neuronal activity, and sometimes to alterations of specific transmitter receptors. This points to a role for functional pharmacology, which implies that, rather than nosological categories, one should treat basic disturbances in cognitive functions, Suplatast tosilate impulse control, perception, information processing, and mood regulation. Since in many cases monotherapy is insufficient to adequately treat the different nosological categories, naturalistic clinical practice requires that most patients be treated according to their symptoms with more than one drug.2 The need for such multiple-drug therapy is due to many factors, such as multiple syndromes, comorbidity, and different target symptoms like negative and positive symptoms in schizophrenia.