BEHAVIORAL, NEUROCHEMICAL, ANATOMICAL AND ELECTROPHYSIOLOGICAL CORRELATES OF PANIC DISORDER - MULTIPLE TRANSMITTER INTERACTION AND NEUROPEPTIDE COLOCALIZATION

Neurochemical accounts of panic disorder focus on peripheral indices o f central transmitter activity, hormonal correlates and therapeutic ef ficacy. Anxiogenic agents augment norepinephrine activity, some anxiol ytics increase serotonin neurotransmission while benzodiazepines and a ntidepressants influence catecholamine, indoleamine and gamma-aminobut yric acid turnover in infrahuman subjects. Reliable correlates of cent ral transmitter activity in panic disorder are not in evidence. While animal models of anxiety may not mirror the symptom profile of panic, neurobiological accounts of panic disorder fail to consider extensive central colocalization of neurotransmitter and putative neurotransmitt ers. In effect, transmitter release in major ascending and descending transmitter systems is modulated by variable neuropeptide interfacing. The behavioral concomitants of psychological disturbance likely follo w from variable neurochemical release induced by stimuli as well as co nditioning and sensitization. The functional role of receptor sites as sociated with multiple neurochemical systems may vary and the sensitiv ity and/or density of receptor sites may be modified. Accordingly, the behavioral and neurochemical concomitants of acute and chronic pathol ogy may be fundamentally different from one another. The present revie w argues that the symptoms of panic disorder and the etiology of the i llness must be evaluated against a background of genetic, organismic a nd experiential factors. Such variables presumably underlie the divers e behavioral symptoms associated with panic disorder and variations in the therapeutic efficacy of pharmacological treatment.