In this review article four neuropeptides: adrenocorticotrope hormone (ACTH), corticotrope releasing hormone (CRH), neuropeptide- Y(NPY) and cholecystokinin (CCK) are discussed with respect to their possible role in the pathogenesis of anxiety disorders. First the presumable working mechanism of these peptides in the brain is mentioned. In addition, the relationship of these peptides and anxiety is outlined using neuroanatomical and electrophysiological research data. Subsequently, animal experiments and human research findings are discussed. Most of the research findings so far are obtained from animal data. Only with respect to CCK, there is increasing evidence, also from human studies, that this peptide might play a role in the pathogenesis of anxiety disorders. The putative role of the other peptides remains to be estab lished in future research.

Within the framework of interactional theories of depression it was examined whether the interaction of 31 severely depressed patients and a psychiatrist was related to the course of depression during hospitalization. Interactional processes were defined on the basis of directly observed behaviour displayed during an interview and by the use of ethological methods. The behavioural structure of such interaction could be described by 6-7 factors. Some of these factors could predict the clinical course of depression, over an interval of tien weeks. The patients who would not improve displayed before treatment (just after admission) more involvement (i.e., looking, gesticulating) coinciding with more general activation (leg and hand movements) than the patients who would improve. The psychiatrist displayed relatively high levels of involvement (encouragement: hm, hm, yes, yes, and yes-nodding) and low levels of general activation (hand movements) in his interaction with patients who would not improve. The results provide support for interactional theories of depression.

Serotonin (5-HT) plays an important role in depression and specific 5-HT reuptake blockers appear to be clinically important antidepressants. It is unclear however, which serotonergic mechanism is involved in the antidepressant effect, certainly when regarding the existence of at least seven 5-HT receptor subtypes. By testing different 5-HT ligands in two animal models of depression (forced swimming and DRL72-S test) and comparison with data from literature, evidence is provided for potential antidepressant qualities of 5-HT1A receptor-agonists and 5-HT1C receptor-antagonists. Compounds binding to 5-HT1B, 5-HT2 and 5-HT3 receptors do not have an antidepressant profile. Results of clinical research support the predicted antidepressive effects of 5-HT1A receptor-agonists.