13 cases of politoxicomania that had undergone stationary treatment and, at the time of observation, were in rehabilitation, comprised the case load of this study. They were compared with 10 test persons in good state of health. In order to obtain circadine hormone profiles for melatonine, cortisol, human growth hormones (HGH) and thyroid stimulating hormones (TSH), blood samples were taken every hour from 6 pm until 7 am the following morning. The test cycle commenced with obtainment of a biochemical blood profile and a drug-oriented urine analysis. The cases were assorted into three therapy groups: Group 1: complete abstinence. Group 2: no hard drug intake. Group 3: acute relapse after a prolonged period of abstinence. This categorization (i.e. abstinence, soft or hard drug intake) was clearly mirrored by significant differences in the hormone profiles: the group of "abstinents" showed remarkably higher melatonine and cortisole levels than the acute relapsive cases. HGH and TSH profiles showed partly pathological levels which appeared unrelated, however, to the incidence of abstinence, or the manner of drug intake. Compared to the healthy control group, the test cases showed an increase of liver enzymes (Gamma-GT, SGOT, SGPT and LDH) but there was no marked difference between the 3 user categories themselves. The pathological neuroendocrine findings identified in test patients after a long period of abstinence are indicative of changes possibly based on genetic disposition rather than on abusive habits. The issue of self-inflicted damage, therefore, becomes a questionable one.