In contrast to the usual type of drug studies it is not our intention to single out specific drug effects, but we are interested in cognitive-psychomotor functioning of psychiatric patients across various periods of therapy, whether due to drug treatment or to underlying mental-affective disorders. 3 groups of psychiatric male patients (7 anxious/inhibited depressives, 7 schizophrenics, 6 patients with psychotic episodes) matched for age (mean = 30 years) and education (no academic trainig) with a group of healthy controls (n = 7) were examined three times during the first 6–8 weeks of their ordinary clinical therapy. The major criterion for the inclusion of a patient next to these diagnostic categories was an initial favorable response to the specified drugs (amitriptyline for the depressives, haloperidol for the schizophrenics, and thioridazine for the patients with psychotic episodes). Each subject was tested in an experimental laboratory with respect to cognitive-psychomotor performance (vigilance, divided attention, choice reaction time), mood, subjective fitness for driving, depression, and paranoia. All groups of patients improved significantly between the acute and the chronic phase. However, healthy controls showed a sharper increase of achievement. While the depressives and the patients with psychotic episodes function on a level of questionable fitness for driving, schizophrenics vary greatly intra- and interindividually, generally on a lower level.