The benefit of neuroleptic drugs in the treatment of schizophrenic patients is objectively beyond any doubt. However, most patients discontinue their neuroleptic drugs within some months. This low compliance might be caused by the lack of insight into the disease and the necessity of therapy. Also of major importance are adverse effects, not restricted to motor symptoms, but also affecting cognition and emotion. They are often too subtle to be detected by objective examination, but reported by patients who complain of a reduced quality of life with restrictions of emotionality, straight thinking and spontaneity. This syndrome, similar to negative symptoms of schizophrenia, has been named 'pharmacogenic depression' or 'neuroleptic-induced deficit syndrome'. To investigate this issue of major clinical relevance, a self-rating scale was developed to measure subjective well-being under neuroleptic treatment (SWN). First analyses indicate good practicability, reliability, validity and sensitivity. Data obtained from 280 remitted schizophrenic patients showed that the SWN was significantly correlated to objective psychopathology (Positive and Negative Symptom Scale, PANSS; r = -0.35), quality of life (r = 0.60) and other self-ratings of mood states [Profile of Mood Scale (POMS), Self-rating Depression Scale (SDS), Befindlichkeits Scale (BFS); r = 0.25-0.75]. A repeated application after 3 months in 53 patients did not show any change in SWN in those with constant neuroleptic medication, but there were marked alterations if the dosage or the drug was changed. The SWN in 28 patients treated with clozapine because of therapy resistance or major side effects was, despite negative selection, significantly better (t = 1.79, p = 0.03) than in 38 patients under classical neuroleptics. Moreover, even at dismissal, patients who were non-compliant 4-6 months later (n = 14) differed significantly (t = 3.21, p = 0.02) in SWN, but not in PANSS, from those who remained compliant (n = 34). These data indicate that the SWN is a useful tool for investigating a hitherto neglected psychopathological dimension. Subjective effects of neuroleptics are measurable, affect patients' quality of life and should be considered more thoroughly in clinical routine as well as in clinical trials of potential neuroleptic drugs.