Antipsychotic medication represents the first-line treatment for schizophrenia. While it is undisputed that antipsychotics ameliorate positive symptoms, the exact cognitive and emotional pathways through which the effect is exerted has remained unclear. The present study investigated the subjective effects of antipsychotics across various domains of cognition and emotion in both patients with psychotic symptoms and patients with other psychiatric diagnoses. A total of 69 patients with a probable history of psychosis or psychotic symptoms and 26 patients with psychiatric diagnoses other than psychosis participated in a survey conducted over the Internet. Multiple control measures aimed to secure response validity. All patients were currently or had previously been treated with antipsychotic agents. A questionnaire comprising 49 items and measuring possible effects of antipsychotics on cognition and emotion was administered. For 30 out of 49 items a clear response pattern emerged, which was similar for patients with psychotic disorders and patients with other diagnoses. Factor analysis of these items revealed three main effects of antipsychotic medication related to doubt and self-doubt, cognitive and emotional numbing, and social withdrawal. Antipsychotic treatment appears to be connected to a number of negative subjective effects on cognition and emotion. Further studies are warranted to assess how these effects impact on the patients' subjective well-being and quality of life, as well as their association with antipsychotic efficacy on one hand, and adherence rates on the other. Induction of doubt and dampening of emotion may be one reason why antipsychotics work and at the same time offer an explanation why they are experienced as rather unpleasant and are eventually discontinued by many patients.