Schizophrenia is a chronic disorder with a high risk of poor outcome in terms of symptoms and social functioning and possibly also progressive brain alterations. The relapse rate is high and each relapse can induce further aggravations, both in psychosocial as well as in neurobiological terms. Thus, acute and long-term treatment with the highest degree of effectiveness should be provided to the patients in acute and long-term treatment.

Neuroleptic medication is the most important part of the treatment regimen for schizophrenic patients. The efficacy of neuroleptics in the acute and long-term treatment of schizophrenia is very well proven and the effect size is comparatively high. The second-generation antipsychotics (SGAs) have advantages over the neuroleptics of the first-generation (FGAs), and high expectations have therefore been put into them for the treatment of schizophrenia. Their better extrapyramidal-motor tolerability and efficacy in treating negative, depressive and cognitive symptoms, in addition to positive symptoms, supposedly result in a more favourable influencing of the overall course of the disease and in a higher quality of life for the patients, thus improving their acceptance by patients and leading to increased compliance. Differences in the pharmacological profile can be identified among others by receptor imaging approaches.