Non-compliance is a major problem in the treatment of schizophrenic patients, a problem which is due to the patient's mental condition, to disturbing side effects of the medication, to a defective doctor-patient relationship, and to a general scepticism towards chemical treatment of mental symptoms. The major advantage of depot administration of neuroleptic drugs is the assurance of compliance leading to fewer relapses and rehospitalizations. Depot neuroleptics also eliminate bioavailability problems related to absorption and first pass metabolism and give a stable plasma concentration. Finally, depot neuroleptics provide a better and safer way to use the lowest effective dose principle thereby reducing the frequency of side effects, including the subjectively distressing mental side effects such as akathisia, dysphoria and neuroleptic-induced deficit syndrome. Disadvantages include delayed disappearance of potentially irreversible and unpleasant side effects after discontinuation and, for many patients, a feeling of being controlled. Administered in the proper way, with suitable information to the patient and relatives, depot neuroleptics improve the quality of antipsychotic treatment, reduce relapse frequency, stabilize the therapeutic effect and diminish the level of side effects.