Neuroleptic treatment of negative symptoms in schizophrenic patients. Efficacy problems and methodological difficulties.

The development and evaluation of the use of neuroleptics for negative symptoms of schizophrenia is becoming more and more of interest. However, severe methodological problems can lead to wrong conclusions in this field. The differentiation between primary and secondary negative symptoms and the interrelationship between negative symptoms, depression and akinesia have to be carefully considered. Many studies in this field are not conclusive because of such methodological pitfalls. After a careful review of published studies in this field no final conclusions can be drawn as to whether neuroleptics in general are effective in primary minus symptoms or whether certain neuroleptics are superior to others. Negative symptoms accompanying productive symptoms do improve with the neuroleptic treatment of the productive symptoms.