BACKGROUND: Negative symptoms of schizophrenia are often confounded by overlapping depressive and parkinsonian symptoms. The role of medication as an aetiological factor in the development of these symptoms is an important issue for prevention and treatment. METHODS: A total of 45 inpatients in chronic wards who met RDC criteria for schizophrenia were assessed with the Hamilton depression rating scale (HDRS) and negative symptom rating scale (NSRS) and the targeting abnormal kinetic effect scale (TAKE). RESULTS: No significant correlation was found between the total scores on the vegetative superfactor of the HDRS and the NSRS. Duration of neuroleptic treatment was positively correlated with depressive symptoms (r=0.299, P < 0.05) and negative symptoms (r=0.443, P < 0.001). Dose of antipsychotic was also correlated positively with negative symptoms (r=0.260, P < 0.05). Age was negatively correlated with depressive symptoms as assessed by the HDRS (r=0.306, P <0.05). CONCLUSION: The data suggest that depressive and negative symptoms can be separated in chronic schizophrenia, while pointing to a possible role of antipsychotic medication in the aetiology. LIMITATIONS: The study was conducted in a small chronically hospitalised population treated with relatively high doses of antipsychotics. It is not clear that the results obtained here would be applicable to an acute patient population.
BACKGROUND: Negative symptoms of schizophrenia are often confounded by overlapping depressive and parkinsonian symptoms. The role of medication as an aetiological factor in the development of these symptoms is an important issue for prevention and treatment. METHODS: A total of 45 inpatients in chronic wards who met RDC criteria for schizophrenia were assessed with the Hamilton depression rating scale (HDRS) and negative symptom rating scale (NSRS) and the targeting abnormal kinetic effect scale (TAKE). RESULTS: No significant correlation was found between the total scores on the vegetative superfactor of the HDRS and the NSRS. Duration of neuroleptic treatment was positively correlated with depressive symptoms (r=0.299, P < 0.05) and negative symptoms (r=0.443, P < 0.001). Dose of antipsychotic was also correlated positively with negative symptoms (r=0.260, P < 0.05). Age was negatively correlated with depressive symptoms as assessed by the HDRS (r=0.306, P <0.05). CONCLUSION: The data suggest that depressive and negative symptoms can be separated in chronic schizophrenia, while pointing to a possible role of antipsychotic medication in the aetiology. LIMITATIONS: The study was conducted in a small chronically hospitalised population treated with relatively high doses of antipsychotics. It is not clear that the results obtained here would be applicable to an acute patient population.