Dexamethasone suppression test in chronic schizophrenia

Abstract

SummaryDexamethasone suppresson test (DST) was administered to 26 chronic schizophrenic inpatients who were on stable doses of neuroleptics for over 3 months. Clinical assessments were made on the Brief Psychiatric Rating Scale (BPRS), the Manchester Scale (KGV) and the Scale for the Assessment of Negative Symptoms (SANS). Patients’ neuroleptic treatment was then stopped for 4 weeks and the clinical assessements and the DST repeated. Thirty two percent of the patients showed DST non-suppression which was mostly stable over the 4-week period of the study and was unaffected by the neuroleptic treatment. Contrary to some reports in the literature, the clinical rating scores (including those for depression and negative symptoms), in our patients, showed no relationship with the DST status. We suggest that the DST abnormality in chronic schizophrenies may result from two quite different mechanisms: one due to stress assoeiated with transient psychopathology such as agitation, anxiety, depression or psychotic perturbation which is transient, the other resulting from structural abnormalities in the brain and which remains stable over time.