Dexamethasone suppression test in first-episode schizophrenia.

OBJECTIVES: Higher rates of dexamethasone test (DST) nonsuppression in schizophrenia have been attributed to depressive symptoms, suicidality and negative symptoms. No study concerning first-episode schizophrenia has yet been published.

DESIGN: In patients hospitalised for the first time with first-episode schizophrenia the DST has been performed before, at the end of the acute treatment and after one year. At the same time the clinical evaluation with PANSS was performed. A cortisol value >5 microgram/dl in either of the postdexamethasone samples indicated nonsuppression of cortisol.

RESULTS: A total of 56 males were included. 18% of pts were DST nonsuppressors at medication-free baseline, 5% and 16% after acute treatment and after one year respectively. After 1 year 42/56 of patients fulfilled the criteria of remission. The rate of nonsuppression was 21.4%, 5% and 16.4% in remitters and 7%, 7% and 14.3% in nonremitters. Significant differences in the whole group were found between postdexamethasone cortisolemia at discharge on the one hand and on admission and at the one-year follow-up on the other. Significant correlations were observed between postdexamethasone cortisolemia and negative symptoms at the end of acute treatment.

MAIN FINDINGS: In first-episode schizophrenia the short-term treatment led to a decrease in cortisolemia and rates of nonsuppression and an increase at a one-year follow-up.

CONCLUSIONS: Rates of DST nonsuppression in schizophrenia including first-episode schizophrenia are influenced by the stage of illness and medication status. The impairment of feedback regulation of cortisol secretion may be related to different biopathogenetic mechanisms depending on the phase of the illness.