1. INTRODUCTION Dysregulation of Hypothalamic-Pituitary-Adrenal, (HPA), axis has been hypothesized to participate in the emergence of psychosis, yet findings have been inconsistent. DEXAMETHASONE SUPPRESSION TEST IN AT RISK FOR PSYCHOSIS FIRST EPISODE PSYCHOSIS AND SCHIZOPHRENIA PATIENTS AND RELATED PSYCHOPATHOLOGICAL IMPLICATIONS E Karanikas 1, E Ntouros 1, D Oikonomou 1, V Ntouros 1, P Panagiotidis 1, D Antoniadis 2, G Garyfallos 1 424 General Military Hospital, Psychiatric Clinic,Thessaloniki, Greece 2 Aristotle University, 2 nd Psychiatric Department, Thessaloniki, Greece

2. HYPOTHESIS The aim of the study was to investigate the hypothesis that HPA axis sensitivity as evaluated through application of Dexamethasone Suppression Test, (DST), differs in populations being in various stages of psychosis. The aim of the study was to investigate the hypothesis that HPA axis sensitivity as evaluated through application of Dexamethasone Suppression Test, (DST), differs in populations being in various stages of psychosis. DEXAMETHASONE SUPPRESSION TEST IN AT RISK FOR PSYCHOSIS FIRST EPISODE PSYCHOSIS AND SCHIZOPHRENIA PATIENTS AND RELATED PSYCHOPATHOLOGICAL IMPLICATIONS E Karanikas 1, E Ntouros 1, D Oikonomou 1, V Ntouros 1, P Panagiotidis 1, D Antoniadis 2, G Garyfallos 1 424 General Military Hospital, Psychiatric Clinic,Thessaloniki, Greece 2 Aristotle University, 2 nd Psychiatric Department, Thessaloniki, Greece

3. METHODS In this crossover study, serum cortisol levels were measured in four participant groups consisted of first episode of psychosis patients (FEP, n:28) being drug naïve or minimally treated (<3 days), chronic schizophrenia patients under treatment (SCZ, n: 17), at risk for psychosis prodromal subjects (ARP, n:9) and healthy controls (HC, n: 23). The evaluation took place at 08:00 at day 1 and 1 mg of dexamethasone was given orally at 23:00 of the same day. On day 2 serum cortisol was measured at 08:00. All patients were psychopathologically evaluated with the use of PANSS. In this crossover study, serum cortisol levels were measured in four participant groups consisted of first episode of psychosis patients (FEP, n:28) being drug naïve or minimally treated (<3 days), chronic schizophrenia patients under treatment (SCZ, n: 17), at risk for psychosis prodromal subjects (ARP, n:9) and healthy controls (HC, n: 23). The evaluation took place at 08:00 at day 1 and 1 mg of dexamethasone was given orally at 23:00 of the same day. On day 2 serum cortisol was measured at 08:00. All patients were psychopathologically evaluated with the use of PANSS. DEXAMETHASONE SUPPRESSION TEST IN AT RISK FOR PSYCHOSIS FIRST EPISODE PSYCHOSIS AND SCHIZOPHRENIA PATIENTS AND RELATED PSYCHOPATHOLOGICAL IMPLICATIONS E Karanikas 1, E Ntouros 1, D Oikonomou 1, V Ntouros 1, P Panagiotidis 1, D Antoniadis 2, G Garyfallos 1 424 General Military Hospital, Psychiatric Clinic,Thessaloniki, Greece 2 Aristotle University, 2 nd Psychiatric Department, Thessaloniki, Greece

4. RESULTS RESULTS Post dexamethasone serum cortisol values did not differ among groups, (p=0.374). Neither did the variation of cortisol levels as evaluated after subtracting post dexamethasone cortisol values from pre dexamethasone ones, (p=0.316). In FEP group the change of cortisol levels resulting from DST suppression positively associated with Positive scale score(r=0.42,p=0.034), Negative scale score (r=0.448,p=0.017) and Total PANSS score (r=0.556,p=0.002) while in the SCZ goup only the Negative score significantly negatively correlated with post dexamethasone cortisol levels(r= -0.531,p=0.034 DEXAMETHASONE SUPPRESSION TEST IN AT RISK FOR PSYCHOSIS FIRST EPISODE PSYCHOSIS AND SCHIZOPHRENIA PATIENTS AND RELATED PSYCHOPATHOLOGICAL IMPLICATIONS E Karanikas 1, E Ntouros 1, D Oikonomou 1, V Ntouros 1, P Panagiotidis 1, D Antoniadis 2, G Garyfallos 1 424 General Military Hospital, Psychiatric Clinic,Thessaloniki, Greece 2 Aristotle University, 2 nd Psychiatric Department, Thessaloniki, Greece

5. CONCLUSION/ CONCLUSION/DISCUSSION The application of DST in different stages of psychosis from prodrome up to chronicity did not suggest aberrant sensitivity of HPA axis function. This finding contrasts the positive association of cortisol suppression with psychopathology and sets the framework for further research into additional parameters playing a role in HPA axis response in psychosis DEXAMETHASONE SUPPRESSION TEST IN AT RISK FOR PSYCHOSIS FIRST EPISODE PSYCHOSIS AND SCHIZOPHRENIA PATIENTS AND RELATED PSYCHOPATHOLOGICAL IMPLICATIONS E Karanikas 1, E Ntouros 1, D Oikonomou 1, V Ntouros 1, P Panagiotidis 1, D Antoniadis 2, G Garyfallos 1 424 General Military Hospital, Psychiatric Clinic,Thessaloniki, Greece 2 Aristotle University, 2 nd Psychiatric Department, Thessaloniki, Greece

6. REFERENCES Borges S, Gayer-Anderson C, Mondelli V. (2013). A systematic review of the activity of the hypothalamic-pituitary-adrenal axis in first episode psychosis. Psychoneuroendocrinology. 38:603- 611 Bradley AJ, Dinan TG.(2010). A systematic review of hypothalamic-pituitary-adrenal axis function in schizophrenia:implications for mortality.J Psychopharmacol 24: 91-117 DEXAMETHASONE SUPPRESSION TEST IN AT RISK FOR PSYCHOSIS FIRST EPISODE PSYCHOSIS AND SCHIZOPHRENIA PATIENTS AND RELATED PSYCHOPATHOLOGICAL IMPLICATIONS E Karanikas 1, E Ntouros 1, D Oikonomou 1, V Ntouros 1, P Panagiotidis 1, D Antoniadis 2, G Garyfallos 1 424 General Military Hospital, Psychiatric Clinic,Thessaloniki, Greece 2 Aristotle University, 2 nd Psychiatric Department, Thessaloniki, Greece