Hair cortisol in drug-naïve first-episode individuals with psychosis. 
To compare hair cortisol concentrations (HCC) in drug-naïve first-episode psychosis (FEP) patients and healthy controls and to investigate the correlations between HCC and psychopathology.  Twenty-four drug-naïve FEP patients and 27 gender- and age-matched healthy control subjects were recruited.  The Structured Clinical Interview for DSM-IV (SCID-1) was used to confirm/rule out diagnoses, and the Positive and Negative Symptoms Scale (PANSS) was used to assess symptom severity.  Hair samples (2-3 cm long) obtained from the posterior vertex region of the scalp were processed in 1-cm segments considering a hair growth rate of 1 cm per month.  The 1-cm segments were classified according to their proximity to the scalp: segment A was the closest to the scalp and referred to the month prior to inclusion in the study.  Segments B and C referred to the 2nd and 3rd months prior to the time of evaluation respectively.  Hair steroid extraction was performed using a known protocol.  Two-way analysis of covariance (ANCOVA) with gender and age as covariates revealed a group effect (F1.106 = 4.899, p = 0.029) on HCC.  Between-segment differences correlated with total PANSS score and with PANSS General Psychopathology subscale and total score.  Our findings suggest that hypothalamic-pituitary-adrenal (HPA) axis, as assessed by long-term (3-month) cortisol concentration, is abnormal in the early stages of psychosis.  The magnitude of changes in HCC over time prior to the FEP correlates to psychopathology.  HPA axis abnormalities might begin prior to full-blown clinical presentation requiring hospital admission.