Aim: to determine if there is an association between serum testosterone levels and cognitive and psychopathology scores in women with chronic schizophrenia.
Methods: baseline data was used from two randomised controlled trials of women with chronic schizophrenia. Serum testosterone was measured on a single sample. Cognition was measured using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), on which a higher score equates to better cognition. Psychopathology was measured using the Positive and Negative Syndrome Scale (PANSS), with a higher score indicating more severe psychosis. As data were not normally distributed Spearman correlations were used to assess the associations between testosterone and cognitive and psychopathological variables. For variables in which a significant correlation was found, women with testosterone levels in the lowest quartile were compared to women with levels in the highest quartile using the Mann-Whitney U test.
Results: data on cognition were available for 165 women and for psychosis on 265 women, aged 19-51 with mean length of illness 11.8 years (±7.5). Mean testosterone was 1.45nmol/L (± 0.75), mean PANSS 77.71 (±59.35) and mean total RBANS score was 76.41 (±16.5) indicating marked cognitive impairment across the group. Significant correlations were seen between serum testosterone levels and RBANS measures of verbal memory (story recall [-0.19, p=0.016], immediate memory [-0.18, p=0.020], delayed memory [-0.195, p=0.012]), as well as total RBANS score (-0.155, p=0.047). Significant correlations were seen between testosterone and the following symptoms of psychosis: difficulty in abstract thinking (0.18, p=0.023), ‘lack of spontaneity and flow of conversation’ (0.022, p=0.005), motor retardation (0.18, p=0.023), lack of judgement and insight (0.20, p=0.01), preoccupation (0.16, p=0.04).
Significant differences between women with testosterone levels in the lowest quartile compared with the highest quartile were seen for delayed memory (p=0.05), story recall (p=0.039) and ‘lack of spontaneity and flow of conversation’ (p=0.01).
Conclusion: in women with chronic schizophrenia, higher testosterone levels are associated with poorer cognition, in particular, verbal memory. This is a new finding which has not been reported before in women with schizophrenia.