Sex moderates the relationship between cognitive disorganisation and visual backward masking: potential implications for an endophenotype of schizophrenia.

Schizophrenia is a severe mental disorder that impairs individuals’ life, often chronically and from early adulthood on. There is a search for endophenotypes, i.e. stable markers of the genetic underpinnings of the disease. Visual backward masking (VBM) is a potential endophenotype, because performance is impaired in patients with schizophrenia, their relatives, and healthy individuals scoring high on cognitive disorganisation (CD), a schizotypal feature. The latter finding is based on mainly female participants. To test whether relative VBM deficits are present in both high female and male CD scorers, we investigated VBM in 14 men and 15 women. In line with our previous study (Cappe et al., in press), we assessed i) schizotypy with a validated self-report questionnaire, ii) VBM for 5 and 25 element gratings, and iii) total erros in a frontal lobe task (Wisconsin Card Sorting Task). Results showed enhanced VBM deficits as a function of high CD scores, but only in women. Total errors did not differ as a function of sex and CD group, although total errors correlated negatively with VBM performance for the 5 element grating in women. These findings provide further support for VBM to be an endophenotype. Whether this conclusion, at least in healthy individuals, is specific to women needs to be investigated in future studies. The sex-specific finding either indicate that hormonal levels might influence the relationship between VBM performance and schizotypy or reflect a response bias in the schizotypy questionnaire more pertinent in men than women