Summary details of the final sample of participants.

Note: * In the UK, the number of years in education required to achieve A level is 14. The patient records did not give full details of level of education, so patient participants were asked whether they had attended university (just one who had dropped out in year 1, hence no undergraduate participants were included in the matched control group). Based on the available data (N = 25 for controls and N = 21 for patients) the median level of education was 12 years for both patient and control participants, and on a Mann-Whitney U test there was no significant difference between the patient and control groups, p = 0.088.