a mother in a manual social class, with lower educational qualifications, and with depressive symptoms when the individual was aged 11. Further, those who received the questionnaire but did not return it differed from respondents in similar ways. The results from the imputation models indicate that the differences between respondents and non-responders did not have a large impact on prevalence figures for self-harm or risk factor associations. This may be because males were more likely to have missing data yet were less likely to self-harm, whereas those with low educational performance were more likely to have missing data and were more likely to self-harm, so these features of the missing data may have cancelled each other out.
