Studies have reported that offspring exposed to parental suicidal behaviours are at risk of a variety of problems, most notably, suicidal behaviours and affective disorders. Research to date has largely focussed on the impact of parental suicide and has been bas,ed on populations in contact with psychiatric services. Most studies have addressed offspring suicidal behaviour as an outcome; little is known about the impact of parental suicidal behaviours on other aspects of their children's wellbeing. This thesis aims to investigate the association of parental self-harm with selfharm, suicidal thoughts, depression, and academic performance in their offspring in a community-based prospective birth cohort - the Avon Longitudinal Study of Parents and Children (ALSPAC). Parental suicide attempt was self-reported on 10 occasions from pregnancy until the children were 11 years old. Children self-reported lifetime self-harm and suicidal thoughts at age 16-17 years. Symptoms of depression we're self-reported at age 10, 13, and 16-17 years. Academic performance was based on results from two national assessment exercises conducted at age 11-16 years. The analytic sample varies according to the exposure and outcomes being assessed but as an example: 4,396 mother-child and 2,541 father-child pairs were included in the analysis of the association of parental suicide attempt and offspring self-harm. Controlling for relevant confounders, maternal suicide attempt was associated with a 3-fold increased odds of self-harm with suicidal intent in their offspring [Adjusted odds ratio (aOR) 2.94, 95% confidence interval (CI) 1.43-6.07] but not with self-harm without suicidal intent (aOR 0.83, 95% CI 0.35-1.99). Offspring whose mother had attempted suicide were at an increased risk of suicidal thoughts and plans (aOR 5.04, 95% ,CI 2.24-11.36; aOR 2.17,95% CI 1.07-4.38, respectively). Findings in relation to paternal suicide attempt were similar to those of maternal suicide attempt, but were somewhat weaker and consistent with chance. Offspring whose mother had attempted suicide had also 26% higher mean score of symptoms of depression in adolescence relative to unexposed offspring (P=1.26, 95% CI 1.05 to 1.51, p=O.01). Paternal suicide attempt was associated with somewhat elevated mean score of depression but the evidence was weak and mostly consistent with chance. Adolescents whose mother had attempted suicide were less likely than their peers to achieve level five or above in English, Maths and Science combined at age 14 years (aOR 0.65,95% CI 0.43-0.97) and less likely to obtain five or more qualifications (i.e. GCSEs/GNVQs) at a top grade by age 16 years (aOR 0.41,95% CIO.17-0.96). Paternal suicide attempt was inversely associated with their offspring's likelihood of obtaining at least five qualifications by age 16 years (aOR 0.16, 95% CI 0.06-0.46). This thesis demonstrates that non-fatal suicidal behaviours in parents represent a major risk of psychiatric morbidity and poorer academic performance in their offspring. It suggests that interventions aimed at individuals with suicidal behaviours should identify individuals with parenting responsibilities and assess the needs of their children as well.