The aim of this project is to study self-harm and suicide attempts and ideation in adolescents and young adults (AYAs). We will use ALSPAC data to classify the cohort into different psychopathology groups (i.e. groups displaying similar psychiatric condtions like anxiety, depression etc.) and then to see which groups are at most risk of later self-harm or suicide. Furthermore, we will study how people transition between these different latent or hidden groups over time. Ultimately, we wish to examine the aetiology of, and then the trajectories to, self-harm and suicide in AYAs and get a clear picture as to the risk factors and life circumstances for those in the AYA group who later end up exhibiting this sort of behaviour. If this analysis is successful, we then hope to create a risk prediction model for self-harm and/or suicidal ideation and behaviour in AYAs so that implementation efforts can be put in place to prevent future self-harm and suicidal behaviour in AYAs.