Anorexia nervosa (AN) has the highest mortality out of all psychiatric conditions, early onset (between 12-15 years), and long-term health issues. Although the exact cause of AN is not yet fully understood, it is known that a complex combination of environmental and genetic factors plays a role in its development. Genetics alone are estimated to explain 50 to 60% of risk for AN. Recently, a large-scale genome-wide association study (GWAS) identified eight genomic regions associated with AN, as well as evidence that the genetic architecture of AN overlaps that of metabolic and anthropometric traits, such as body-mass index (BMI) and risk for type-2 diabetes. In this study, we will analyze AN GWAS results to compute polygenic risk scores (PRS) for ALSPAC participants, allowing us to estimate the genetic risk for AN for each participant. We will test how genetic risk for AN is associated with behavioural and emotional problems during childhood and whether these associations are development-specific by modeling psychopathology measures longitudinally. We will also test associations between AN and physical growth during early life. Given the patterns of genetic associations between AN and BMI, we will test whether genetic risk for AN that has been adjusted for genetic correlations with BMI affects previously identified associations.