Preventing suicidal thoughts and behaviours (STB) among youth is a global public health priority. STB are known to have a heritable basis, and the development of risk for STB likely arises from complex gene-environment interactions across the life course. Lannoy et al. (Journal of Child Psychology and Psychiatry, 63, 2022 and 1164) describe a study in which polygenic risk for suicide attempt, as well as recent negative life events, were related to recent suicidal ideation in adolescents of about 17 years old. Building on this important work, we highlight several critical areas of focus for research in suicide genetics, including problems of measurement, as well as priorities for better uncovering the specific aetiological pathways to STB., (© 2023 Association for Child and Adolescent Mental Health.)