Substance use disorders (SUD: alcohol, tobacco, cannabis and illicit drugs) are amongst the top 10 contributors to preventable causes of death worldwide (e.g. COPD, road injury, liver cancer). Despite the modest global prevalence of illicit drug use disorders, they are responsible for nearly 1% of all-cause disability adjusted life years (Lynskey; Degenhardt);

Heritable influences contribute to 50% of the variation in SUDs (SCZh2=0.8>SUDh2=0.5>MDDh2=0.3), yet identification of common or rare variation is relatively recent.

Genomewide significant results have begun to emerge for alcohol (ref), cocaine (ref) and opioid (ref) dependence phenotypes but reproducibility is limited.

Increasing sample sizes via mega-analysis has accelerated the pace of discovery for Schizophrenia and Tobacco Smoking. PGC expects similar discoveries for Bipolar Disorder, Major Depressive Disorder, Autism and ADHD.