Estimating genetic correlation across multiple psychiatric disorders using GWAS data has become a standard analysis after the primary GWAS. Although SNP-based heritability is, based on current data, low (Table 1), these analyses have confirmed that SUDs are genetically correlated with other psychiatric disorders and behavioural traits, with the strongest overlap (besides other SUDs) observed for depression, anxiety, posttraumatic stress disorder, neuroticism, and risk-taking behaviours42, 77–83 (Figure 2). However, as detailed above, differences have been observed between SUD traits defined based on dependence criteria and phenotypes related to substance consumption/use. The dependence-based traits tend to have significantly higher genetic correlation with psychopathology-related traits than the use-based traits12, 14, 41, 82. This pattern — dependence for a given substance is genetically different from abuse — is seen across the small number of substances where there is sufficient data to make a comparison (e.g. alcohol and cannabis), but for many other SUDs insufficient data exist (e.g. for opioids and cocaine) for this pattern to be potentially confirmed as universal. An exception to the difference between frequency/quantity versus dependence is nicotine, where a high
