The published TAG meta-analysis results (downloaded from the Psychiatric Genomics Consortium website https://www.med.unc.edu/pgc/downloads) combined the SNP-based summary statistics of 16 participating cohorts including individuals of European ancestry from Europe and United States. The TAG sample has been described in detail elsewhere (see Table 1 and the Supplementary Information in 13). In short, the samples were collected mainly between 1970 and 2006. Across the participating studies, the mean age ranged from 39.6 to 72.3 years. In the total combined sample, 64.37% of the participants were females. Data on smoking status (ever/never smoked regularly) were available for N=69,409 individuals. Of these, 39,022 individuals declared to have smoked regularly (i.e., a regular smoker - according to the Center for Disease Control's definition - declared to have smoked at least 100 cigarettes during the lifetime). Data on quantity smoked were available in N=38,181 ever regular smokers, measured either as the average or the maximum number of cigarettes per day (two measures highly correlated over time (>0.71) in longitudinally followed samples17). The mean quantity smoked per day varied between 13.1 and 23.4 cigarettes across the
