Individuals diagnosed with depression are at an increased risk of developing other psychiatric disorders as documented in Extended Data table 1 and a large body of studies 9,10, but little is known about the genetic constitution of those that develop these conditions. We examined the polygenic architecture of individuals with depression who have also developed anxiety, bipolar disorder, schizophrenia and/or SUD, using mvPRS analyses and PRSs from depression and eight psychiatric phenotypes genetically correlated with depression (Supplementary Table S5A and Figure S8A). This analysis showed that the subgroup of individuals with depression with a co-diagnosis of anxiety had a significantly increased PRS for 5 out of 9 psychiatric phenotypes tested compared to those with depression without anxiety, i.e. DEP-PRS (P=4.9 x 10−10), ANX-PRS (P=1.8 x 10−14), SZ-PRS (P=7.4 x 10−05), ASD-PRS (P=0.021) and Neuroticism-PRS (P=1.5 x 10−13) (Extended Data Figure 2, see Supplementary Table S18A for differences in effect sizes between depression-subtypes). Likewise, individuals with depression who had transitioned to bipolar disorder had a significantly increased PRS for 3 out of 9 psychiatric phenotypes tested compared to those with depression
