There is an ever growing body of evidence that there are shared genetic components between behavioural and psychiatric disorders16, 17. Using the meta-analysed results in the current study this was evidenced by significant genetic correlations for depression with neuroticism, anorexia nervosa, attention deficit hyperactivity disorder (ADHD), schizophrenia, and bipolar disorder. The MR analysis also identified a putative bi-directional casual effect between depression and neuroticism. Removing regions which were used to test the effect in both directions indicated that a putative effect remained only for neuroticism on depression. This uni-directional effect does make more sense intuitively as neuroticism is a stable trait whereas depression is a more episodic condition.
