The results for neuroticism were predictive for MDD. Future analyses may focus on whether the MAGI1 locus and polygenic variance for neuroticism is also associated with psychiatric disorders that are phenotypically associated with neuroticism, such as Borderline personality disorder, bipolar disorder, schizophrenia, ADHD and substance use disorders. This could be achieved by combining data from with GPC with those available within the PGC65 and the Social Science Genetic Association Consortium66. Novel methodologies will be needed to test whether neuroticism represents a causal risk factor for MDD and other disorders, whether reverse causality is also present, or whether the genetic association between neuroticism and psychiatric disorders reflects an underlying common liability.57,67–69 It is expected that such studies will increase our understanding of the role that emotional instability plays in the occurrence and course of psychiatric disorders and other important health outcomes.
