New research has found genetic markers linking schizophrenia with personality traits for the first time, shedding new light on the shared genetic 
influences for personality and psychological disorders.
The findings, published in Nature Genetics, are consistent with research in recent decades showing that personality traits and psychological disorders are related.
In their paper, the researchers said their findings – identifying six variants associated with personality traits as well as genetic correlations between personality traits and psychiatric disorders – suggest that “part of the interrelation between personality traits and schizophrenia arises from a shared genetic basis.”
While past studies have found genetic associations for both schizophrenia and personality – there are literally hundreds of single nucleotide polymorphisms (SNPs) associated with schizophrenia, for instance – this is the first time that researchers have found indications that they share genetic influences, which in turn can help explain the clinical association between the two.
To discover these findings, a team of scientists, looked at data from a 23andMe genome wide association study on what are called the “Big Five” personality traits – neuroticism, extraversion, openness to experience, agreeableness and conscientiousness – and compared that data to findings from 
other genome wide association studies on schizophrenia. (Last week some of the same scientists who worked on this study, announced their findings from the largest genetic study to date on schizophrenia. That study identified eight locations in the genome with copy number variants associated with schizophrenia risk.)
The researchers working on this latest study found that for all of the personality traits except conscientiousness, there was a polygenic overlap with schizophrenia. In addition, the researchers found that two specific genetic markers associated with neuroticism and five markers associated with openness to experience are also associated with schizophrenia.
The researchers were able to replicate their findings to confirm these associations.
In all, the researchers used data from more than 140,000 people, including data from the Genetics of Personality Consortium, and from about 60,000 customers of 23andMe who consented to participate in research.
The findings are significant because they offer real clues to suggest that personality traits and schizophrenia share some of the same genetic influences. This in turn could help enlighten researchers studying the neurobiological process behind personality and the causes for conditions like schizophrenia.
You can find the paper in Nature Genetics.
