Many individual studies have been done to investigate possible effects of the rs6313 polymorphism on
phenotypes such as
personality traits or disorders and their
endophenotypes. The C-
allele has been associated with higher
extraversion personality scores among
borderline personality disorder patients and the presence of visual and auditory
hallucinations in patients with
late-onset Alzheimer's disease. Multiple studies have found that individuals with schizophrenia who are homozygous for the C-allele tend to do worse on working memory tasks than do individuals with a T-allele. Rs6313 has also been shown to be associated with
novelty seeking among Italian
mood disorder patients and
reward dependence in a German population. The SNP may also be associated with
rheumatoid arthritis. One study found no association between the SNP and suicidal behavior in a Chinese population, and another found no association with fibromyalgia syndrome. ==References==