Schizophrenia and bipolar disorder, although diagnostically separate, likely share elements of their genetic etiology. This study assessed whether the COMT Val158Met polymorphism has shared or specific associations with clinical phenotypes evident in schizophrenia and bipolar disorder. Schizophrenia and bipolar patients completed a clinical assessment encompassing premorbid functioning and current and lifetime symptomatology. Multivariate analyses yielded a three-way interaction of diagnosis, COMT genotype for lifetime symptomatology. The COMT Val allele was associated with greater positive symptomatology in schizophrenia, whereas Met homozygosity was associated with greater positive symptomatology in bipolar disorder. Findings support the COMT Val158Met polymorphism conferring vulnerability for different clinical phenotypes in schizophrenia and bipolar disorder. Lifetime symptomatology may be particularly useful in determining the relationship between genes and clinical phenotypes across mental disorders.
Bibliographical noteFunding Information:
Funding for this study was provided by Department of Veterans Affairs Medical Research Service, the Mental Illness and Neuroscience Discovery (MIND) Institute, the National Institutes of Mental Health (5R24MH069675), and the Mental Health Patient Service Line at the Veterans Affairs Medical Center, Minneapolis Minnesota; the funding sources had no further role in study design; in the collection, analysis and interpretation of data; in the writing of the report; and in the decision to submit the paper for publication.
- Positive symptoms
- Symptom dimensions