Now, Dr. Roffman's team is looking at the combination of MTHFR and another gene -- COMT (catechol-O-methyltransferase) -- that affects dopamine levels in the brain. Although the two genes have separately been associated with schizophrenia, Dr. Roffman's just completed study finds that when these genes interact, a specific subset of patients is at greater risk for cognitive impairment. In individuals who carry the risk variants of both MTHFR and COMT, lower-than-normal levels of dopamine in the part of the brain called the prefrontal cortex may cause problems with information processing and working memory. Using functional neuroimaging, Dr. Roffman and his colleagues also found that the same combination of MTHFR and COMT variants were associated with abnormally low activity in the prefrontal cortex.
"We now have the techniques to determine how genes combine to produce schizophrenia symptoms," Dr. Roffman explained. "As we gain a better understanding of individual biogenetic pathways, we can identify high-risk groups and those most likely to benefit from specific treatments."
Genes and Depression
If a better understanding of genes may lead to customized therapies for schizophrenia, can the same be true for new depression treatments? Answering this question is especially important now that a 2006 government study found that a significant number of people with clinical depression more than half are not helped by their initial course of antidepressant treatment, whether medication or talk therapy. In addition, antidepressant medications often
|Contact: Kristen Simone|
NARSAD, The Mental Health Research Association