According to two recent studies published both in JAMA Psychiatry and Brain, psychiatric disorders such as depression, addiction and schizophrenia have common biological basis. Findings indicate that this novel data might be targeted for diagnostic purposes and the development of new treatments. Both studies conducted by researchers at the University of Cambridge and Stanford University used the brain atrophy section of BrainMap database (contains information on functional and structural neuroimaging experiments) and the Research Imaging Institute at the UT Health Science Center in San Antonio.
Psychiatric diagnoses are currently distinguished based on sets of specific symptoms. Accordingly, most neuroimaging studies have compared brain structure or function in patients with a single, specific diagnosis with healthy participants. In turn, even closely related diagnostic categories are rarely compared with each other. Nonetheless, neuroimaging research is suggestive of common neurobiological abnormalities across phenotypically related diagnoses.
To further test this hypothesis, Peter T. Fox, M.D., director of the Research Imaging Institute and professor at the School of Medicine, UT Health Science Center, and colleagues conducted a meta-analysis study that used structural neuroimaging in multiple psychiatric diagnoses, followed by parallel evaluation of three large-scale data sets of healthy participants to interpret structural findings in the meta-analysis. The research team was able to retrieve a total of 193 studies representing 15,892 individuals with 6 diverse diagnostic groups (depression, bipolar disorder, schizophrenia, obsessive-compulsive disorder, addiction and anxiety).
Results from this meta-analysis showed that gray matter loss was observed across all diagnoses in the right insula, the dorsal anterior cingulate, and the left insula. Conversely, there were few diagnosis-particular effects which distinguished schizophrenia and depression from other diagnoses.
In the follow-up analyses with three independent healthy participant data sets, the researchers found that the common gray matter loss regions formed a tightly interconnected network during tasks and at resting, with lower gray matter in this network linked with poor executive functioning.
Based on the results the researchers suggest that there is a similarity in psychiatric diagnoses in terms of integrity of an anterior insula/dorsal anterior cingulate–based network, which may be associated with deficits in executive function that are seen across diagnoses. “Both studies make the point that psychiatric disorders have several brain-imaging abnormalities in common, despite being ostensibly different diseases,” Dr. Fox, a co-author on both papers, said in a recent news release.