White Matter Reductions Associated With Schizophrenia Differ By Symptomology
Previous studies have shown that changes in brain structure can be observed in schizophrenia. Now, shortly after recent findings showed that schizophrenia may actually be a class of mental disorders made up of 8 unique conditions, a new study says the specific areas of the brain with reduced grey matter in patients with schizophrenia differ according to their predominant symptoms.
Tianhao Zhang and colleagues from the University of Pennsylvania used factor analysis to group 163 patients diagnosed with schizophrenia according to their predominant symptoms. One group included 57 people with predominant positive symptoms, 55 had negative symptoms, and 51 had disorganized symptoms.
All three groups showed significant grey matter alterations and reductions compared to control participants, with most changes occurring in the prefrontal and perisylvian regions, but the patterns were unique among the groups. Those with predominant positive or negative symptoms had widespread regions with significant reductions, while those with disorganized symptoms only had small areas affected.
Those with negative symptoms exhibited most reductions in the right cerebellum, while the positive symptom group showed reductions in the left interior orbitofrontal cortex and right thalamus. Patients with positive symptoms also had the largest number of affected areas, including bilateral reductions in the interior orbitogrontal cortex.
“The pattern of [grey matter] reductions revealed by our analysis is strikingly consistent with the topography of the dopaminergic pathways in the brain, and in particular of the mesolimbic and mesocortical pathways, which include projections from the ventral tegmental area to the limbic, frontal, and insular cortices”, write the researchers in Schizophrenia Bulletin.
“Besides adding to our knowledge of the biological underpinnings of schizophrenia, these patterns of structural differences between subgroups may serve in the future as early biomarkers of disease subtypes, hence for biomarker-based patient stratification in clinical psychiatry”, the team concludes.