NEW DELHI: Schizophrenia is a neuropsychiatric disorder characterised by recurrent episodes of psychosis, including hallucinations, delusions, and disorganised thinking, and given that it runs in families, researchers are focusing on genetic testing and analyses to pinpoint risk factors.
Recent genomic research has identified nearly 300 common genetic variants and over 20 rare variants as significant risk factors for schizophrenia.
Patrick Sullivan, of The Royal Australian and New Zealand College of Psychiatrists (FRANZCP), the Yeargan Distinguished Professor of Psychiatry and Genetics at the UNC School of Medicine, along with researchers from the Karolinska Institute in Stockholm, have developed a detailed overview of the genetics of schizophrenia.
Their comprehensive review, published in Nature Reviews Neuroscience, comprises discoveries from extensive genome-wide association studies, whole-exome sequencing, and other analyses.
Concurrently, research on the brain's functional organisation has illuminated the complex cellular composition and interconnections within the brains of both neurotypical individuals and those with schizophrenia, where apathy, social withdrawal, and poor emotional control are other symptoms.
The findings underscore the surprising complexity of schizophrenia's mechanisms, pointing to the involvement of multiple genes rather than a single gene. This polygenicity presents challenges due to the absence of robust theoretical frameworks and experimental tools.
Sullivan and his colleagues reviewed these complexities and proposed future research directions in their Nature Reviews Neuroscience article. However, they also highlight the importance of environmental factors - such as lifestyle, drug use, poverty, stress, and birth complications - in addition to genetic risks.
While these factors are harder to study than the genome, they are crucial because some are modifiable. "The findings to date resoundingly indicate complexity," wrote Sullivan, who also directs the UNC Center for Psychiatric Genomics and the UNC Suicide Prevention Institute.
"Rather than being a deterrent to future research, this knowledge underscores the importance of accepting schizophrenia as a genetic and environmental enigma and scaling our research accordingly to improve the lives of those impacted by schizophrenia."