Schizophrenia is one of the most severe and researched mental illnesses worldwide. Discoveries are still uncovered from studies into new diagnoses, genetics, variations, therapies, and medical histories. Schizophrenia typically manifests between the stages of adolescence to early adulthood at social, physical, and mental health costs (i.e., suicide).
Impairments in social and cognitive performance are common symptoms of mental disorders, but those diagnosed with Schizophrenia have higher variations of functional capacity, hallucinations, and delusions. Cognitive deficits span many neurological domains, from attention, working and episodic memory, and semantic processing to language development (Alkan & Evans, 2022). Many of these issues have no immediate cures. However, through long periods of treatment and antipsychotic medications to manage these symptoms for day-to-day functioning, people can achieve life goals, pursue a career, or continue their education.
Recent research has further followed the link between genetics and mental disorder. There are large numbers of common alleles and rare copy number variants (CNV) associated with schizophrenia (Trubetskoy et al., 2022). Genetic analysis suggests neural activity in the excitatory and inhibitory neurons of the central nervous systems. To further address this possibility, a 2022 research study analyzed how brain activity, specifically reduced grey matter volume in the frontotemporal region, can be predictive of Schizophrenia (Alkan & Evans, 2022). A possible reason for Schizophrenia can be that mutations appearing in the genome can lead to neuronal disruption in brain communication across the multiple synapses. In a large genome-wide association study, 76,55 individuals diagnosed with Schizophrenia were tested against a control group of 243,649 to test if there were any common variant associations of 287 genome loci (Trubetskoy et al., 2022). Schizophrenia has a high heritability rate of 60-80%, attributed to common links between specific alleles leading to a question regarding whether or not there are any typical or rare in common nucleotide-genome sequences that have mutated during transcription and translation. Trubetskoy et al., 2022 further identified some genetic candidates: glutamate receptor subunit GRIN2A, transcription factor (TF) SP4, STAG1, and FAM120A, in which variant associations exist during transcription or gene regulation pathways, which might have given these genes highly pathogenic roles affecting the disorder. Furthermore, along with supportive and extensive gene regulatory networks within the human body, the neurons within the CNS also play integral components in turning on abnormal neuronal function for Schizophrenia.
Studies used transcranial magnetic stimulation (TMS) or other non-invasive techniques to determine which of the neuronal activity sites are the significant sites of pathology in the mental disorders, not only Schizophrenia but many other neurological disorders to mental illnesses like depression or anxiety. Previous literature has shown that prefrontal stimulus activity is a potential treatment site for major depressive disorder. TMS acts as a brain intervention to modulate activity in discrete cortical regions and other neural circuits (George et al., 2010). Significant effects of TMS used to determine activity in those with Schizophrenia suggest that the prefrontal cortex stimulation can help establish a stricter psychometric scale for the range of symptoms of Schizophrenia (Lorentzen et al., 2022). By taking all the ongoing research on the specific cortical regions that might be affected, studies can remove any bias to further analyze more on the disruptive variants in the various transcription factors (SP4) or receptor subunits (GRIN2A) that interact in neurodevelopmental disorders. The research tries to isolate and enrich certain regions where the gene expression occurs at determining the convergence of the variant associations. According to the National Institutes of Health, these health conditions change an individual’s thinking patterns, feelings, or behavior. However, not all categorized brain diseases are mental illnesses. Some disorders like epilepsy or Parkinson’s disease are brain disorders, while some are neurodegenerative, like Lou Gehrig’s Disease. Suppose future studies can find genetic associations that determine how mental illnesses are different on a genetic association. Pharmaceutical companies can develop future diagnoses or treatments more accordingly to inhibit specific variants, which will help relieve the negative symptoms of individuals struggling with mental disorders.
References
Alkan, E., L. H. Evans, S. Relationships between cognitive performance, clinical insight and regional brain volumes in schizophrenia. Schizophr 8, 33 (2022). https://doi.org/10.1038/s41537-022-00243-x
George MS, Lisanby SH, Avery D, et al. Daily Left Prefrontal Transcranial Magnetic Stimulation Therapy for Major Depressive Disorder: A Sham-Controlled Randomized Trial. Arch Gen Psychiatry. 2010;67(5):507–516. doi:10.1001/archgenpsychiatry.2010.46
Lorentzen, R., Nguyen, T.D., McGirr, A. et al. The efficacy of transcranial magnetic stimulation (TMS) for negative symptoms in schizophrenia: a systematic review and meta-analysis. Schizophr 8, 35 (2022). https://doi.org/10.1038/s41537-022-00248-6
National Institutes of Health (US); Biological Sciences Curriculum Study. NIH Curriculum Supplement Series [Internet]. Bethesda (MD): National Institutes of Health (US); 2007. Information about Mental Illness and the Brain.Available from: https://www.ncbi.nlm.nih.gov/books/NBK20369/
Trubetskoy, V., Pardiñas, A.F., Qi, T. et al. Mapping genomic loci implicates genes and synaptic biology in schizophrenia. Nature (2022). https://doi.org/10.1038/s41586-022-04434-5
Image from: https://www.newsweek.com/artist-uses-sketches-simulate-how-his-schizophrenia-feels-viral-videos-1668691
