Larger brains prone to suffer from mental disorders, find researchers

Larger brains prone to suffer from mental disorders, find researchers

Lately, mental disorders, like anxiety, depression and bipolar disorder, have become quite common among people across all age groups. With emotional ups and downs due to setbacks in personal and professional life, many people are on the verge of developing mental disability. A 2016 study by researchers from the Washington University and Babes-Bolyai University, Romania has come up with a unique explanation why mental disorders are more common in mammals, especially human beings. The study was performed on macaque, a primate belonging to the genus Macca.

Published in the journal PLOS Biology, the study used the techniques of exponential distance rule (EDR), which refers to a consistent relationship between distances and connection strength. One of the most important predictions made by the study was that irrespective of the brain size, there are far less long-range nerve fibers than short range ones in the brain. This means that the closer the two cortical regions are (such as visual cortex or auditory cortex), the more the ability to pass on messages.

Mammalian brain has weaker long-distance connections

Mammals have larger brains as opposed to rodents, and therefore, they have a much weaker long-distance connectivity, a reason for high probability of mental disorders in them. Compared to smaller brains, any message relayed within the larger brains has to travel far longer distances, which, in turn, increases the chances of message getting lost on the way of transmission.

Though brains of both mammals and rodents have a similar global architecture of cortical network, mammalian brain has weaker long-distance connections. Further substantiating this aspect of brain disconnect and mental disorder, the study authors pointed out, “low weight of human long-range connections may contribute to an increased susceptibility to disconnection syndromes, such as have been proposed for Alzheimer’s disease and schizophrenia.” The human brain, which is five times the size of the brain of the macaque brain, is characterized by the same weak connectivity. However, the study is still open to speculation and further studies are required to establish the veracity of the findings.

Mental disconnect and its relation with schizophrenia and other mental disorders

Norman Geschwind in the year 1965 identified disconnection syndromes as “higher function deficits that resulted from white matter lesions or lesions of the association cortices, the latter acting as relay stations between primary motor, sensory and limbic areas.” Dissociation frequently plays a vital role in schizophrenia and bipolar and degenerative diseases like Alzheimer’s, although there is a lack of empirical data to substantiate the specific manifestations of these disorders.

Schizophrenia is a chronic mental disorder that affects the way one thinks and behaves. An old study had revealed that there is reduced inter-hemispherical cortical activity in patients who are drug free and those who are receiving typical antipsychotic drugs, thereby validating that schizophrenia is a disconnection syndrome.

Similarly, patients with Alzheimer’s show a pattern of memory and cognition-related defects that arise because of the cerebral abnormalities. Previous studies have shown that patients showing the onset of this disorder have a poor interhemispheric communication, symbolizing a disconnection syndrome.

Road to recovery

Having a mental illness is not the end of the road. There are many success stories that indicate that timely treatment and family support can ensure highly successful and enriching lives in people with extremely debilitating mental illnesses.

If you or your loved one is suffering from any mental health problems, contact the California Mental Health Helpline for guidance on mental health centers in California offering comprehensive treatment programs. Call us at our 24/7 helpline number 855-559-3923 or chat online with our specialists to get advice on the best mental health rehabilitation centers in California.