Schizophrenia and Bipolar Disorder Linked With Dendritic Spine Loss in Brain

Researchers provide evidence of a strong relation between both schizophrenia and bipolar disorder and loss of dendritic spine in the brain.

Dendritic spines are known to play a key role in a variety of brain functions.  Studies conducted earlier have shown spine loss in the dorsolateral prefrontal cortices in a person with schizophrenia (SZ). In the current study, researchers at McLean Hospital and Harvard Medical School found that schizophrenia (SZ) and bipolar disorder (BP) are associated with dendritic spine loss in the brain indicating the two different disorders may have some common pathophysiological features.

In order to determine whether spine pathology occurs in those with a distinct disorder other than SZ, the researchers also included people with BP in the study. They evaluated the postmortem human brain tissues of 14 people with SZ, 9 with BP and 19 unaffected individuals who belonged to the control group.

Schizophrenia is a challenging mental disorder that is characterized by abnormal social behavior. It is estimated 2.2 million Americans are affected with this severe brain disorder. Bipolar disorder is a mental illness that is characterized by serious mood swings. Commonly known as manic depression, this disorder is known to affect 2 million American adults.

On analyzing the human brain tissue, the researchers noticed a 10.5 percent drop in the average spine density in those with BP and in those with SZ there was a 6.5 percent drop when compared to the control group.

A significant reduction in the average number of spines per dendrite was seen in both people with SZ and BP. Also these people had lost average dendrite length when compared to the control group.

"The current study suggests that spine pathology is common to both SZ and BP. Moreover, the study of the mechanisms underlying the spine pathology might reveal additional similarities and differences between the two disorders, which could lead to the development of novel biomarkers and therapeutics."

The finding was documented in JAMA Psychiatry.