A new study reveals that grip strength is connected to brain function in early psychosis, suggesting new treatment avenues and offering a powerful biomarker for the condition.
Psychosis, often marked by delusions and hallucinations, may have a subtler origin that researchers are now beginning to understand. Researchers from Indiana University and Vanderbilt University Medical Center have made a significant breakthrough by studying an overlooked aspect: grip strength.
In a landmark study published on June 25 in the American Journal of Psychiatry, the researchers delve into how motor abilities like grip strength offer crucial insights into psychosis.
“Poor grip strength has been associated with many negative outcomes in a variety of people: lower well-being, higher risk of mortality, poor day-to-day functioning, poor quality of life. Grip strength seems to capture that things are not going well,” senior author Alexandra Moussa-Tooks, an assistant professor in the Department of Psychological and Brain Sciences at Indiana University, said in a news release. “But it hasn’t been well studied in relation to brain function or early psychosis. Our study looks at how grip strength may be an important sign of brain and psychological health in early psychosis.”
The research marks the first time scientists have linked grip strength and overall well-being to shared patterns of brain connectivity.
It suggests that impairments in these areas could reflect alterations in “resting-state functional connectivity” — a critical measure of brain network function. This insight could be pivotal in understanding psychosis.
The study analyzed data from the Human Connectome Project for Early Psychosis, conducted between 2016 and 2020, which included 89 individuals in the initial five years of psychotic illness and 51 healthy controls.
The findings revealed that those with early psychosis had lower grip strength and well-being scores compared to the control group. These variables were connected to three brain regions: the anterior cingulate cortex, sensorimotor cortex and cerebellum, all linked to the default mode network.
Higher grip strength and better well-being were associated with stronger connectivity between these regions and the default mode network.
“Our findings are particularly exciting because they identify potential brain targets for new treatments for psychosis,” added first author Heather Burrell Ward, an assistant professor of psychiatry and behavioral sciences at Vanderbilt University Medical Center.
Techniques like transcranial magnetic stimulation (TMS) could be used to improve connectivity within the default mode network, and motor training exercises might boost brain network strength indirectly.
Moussa-Tooks emphasized the practical advantages.
“Grip strength and other motor functions are easily assessed and more readily interpretable than complex tasks often used to study psychosis,” she said. “Our work is showing that these seemingly simple metrics can help us understand disturbances not only in the motor system but across complex brain systems that give rise to the complex symptoms we see in psychosis.”
Drawing an analogy, she explained, “If psychosis is a house on fire, symptoms such as delusions and hallucinations are the smoke. In a fire, you don’t target the smoke; you target the fire and its source. And yet, currently, that’s not how we approach treatment for psychosis. Motor disturbances help us get closer to identifying where the fire may have started and spread. They are more fundamental in the sense that they’re easier to link to different disturbances in the brain.”
With these findings, the researchers move closer to identifying the roots of psychosis, mapping new paths for understanding and treating this elusive disorder. By linking motor function to mental health, they highlight the potential of grip strength as a powerful biomarker and a target for innovative treatments.
Source: Indiana University