Researchers have discovered that something as simple as weakened grip strength may be an early warning sign of psychosis—a complex mental condition marked by distorted thinking, delusions, and hallucinations. Published in the American Journal of Psychiatry, the study adds to a growing body of evidence that subtle changes in physical functioning, especially motor skills, may be deeply intertwined with brain health and psychiatric conditions.The findings point to a potential paradigm shift in how clinicians may one day screen for psychosis—by using an everyday, easily measurable physical marker. As mental health professionals and researchers seek better ways to identify and treat psychosis before it fully develops, the humble handgrip test may soon become a vital tool in the psychiatric toolkit.What is Psychosis?Psychosis is a term that describes a range of symptoms where a person loses touch with reality. Classic signs include delusions (false beliefs) and hallucinations (seeing or hearing things that aren’t there). However, the journey into psychosis often begins long before these dramatic symptoms appear. Early warning signs can be subtle—changes in behavior, social withdrawal, trouble thinking clearly, or a decline in self-care.Psychosis typically emerges in late adolescence or early adulthood, but it can affect people at any age. It’s a feature of several mental health disorders, including schizophrenia, bipolar disorder, and severe depression, and can also arise in older adults as a result of neurological conditions like Parkinson’s or Alzheimer’s disease.The study involved 89 participants recently diagnosed with psychosis (within the past five years), compared with 51 individuals in good mental and physical health. Participants underwent grip strength tests, well-being assessments, and brain imaging scans.Not only did those with psychosis show significantly lower grip strength, but this weakness was also tied to changes in the brain's default mode network—a complex system that becomes active during rest, daydreaming, or inward-focused thoughts. Researchers found that lower grip strength correlated with reduced connectivity in three key brain regions:The anterior cingulate cortex,The sensorimotor cortex, andThe cerebellum.All three play vital roles in motor function, cognition, and emotion. When connectivity among these regions decreased, so did physical grip strength and overall psychological well-being.Why A Strong Grip Strength Important?Grip strength has long been recognized as a general indicator of health. Lower grip strength is associated with higher mortality risk, reduced quality of life, and poorer day-to-day functioning. But its connection to mental health—and specifically to psychosis—is a new and important insight.“Grip strength seems to capture that things are not going well, but it hasn’t been well studied in relation to brain function or early psychosis,” said Dr. Alexandra Moussa-Tooks, senior researcher and assistant professor of psychological and brain sciences at Indiana University.The study’s findings suggest that changes in grip strength may reflect underlying disturbances in brain network function—what researchers call “resting-state functional connectivity.” In other words, the physical symptom of a weakening grip could be a visible sign of invisible changes happening in the brain.While it may seem far-fetched to connect your ability to open a pickle jar with your mental stability, grip strength is increasingly being recognized as a proxy for overall health—both physical and cognitive. Past research has linked low grip strength to a higher risk of cardiovascular disease, frailty, depression, and even early mortality.This new study takes it a step further by linking grip strength to resting-state functional connectivity in the brain—a measure of how different parts of the brain interact when a person is not actively doing a task. The less synchronized these connections, the more likely a person is to experience disturbances in thought, behavior, and even basic physical abilities.Dr. Heather Burrell Ward, lead author and assistant professor of psychiatry at Vanderbilt University Medical Center, said the findings "identify potential brain targets for new treatments for psychosis," including the possibility of using magnetic brain stimulation or exercise to strengthen neural connections.Symptoms of Psychosis“If Psychosis Is a Fire, Symptoms Are the Smoke”Traditionally, treatment for psychosis has focused on managing the “smoke”—the overt symptoms like delusions and hallucinations. But as Dr. Moussa-Tooks explains, “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, such as reduced grip strength, may be among the earliest signs that something is amiss in the brain. Because these changes are more fundamental and easier to measure than complex cognitive symptoms, they could help clinicians identify and address psychosis at its source—potentially before full-blown symptoms develop.What Causes Psychosis?Psychosis is a complex condition with no single cause. It arises from a combination of genetic vulnerability, brain development differences, and environmental stressors or trauma. While it can be a symptom of mental illnesses like schizophrenia or bipolar disorder, it can also occur independently or as part of physical illnesses, particularly in older adults.Recognizing early warning signs—whether behavioral, emotional, or physical—can make a crucial difference in outcomes. Early intervention is associated with better long-term recovery and improved quality of life.Could a handgrip test become a new mental health screening tool? The researchers believe it's possible.“Grip strength and other motor functions are easily assessed and more readily interpretable than complex tasks often used to study psychosis,” said Moussa-Tooks. “Our work shows that these simple metrics could have profound implications in early detection and treatment.”Such early detection tools are especially critical, as earlier intervention in psychosis typically leads to better outcomes. The current model, which relies heavily on self-reported symptoms or behavioral changes, is reactive and often too late.As science continues to uncover the deep connections between brain and body, one thing becomes increasingly clear—sometimes, holding on tightly might be the very first step to staying mentally well.