Motor issues—such as coordination problems, motor slowing, or sudden, uncontrolled movements—have been recognized as signs of psychological disorders since the 1800s. How they map to mental health conditions, however, remains unknown.
"When things have been observed since really early ideas of disorders, that means something," said Jessica Fattal, a graduate student in Vijay Mittal's lab at Northwestern University.
Motor abnormalities have been best described in psychosis but are also observed in depression , bipolar disorder, attention-deficit/hyperactivity disorder , schizophrenia , and autism spectrum disorder . Motor function is easy to measure, well described in terms of circuitry, developmentally relevant, and vital for navigating the world, from daily functioning to social interactions.
Understanding how motor abnormalities relate to psychological disorders may help provide insight into mechanisms underlying mental health issues, disease progression, and potential treatments. However, whether motor symptoms signal risk of mental illness in general or point to a specific disorder is unclear.
"Is it that motor symptoms are just kind of broadly related to any psychopathology and you can't really differentiate at all between them? Or is it that maybe, for example, in psychosis, they're really important, but in anxiety, they're not related at all?" asked Fattal.
In a 2026 Clinical Psychological Science paper , Fattal addressed these questions using the Hierarchical Taxonomy of Psychopathology (HiToP), which aims to view mental illnesses on a spectrum rather than as discrete diseases. Broader dimensions (such as psychosis and internalizing) split into related issues (like dissociation, fear, and distress), which may break down further into specific symptoms. HiToP is an ideal framework to characterize psychopathology transdiagnostically and help uncover overlap in clinical symptoms.
"It's a model that's able to ask questions about the specificity of different symptom clusters in this hierarchical structure, but it's also a model that allows symptoms to relate to things differently," said Fattal. "We're able to ask these questions both across and within [disorders], in a way that not a lot of other systems are quite as well powered or well constructed to do."
Participants in Fattal's study did not have previously reported mental health diagnoses. Nearly 3,500 filled out questionnaires regarding psychotic-like experiences, depression, anxiety , mania, dissociation, and substance abuse, as well as self-reported motor symptoms, such as early developmental delays, uncontrolled movements, coordination issues, and physical activity levels.
Fattal ran models to see which structure best fit movement and psychological symptoms. If motor symptoms are a marker of general risk for mental illness, motor symptoms would relate to broad dimensions without clearly differentiating between psychological symptom domains, and the 1-factor model would outperform the other factor structures. On the other hand, if motor symptoms predict specific psychological symptoms, they would relate to specific symptom dimensions, and the 10-factor model would fit best.
"The more symptom clustery models did better across the board," said Fattal. "It seemed like between five and eight factors worked the best, which means there's some value to differentiating between symptoms."
Overall motor problems, dyskinesia (sudden, uncontrolled movements), and coordination abnormalities were all positively related to psychological symptom domains such as distress, dissociation, and fear, suggesting that greater motor abnormalities are related to greater psychopathology. Physical activity was positively related to mania and substance abuse and negatively related to detachment, fear, and distress.
"[The psychological symptoms studied] all are related to more motor symptoms, but maybe there's just differentiation in the quantity at which they're associated with them," said Fattal. "For some motor symptoms like physical activity, there's some differentiation in direction as well."
The work suggests motor abnormalities are both predictors of mental health illness in general and predictors of more specific disorders, such as psychosis and depression.
"It supports both theories," said Fattal, noting that although it's frustrating to not have a clear answer, the finding does fit with existing literature. "So many different domains of psychological functioning have been related to motor symptoms, but we also know that it's really important in certain disorders like psychosis. Those feel kind of contradictory, but it was exciting in this study that we were able to find that maybe they're not so contradictory, but it's a little bit more of a complicated picture than we can get in broad strokes."
She said she believes the research justifies thinking transdiagnostically and more intentionally integrating motor symptoms into HiToP.
"The big takeaway is that we should keep thinking about motor signs," she said. "We need more research and to continue thinking practically about how we can integrate these things into practice and into helping people with serious mental illness."
Reference
Fattal, J., Ellman, L., Schiffman, J., Hirjak, D., Parmacek, S., Cowan, H., & Mittal, V. (2026). Motor abnormalities and HiToP: Incorporating a psychomotor perspective into a hierarchical dimensional symptom framework. Clinical Psychological Science.
