UC San Diego

Background

A number of motor abnormalities have been reported in psychotic disorders, including dyskinesia and psychomotor slowing. There is also evidence for many of the same motor abnormalities in biological first-degree relatives and accruing evidence for motor abnormalities in bipolar disorder. In addition to motor dysfunction, there are also shared symptom domains amongst these populations.

Objectives

We explored the associations of (1) current and lifetime psychosis and mood symptom domains and (2) domains of psychosis proneness with various domains of motor function in a transdiagnostic sample (n = 149).

Method

Individuals with schizophrenia, schizoaffective disorder, or bipolar disorder, biological first-degree relatives of individuals with a psychotic disorder, and controls completed measures of psychomotor speed and movement fluidity, and neural activity related to motor preparation (stimulus-locked lateralized readiness potential, S-LRP) and execution (response-locked LRP) was assessed using EEG. All participants completed the Brief Psychiatric Rating Scale; patients were additionally assessed for lifetime psychosis and mood episode symptoms, and relatives and controls completed the Chapman psychosis proneness scales.

Results

Multiple regression revealed levels of current negative symptoms and mania were significantly positively associated with psychomotor slowing even after accounting for current antipsychotic medication dosage and duration of illness. S-LRP onset latency was significantly positively associated with magical ideation.

Conclusion

Domains of motor function are associated with various mood and psychosis symptom domains in a transdiagnostic sample, which may provide insight into brain abnormalities relevant to the expression of symptoms across disorders.