Motor impairments in early onset schizophrenia

Motor impairments are frequent both at and before diagnosis. In childhood, impairments in general fine and gross motor function are among others identified using test batteries, and while elements of coordination are assessed in onset schizophrenia, the assessment of general motor functions is absent. Thus, we aimed to assess general motor function including childhood motor function in adolescents with schizophrenia in comparison with healthy controls and examine clinical correlates to general motor function.

General fine and gross motor function was assessed using two standardized age-normed test batteries and a questionnaire in 25 adolescents with schizophrenia compared with age and gender-matched controls using t-test and χ² -test. Stepwise linear regression assessed potential developmental predictors on motor function including complications during childbirth, reported childhood motor function, executive function including false discovery rate q-values. Associations with schizophrenia symptom severity, executive function, cognitive function were assessed using Pearson's correlation and the impact of antipsychotic medication using t-test.

All measures of motor function but one significantly differentiated adolescents with schizophrenia from healthy controls. The presence of schizophrenia (β =4.41, β = 10.96), explained the main part of the variance however, childhood motor function (β = .08) also added significantly to motor function. Executive function (β = -.45) was important for childhood motor function. Severity of schizophrenia was associated with strength (p < .0011) and manual coordination (p = .0295), and receiving antipsychotics affected manual dexterity (p = .0378).

The documentation of significant differences in general motor function in early onset schizophrenia compared with healthy controls highlights the need for general motor assessments and potential interventions.