Facial measurement differences between patients with schizophrenia and non-psychiatric controls

Several previous reports suggest that facial measurements in patients with schizophrenia differ from those of non-psychiatric controls. Because the face and brain develop in concert from the same ectodermal tissue, the study of quantitative craniofacial abnormalities may give clues to genetic and/or environmental factors predisposing to schizophrenia. Using a predominantly African American sample, the present research question was two-fold: (1) Do patients differ from controls in terms of a number of specific facial measurements?, and (2) Does cluster analysis based on these facial measurements reveal distinct facial morphologies that significantly discriminate patients from controls?

Facial dimensions were measured in 73 patients with schizophrenia and related psychotic disorders (42 males and 31 females) and 69 non-psychiatric controls (35 males and 34 females) using a 25-cm head and neck caliper. Due to differences in facial dimensions by gender, separate independent samples Student's t-tests and logistic regression analyses were employed to discern differences in facial measures between the patient and control groups in women and men. Findings were further explored using cluster analysis. Given an association between age and some facial dimensions, the effect of age was controlled.

In unadjusted bivariate tests, female patients differed from female controls on several facial dimensions, though male patients did not differ significantly from male controls for any facial measure. Controlling for age using logistic regression, female patients had a greater mid-facial depth (tragus-subnasale) compared to female controls; male patients had lesser upper facial (trichion-glabella) and lower facial (subnasale-gnathion) heights compared to male controls. Among females, cluster analysis revealed two facial morphologies that significantly discriminated patients from controls, though this finding was not evident when employing further cluster analyses using secondary distance measures. When the sample was restricted to African Americans, results were similar and consistent.

These findings indicate that, in a predominantly African American sample, some facial measurements differ between patients with schizophrenia and non-psychiatric controls, and these differences appear to be gender-specific. Further research on gender-specific quantitative craniofacial measurement differences between cases and controls could suggest gender-specific differences in embryologic/fetal neurodevelopmental processes underpinning schizophrenia.