Disrupted cerebral dominance is present in the ultrahigh risk period of psychosis; thus, decreased dextrality may serve as a novel biomarker for the progression of psychosis risk, according to a study involving 94 demonstrated right-handed neuroleptic free participants.
Investigators assessed a group at ultrahigh risk of psychosis (n=38) and healthy controls (n=56) using structured clinical interviews and a handwriting task performed with a tablet computer. They calculated a laterality quotient (LQ) using kinematic variables from each participant's left and right hands. A subset (26 ultrahigh risk and 29 controls) were interviewed 12 months later.
The ultrahigh risk group showed decreased dextrality vs healthy controls. At follow-up, decreased dextrality accounted for 8% of the variance in worsened positive symptoms within the ultrahigh risk group.
Citation: Dean D, Orr J, Newberry R, et al. Motor behavior reflects reduced hemispheric asymmetry in the psychosis risk period. Schizophr Res. 2015; October 19, 2015. doi: http://dx.doi.org/10.1016/j.schres.2015.10.017.