Cognitive dysfunction in childhood-onset pathologic skin picking

ObjectiveThere has been little research examining cognitive correlates of childhood-onset pathologic skin picking.MethodsOf 50 subjects with Pathological Skin Picking (PSP), 24 (48%) (mean age 32.3±12.2 years; PSP onset at 7.67±2.54 years; 87.5% female) reported onset of skin picking before age 11 years. These subjects were compared to 26 subjects with later onset of picking after age 11 years (mean age 34.2±14.5 years; PSP onset 18.04±9.51 years; 92.3% female) on measures of symptom severity, comorbidity, and social functioning. Both groups undertook cognitive assessments using the Stop-signal task (assessing response impulsivity) and the Intra-dimensional/Extra-dimensional (ID/ED) Set Shift task (assessing cognitive flexibility).ResultsThere were no significant clinical differences based on age of PSP onset. Early and later onset PSP showed significantly prolonged stop-signal reaction times (i.e., worse inhibition) versus healthy controls, but, contrary to our hypothesis, only the later onset patients manifested significantly elevated errors on the set-shifting task versus controls (i.e., cognitive inflexibility: total errors corrected and errors for the extradimensional shift stage).ConclusionThese results indicate overlapping clinical features and impulse dyscontrol between early and later onset PSP, but heterogeneity with respect to set-shifting dysfunction. Future work should explore possible subgroups in PSP and whether age of onset and cognitive functioning is predictive of treatment outcomes.

► Overall, the PSP subjects demonstrated impaired motor inhibitory control and cognitive flexibility. ► Later onset PSP was associated with impaired cognitive flexibility compared to childhood-onset PSP. ► No significant demographic or clinical differences were found based on age of PSP onset. ► Results suggest PSP may be heterogeneous with respect to cognition based on age of onset