Repetitive Behaviour in Rubinstein-Taybi syndrome: A 10-year follow-up.

Background: Rubinstein–Taybi syndrome (RTS) is caused by an alteration to the CREBBP gene or EP300 gene. Cross‐sectional research has indicated repetitive behaviour (RB) coupled with preserved social communication abilities in RTS; however, few studies have examined these characteristics longitudinally. In addition, there is limited research examining the causal mechanisms of RB in RTS. Two theories that have been proposed to explain RB are the executive dysfunction hypothesis and the theory that RB may serve to decrease anxiety. These theories were examined in this longitudinal questionnaire study.Methods: Twenty‐nine parents/carers of individuals with RTS (58.6% male; Mage = 27.9 years) who participated in baseline assessments in 2007 (T1) completed a follow‐up assessment in 2017 (T2; retention rate from 104 = 28%). Measures delivered at T1 and T2 included the Wessex Questionnaire, The Activity Questionnaire (TAQ) and the Social Communication Questionnaire (SCQ). Additional measures added at T2 included the Behaviour Rating Inventory of Executive Function – Preschool Version (BRIEF‐P) and the Anxiety, Depression and Mood Scale (ADAMS).Results: Impulsivity increased between T1 and T2 (Z = 0.25; p = .012). Increases in impulsivity were strongly associated with increases in RB (r = .60; p = .001) but not social or communication difficulties (ps > .05). Inhibition/self‐control difficulties, as measured by the BRIEF‐P, were associated with RB at T2 (r = .38, p = .044) and several mental health issues including hyperactivity (r = .75, p < .001), depression (r = .58. p = .001) and generalised anxiety (r = .63, p < .001). At T2, RB was only associated with compulsive behaviour on the ADAMS (r = .60, p = .001).Conclusions: There is limited evidence for a direct link between anxiety and RB in RTS; however, difficulties with behavioural and/or emotional regulation may contribute to repetitive behaviour and mental health difficulties.