The association between attachment style and social functioning in patients with non-affective psychotic disorders, unaffected siblings and healthy controls

Objective: In patients with psychotic disorders, insecure attachment styles and impaired social functioning are highly prevalent. Our aim was to explore the multi-cross-sectional and longitudinal associations between attachment style and social functioning. Methods: This study was performed in a subsample of 119 patients with non-affective psychotic disorders, 128 unaffected siblings and 66 healthy controls within the Genetic Risk and Outcome of Psychosis (GROUP) Study. Attachment style (using the Psychosis Attachment Measure) and three social functioning domains, namely withdrawal, interpersonal behaviour and pro-social activities as measured with the Social Functioning Scale (SFS) were assessed on two moments in time. Generalized linear mixed models and linear regression models were used. Bonferroni correction for multiple testing was applied. Results: In the patient group, a significant negative association was found between avoidant attachment and pro-social functioning. In the sibling and control group, we found significant negative associations between avoidant attachment and the social functioning domains withdrawal and interpersonal behaviour. We also found a significant negative association between anxious attachment and the social functioning domain withdrawal in siblings. Higher levels of insecure anxious attachment at baseline predicted a reduction of the social functioning domain interpersonal behaviour in siblings over a period of three years on a trend level. Conclusions: Findings indicate that levels of insecure attachment are elevated in patients with psychotic disorders and have a negative association with social functioning in both patients, siblings and controls. These findings warrant specific attention for attachment style in the treatment of patients with psychotic disorders and individuals with an increased vulnerability for developing psychosis.