The role of illness engulfment in the association between insight and depressive symptomatology in schizophrenia.
Good clinical insight in schizophrenia tends to be associated with better outcomes, but also with increased depression. We hypothesized that illness engulfment, a process whereby an individual's self-concept becomes defined solely by illness and the 'patient identity' becomes primary, is a mediating and/or moderating factor in the association between insight and depressive symptomatology in schizophrenia. Mediation and moderation analyses were conducted using the PROCESS macro on data from 140 individuals with enduring schizophrenia who completed measures of the insight dimension of 'Awareness of Illness and Need for Treatment' (AINT), the Calgary Depression Scale, and the Modified Engulfment Scale. There was a significant indirect effect of AINT, mediated through engulfment, on depressive symptomatology (95% CI = 0.017 to 0.143), independent of duration of illness and current severity of positive symptoms. Moderation analysis revealed a significant interaction effect between level of engulfment and AINT, on depressive symptomatology, b = 0.005, t (134) = 2.814, p < .01, 95% CI = 0.002 to 0.009, controlling for the duration of illness and current severity of positive symptoms. At low levels of engulfment, higher AINT was associated with lower depression scores; while at high levels of engulfment, higher AINT was associated with higher depression scores. Illness engulfment may be an important process by which insight influences mood in schizophrenia. Insight interventions that also target engulfment may reduce the risk of increased depressive symptomatology.