A multi-dimensional approach to the relationship between insight and aggressiveness in schizophrenia: Findings from the FACE-SZ cohort.

Background: Aggressiveness is a stigma frequently associated with schizophrenia. The role of insight as a risk factor of aggressiveness remains contradictory; mainly because single measures of these states mask their complexity and heterogeneity.

Methods: This study was conducted on 666 patients aged 15 and above with a DSM-IV-TR diagnosis of schizophrenia spectrum disorder, drawn from the French national network of schizophrenia expert center database. Collected data comprised socio-demographics and standardized psychiatric assessments. Aggressiveness was evaluated using the Buss-Perry Aggression Questionnaire and insight using the Scale to assess Unawareness of Mental Disorder (SUMD) and Birchwood Insight Scale (BIS).

Results: Hostility was the aggressiveness dimension the most strongly associated with SUMD insight dimensions. Patients aware of their illness were nearly twice as likely to show hostility than those seriously unaware (OR = 1.95, 95% CI.: 1.08-3.5), but not when further adjusting for depression. Similarly, those aware of the consequences of their illness and of their symptoms were more hostile. Patients moderately aware of illness consequences had a higher risk of both anger and physical aggressiveness than those unaware (OR = 2.63, 95% CI.: 1.42-4.86, OR = 2.47, 95% CI.: 1.33-4.60, respectively), even when adjusting for depression for anger.

Conclusion: Our study confirms that a multi-dimensional approach to insight and aggressiveness is essential to understand the types of links between these clinical states. Insight may trigger the expression of an underlying hostile tendency, maybe via depression and self-stigmatisation. This should be taken into account in therapeutic approaches to improve insight.