Metacognition, mental disorders and aggressive behaviour: a longitudinal study

Metacognitive functions play a key role in understanding which elements might lead a person with severe mental disorder to commit violent acts against others. Indeed, understanding internal states such as thoughts, emotions, desires, fears and goals, both their own and those of others and differentiating between them, is needed in order to guide behaviour towards the resolution of interpersonal conflict. This is a fundamental aspect of affronting the risk of committing aggressive acts. The aims of the study were the following: (a) to investigate the differences between patients with a poor metacognitive functioning and patients with a good metacognitive functioning in relation to history of violence; (b) to explore the differences between patients with a poor metacognitive functioning and patients with a good metacognitive functioning in relation to other important aspects potentially involved in aggressive behaviour such as personality traits, anger, impulsiveness, hostility and emotion recognition; (c) to investigate the differences between patients with a poor metacognitive functioning and patients with a good metacognitive functioning in relation to aggressive behaviour displayed by patients during the one year follow-up; (d) to analyse the predictors of aggressive behaviour and evaluate if the metacognitive functions associated with other investigated aspects are related to aggressive behaviour during the one-year follow-up. The sample included 180 patients: 56% outpatients and 44% inpatients, the majority were male (75%) with a mean age of 44 (+9,8) years and half of them had a history of violence. The sample was split into two groups: Poor Metacognition (PM) group and Good Metacognition (GM) group, according to MAI evaluation scores. The PM patients reported a history of violence more frequently than GM patients (considering MAI total score), and in particular patients with poor monitoring, differentiating and decentering. Furthermore, PM patients showed less ability in emotion recognition and more frequently paranoid and narcissistic personality traits compared to GM patients. Concerning hostility, impulsivity and anger, no significant differences were found, except for ‘Negativism’ (i.e., BDHI subscale) that was higher in PM patients. During the 1-year follow-up, no differences between the PM group and the GM group in aggressive behaviours (verbal, against objects, self-aggression, against people) were found. The strongest predictors of aggressive behavoiur were: Borderline and Passive-Aggressive personality traits, history of violence, anger and hostility. The metacognitive functions alone did not predict aggressive behaviour, but metacognitive functions interacted with hostility manifested through direct and indirect aggression (two BDHI subscales) and with angry reaction through aggressive behaviour (one STAXI-2 subscale) in predicting aggressive behaviour. Indeed, these aspects predicted aggressive behaviour only in PM patients and not in GM patients. This study leads to important conclusions: (a) certain aspects closely related with violence (e.g., hostility, anger) are predictive of aggressive behaviour only in patients with poor metacognition, thus good metacognition is a protective factors; (b) poor metacognition is associated with history of violence, which in turn increases the risk of committing aggressive behaviour. For this reason and considering that research in this field is still very limited, further studies are needed to deepen the role of metacognitive functions in relation to aggressive behaviour and to investigate whether psychotherapy focused on metacognitive functions is effective to prevent and/or reduce interpersonal violence.