Alexithymia and aggression in forensic patients with a SUD

Journal of Forensic Psychology Research and Practice | 2026, Vol. 26, No. 5, p. 884 - 901

Alexithymia and aggression in forensic patients with a substance use disorder

Luuk F. J. A. Veldhuis, MSc; Addiction Healthcare, Tactus Addiction Treatment, Deventer, The Netherlands

Hein A. de Haan, PhD; Addiction Healthcare, Tactus Addiction Treatment, Deventer, The Netherlands

Carmen S. Sergiou, PhD; Department of Psychology, Education and Child Studies, Erasmus Universiteit Rotterdam, Rotterdam, The Netherlands; Department of Child and Adolescent Psychiatry & Psychosocial Care, Amsterdam University Medical Centre, Amsterdam, The Netherlands

Vincent Janssen, MSc; Centre of Excellence for Neuropsychiatry, Vincent van Gogh, Venray, The Netherlands

Josanne D. M. van Dongen, PhD; Department of Psychology, Education and Child Studies, Erasmus Universiteit Rotterdam, Rotterdam, The Netherlands

In this study we explored the relationship between alexithymia and aggression in forensic inpatients with SUD (N = 50), while controlling for empathy and psychopathic traits. Participants completed standardized questionnaires to measure these traits. Significant positive associations emerged between alexithymia and both reactive and proactive aggression. Alexithymia remained related to reactive aggression when empathy and psychopathy were accounted for. These findings suggest that alexithymia may play a meaningful role in aggression among forensic patients with SUD and could represent a potential target for intervention, although the findings should be interpreted with care owing to various limitations of the study.

Alexithymia; aggression; substance use disorder; psychopathy; empathy

This article examined the relationship between alexithymia and aggression among forensic patients with substance use disorders (SUDs). The authors described alexithymia as a trait characterized by “difficulty identifying, describing, and differentiating between one’s own feelings and bodily sensations.” Previous research suggests that individuals with alexithymia may misinterpret their emotional experiences, contributing to difficulties with emotion regulation and aggressive behavior. Specifically, reactive aggression, characterized as an emotionally driven response to provocation, has been associated with alexithymia, whereas proactive aggression is considered less emotionally driven and more goal-oriented. The authors also highlighted the conceptual overlap between alexithymia, empathy, and psychopathic traits, emphasizing the importance of examining their independent contributions to aggression. The primary aim was “to elucidate the unique relation between alexithymia and aggression in forensic patients with SUD,” while accounting for empathy and psychopathic traits. The authors hypothesized that “alexithymia is positively related to aggressive behavior, especially reactive aggressive behavior, when empathy and psychopathic traits are controlled for” (p. 885-887).

The study included 50 male forensic patients with SUD, ranging in age from 22 to 62 years, recruited from two forensic institutions in the Netherlands. Participants were required to have “a current SUD diagnosis according to the DSM-5” and “an index offense of aggression.” Participants were also required to remain abstinent from substances during the study. Standardized self-report questionnaires were administered to assess alexithymia, psychopathic traits, empathy, and aggression. Alexithymia was measured using the Toronto Alexithymia Scale-20 (TAS-20), psychopathic traits using the Self-Report Psychopathy Scale–Short Form (SRP-SF), empathy using the Interpersonal Reactivity Index (IRI), and reactive and proactive aggression using the Reactive and Proactive Aggression Questionnaire (RPQ). The researchers calculated Pearson correlation coefficients to examine relationships between variables and conducted “stepwise multivariate linear regression models” to examine the relationship between alexithymia and total, reactive, and proactive aggression while accounting for potentially confounding variables (p. 888-891).

Descriptive findings indicated that 32% of participants reported low or absent alexithymia, 42% reported moderate alexithymia, and 26% reported high alexithymia. Correlational analyses showed that alexithymia was positively associated with total aggression (r = .32), reactive aggression (r = .29), and proactive aggression (r = .31), with all three correlations reaching statistical significance. The authors reported that “alexithymia was univariately associated with reactive aggression and also with proactive aggression,” which contradicted their initial hypothesis that alexithymia would primarily relate to reactive aggression. Alexithymia was also positively correlated with psychopathic traits (r = .34) and negatively correlated with empathy (r = −.32). Additionally, psychopathic traits were positively associated with total aggression (r = .48), reactive aggression (r = .31), and proactive aggression (r = .57). In contrast, empathy was not significantly associated with aggression. The authors noted that “empathy was negatively associated with alexithymia but not psychopathy and aggression” (p. 893).

Multivariate analyses indicated that alexithymia's relationship with aggression weakened after accounting for psychopathic traits and empathy. The model examining total aggression explained 26.1% of the variance (R² = .261, p < .001), while the model examining reactive aggression explained 18.6% of the variance (R² = .186, p = .048). The authors reported that “alexithymia remained to be associated with aggression and, specifically, reactive aggression but not proactive aggression, when controlling for psychopathy and empathy.” However, they emphasized that “the unstandardized beta weights of alexithymia in the multivariate models were nonsignificant,” indicating that alexithymia was not a statistically significant individual predictor after accounting for the other variables. The authors suggested that this finding was “likely due to the low number of participants” and cautioned against drawing definitive conclusions. Furthermore, the findings indicated that “the role of alexithymia in predicting (reactive) aggression weakened when controlled for psychopathic and to a lesser extent empathic traits.” The authors also identified a strong correlation between reactive and proactive aggression, suggesting that conclusions regarding the distinct relationship between alexithymia and specific forms of aggression should be interpreted cautiously (p. 893-894).

The findings suggest that alexithymia may represent an important consideration in assessing and treating aggression among forensic patients with SUD. The authors proposed that “alexithymia could, therefore, be an addition in risk assessment of aggressive and violent behavior in the future” and may also contribute to understanding aggression among individuals with psychopathic traits. Additionally, the authors suggested that “alexithymia could be an interesting target for treatment programs,” given its prevalence among forensic and SUD populations and its associations with aggression and criminal recidivism. They highlighted existing research suggesting that dialectical behavior therapy–based interventions “may be associated with a decrease in reported alexithymia and an increase in the ability to identify emotional states.” Mindfulness-based interventions, psychoeducation, and mentalization-based approaches were also discussed as potentially beneficial strategies for improving emotional awareness and identification. However, the authors acknowledged that “little is known about treating alexithymia within a SUD and/or forensic population” and emphasized the need for additional research examining interventions targeting alexithymia (p. 894-895).

“The data were collected as part of a larger study focusing on reducing aggression and improving empathy, resulting in some limitations to this study’s aim. For instance, although the sample size was sufficient for the findings reported in Sergiou et al. (2022), the sample size was small for answering our research questions, limiting power and reliability. While multivariate test results within our multiple regression were largely in line with our hypothesis, the univariate tests did not yield unambiguous results and, therefore, our conclusions should be interpreted carefully and replicated in a larger sample. Furthermore, our research data mainly consists of self-report data, which might lead to methodological problems, such as validity issues, especially in forensic patients (Hornsveld et al., 2017); test situations or interviewssuch as the PCL-R could have provided a broader source of data. Additionally, the sample consisted of SUD patients and no females were included in the sample, although the associations between alexithymia and aggression may bedifferent for females (Burghart & Mier, 2022; Mancinelli et al., 2021); thus, generalization of the results might be limited to males and those with SUD. Moreover, as we mentioned in the introduction, SUD plays a role in both alexithymia and the sample (who are not using substances in the intramural setting). In an outside setting, where drug use might play a role, the results and interactions between the personality traits and aggression might differ” (p. 895-896).