Introduction
Violent behavior remains a serious public health concern worldwide, often leading to physical injury, psychological trauma, and societal disruption. Many researchers have explored biological factors that contribute to impulsive violence, with serotonin, a neurotransmitter involved in mood regulation, being a key focus of investigation.
Sertraline, a selective serotonin reuptake inhibitor (SSRI), is widely prescribed for depression, anxiety, and other mood disorders. Given its influence on serotonin levels, scientists hypothesized that sertraline might also reduce impulsive and violent behaviors, especially in individuals prone to such acts. This led to a crucial question: can medication like sertraline help prevent offenders from reoffending violently?
To explore this, a significant clinical trial called ReINVEST was conducted, aiming to assess whether sertraline could effectively decrease the rate of violent reoffenses among high-risk, impulsive men.
Design of the ReINVEST Trial
The ReINVEST study was a rigorous randomized, double-blind, placebo-controlled trial carried out in New South Wales, Australia. It focused on men aged 18 or older, each with at least two prior violent convictions and high impulsiveness scores.
Participants underwent a 4-week run-in phase where everyone received sertraline, to ensure their response was tolerable. Then, they were randomly assigned to receive either 100 mg of sertraline daily or a matching placebo, without knowing which they received.
The main goal was straightforward: track whether participants committed a violent offense within 12 months, as recorded in state reoffending databases. The study prioritized an intention-to-treat analysis, meaning all participants were included in the final assessment regardless of whether they strictly adhered to the treatment.
Key Findings and Results
Between 2013 and 2021, 630 men participated in the trial—about half in each group. Unfortunately, participant engagement declined over time: only 204 men remained involved at the end of the 12 months.
When the data were analyzed, the results showed that 22.6% of men on sertraline committed a violent reoffense, compared to 22.5% in the placebo group. The difference was statistically insignificant, suggesting that sertraline did not reduce the risk of future violence.
Additionally, serious adverse events, such as hospitalization or severe side effects, occurred in a slightly lower percentage of men taking sertraline (6.9%) compared to placebo (9.3%), indicating that the medication was relatively safe.
Understanding the Implications
The findings from ReINVEST provide important insights for clinicians, policymakers, and researchers. Despite biological evidence suggesting serotonin’s role in impulsivity and aggression, simply increasing serotonin levels with sertraline does not seem sufficient to prevent violent reoffending.
Interestingly, post-hoc analyses hinted at a possible specific effect on domestic violence, although this was not statistically definitive. It raises the possibility that certain subgroups or specific types of violence might respond differently to treatment.
This underscores a vital lesson: managing violent behavior is complex and likely requires multifaceted approaches, including psychological interventions, social support, and environmental changes.
Looking Ahead: Practical Strategies and Future Research
While pharmacotherapy alone may not be the silver bullet, integrating medications with behavioral therapies, such as anger management and social skills training, could offer more comprehensive solutions.
Moreover, large-scale studies are needed to better understand which individuals might benefit from pharmacological interventions and under what conditions.
Ultimately, reducing violent reoffending relies on combining biological insights with effective rehabilitation methods, community engagement, and policies aimed at early prevention.
Conclusion
The ReINVEST trial highlights that sertraline, despite its biological plausibility, does not significantly cut the risk of violent reoffending in impulsive men. This emphasizes the need for continued research into a combination of therapies and interventions to address the complex roots of violence.
As science advances, a more nuanced understanding of the interplay between biology, environment, and behavior will be essential in developing effective strategies to protect individuals and society from violence.
Reference：
Butler T, Akpanekpo EI, Knight L, Robledo K, Greenberg D, Ellis A, Allnutt S, Wilhelm K, Jones A, Scott R, Ton B, Grant L, Mitchell P, Tynan R, Jones J, Villa D, Chappell D, Dixon C, Churchill A, Gebski V, Keech T, Schofield PW. Sertraline to reduce recidivism in impulsive violent offenders (ReINVEST): a randomised double blind clinical trial. EClinicalMedicine. 2025 Nov 27;90:103668. doi: 10.1016/j.eclinm.2025.103668. PMID: 41399477; PMCID: PMC12702300.