UNSW Sydney World-First Study: Sertraline Reduces Domestic Violence Reoffending in Impulsive Men

In a groundbreaking advancement from Australian higher education, researchers at UNSW Sydney have pioneered a world-first clinical trial demonstrating that a common antidepressant can significantly lower rates of domestic violence reoffending among highly impulsive men. The ReINVEST trial, conducted by the Justice Health Research Program at UNSW's Kirby Institute in collaboration with the University of Newcastle, offers new hope for addressing one of Australia's most pressing social issues through evidence-based pharmacological intervention combined with psychosocial support.

The study highlights UNSW Sydney's leadership in translational research, bridging mental health, criminology, and public safety to develop practical solutions for complex societal challenges. By targeting impulsivity—a key driver of reactive aggression—this research underscores the potential of university-led initiatives to inform policy and clinical practice nationwide.

The ReINVEST Trial: A Novel Approach to Violence Prevention

The ReINVEST trial, formally known as a pharmacotherapy-based intervention to reduce domestic violence offending, was a double-blind, placebo-controlled randomized clinical trial spanning from 2013 to 2022. Led by Professor Tony Butler from UNSW Sydney's Kirby Institute, the study screened 1,738 men in New South Wales through community corrections offices and courts. Eligibility required a history of at least two violent convictions and a high score (≥70) on the Barratt Impulsiveness Scale, version 11, indicating significant impulsivity.

Following a four-week single-blind run-in phase where all participants received sertraline—a selective serotonin reuptake inhibitor (SSRI) commonly prescribed as Zoloft—the 630 eligible men were randomized 1:1 to either continue sertraline (100mg daily, up-titrated as needed to 200mg) or switch to placebo for 12 months. Crucially, both groups received intensive psychosocial support, including trauma-informed counseling, 24-hour crisis lines, partner safety planning, and assistance with housing, employment, and substance use issues. This holistic model addressed the multifaceted needs of participants, many of whom had histories of childhood trauma, mental health disorders, and marginalization.

The primary outcome was the first convicted violent offense within 12 months, tracked objectively via linkage to the NSW Reoffending Database by the Bureau of Crime Statistics and Research (BOCSAR). Secondary outcomes included domestic violence offenses, self-reported behaviors, and psychometric measures like anger and impulsivity.

Key Findings: Targeted Reduction in Domestic Violence

While the trial did not show a significant difference in overall violent reoffending at 12 months (22.6% sertraline vs. 22.5% placebo; relative risk [RR] 1.00, 95% CI 0.75–1.34, p=0.99), post-hoc analyses revealed a promising selective effect on domestic violence. At 12 months, domestic violence offending was 19.1% in the sertraline group versus 24.8% in placebo (RR 0.77, 95% CI 0.57–1.04, p=0.089). By 24 months, the difference reached statistical significance: 28.2% vs. 35.7% (RR 0.79, 95% CI 0.63–0.99, p=0.045).

For repeated domestic violence offending (more than one offense over 24 months), sertraline reduced rates by 44% compared to placebo. Adherence mattered: among men taking medication more than 50% of the time, the reduction was 30% at 24 months, and up to 52% for those with high psychological distress at baseline. The run-in phase alone produced notable improvements: 55% reduction in depression, 44% in psychological distress, 35% in anger, and 20% in impulsivity.

Safety was favorable, with fewer serious adverse events in the sertraline group (6.9% vs. 9.3%). Self-reported outcomes showed trends toward less substance use and alcohol consumption, though not statistically significant.Full results published in eClinicalMedicine.

Perspectives from Partners and Families

A companion qualitative study interviewed 27 women connected to trial participants (partners, ex-partners, mothers). Over 92% reported reductions in men's impulsivity and violence, describing homes shifting from "terrified quiet" to "peaceful quiet." Changes spanned individual self-regulation, safer relationships, and social reintegration like employment. Women credited sertraline for boosting motivation and competence, alongside supportive clinicians who engaged families respectfully. Self-Determination Theory framed these shifts as fulfilling needs for autonomy, competence, and relatedness.Partner experiences detailed here.

Scientific Rationale: Sertraline and Impulsive Aggression

Sertraline enhances serotonin signaling in the brain, improving impulse control and emotional regulation. Impulsivity, measured by the Barratt scale, correlates strongly with reactive aggression in domestic settings, where violence often erupts from heated, emotionally charged conflicts. Unlike instrumental violence, domestic incidents are typically impulsive, making SSRIs a targeted tool. Prior pilot studies and meta-analyses supported this, showing SSRIs reduce aggression in impulsive populations without major depression.

The trial's wraparound support was vital, as standalone pharmacotherapy yields poor adherence in justice-involved men distrustful of services. Cost-effectiveness stands out: ~A$7,000 per participant annually versus A$150,000 for incarceration.

Context: Domestic Violence in Australia and NSW

Domestic and family violence (DFV) affects 1 in 6 Australian women since age 15, with NSW recording over 40,000 incidents quarterly. Reoffending rates hover at 30-50% within two years, straining systems. BOCSAR data shows 49.3% adult reoffending post-custody in 2024. Traditional interventions like generic behavior change programs show limited success (10-20% reduction), highlighting need for tailored approaches. UNSW's research positions universities as key innovators in prevention.NSW DFV stats.

Navigating Criticisms and Limitations

The trial faced backlash: advocates argued it medicalizes choice-based violence rooted in gender inequality, diverting funds from victims (NSW services underfunded amid 22% referral surge). A psychiatrist claimed increased violence in some cases, though unverified. High attrition (75% non-adherent by 12 months) and reliance on convictions (under-reporting DV) limit power. General violence null result suggests specificity to DV contexts. Researchers counter that impulsivity is treatable, not excusing behavior, and evidence trumps ideology—social programs underperform.

Balanced rollout must prioritize victim safety, monitoring, and complementary primary prevention.

UNSW Sydney's Role in Justice Health Research

UNSW's Kirby Institute, world-renowned for HIV/AIDS, excels in justice health, studying incarceration's health impacts. ReINVEST exemplifies interdisciplinary work: population health, psychiatry, criminology. Funded by NHMRC and NSW Dept of Communities and Justice (~A$6.9m), it demonstrates universities' value in high-risk research amid controversy. Kirby's model—independent, trust-building—boosted engagement in skeptical populations.

Policy Implications and Future Outlook

ReINVEST calls for health-justice integration: SSRI screening for impulsive DV offenders, long-acting formulations for adherence, subgroup analyses (e.g., high-distress men). NSW Minister Jodie Harrison welcomes evidence for multi-pronged strategies. Nationally, amid DFV crisis (5 murders in Jan 2026), universities like UNSW can scale models cost-effectively. Future trials: combination therapies, Indigenous adaptations (10% participants Aboriginal), long-term follow-up.

Australia's higher education sector, via ARC/NHMRC grants, drives such innovations, positioning unis as societal problem-solvers.

Expert Voices and Broader Impact

"The house became peaceful quiet instead of terrified quiet," one partner shared. Prof Butler: "Vindicated... we targeted the right issue." Psychologist Lee Knight emphasized support's role. Michael Salter (UNSW) advocates evidence over dogma. Globally, trial inspires similar efforts, affirming SSRIs' role in aggression management.

UNSW's breakthrough not only advances science but saves lives, reinforcing Australian universities' global research prowess.Expert analysis.

Photo by Dominic Kurniawan Suryaputra on Unsplash