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Dual harm refers to when a patient harms themself and acts aggressively toward others or objects. When these behaviours occur together, patients often need closer monitoring and more coordinated care.
In a study published in PLoS One, Mark Mohan Kaggwa, Bailea Erb, Sébastien Prat, Arianna Davids, John Bradford, Gary Chaimowitz, and Andrew Olagunju examined which factors were associated with dual harm among forensic patients in Ontario. Their findings highlight the need for integrated, trauma-informed care planning that addresses self-harm and aggression together.
This is a plain language summary of:
Kaggwa, M. M., Erb, B., Prat, S., Davids, A., Bradford, J., Chaimowitz, G. A., & Olagunju, A. T. (2024). Dual harm among patients in the Ontario forensic mental health system. PLoS One, 19(12), e0316364. https://doi.org/10.1371/journal.pone.0316364
Understanding of Dual Harm Better
Earlier research shows that patients who dual harm tend to stay longer in forensic hospitals and participate less in rehabilitation programs, which can make recovery more challenging for patients and care delivery more complex for their clinical teams.
The research team analyzed data from 1,240 forensic mental health patients using Ontario Review Board records from 2014 to 2015. They examined how age, education, psychiatric diagnosis, and past behaviour were associated with engaging in self-harm and aggression. This analysis offers one of the first large-scale descriptions of how self-harm and aggression occur together in a forensic setting and may help clinical teams identify patients who are more likely to engage in both behaviours.
Key Findings
About 3.6% of patients engaged in both self-harm and aggression during the reporting year. Nearly 18% had done so at some point in their lives. Most aggressive incidents involved verbal behaviour or damage to objects, while physical aggression toward others was less common.
A previous history of self-harm and aggression was the strongest indicator of engaging in dual harm again. Neurodevelopmental disorders were also associated with a higher likelihood of dual harm. Personality disorders were associated only with cases involving sexual aggression. In contrast, older age and postsecondary education were associated with lower odds of dual harm.
Dr. Kaggwa and his colleagues also found a strong association between self-harm and aggression. Patients who engaged in aggression toward objects or others were more likely to self-harm during the same period, even after accounting for age, diagnosis, and other clinical factors. The strongest association was between self-harm and aggression toward objects.
Why Dual Harm Matters for Care and Policy
Although relatively uncommon, dual harm has important implications for patient safety, requiring close monitoring and structured support. These overlapping risks also affect care planning and the day-to-day functioning of forensic mental health settings, increasing pressure on staff and affecting therapeutic environments by requiring more intensive supervision and longer periods of coordinated care. All of this makes early identification and integrated care planning vital because patients with a history of dual harm are much more likely to engage in it again.
The research team suggests that self-harm and aggression may be better addressed together, rather than as separate clinical issues, because they often occur together and influence each other in practice. Trauma-informed, skills-based approaches that support emotional regulation and reduce isolation may help meet the needs of patients who engage in dual harm.
Dr. Kaggwa and his colleagues outlined several priorities for forensic services and policy-makers. They recommend that forensic programs:
- screen routinely for both self-harm and aggression;
- provide targeted support and close monitoring for patients with a history of dual harm, neurodevelopmental disorders, or recent self-harm or aggression;
- follow up proactively with patients known to be vulnerable or at higher risk; and
- allocate sufficient resources for prevention, staff training, and coordinated care.
Because many individuals who harm others or objects are also at high risk of harming themselves, the authors emphasize the importance of identifying dual harm early and responding in a coordinated way. They recommend that clinical, correctional, and law enforcement teams work together to screen for dual harm and provide supportive monitoring for those who are at higher risk.
Looking Ahead
Recognizing self-harm and aggress as co-occurring behaviours, rather than treating them separately, can help guide care planning by identifying patients who may benefit from targeted intervention and supportive monitoring. Looking ahead, the authors indicate that trial studies are needed to test which integrated interventions are most effective and to better understand modifiable risks of dual harm.
Written by Kyle Roerick and approved by Dr. Mark Mohan Kaggwa.
