Laurence Roy and Carolina Bottari at Université de Montréal's School of Rehabilitation have documented something researchers say has never been captured before: the complete life journeys of people with brain injuries who are now experiencing homelessness. What they found challenges our understanding of how people end up on the streets—more than half of homeless individuals have suffered a brain injury at some point in their lives, typically years before homelessness set in.
The discovery emerged from a research program launched in response to a 2023 call for proposals from Quebec's Ministry of Health and Social Services and the Fonds de recherche du Québec. Rather than analyzing broad trends, Roy, Bottari, and doctoral student William Jubinville chose to listen directly to the people affected. They conducted in-depth interviews with 26 individuals living with or formerly experiencing homelessness alongside brain injury, publishing their findings in the journal Brain Injury. "To our knowledge, this is the first time anyone has documented the life journeys of people with brain injuries who are experiencing homelessness," Jubinville said.
The brain injuries themselves varied—traumatic brain injuries from blows to the head or concussions, strokes, brain tumors, or alcohol-related injuries. What matters is that these injuries typically occurred before homelessness, not because of it. A traumatic brain injury doesn't inevitably lead to homelessness, but it creates a profound vulnerability. According to Bottari, "A TBI impacts many aspects of cognition, including memory, attention, problem-solving and money management, as well as emotions and behavior." That burden ripples through families and support networks, often becoming unsustainable over time.
The researchers found that the injury's trajectory toward homelessness was rarely simple. For some, the brain injury was one factor among many; for others, it was the decisive turning point. One participant lived a relatively stable life until a brain injury "turned everything upside down," Jubinville recalled. In other cases, the deterioration was more gradual.
What strikes Roy most is how many moments in these individuals' lives offered opportunities for intervention—moments that were missed. "There are so many moments in these individuals' life trajectories when the brain injuries could have been detected—for example, by youth protection services or the correctional system," Roy said. Yet even when people do receive support, it often fails them. Traditional interventions designed for other populations simply don't work for people navigating both brain injury and homelessness simultaneously.
A parallel literature review published in the Annals of Physical and Rehabilitation Medicine revealed systemic fractures in care. An earlier study by Quebec health care and community professionals, published in Disability and Rehabilitation, identified significant gaps: a disconnect between health care services and the realities of homelessness, and a heavy reliance on community groups lacking expertise in traumatic brain injury. Roy described this as "institutional structures that operate in silos and deliver treatment limited to isolated 'episodes of care.'"
The challenge is intensifying. Roy warned of a "perfect storm" created by shorter rehabilitation stays, an aging population bringing more non-traumatic brain injuries like strokes, and eroding support networks. As the needs grow, the current fragmented system grows more inadequate. According to Bottari, the high prevalence of pre-homelessness brain injuries points to an urgent truth: these individuals need longer follow-up from rehabilitation services, not less.