Every year, millions of family members and friends provide care for loved ones undergoing cancer treatment, often at great emotional cost. A new scoping review, published in Archives of Geriatrics and Gerontology Plus, confirms the toll that this work can take on caregivers’ mental health.

According to the review, most studies show that more than 15% of those who care for loved ones with cancer suffer from post-traumatic stress disorder (PTSD).

“Caregivers remain largely overlooked in psychosocial oncology care, leaving many without the support they need,” says lead author Elizaveta Klekovkina, a social worker in the Department of Supportive Care at Princess Margaret Cancer Center.

The comprehensive literature review found that caregivers with pre-existing mental health conditions, lower social support, and higher caregiver burden were at greater risk of PTSD. Additionally, patient-related factors such as disease severity, symptom burden, and perceived likelihood of death also contributed to caregiver distress.

“Identifying these risk factors is important for developing targeted interventions to prevent and alleviate traumatic stress in caregivers,” says co-author Maya Stern, also a social worker from the Department of Supportive Care at Princess Margaret Cancer Center. Stern and Klekovkina are both recent graduates of the Master of Social Work program at the University of Toronto’s Factor-Inwentash Faculty of Social Work.

The study also found that caregivers of patients with head and neck cancer or acute leukemia were among the most distressed, with up to 37% of them meeting PTSD criteria.

The most commonly reported PTSD symptoms were intrusive thoughts and hypervigilance. Unlike in other forms of trauma, avoidance, typically a key symptom of PTSD, was not an option, as caregivers remained deeply involved in their loved one’s cancer care.

The scoping review uncovered 23 studies that examined the relationship between traumatic stress and caregivers of adult cancer patients. However, the majority of published studies are cross-sectional, with small sample sizes, and a lack of racial and gender diversity.

“We were surprised to find so few studies on traumatic stress among caregivers of adult cancer patients,” says co-author Carmine Malfitano, director of research and education at the Center for Psychology and Emotional Health and clinical social work specialist at the Princess Margaret Cancer Center.

“There is an urgent need for further research to reduce this gap in the literature and to develop proactive, evidence-based interventions to better integrate caregiver support in oncology care.”

Improving support will require more proactive screening, say the researchers.

“If left unaddressed, traumatic stress in caregivers can have long-term impacts on their mental and physical health,” says senior author Esme Fuller-Thomson, Director of the Institute for Life Course & Aging at the University of Toronto.

“The high prevalence of PTSD among adult cancer caregivers underscores the need to ensure they receive early support, especially at key points such as diagnosis, recurrence, or treatment transitions.”