Long-Term Mental Health Outcomes in Mothers and Siblings of Children With Cancer: A Population-Based, Matched Cohort Study

Although a diagnosis of childhood cancer can have a profound effect on the entire family unit, its impact on the long-term mental health of family members is not well characterized. A provincial childhood cancer registry in Ontario, Canada, was linked to birth records to identify separate population-based cohorts of mothers and siblings of children diagnosed with cancer between 1998 and 2014. The mother and sibling cohorts were matched to corresponding population controls and linked to health services data. The rate of mental health-related outpatient visits (family physician, psychiatrist) and the incidence of severe psychiatric events (psychiatric emergency department visit, psychiatric hospitalization, suicide) were compared between mothers and siblings and their controls. Possible predictors of mental health outcomes were examined, including demographics, characteristics of the cancer-affected child, and cancer treatment. We identified 4,773 mothers and 7,897 siblings of children diagnosed with cancer during the study period. Compared with controls, both groups experienced elevated rates of outpatient visits (mothers: rate ratio [RR], 1.4; < .0001; siblings: RR, 1.1; < .0001). The risk of severe psychiatric events was not increased in either cohort. Mother and sibling demographic factors associated with increased risk of adverse mental health included younger maternal age at cancer diagnosis, low socioeconomic status, and rural residence among mothers and older sibling age among siblings. Treatment-related variables pertaining to the cancer-affected child were not associated with mental health outcomes. Mental health outcomes clustered within families. Both mothers and siblings experience elevated and prolonged need for mental health-related health care as compared with the general population. Demographic risk factors predict subpopulations at highest risk. Increased psychosocial support for family members during and after cancer therapy is warranted.