Grant: Project Grant

Post-traumatic stress disorder (PTSD) affects millions of Canadians and their families. Children of parents with PTSD are more at risk of developing symptoms of various psychopathologies, such as internalizing (e.g., depression, anxiety) and externalizing (e.g., substance or alcohol use disorder) conditions. Starting at puberty, girls report more internalizing symptoms than boys, where the reverse is true for externalizing symptoms. It is unknown what makes some children more at risk of developing such symptoms. Individuals suffering from PTSD secrete fewer stress hormones (cortisol). Children of parents with PTSD also exhibit lower cortisol levels, with stronger effects when the mother has PTSD. It is unclear whether cortisol secretion is a vulnerability factor for these children to develop mental health symptoms. We aim to investigate whether cortisol profiles in children vary based on several factors (their mother's trauma exposure, the severity of their PTSD symptoms, the child's sex, gender, puberty, and pubertal timing) and how these relate to mental health outcomes over a 4-year period. At Time 1, we will recruit 300 mother-child dyads (healthy boys and girls aged between 8 and 12, without a trauma history), where mothers differ based on trauma history and PTSD symptoms (no trauma history, trauma history with varying degrees of PTSD symptoms). At T1, T2 (+2 years), and T3 (+4 years), PTSD symptom severity is evaluated for mothers, and internalizing symptoms, externalizing symptoms, sex, gender-related variables, and pubertal development are measured in children. At each time point, mothers and children provide saliva samples for cortisol quantification. As children of parents with PTSD are more vulnerable to mental health symptoms, it is essential to study whether/how cortisol modulates this vulnerability. This could help to identify at-risk children and in deploying preventive interventions to decrease the transmission of risk within families.