Grant: Master's Award: Canada Graduate Scholarships

Major Depressive Disorder (MDD) affects over 280 million individuals and accounts for more years of ‘healthy’ life lost than any other medical condition. Depression is 2-3x more common in women than men, and a disproportionate amount of burden is attributable to recurrent depression. Evidence shows that half of all individuals at initial onset of MDD will go on to experience recurrent depression. However, it cannot be reliably forecasted at the time of initial depression onset who is and is not prone to multiple lifetime recurrences. Recurrence prone individuals may possess underlying liabilities that render them susceptible to multiple lifetime episodes. In contrast, those with only a single lifetime episode may be those who become depressed in the face of a major stressful life event. One way to investigate this distinction is to compare individuals whose first onset episode is preceded by a stressful life event to individuals whose first episode is not preceded by a stressful life event on various underlying liabilities for recurrence. The objectives are to 1) examine whether individuals whose first episode of MDD is precipitated by a major stressful life event differ from those whose first episode onsets in the absence of a stressful event on neuroticism, hippocampal and amygdalar volume, and first-degree family member history of depression, and 2) determine whether these differences are stronger in women versus men. This study will leverage a sample of ~300 individuals on their first episode of MDD from the Canadian Biomarker Network for Depression (CAN-BIND), a 7-site, pan-Canadian initiative. Results will address the gender gap in burden of depression and inform the dissemination of tailored treatment and maintenance resources to those who need them most.