Do early adverse experiences establish a cognitive vulnerability to depression on exposure to mirroring life events in adulthood?

Background: We pursue a ‘lock and key’ hypothesis which posits that early adverse events (‘locks’) create an increased vulnerability to depression in the face of mirroring life events (‘keys’) in adulthood. Here we examine whether any such vulnerability links are cognitively mediated. Methods: We study a sample of 96 clinically depressed patients who reported an identifiable ‘cognitive schema’ being activated when depressed. We examine for significant associations between early adverse events and later precipitants to the patients’ depression, and then assess the extent to which any identified links are cognitively mediated. Results: Qualitative analyses suggested quite strong associations between early childhood experiences and identified schemas, while the quantitative analyses identified few links. Limitations: These contrasting results may present a challenge to the hypothesis or reflect methodological limitations, and we therefore detail some of the complexities involved in identifying cognitive schemas.