Relationship between pet ownership and risk of high depressive symptoms in adolescence and young adulthood

Background: Only few longitudinal studies with high risk of bias have examined relationship between pets and adolescents' mental health. Methods: Our prospective cohort study followed depression-free US adolescents aged 12-18, enrolled in the Growing Up Today Study from pet ownership assessment in 1999 to possible occurrence of high depressive symptoms defined based on the McKnight Risk Factor Survey between 2001 and 2003. Propensity-score-adjusted odds ratios (ORs) and 95 % confidence intervals (CIs) were estimated using generalized estimating equation models.Results: Among 9631 adolescents [42.4 % male, mean age 14.9 years (SD 1.6)], we found no association between pet ownership and risk of high depressive symptoms (ORany_pet = 1.14; 95%CI, 0.95-1.38). Stratified analyses revealed no evidence of effect modification by sex, but effect modification by maternal history of depression (depressed mothers ORany_pet = 0.83; 95 % CI: 0.58-1.19, non-depressed mothers ORany_pet = 1.27; 95 % CI: 1.02-1.58; Pintx = 0.03), which differed further by children's sex. Effects were more pronounced among children with a history of childhood abuse (ORany_pet = 0.41 (0.14-1.15); Pintx <= 0.03). No major differences by type of pet owned were observed in any of these analyses. Limitations: Our sample is predominantly white and all are offspring of nurses with a similar academic background which could affect generalizability.Conclusions: Overall, we found no association between pet ownership and depression during adolescence, however subgroup analyses indicated some individuals may benefit from a pet. Future longitudinal studies with more detailed exposure assessments, including pet attachment are needed to further explore the potential of human-animal interaction on mental health.