Do different types of stress differentially alter behavioural and neurobiological outcomes associated with depression in rodent models? A systematic review.

Cataloguing the effects of different types of stress on behaviour and physiology in rodent models has not been comprehensively attempted. Here, we systematically review whether chronic exposure to physical stress, psychosocial stress, or both types of stress can induce different behavioural and neurobiological outcomes in male and female rodents. We found that physical stress consistently increased depressive-like behaviour, impaired social interaction and decreased body weight, while psychosocial stress consistently increased both anxiety- and depressive-like behaviour, impaired social interaction and learning and memory, increased HPA axis activity, peripheral inflammation and microglial activation, and decreased hippocampal neurogenesis in male rodents. Moreover, we found that the combined effect of both stress types resulted in a more severe pathological state defined by increased anxiety- and depressive-like behaviour, impaired social interaction and learning and memory, increased HPA axis activity and central inflammation, and reduced hippocampal neurogenesis and neural plasticity in male rodents. Phenotypes for females were less consistent, irrespective of the type of stress exposure, on account of the limited number of studies using females. This review highlights that the type of stress may indeed matter and will help animal researchers to more appropriately choose a stress/depression model that fits their research purposes.

Social Anxiety, Stress Type, and Conformity among Adolescents.

Social anxiety and stress type can influence strong conformity among adolescents; however, the interaction between them is not clear. In this study, 152 adolescents were recruited and assigned one of two conditions: an interaction and a judgment condition. In the interaction condition, adolescents with high social anxiety (HSA) were less likely to conform when completing a modified Asch task, compared to adolescents who had low social anxiety. In the judgment condition, adolescents with HSA were more likely to conform to the opinions from the unanimous majority. The results suggest that adolescents with HSA may show different styles of strong conformity with the change of stress type. We believe that socially anxious adolescents avoid potential social situations with weaker conformity, while avoiding negative evaluations from others with stronger conformity. These findings contribute to a better understanding of the social dysfunctions among adolescents with HSA and provide a new direction for clinical interventions.