Emotion dysregulation as a partial mediator between reinforcement sensitivity and posttraumatic stress symptoms

• FFFS sensitivity (not BIS sensitivity) was positively associated with PTSS.
• Emotion dysregulation mediated the relationship between FFFS sensitivity and PTSS.
• People with high FFFS sensitivity reported higher levels of emotion dysregulation.
• This in turn was associated with greater PTSS.

The reinforcement sensitivity theory (RST) asserts that three brain subsystems (i.e., the Behavioral Approach System [BAS], the Behavioral Inhibition System [BIS], and the Fight–Flight–Freeze System [FFFS]) underlie individual variations seen in personality and psychopathology. Though revised by Gray and McNaughton (2000), many researchers continue to utilize the original, and now outdated, theory of reinforcement sensitivity. Additionally, while there is an abundance of research investigating the association between reinforcement sensitivity and psychopathology, the underlying mechanisms between these constructs remain largely unknown. Therefore, the aim of the current study was to test whether emotion dysregulation acted as a partial mediator between FFFS sensitivity and posttraumatic stress symptoms (PTSS) under the revised RST framework. Data was collected from 282 undergraduate students at a Midwestern university who experienced at least one potentially traumatic event. Bootstrapping was used to test the significance of the indirect effect (e.g., amount of mediation) of FFFS sensitivity on PTSS. The indirect effect was significant (2000 bootstrapped CI_95 = .11−.25), indicating that emotion dysregulation partially mediated the relationship between FFFS sensitivity and PTSS. More specifically, individuals with high FFFS sensitivity reported higher levels of emotion dysregulation, which in turn was associated with greater PTSS scores.