Abstract

Experiencing early life stress (ELS) and subsequent dysregulation of the hypothalamic-pituitary-adrenal (HPA)
axis may play a role in the aetiology of mental health disorders. However, the exact mechanisms linking HPAaxis
dysregulation with the development of psychopathology have not been fully delineated. Progress in this area
is hampered by the complex and often conflicting associations found between markers of HPA-axis function and
risk factors for mental health disorders such as impaired executive function (EF) and ELS. This study investigated
the association of the cortisol awakening response (CAR) with ELS and EF in a healthy adult male population
(n =109, aged 21–63). As previous inconsistencies in CAR and ELS association studies may be the result of not
considering ELS-related factors such as cumulative exposure, type of stressor and developmental timing of ELS,
these were also investigated. The main findings were that the CAR was significantly elevated in individuals
reporting ELS compared to those reporting no ELS (p =0.007) and that an elevated CAR predicted poorer
problem solving/planning (p=0.046). Cumulative exposure, type of stressor and developmental timing of ELS
were also found to impact significantly on the CAR. These results suggest that ELS is associated with chronic
changes in HPA-axis function and that these changes may be associated with impairments in problem solving/
planning. Future work should investigate further the neurobiological mechanisms linking ELS, the CAR and EF
and their role in conferring risk for the development of mental health disorders.