An Investigation of Executive Function Impairment in Adolescents and Adults with Depression

Depressive illness has been associated with impairment in executive functioning (EF); however the relationship between neurocognitive dysfunction and depressive illness is not well understood. Similar deficits in EF in depressive illness have been demonstrated in the research among adults and adolescents, although the research among youth is limited. Additionally, no published reports were found that have examined developmental differences in EF among youth and adults with depression. The current pilot study sought to provide information on the influences of age and depressive illness status on EF, as well as the extent to which deficits in EF are evidenced in youngsters with depression. An additional purpose of this study was to provide information on the utility of age-appropriate measures in assessing EF in youth. Data were analyzed on 105 participants (depressed adolescents and depressed adults, and their healthy counterparts) on ten outcome measures of EF. The performance of all groups fell within the average range across all ten outcome measures; however, significant group differences emerged on several outcomes on the Woodcock-Johnson III Tests of Cognitive Abilities (WJ-III COG). Additionally, adolescents with depression demonstrated a decreased performance across the majority of EF measures compared to their healthy counterparts, although these differences were not significant. Results from the current study revealed a significantly lower performance among depressed adolescents compared to both depressed and healthy adults on tasks involving processing speed, interference control and sustained attention ability. This finding suggests that depressive illness during early life may have mild effects on select executive functions (EFs), such as those that remain underdeveloped in youth. Results also revealed a decreased performance among both depressed and healthy adolescents compared to healthy adults on tasks involving planning ability, interference control or inhibition, and mental flexibility. This finding suggests that EF may be less reliable in youth, due to the ongoing maturation of this system in youngsters, and may improve with age. Finally, differences in performance in EF emerged only on the WJ-III COG, but not on other measures, which suggests that the WJ-III COG offers sensitivity in detecting developmental differences in EF among youth and adults.