Rebecca Girlinghouse, MA
WKPIC Doctoral Intern
This study sought to determine if childhood trauma has an impact on attention and the ability to inhibit responses in those with bipolar disorder. The authors hypothesized that a history of childhood trauma would affect response inhibition in all participants. However, they believed those with a bipolar disorder diagnosis and a history of childhood trauma would have the largest difficulty with inhibitory control. In addition, the authors examined whether or not the difficulty of a cognitive task affected participants’ ability to inhibit responses.
Participants included 233 individuals diagnosed with bipolar disorder (191 with Type I and 42 with Type II) and 90 healthy controls. Individuals diagnosed with bipolar disorder were excluded from the study if they had a history of schizophrenia; schizoaffective disorder, depressive type; active substance dependence; active symptoms of mania or depression; or medical illness associated with depression. All participants were given the Childhood Trauma Questionnaire in order to assess for childhood traumatic experiences. Based on the score obtained, participants were placed into one of four groups: bipolar disorder trauma (n=117), bipolar disorder normative (n=116), healthy control trauma (n=17), and healthy control normative (n=73). All participants then engaged in a Parametric Go/No-Go task which assess attention, working memory, processing speed, and inhibitory control. Additionally, this task required participants to complete three levels of difficulty. In this task, participants must press a key when specific target letters appear on a screen. However, they must refrain from hitting the key when any other non-target letter is presented.
Results indicated that participants in both trauma groups showed a significantly poorer performance on inhibitory control. Additionally, both bipolar disorder groups evidenced significantly slower response times during the task when compared to the two healthy control groups. However, no group differences were found on easier levels of the task. The authors also noted that a history of childhood trauma predicted more severe and chronic symptoms as well as a history of substance use in those diagnosed with bipolar disorder.
These findings appear to suggest childhood trauma negatively effects the development of inhibitory control regardless of the presence of a psychiatric disorder. Additionally, research has shown that individuals with bipolar disorder tend to have greater difficulty with inhibition when compared with healthy controls. However, this difference seems to disappear when healthy controls have experienced trauma. Therefore, it appears that the effects of trauma may play a larger role in producing difficulty with inhibition than does mental illness. However, the effects of mental illness and trauma on the ability to inhibit responses may only be apparent during more difficult tasks. Additionally, it appears that the presence of bipolar disorder, but not trauma, affects the time in which it takes an individual to respond to a cue.
Marshall, D.F., Passarotti, A.M., Ryan, K.A., Kamali, M., Saunders, E.F., Pester, B., McInnis, M.G., & Langenecker, S.A. (2016). Deficient inhibitory control as an outcome of childhood trauma. Psychiatry Research, 235, 7-12.