Impaired fear inhibition learning predicts the persistence of symptoms of posttraumatic stress disorder (PTSD).

Journal article

Recent cross-sectional studies have shown that the inability to suppress fear under safe conditions is a key problem in people with posttraumatic stress disorder (PTSD). The current longitudinal study examined whether individual differences in fear inhibition predict the persistence of PTSD symptoms. Approximately 2 months after deployment to Afghanistan, 144 trauma-exposed Dutch soldiers were administered a conditional discrimination task (AX+/BX-). In this paradigm, A, B, and X are neutral stimuli. X combined with A is paired with a shock (AX+ trials); X combined with B is not (BX- trials). Fear inhibition was measured (AB trials). Startle electromyogram responses and shock expectancy ratings were recorded. PTSD symptoms were measured at 2 months and at 9 months after deployment. Results showed that greater startle responses during AB trials in individuals who discriminated between danger (AX+) and safety (BX-) during conditioning, predicted higher PTSD symptoms at 2 months and 9 months post-deployment. The predictive effect at 9 months remained significant after controlling for critical incidents during previous deployments and PTSD symptoms at 2 months. Responses to AX+ or BX- trials, or discrimination learning (AX+ minus BX-) did not predict PTSD symptoms. It is concluded that impaired fear inhibition learning seems to be involved in the persistence of PTSD symptoms.

Authors: Sijbrandij, M; Engelhard, I; Lommen, M; Leer, A; Baas, J

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Elsevier
• Journal: Journal of psychiatric research
• Volume: 47
• Issue: 12
• Pages: 1991-1997
• Publication date: 2013-12-01
• DOI: 10.1016/j.jpsychires.2013.09.008
• EISSN: 1879-1379
• ISSN: 0022-3956
• Language: English
• Keywords: Inhibition (Psychology); Predictive Value of Tests; Netherlands; Adolescent; Female; Humans; Fear; Military Personnel; Startle Reaction; Longitudinal Studies; Reaction Time; Male; Stress Disorders, Post-Traumatic; Acoustic Stimulation; Adult; Learning Disorders; Young Adult; Conditioning, Classical