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

• Published in: Journal of psychiatric research Vol. 47; no. 12; pp. 1991 - 1997
• Main Authors: Sijbrandij, Marit, Engelhard, Iris M, Lommen, Miriam J.J, Leer, Arne, Baas, Johanna M.P
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.12.2013; Elsevier
• Subjects: Acoustic startle; Acoustic Stimulation; Adolescent; Adult; Adult and adolescent clinical studies; Anxiety disorders. Neuroses; Biological and medical sciences; Classical conditioning; Conditional discrimination; Conditioning, Classical - physiology; Deployment; Fear; Fear - psychology; Fear inhibition; Female; Humans; Inhibition; Inhibition (Psychology); Learning; Learning Disorders - diagnosis; Learning Disorders - etiology; Longitudinal Studies; Male; Medical sciences; Military; Military Personnel; Netherlands; Post-traumatic stress disorder; Posttraumatic stress disorder; Posttraumatic stress disorder (PTSD); Predictive Value of Tests; Psychiatry; Psychology. Psychoanalysis. Psychiatry; Psychopathology. Psychiatry; Reaction Time - physiology; Reflex, Startle - physiology; Stress Disorders, Post-Traumatic - complications; Stress Disorders, Post-Traumatic - diagnosis; Symptoms; Young Adult; Netherlands; Conditional discrimination; Acoustic startle; Posttraumatic stress disorder (PTSD); Classical conditioning; Fear inhibition; Military; Affect affectivity; Anxiety disorder; Emotion emotionality; Posttraumatic stress disorder; Startle reflex; Stress; Learning; Fear; Symptomatology; Acquisition process; Discrimination; Acoustic stimulus; Inhibition; Predictive factor
• DOI: 10.1016/j.jpsychires.2013.09.008
• ISSN: 0022-3956

Abstract 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.