title: Behaviorally inhibited temperament is associated with severity of post-traumatic stress disorder symptoms and faster eyeblink conditioning in veterans.
abstract: Prior studies have sometimes demonstrated facilitated acquisition of classically conditioned responses and/or resistance to extinction in post-traumatic stress disorder (PTSD). However, it is unclear whether these behaviors are acquired as a result of PTSD or exposure to trauma, or reflect preexisting risk factors that confer vulnerability for PTSD. Here, we examined classical eyeblink conditioning and extinction in veterans self-assessed for current PTSD symptoms, exposure to combat, and the personality trait of behavioral inhibition (BI), a risk factor for PTSD. A total of 128 veterans were recruited (mean age 51.2 years; 13.3% female); 126 completed self-assessment, with 25.4% reporting a history of exposure to combat and 30.9% reporting current, severe PTSD symptoms (PTSS). The severity of PTSS was correlated with current BI (R(2) = 0.497) and PTSS status could be predicted based on current BI and combat history (80.2% correct classification). A subset of the veterans (n = 87) also completed the eyeblink conditioning study. Among veterans without PTSS, childhood BI was associated with faster acquisition; veterans with PTSS showed delayed extinction, under some conditions. These data demonstrate a relationship between current BI and PTSS, and indicate that the facilitated conditioning sometimes observed in patients with PTSD may partially reflect personality traits such as childhood BI that pre-date and contribute to vulnerability for PTSD.
authors.affiliation: Department of Veterans Affairs, VA New Jersey Health Care System, East Orange, NJ 07108, USA. catherine.myers2@va.gov
authors.forename: Catherine E
authors.initials: CE
authors.lastname: Myers
authors.forename: Kirsten M
authors.initials: KM
authors.lastname: Vanmeenen
authors.forename: J Devin
authors.initials: JD
authors.lastname: McAuley
authors.forename: Kevin D
authors.initials: KD
authors.lastname: Beck
authors.forename: Kevin C H
authors.initials: KC
authors.lastname: Pang
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Servatius
mesh_terms: D000328:Adult; D000368:Aged; D001767:Blinking / Q000502:physiology*; D003214:Conditioning, Classical / Q000502:physiology*; D005108:Extinction, Psychological / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D013313:Stress Disorders, Post-Traumatic / Q000209:etiology* / Q000523:psychology; D011795:Surveys and Questionnaires; D013694:Temperament; D014728:Veterans