PTSD affects approximately 14% of OEF/OIF Veterans and leads to considerable personal and societal costs (e.g., increased morbidity, reduced work productivity, poorer relationships). Although cognitive behavioral therapy (CBT) is one of the most effective treatments for PTSD, a substantial portion (approximately 50%) of individuals drop out prematurely, do not respond to treatment, or relapse. Treatment engagement is worse for OEF/OIF Veterans, who attend fewer sessions and have higher dropout rates than civilians and Veterans from other eras. One likely barrier to treatment engagement and effectiveness is the executive functioning problems present in individuals with PTSD. Executive functions (EFs) are the set of higher-level cognitive skills that organize and integrate lower-level cognitive processes in order to perform complex, goal-directed tasks. PTSD has been associated with EF deficits, including impairments in inhibitory control, working memory, and cognitive flexibly, as well as dysfunction in a network of brain regions that support EFs (e.g., prefrontal cortex [PFC], cingulate). EFs are essential for CBT in order to engage the cognitive skills involved in treatment (e.g., self-monitoring, inhibiting distorted thoughts, flexibly generating/evaluating alternative thoughts). This is particularly true for Cognitive Processing Therapy (CPT), a frontline CBT treatment for PTSD, which involves identifying and challenging maladaptive trauma-related thoughts to alter their impact on emotions and behavior. Thus, EF deficits may lead to reduced CPT engagement and responsivity. In fact, worse EF at baseline has been associated with poorer response to CBT in several disorders (e.g., generalized anxiety disorder, obsessive compulsive disorder, schizophrenia). Further, a study of brain functioning during an EF task demonstrated that dysfunction in EF-related brain regions including PFC and cingulate cortex at baseline predicted nonresponse to CBT for PTSD. Directly targeting EF prior to CPT via cognitive training would strengthen executive networks and likely boost treatment effectiveness, allowing Veterans to fully engage in and benefit more from components of CPT (e.g., cognitive restructuring). Evidence suggests that computerized cognitive training improves EF and functioning in EF-related brain regions, increases mental health treatment completion rates, and enhances response to CBT, though this has not yet been tested in a PTSD population. Thus, the main goal of the proposed study is to examine whether administering computerized EF training (CEFT) immediately prior to CPT will improve executive functioning and enhance treatment adherence, completion rates, and psychological and functional outcomes in OEF/OIF Veterans with PTSD. Objective (neuropsychological) and subjective (self- report) measures of EF will be collected to determine if CEFT enhances EF and if this in turn mediates the relationship between treatment condition and PTSD symptom imp...