Forms of cognitive and behavioral therapies (CBTs), including prolonged exposure and cognitive processing therapy, have been empirically validated as efficacious treatments for posttraumatic stress disorder (PTSD). However, the assumption that PTSD develops from dysregulated fear circuitry possesses limitations that detract from the potential efficacy of CBT approaches. An analysis of these limitations may provide insight into improvements to the CBT approach to PTSD, beginning with an examination of negative affect as an essential component to the conceptualization of PTSD and a barrier to the implementation of CBT for PTSD. As such, the literature regarding the impact of negative affect on aspects of cognition (i.e., attention, processing, memory, and emotion regulation) necessary for the successful application of CBT was systematically reviewed. Several literature databases were explored (e.g., PsychINFO and PubMed), resulting in 25 articles that met criteria for inclusion. Results of the review indicated that high negative affect generally disrupts cognitive processes, resulting in a narrowed focus on stimuli of a negative valence, increased rumination of negative autobiographical memories, inflexible preservation of initial information, difficulty considering counterfactuals, reliance on emotional reasoning, and misinterpretation of neutral or ambiguous events as negative, among others. With the aim to improve treatment efficacy of CBT for PTSD, suggestions to incorporate negative affect into research and clinical contexts are discussed.