{'fraction_non_alphanumeric': 0.02625, 'fraction_numerical': 0.0, 'mean_word_length': 5.788135593220339, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Posttraumatic Stress Disorder

The chapter discusses posttraumatic stress disorder (PTSD). PTSD is a severe, prolonged response to witnessing or experiencing traumatic events that may manifest with a variety of cognitive, affective, and physiological symptoms, from irritability and hypervigilance to recurrent dreams and flashbacks. After an overview of this disorder, its developmental features, and the main risk factors identified in the epidemiological literature, the chapter critically reviews existing evolutionary models and suggests new directions for research. The final section applies the criteria developed earlier in the book to classify the disorder within the fast-slow-defense (FSD) model. The author concludes that PTSD can be classified as a defense activation (D-type) condition.