The relationship between complex PTSD and dissociation: longitudinal findings across Western and South Asian female samples

Purpose: Post-traumatic stress disorder (PTSD) and dissociation are common responses to trauma, especially interpersonal and betrayal trauma. Dissociation has been proposed to be a core concept in understanding PTSD. However, little is known about the bidirectional relationship between dissociation and ICD-11 complex PTSD (CPTSD) symptoms. This study examined the relationship between classical PTSD, disturbances in self-organization (DSO), and dissociative symptoms across two culturally different samples. Methods: Participants from Western and South Asian countries completed validated measures of PTSD, DSO, and dissociation two times, approximately six months apart. Results: Across the Western (N = 101) and South Asian (N = 160) samples, at baseline, 71.7% to 84.2% of participants with probable CPTSD exhibited co-occurring dissociative symptoms, while 70.0% to 72.3% of participants with dissociative symptoms had probable PTSD or CPTSD. Dissociative symptoms were less common in participants with probable PTSD (20.0% to 28.6%). In addition, dissociative symptoms predicted subsequent levels of classical PTSD symptoms across the two samples (β = 0.241 to 0.246, p <.01). The predictive role of dissociative symptoms on DSO symptoms was only observed in the South Asian sample (β = 0.231, p =.011). Neither PTSD nor DSO symptoms predicted dissociative symptoms in both samples. Conclusion: This study provides updated and cross-cultural data showing that dissociation is associated with an increase in PTSD symptoms over time, though its association with DSO symptoms is less clear. Assessment, prevention, and treatment of PTSD should take dissociative symptoms into consideration.