Trauma can disrupt the sense of self, as reported by individuals with PTSD who describe feeling disconnected from themselves or emotionally numb. These self-related experiences are linked to the default mode network (DMN), a brain network active during rest and self-referential thought. In people with PTSD, the DMN shows reduced resting-state functional connectivity compared to healthy individuals, with greater reductions tied to more severe PTSD symptoms. Trauma may become intertwined with the sense of self through alterations in the DMN. Understanding these changes during rest and in response to trauma-related cues may inform therapies that address past and present experiences in PTSD treatment.
Adolescents with both a substance use disorder and probable post-traumatic stress disorder report more frequent use of MDMA (ecstasy) than those without PTSD, and they start using substances at a younger age. PTSD symptoms, especially avoidance, appear before first MDMA use, which begins on average 2.2 years after PTSD onset. The association between MDMA use and avoidance symptoms may reflect an attempt to reduce those symptoms or a consequence of regular MDMA use.