As such, the relation between social support and PTSD symptom severity may be explained, in part, due to the release of oxytocin, which is critical for social bonding and regulates the HPA axis along with subcortical structures critical to the stress response [see Lanius et al. (82) for a detailed review of the neurobiology of PTSD, including its dissociative subtype]. The gene discussed is OXT; the disease is post-traumatic stress disorder.