Background: Early life social adversity can influence stress response mechanisms and is associated with anxious behaviour and reductions in callosal area later in life.
Objective: To evaluate the association between perceptions of parental bonding in childhood/adolescence, hypothalamic-pituitary-adrenal (HPA) axis response, and callosal structural integrity in adult victims of severe urban violence with and without PTSD.
Methods: Seventy-one individuals with PTSD and 62 without the disorder were assessed with the Parental Bonding Instrument (PBI). The prednisolone suppression test was administered to assess cortisol levels, and magnetic resonance imaging was used to assess the total area of the corpus callosum (CC), as well as the areas of callosal subregions.
Results: The PBI items related to the perception of 'not having a controlling mother' (OR 4.84; 95%CI [2.26-10.3]; p=0.01), 'having a caring father' (OR 2.46; 95'%CI [1.18-5.12]; p=0.02), and 'not having controlling parents' (OR 2.70; 95%CI [1.10-6.63]; p=0.04) were associated with a lower risk of PTSD. The PTSD group showed a blunted response to the prednisolone suppression test, with lower salivary cortisol levels upon waking up (p=0.03). Individuals with PTSD had smaller total CC area than those without the disorder, but these differences were not statistically significant (e-value =0.34).
Conclusions: Healthy parental bonding, characterized by the perception of low parental control and high affection, were associated with a lower risk of PTSD in adulthood, suggesting that emotional enrichment and the encouragement of autonomy are protective against PTSD in adulthood.