Associations between telomere length and symptoms of posttraumatic stress disorder and appetitive aggression in trauma-exposed men.

Exposure to community violence is common in South Africa and negatively impacts on biopsychosocial health. Posttraumatic stress disorder (PTSD) is characterised by symptoms of intrusion, avoidance, hypervigilance and negative alterations in cognition and mood, and can develop consequent to trauma exposure. Individuals who repeatedly experience and witness violence may also come to view it as appealing and rewarding. This appetitive aggression (AA) increases the likelihood of perpetrating violence. Telomeres are repetitive nucleotide sequences that protect the ends of chromosomes. Telomere length (TL) attrition is a stress-sensitive marker of biological aging that has been associated with a range of psychiatric disorders. This study investigated the cross-sectional relationship between TL and symptoms of PTSD and AA in South African men residing in areas with high community violence. PTSD and AA symptom severity was assessed in 290 men using the Posttraumatic Stress Disorder Symptom Scale - Interview (PSS-I) and Appetitive Aggression Scale (AAS), respectively. Quantitative polymerase chain reaction was performed on DNA extracted from saliva and used to calculate relative TL (rTL). Regression models were used to assess the relationships between rTL and PSS-I and AAS scores. Network analyses using EBIC glasso methods were performed using rTL and items from each of the AAS and PSS-I measures. Both PSS-I (p = 0.023) and AAS (p = 0.016) scores were positively associated with rTL. Network analyses indicated that rTL was weakly related to two PSS-I and five AAS items but performed poorly on indicators of centrality and was not strongly associated with measure items either directly or indirectly. The positive association between rTL and measures of AA and PTSD may be due to the induction of protective homeostatic mechanisms, which reduce TL attrition, following early life trauma exposure.

DNA methylation and psychotherapy response in trauma-exposed men with appetitive aggression.

Exposure to violence can lead to appetitive aggression (AA), the positive feeling and fascination associated with violence, and posttraumatic stress disorder (PTSD), characterised by hyperarousal, reexperience and feelings of ongoing threat. Psychotherapeutic interventions may act via DNA methylation, an environmentally sensitive epigenetic mechanism that can influence gene expression. We investigated epigenetic signatures of psychotherapy for PTSD and AA symptoms in South African men with chronic trauma exposure. Participants were assigned to one of three groups: narrative exposure therapy for forensic offender rehabilitation (FORNET), cognitive behavioural therapy or waiting list control (n = 9-10/group). Participants provided saliva and completed the Appetitive Aggression Scale and PTSD Symptom Severity Index at baseline, 8-month and 16-month follow-up. The relationship, over time, between methylation in 22 gene promoter region sites, symptom scores, and treatment was assessed using linear mixed models. Compared to baseline, PTSD and AA symptom severity were significantly reduced at 8 and 16 months, respectively, in the FORNET group. Increased methylation of genes implicated in dopaminergic neurotransmission (NR4A2) and synaptic plasticity (AUTS2) was associated with reduced PTSD symptom severity in participants receiving FORNET. Analyses across participants revealed a proportional relationship between AA and methylation of TFAM, a gene involved in mitochondrial biosynthesis.