INTRODUCTION: Cortisol levels decrease or show no change in PTSD, although there are some exceptional cases. In the model proposed by Yehuda, PTSD was associated with increased adrenergic response and/or lack of a sufficient amount of cortisol in the circulation following trauma. In general, studies conducted on patients with PTSD have found lower BDNF levels compared to the control groups. A study of patients with PTSD and healthy controls who did not have a history of trauma found lower BDNF levels in patients with PTSD1 . Another study compared BDNF levels between patients with or without PTSD after trauma and reported lower BDNF levels in patients with PTSD2 . To our knowledge, there are no studies in the literature that evaluated cortisol and BDNF levels in adolescent and child victims of sexual abuse. The aim of the present study was to compare BDNF, cortisol, and ACTH levels in a special group of patients comprised of children and adolescent patients with or without PTSD after experiencing sexual assault, which is a catastrophic form of trauma.
METHOD:
Study Sample: The study was conducted in the Department of Child Psychiatry at Dicle University. The study data were collected between January 2013 and May 2013. The study included 55 children aged between 6 and 17 years, 13 of which were males and 42 were females. The patients were divided into two groups, with or without PTSD, based on the results of a structured psychiatric interview. Children who had mental retardation, history of head trauma, and those who received oral contraceptives, previous or current cortisol therapy or vitamins, and patients who had morbid obesity, chronic systemic disorders, and active infection were excluded in order to prevent interference with biochemical parameters. Two psychiatrists evaluated the patients, and parents provided informed consent in order for their children to participate in the study. Approval was obtained for the study from the Non-Interventional Clinical Research Ethics Committee at Dicle University Faculty of Medicine. Study Procedures: Sociodemographic features of the participants were obtained and a clinical data form was completed. This was followed by a structured psychiatric interview (K-SADS-PL and CAPS-CA) and administration of the self-reported Children’s Depression Inventory (CDI). Finally, a 2 ml venous blood sample was obtained for biochemical tests. Scales: Affective Disorders and Schizophrenia for School Age Children-Present and Lifetime Version (K-SADS-PL): The schedule (K-SADSPL) was originally developed by Kaufman et al. It was adapted to the Turkish language by Gökler et al. in 2004. K-SADS-PL is administered during an interview with the parents and children, and the final evaluation is performed using input from all data sources. Clinician-Administered Post-Traumatic Stress Disorder Scale for Children and Adolescents (CAPS-CA): CAPS-CA is a semi-structured interview developed to evaluate the frequency and severity of present and past PTSD in children and adolescents according to DSM-III and DSM-4 diagnostic criteria. It was adapted from the Clinician-Administered Post-Traumatic Stress Disorder Scale (CAPS) by Nader et al. in 1996. The scale evaluates 17 symptoms of post-traumatic stress disorder based on DSM-4 and eight tables related to PTSD. It was adapted to the Turkish language by Karakaya et al. in 2007. The Children’s Depression Inventory (CDI): The Children’s Depression Inventory developed by Kovacs based on the Beck Depression scale was used in this study. However, questions specific to the childhood period such as school success and relationship with friends were added. The scale was adapted to the Turkish language by Öy and contains 27 items: Each item is scored as 0, 1, or 2 points depending on the severity of the symptom. Biochemical Analysis: Blood samples were obtained in the morning between 10:00 and 12:00 am. Cortisol, ACTH, and BDNF levels were evaluated using ELISA method and ready-to-use ELISA kits. Statistical Analysis: The statistical analysis was performed using SPSS 15.0 software package. A p-value below 0.05 was considered statistically significant.
RESULTS: The mean age was 14.16±2.62 years (range: 6-17 years) among the victims of sexual abuse. Of these victims, 27 (49%) were diagnosed with PTSD. There was no significant difference between patients with or without PTSD in terms of gender, place of living, school success, employment status of the parents, smoking, and menstrual cycle for adolescents. Regarding the parameters related to sexual abuse, 60% (n=33) of the victims experienced sexual abuse involving penetration. Of the victims, 56% (n=31) experienced a single incident of assault and 44% (n=24) experienced multiple assaults. Of the victims, 24% (n=13) experienced sexual abuse within the family (incestuous) and 76% (n=42) experienced sexual abuse committed by non-related persons. There was no significant difference between patients with or without PTSD in terms of relationship with the abuse and presence of penetration (p=0.30 and p=0.70, respectively). However, the rate of PTSD was higher in patients who experienced multiple sexual assaults compared to the victims of a single assault (p<0.001). There was no significant difference between patients with or without PTSD in terms of cortisol, ACTH, and BDNF levels. Likewise, there was no significant difference between patients with or without depression in terms of cortisol, ACTH, and BDNF levels. There were no correlations between CAPS scores and cortisol, ACTH, and BDNF levels between patients with or without PTSD. The mean time that had elapsed since the first sexual abuse until the date of examination was 21.5±22.4 months (3-110 months). In the PTSD group, cortisol levels decreased with increasing time after trauma, and there was no significant correlation with the cortisol levels in patients without PTSD (r=-0.46, p=0.01 and r=-0.07, p=0.73, respectively). There was no correlation between time that had elapsed since trauma and BDNF levels.
DISCUSSION: In the current study, the presence of PTSD had no influence on cortisol and ACTH levels in children who had experienced sexual abuse, and cortisol levels decreased with increasing time after trauma in the PTSD group. The studies conducted on patients with PTSD often reported increased levels of CRH in the CSF and a decrease or no change in cortisol levels. Plasma, saliva, and urinary cortisol and plasma ACTH levels were found to be similar between patients with or without PTSD after trauma. Plasma cortisol levels decreased in the two groups, and it was reported that cortisol levels did not predict the development of PTSD. There are findings suggesting that low cortisol levels after exposure to trauma might have increased the risk of developing PTSD. There are also studies suggesting that no relationship between cortisol levels and the development of PTSD exists. In the present study, cortisol levels decreased as the time elapsed since the trauma increased in the PTSD group. It is therefore assumed that these individuals will have lower than normal cortisol levels in adulthood. In the present study, presence of PTSD had no effect on BDNF levels in child victims of sexual abuse, and there was no correlation between BDNF levels and the time that had elapsed since the trauma. In general, studies conducted on patients with PTSD have found lower BDNF levels compared to the control group1,2. BDNF levels were compared between patients with or without PTSD after trauma, and BDNF levels were lower in patients with PTSD (2). In the study by Hauck et al., serum BDNF levels were higher in patients who experienced sexual assault in the last one year compared to the control group; however, BDNF levels did not differ significantly among those who experienced trauma beyond the last one year3 . In conclusion, there was no significant difference between children and adolescents with or without PTSD in terms of cortisol, ACTH, and BDNF levels. However, the decrease in cortisol levels with increasing time after trauma in PTSD group points to the possible role of cortisol in the pathophysiology of the disease. Longitudinal studies on a larger sample are required in order to confirm the findings of the current study that was conducted in children and adolescent patients.