Investigation of Serum Brain Derived Neurotrophic Factor Levels in Children and Adolescents Aged 12 to 18 Years with Depressive Disorder

Abstract

Objective: It has been suggested that the neuroplastic processis associated with the pathogenesis of psychiatric disorders including depressive disorder. It is thought that brain derived neurotrophic factor (BDNF) is an important factor in neuroplasticity in depressive disorder. BDNF is play an important role in survival of neurons, synaptic plasticity, formation of synaptic connections and neurodevelopment. Insulin like growth factor-1 (IGF-1) is found in various areas of the brain. IGF-1 is involved in brain growth, development and mylination, also in brain plasticity. IGF-1 affect the genesis of neurons, astrocytes, oligodendrocytes and endothelial cells. In this study we aimed to evaluate serum levels of BDNF and IGF-1, which is also accepted as a neurotrophic factor, in children and adolescents between 12-18 years with depressive disorder. Methods: The patient group was composed of 35 subjects (26 females; 9 male), while the control group was composed of 22 subjects (14 females; 8 male). Sociodemographic form, Kovac’s depression scale, and state-trait anxiety inventory were applied to all subjects. Serum BDNF and IGF-1 levels were measured with ELISA. Moreover complete blood count, biochemical tests, thyroid and sex hormones were tested.Results: There was no significant difference between the patient group and the control group in terms of the BDNF and IGF-1 levels (respectively p values 0.547 and 0.968). When the groups divided into female and male subgroups, statistically significant differences were not found again. Moreover age, gender, menstrual states, suicide attempts, suicide thoughts, smoking and Body Mass Index had no effects on the BDNF. There was also no effects on IGF-1 levels, except age. There was negative correlation between age and IGF-1 in all subjects.Conclusion: The results of this study do not support the association of depressive disorder with changes in serum BDNF and IGF-1 levels in children and adolescents. But larger prospective studies are needed to show better the effects of these factors.