The evaluation of serum BDNF levels in adolescents with bipolar disorder type I

Purpose: The aim of the present study is to investigate whether the variables of the disorder effect serum BDNF levels in the adolescents with Bipolar Disorder type I and to compare the possible serum BDNF level changes with healthy adolescents.Method: Twenty five adolescents aged between 15 and 19 with Bipolar Disorder type I according to DSM-IV criteria that either already been followed up or got the diagnosis after their admission to Dokuz Eylül University, Department of Child and Adolescent Psychiatry between June 2008 and June 2009 were included in the study. The diagnosis of all cases was established using K-SADS P-L and affective module of WASH-U-K-SADS. Seventeen adolescents between 15 and 19 years old and without any psychiatric diagnosis were included in the healthy control group selected from epidemiologic catchment area of the university. BDNF serum levels were measured with sandwich-ELİSA, using a commercial kit according to the manufacturer?s instructions (Millipore,ChemiKine,CYT306.) The blood samples were taken during euthymic phase. The phase of euthymia was defined according to YMRS (Young Mania Rating Scale) and HAM-D (Hamilton Depression Rating Scale) and the scores below 7 were considered as euthymia in both scales.Findings: The evaluation and comparison of BDNF serum levels between the patient and the control group revealed no significant difference. In the patient group, the patients treated with Li, had significant lower BDNF levels than the others.Result: Normal BDNF serum levels we found in euthymic state in adolescents and early adulthood, similar to normal BDNF levels in adult BB samples, may be related to developmental level and age range of our study group, but it may also show a common neurobiological basis of pediatric and adult bipolar disorder. Further investigations evoluating BDNF levels in early stages of pediatic bipolar disorder in different mood states and BDNF level changes in different developmental stages will help to identify the underlying pathophysiology of early-onset and late-onset bipolar disorder and the role of BDNF in this pathophysiology and in brain development.