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Papers by sevay alşen

Bulletin of Clinical Psychopharmacology, 2015

Plasma norepinephrine and dopamine levels in prepubertal male children with attention-deficit hyp... more Plasma norepinephrine and dopamine levels in prepubertal male children with attention-deficit hyperactivity disorder do not change with 8 weeks of methylphenidate treatment Objectives: The aim of this study was to determine plasma norepinephrine and dopamine levels at baseline and after 8 weeks of stimulant treatment in pre-pubertal male children with ADHD. Methods: The study group consisted of 50 children (6-12 years old) diagnosed with ADHD. The control group comprised students from a primary school within the epidemiological catchment area of the clinic and was matched for class and age to the ADHD patients. The Kiddie Schedule for Affective Disorders and Schizophrenia for School Aged Children-Present and Lifetime Version (K-SADS-PL) was used to diagnose ADHD and allowed comorbidities. Mental retardation was ruled out with the Wechsler Intelligence Scale for Children-Revised (WISC-R) and impaired functioning. We evaluated disorder severity at the time of assessment using the Clinic Global Impression Scale (CGI). The DuPaul ADHD Rating Scale-IV (ARS) was also used. All patients were treatment-naive. The parents were advised to use OROS methylphenidate daily with no drug holidays during weekends. No rescue medications (immediate-release methylphenidate) were allowed. The dose started at 18 mg and was titrated to 54 mg in 4 weeks to yield average doses of 1 mg/kg/ day. Baseline and endpoint plasma DA and NE were measured. Results: Baseline plasma NE and DA levels had no statistically significant differences between ADHD patients `and controls (232.0±67.3 versus 232.2±65.3 pg/mL and 169.3±48.4 versus 186.9±40.5 pg/mL). Plasma NE levels in all ADHD subgroups decreased with 8 weeks of stimulant treatment, while changes in DA levels were more complex. Plasma DA levels decreased with treatment in the ADHD-inattentive subgroup but were elevated in the hyperactive/impulsive and combined subgroups. There were no statistically significant differences between ADHD subgroups for these variables. Endpoint NE levels were correlated with endpoint DA levels. There were no statistically significant differences between ADHD subgroups. Plasma NE levels were not related to symptom severity or treatment response. In contrast, baseline DA levels were negatively correlated with ARS total scores. Conclusions: We found no statistically significant differences between plasma levels of NE and DA in a prepubertal male sample with ADHD and controls. Plasma DA and NE levels were correlated at both baseline and the endpoint. Although there was a signal that baseline DA levels may correlate with ADHD symptoms as evaluated via ARS, this was not true for endpoint analyses. Because this negative correlation disappeared after treatment, this finding about baseline DA levels may also be evaluated as an early treatment neuromarker. The negative results could also be explained by our focus on plasma. The recent consensus is that urinary levels of NE and DA may be more informative in patients with ADHD and that concurrent evaluation of multiple neurotransmitter systems (i.e., neuropeptide Y and NE) may be more informative. Further studies may benefit from concurrent measurements of plasma and urinary levels of catecholamines and their metabolites.

Journal of Affective Disorders, 2015

Background:The amygdala is repeatedly implicated as a critical component of the neurocircuitry re... more Background:The amygdala is repeatedly implicated as a critical component of the neurocircuitry regulating emotional valence.Studies have frequently reported reduced amygdala volumes in children and adolescents with bipolar disorder (BD).Brain derived neurotrophic factor (BDNF) and nerve growth factor (NGF) play critical roles in growth, differentiation, maintenance, and synaptic plasticity of neuronal systems in adolescent brain development. The aim of the present study was to assess amygdala volumesand its correlation with serum levels of NGF and BDNF in euthymic adolescents with BD and healthy controls. Methods:Using structural MRI, we compared the amygdala volumes of 30 euthymic subjects with BD with 23 healthy control subjects aged between 13 and 19 yearsduring a naturalistic clinical follow-up. The boundaries of the amygdala were outlined manually.Serum BDNF and NGF levels were measured using sandwich-ELISA and compared between the study groups. Results:The right or left amygdala volume did not differ between the study groups.The right and left amygdala volumes were highly correlated with levels of BDNF in the combined BD group and the valproate-treated group.Both R and L amygdala volumes were correlated with BDNF levels in healthy controls. The left amygdala volumes were correlated with BDNF levels in the lithium-treated group. Limitations:This cross-sectional study cannot inform longitudinal changes in brain structure. Further studies with larger sample sizes are needed to improve reliability. Conclusions: The correlations between amygdala volumes and BDNF levels might be an early neuromarker for diagnosis and/or treatment response in adolescents with BD.

Journal of affective disorders, 2012

BACKGROUND: Structural neuroimaging studies in bipolar disorder (BD) have consistently identified... more BACKGROUND: Structural neuroimaging studies in bipolar disorder (BD) have consistently identified several anatomical abnormalities in many brain areas related to mood regulation. Hippocampus is one of the key components of emotional regulatory networks in the brain. Evidence about hippocampal changes in BD is quite limited and inconsistent particularly for adolescent onset BD. It is aimed to compare hippocampus volumes of euthymic BD-I adolescents with healthy controls using structural MRI. METHODS: Hippocampal volumes of seventeen youths between 13 and 19 age period with DSM-IV BD (seven boys) and twelve healthy comparison subjects (five boys) were compared using structural MRI. Differences in hippocampal volumes between groups were tested. RESULTS: There was no significant difference between the right and left hippocampus volumes of patients with BD and the control group. However boys tended to have significantly larger right hippocampal volumes than girls both in BD and control g...

Turkish journal of emergency medicine, 2006

Attention deficit/hyperactivity disorder is one of the most common neurodevelopmental disorders. ... more Attention deficit/hyperactivity disorder is one of the most common neurodevelopmental
disorders. The pathophysiology is thought to involve noradrenaline and dopamine. The
role of dopamine transporter (DAT) was evaluated in imaging studies using mostly dopamine
reuptake inhibitors. Atomoxetine is a selective noradrenaline reuptake inhibitor. Here we report
the results of a pilot study conducted to evaluate changes in striatal DAT after 8 weeks of
atomoxetine treatment. Our results suggest that 8 weeks of atomoxetine treatment may change
striatal DAT bioavailability as measured via SPECT but that change was not correlated with
genotype or clinical improvement.