S80
Clinical neuropsychopharmacology
P.4.015 Long term therapy with methylphenidate induces modest effects on growth in ADHD children C. Balia1 ° , A. Anedda1 , F. Granitzio1 , S. Carucci1 , A. Zuddas1 . 1 Cagliari University Hospital, Dept Biomedical Science, Cagliari, Italy Background: Although stimulants are the most effective medication for Attention Deficit Hyperactivity Disorder (ADHD), poor growth is a common concern, especially with children already on the lower growth percentiles. Studies providing longitudinal data indicate a reduction in both height and weight gain: these effects are usually minimal, but there is substantial variability with some children completely unaffected, whereas others shows significant growth suppression [1]. Objectives: To evaluate whether long term immediate release methylphenidate (IR-MPH) therapy (one or two years) interferes with the growth of ADHD children and to assess whether the effects on growth are related to the length of the treatment or to the daily dose. Methods: Growth parameters were collected from 90 ADHD aged 6 to 14, enrolled at one of the site of the Italian National Register for ADHD. All patient were on IR-MPH and with a minimum follow-up of 12 months. 65 were Drug Na¨ıve (DN), 25 were already on MPH since 1−3 years prior to enrollment in the Registry (PR). Weight, height, BMI, height Z-score and BMI Z-score were recorded at each follow-up visit (baseline and after 6, 12, 18, 24 months). Growth velocity SDS and height deficit were calculated after 12 and 24 months. Data Analysis: Categorical data were analysed using contingency tables (c2 ), continuous variables were compared by one-way ANOVA. Repeated measures ANOVA was performed for height and BMI z scores at baseline, 6, 12, 18, 24 month follow up and for height velocity SDS at 12 and 24 months. Results: At baseline Height Z-scores of the entire sample was −0.33±0.98, BMI Z-score was equal to 0.19±1.14. During the 24 months in the study, subjects gained in absolute values of height and weight. Height Z-score showed a significant decrease only from T12 to T24 (p = 0.05). BMI Z-score decreased significantly at T12 (p < 0.001) remaining essentially unchanged at T24. Height deficit was about 0.5 cm at 12 months and 1.3 cm after 24 months. MPH dose/kg/day changed from 0.49±0.21 mg when starting medication, to 0.68±0.24 at T12 and to 0.75±0.25 at T24. No significant differences were found on growth parameters at baseline when stratifying between DN and PR. As in the total sample, in both groups a significant decrease in BMI Z-score from baseline to T12 (p < 0.001) and in height Z-score between
T12 and T2 (p = 0.05) was found. No changes in growth velocity from baseline to the different times considered, were observed, neither in DN nor in PR. Discussion: The findings of the present study suggest that the effects of MPH on growth are relatively small and unlikely to be of clinical concern for this population. Expected and actual deficit in growth should be considered in the context of the benefits the patient receives from the medication. In the present sample the height deficit appears to be more related to the maximum pro/die dose rather than to the length of therapy. More research is needed to better elucidate the mechanism of growth suppression and to implement specific treatment strategies for ADHD children. Reference(s) [1] Pliszka, S.R., Matthews, T.L., Braslow, K.J., Watson, M.A., 2006. Comparative Effects of Methylphenidate and Mixed Salts Amphetamine on Height and Weight in Children With Attention-Deficit/ Hyperactivity Disorder. J Am Acad Child Adolesc Psychiatry 45, 520–526. P.4.016 Regional differences of SERT occupancy in major depression: an in vivo PET study using [11 C]DASB P. Baldinger1 ° , G.S. Kranz1 , M. Savli1 , W. Wadsak2 , D. Haeusler2 , A. Hahn1 , M. Mitterhauser2 , C. Philippe2 , S. Kasper1 , R. Lanzenberger1 . 1 Medical University of Vienna, Dept of Psychiatry and Psychotherapy, Vienna, Austria; 2 Medical University of Vienna, Dept of Nuclear Medicine − PET Center, Vienna, Austria Objective: The blockage of serotonin transporters (SERT) responsible for serotonin reuptake from the synaptic cleft into the presynaptic neuron is the primary mechanism of action of selective serotonin reuptake inhibitors (SSRIs). One might assume that the selective affinity of an SSRI for SERT and hereby its antidepressant effectiveness might be similar throughout the brain. However, SERT activity mediated via various factors may differ between regions as SERT is a priori not equally distributed in the brain. Furthermore, as SERT internalisation process and thereby its availability in a distinct area depends on its activity, SERT occupancy by an SSRI might equally vary throughout the brain [1]. Here, we investigated whether SERT occupancy by escitalopram/citalopram is equally distributed in brain areas known to play a role in major depression using positron emission tomography (PET). Methods: 19 outpatients (13 females; age 42.3±7.8 years (mean±SD)) suffering from major depressive disorder (17-item HAMD 16, no pharmacological