Response to Fluvoxamine in the Obsessive-Compulsive Disorder Patients: Bayesian OrdinalQuantile RegressionSoheila Khodakarim1*, Samad Safiloo2, Yadollah Mehrabi3, Sareh Asadi41Department of Medical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran 2 Department ofMedical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran 3 Department of Public Health andSafety, Shahid Beheshti University of Medical Sciences, Tehran, Iran 4 Department of Neurobiology Research Center,Shahid Beheshti University of Medical Sciences, Tehran, IranCorresponding author: Khodakarim S,Department of Medical Sciences, ShahidBeheshti University of Medical Sciences,Tehran, Iran, E-mail: [email protected]: Aim of study is identifying the predictors of fluvoxaminetherapyin OCD patients. Obsessive-Compulsive Disorder (OCD) is a chronicneuropsychiatric disorder associated with unpleasant thoughts or mentalimages making the patient repeat physical or mental behaviors to relievediscomfort. 40-60% of patients do not respond to Serotonin ReuptakeInhibitors, including fluvoxamine therapy. Here, we identify the predictorsof fluvoxamine therapy in OCD patients by Bayesian Ordinal QuantileRegression Model.Design/methodology/approach: This study was performed on 109 patientswith OCD. Three methods including bayesian ordinal quantile, probit andlogistic regression models were applied to identify predictors of response tofluvoxamine. The accuracy and weighted kappa were used to evaluate thesemodels.Findings: Our result showed that rs3780413 (mean=-0.69, sd=0.39) andcleaning dimension (mean=-0.61, sd=0.20) had reverse effects on response tofluvoxamine therapy in bayesian ordinal probit and logistic regressionmodels. In the 75th quantile regression model, marital status (mean=1.62,sd=0.47) and family history (mean=1.33, sd=0.61) had a direct effect, andcleaning (mean=-1.10, sd=0.37) and somatic (mean=-0.58, sd=0.27)dimensions had reverse effects on response to fluvoxamine therapy.Originality/value: Response to fluvoxamine is a multifactorial problem andcan be different in the levels of socio-demographic, genetic and clinicalpredictors. Marital status, familial history, cleaning and somatic dimensionsassociated with response to fluvoxamine therapy.