PS105. Effects of CYP2C19 genotype on steady-state plasma concentrations of escitalopram and desmetyl metabolite in Japanese depressed patients

Objectives: Previous studies have reported associations between Temperament and Character Inventory (TCI) and the response to treatment in patients with major depressive disorder (MDD). We aimed to determine which TCI items could predict the response to treatment with paroxetine in patients with MDD and to provide cut-off values of the scores from these items. Methods: Seventy-three patients were enrolled in this study. Participants completed the TCI and were treated with paroxetine for six weeks. The Montgomery-Asberg Depression Rating Scale (MADRS) was used to evaluate depression. Participants were divided into responders and non-responders. We used a chi-squared test to identify the 10 items with the strongest association with treatment response from among all 240 items on the TCI. We rated the answers to each item associated with treatment response as a “1”, and the answers associated with a non-response were rated as a “0”. We calculated predictive scores using 10 models. Each model consisted of 1–10 scores of the best 1–10 items. We defined cut-off values for predicting treatment responses using a receiver operating characteristic (ROC) curve analysis. Results: Ranked by the strength of the association with treatment response, items 174, 137, 70, 237, 106, 191, 34, 232, 161, and 215 significantly predicted treatment responses. All the models significantly predicted treatment response using a multiple logistic regression analysis. All predictive scores from models 1–10 significantly predicted treatment responses. The predictive score threshold of model 7 was 3/4 with an area under the curve of 0.825, and it showed the highest odds and likelihood ratios (19.3 and 8.86, respectively). Conclusions: Some TCI items showed significant associations with the response to paroxetine treatment in the patients with MDD. We might predict the response using TCI predictive scoring, including items 174, 137, 70, 237, 106, 191, and 34 and a cutoff value of 3/4. PS105 Effects of CYP2C19 genotype on steady-state plasma concentrations of escitalopram and desmetyl metabolite in Japanese depressed patients Shoko Tsuchimine1, Yoshimasa Inoue1, Shinichiro Ochi2, Yutaro Suzuki3, Misuzu Tajiri3, Norio Yasui-Furukori1 1Hirosaki University, Japan, 2Ehime University, Japan, 3Niigata