TY - JOUR T1 - The Effectiveness Of Child-Centered Play Therapy In Aggression Of Children With Oppositional Defiant Disorder TT - JF - intjmi JO - intjmi VL - 10 IS - 4 UR - http://intjmi.com/article-1-718-en.html Y1 - 2021 SP - 83 EP - 93 KW - Play Therapy KW - Child-Centered Play Therapy KW - Aggression KW - Oppositional Defiant Disorder KW - Single-Subject. N2 - Background: The present paper was conducted with the purpose of determining the effect of play therapy with a child-centered approach on reducing the level of aggression in children with oppositional defiant disorder. Method: This study focused on the aggression of 3 children with oppositional defiant disorder and the selected sample was randomly obtained from preschools in Hamadan after direct observation of the child and matching the symptoms of this disorder with those mentioned in DSM-5 by an expert with PhD degree in clinical psychology. The level of aggression was obtained using Aggression Scale for Preschoolers developed by Vahedi, Fathi Azar, Hosseininasab, and Moghadam (2008) which contains 43 questions and measures aggression from different aspects. The statistical method used in this study is a single-subject multiple baseline design using one behavior of the individual in different situations and involves simultaneous observation (two baselines or more) in experimental situations; the situations observed in this study included in classroom situation, during break time and snack time and when having interaction with classmates and the teacher. The child-centered play therapy was conducted according to the principles of Axline theory (1929) in twelve 45-minute sessions. Visual inspection, recovery rate and Cohen’s effect size formula were used for data analysis. Result: The data analysis indicated a significant reduction in aggression symptoms in oppositional disobedience disorder. Conclusion: Therefore, child-centered play therapy was found to be effective in improving the symptoms of aggression in oppositional disobedience disorder and therapists can use this method to help these people. M3 ER -