Adolescence is a critical developmental period where many biological, psychological, and social changes occur simultaneously. These changes can significantly influence adolescents' behavior in later developmental stages, either positively or negatively. Individual Psychology-based group programs and psycho-education practices are well-suited to youth because of their development-oriented and positive approach to human nature. This study investigates the effect of the Social Interest Development Psycho-Education Program on social interest in adolescents. The study adopts a 2x3 mixed experiment model and employs pre-test, post-test, and follow-up measurements via the Social Interest Scale for Adolescents. The researcher conducted the psycho-education program for the experimental group in ten 60-minute sessions and did not intervene in the control group. "Wilcoxon Signed Ranks Test" and "Mann-Whitney U" were used for data analysis. According to the results, a psycho-education program applied to the experimental group increased total social interest. We determined a significant difference between the experimental and the control groups regarding the whole social interest and belonging according to the post-test scores of the students. Social Interest Development Psycho-educational program resulted in improvements in belonging, sensitivity, and help thanks to program implementation. The findings indicate that the Social Interest Development Psycho-educational program is an effective program for developing the total social interest levels of adolescents. In the follow-up test, it was observed that this change continued for the belonging sub-dimension, while the change in the level of social interest was not permanent.

Keywords: Individual psychology, Social interest, Psycho-education program, Adolescents, Experimental method