<![CDATA[Background: Adolescents are a vulnerable age group prone to psychological disorders, one of which is anxiety. Borderline Personality Disorder (BPD) is characterized by emotional instability and interpersonal difficulties that can trigger anxiety. On the other hand, peer support is considered to play an important role in maintaining adolescents’ emotional balance Purpose: This study aimed to determine the relationship between Borderline Personality Disorder (BPD) and peer support with anxiety levels among adolescents at one of senior high school at Lamongan. Methods: This research used a quantitative design with a cross-sectional approach. The sample consisted of 116 twelfth-grade students which was selected through simple random sampling. Instruments used were the BSL-23 questionnaire to measure BPD, a peer support questionnaire, and the HARS scale to measure anxiety. Data were analyzed using Spearman Rank correlation test with SPSS version 22. Result: The results showed that most respondents were in the moderate category of Borderline Personality Disorder (52.6%) and peer support (50.9%), while anxiety was mostly in the severe category (44.0%). There was a significant correlation between Borderline Personality Disorder and anxiety (r = 0.759, p = 0.000). However, no significant correlation was found between peer support and anxiety (r = 0.081, p = 0.390). Implication: The findings indicate that Borderline Personality Disorder is significantly associated with anxiety among adolescents, highlighting the need for psychological interventions to prevent anxiety. Although peer support was not statistically significant, it remains an important factor in maintaining adolescents’ emotional balance. Keywords: Adolescents; Anxiety; Borderline personality disorder; Peer support]]>
