Introduction: Adolescence is undoubtedly one of the most important and critical periods of human life. The results of several studies indicate that suicidal ideation is increasing among adolescents across the world, and it is certainly important to reduce suicidal ideation and other related traumas. Therefore, the purpose of this study was to investigate the effect of
negative mood control training skills on suicidal thoughts, anxiety, and depression in high school female students in Ilam, Iran, during 2018. Materials & Methods: This quasiexperimental
study was conducted based on a pretest-posttest design with a control group. The study population consisted of all female high school students in Ilam, Iran. This study included 60 female students who were selected using a multistage cluster sampling method and the Morgan table. Subsequently, the participants were divided into two groups of experimental and control (30 students per group). The data were collected using the Beck Depression Inventory, Cattell Anxiety Scale, and Maria Kovacs Depression Inventory. Furthermore, the data were analyzed in SPSS software (version 22) through the analysis of covariance (ANCOVA). Ethics code: IR.MEDILAM.REE.1394.126 Findings: The results of ANCOVA showed that negative mood control training skills had a positive and significant effect on reducing suicidal ideation (P=0.000), anxiety (P=0.025), and depression (P=0.034). Discussion & Conclusions: Based on the results of this study, negative mood control training skills reduced the level of suicidal ideation, anxiety, and depression in students

Keywords: Anxiety, Negative mood control skill, Stress, Suicidal ideation