RESUMO
BACKGROUND AND OBJECTIVES: Individuals with low concreteness-experiential thought (CET) tend to have exacerbated depressive symptoms. Interventions aimed at increasing CET have been shown to influence depressive symptoms. The present study examined the effects of increasing CET on depressive symptoms and its protective factors. METHODS: A two-armed experimental intervention was conducted with 86 healthy university students in Japan. They were randomly allocated to the intervention and waitlist groups. Participants in the intervention group engaged in an unguided and web-based (UW) intervention to increase CET (UW-CET). This intervention included a one-off session, to explain the rationale behind increasing CET via a psychoeducation video, and a five-session training on CET over a week. We assessed depressive symptoms, thought styles, and protective factors, such as mindfulness and goal striving, both pre- and-post-assessment and at the one-month follow-up. RESULTS: Participants in the intervention group had marginally increased CET in the follow-up assessments; however, participants in the waitlist group did not. Furthermore, participants in the intervention showed marginally increased mindfulness tendencies and strivings toward their personal goals, but their depressive symptoms were not affected. LIMITATIONS: The present study did not include any active control conditions. Additionally, the sample consisted of only healthy university students. CONCLUSIONS: The findings suggest that the UW-CET can marginally increase adaptive thinking, such as CET, and promote positive psychological aspects in healthy young adults; however, the effect is small. The findings may also help expand clinical implementations to prevent depression in young adults.