Positive interventions (PIs) that are based on the theory of positive psychology have proven to be effective in improving well-being and alleviating depression. However, little research has explored the effect of dosing intervals on experimental effects. As such, this study designed strength-based PIs using cognitive reframing theory and compared flexible and fixed dosing intervals to find out which one could more effectively reduce depression with equal total amounts of dosing. The 8-item Center for Epidemiological Studies Depression Scale (8-item CES-D) and the Positive reframing scale (PRS) were adopted as research instruments. A total of 193 Taiwanese college students were recruited as the research sample and they were randomly assigned to experimental Group A (fixed dosing intervals), experimental Group B (flexible dosing intervals), and the Control Group. The research participants received 17-day interventions with follow-up tests administered in the seventh week of the experiment. Ultimately, 157 participants completed the experiment. According to the ANCOVA results, participants in experimental Group A showed significantly lower degrees of depression than those in the Control Group in both post-test and follow-up stages and displayed greater effect size in the follow-up stage than in the post-test stage. The results indicated that the design of fixed dosing intervals enabled the participants to effectively integrate reflections on reframing learned during PIs into their life. On the contrary, participants in experimental Group B exhibited no significant difference in the degree of depression from those in the Control Group during either the post-test or follow-up stage and manifested poorer effects in the follow-up stage than in the post-test stage. These results demonstrated that fixed dosing intervals achieved better effects than flexible dosing intervals. Participants receiving fixed dosing intervals could more effectively execute cognitive reframing and showed longer-lasting experimental effects, whereas participants using the design of flexible dosing intervals were more prone to forget to implement PIs and attain less positive effects as a result.
Keywords: depression; intervention dosing; positive interventions; positive psychology.