Background Depression impacts the lives of a large number of university students. Mobile-based therapy chatbots are increasingly being used to help young adults who suffer from depression. However, previous trials have short follow-up periods. Evidence of effectiveness in pragmatic conditions are still in lack. Objective This study aimed to compare chatbot therapy to bibliotherapy, which is a widely accepted and proven-useful self-help psychological intervention. The main objective of this study is to add to the evidence of effectiveness for chatbot therapy as a convenient, affordable, interactive self-help intervention for depression. Methods An unblinded randomized controlled trial with 83 university students was conducted. The participants were randomly assigned to either a chatbot test group (n = 41) to receive a newly developed chatbot-delivered intervention, or a bibliotherapy control group (n = 42) to receive a minimal level of bibliotherapy. A set of questionnaires was implemented as measurements of clinical variables at baseline and every 4 weeks for a period of 16 weeks, which included the Patient Health Questionnaire-9 (PHQ-9), the Generalized Anxiety Disorder scale (GAD-7), the Positive and Negative Affect Scale (PANAS). The Client Satisfaction Questionnaire-8 (CSQ-8) and the Working Alliance Inventory-Short Revised (WAI-SR) were used to measure satisfaction and therapeutic alliance after the intervention. Participants' self-reported adherence and feedback on the therapy chatbot were also collected. Results Participants were all university students (undergraduate students (n = 31), postgraduate students (n = 52)). They were between 19 and 28 years old (mean = 23.08, standard deviation (SD) = 1.76) and 55.42% (46/83) female. 24.07% (20/83) participants were lost to follow-up. No significant group difference was found at baseline. In the intention-to-treat analysis, individuals in the chatbot test group showed a significant reduction in the PHQ-9 scores (F = 22.89; P < 0.01) and the GAD-7 scores (F = 5.37; P = 0.02). Follow-up analysis of completers suggested that the reduction of anxiety was significant only in the first 4 weeks. The WAI-SR scores in the chatbot group were higher compared to the bibliotherapy group ( t = 7.29; P < 0.01). User feedback showed that process factors were more influential than the content factors. Conclusions The chatbot-delivered self-help depression intervention was proven to be superior to the minimal level of bibliotherapy in terms of reduction on depression, anxiety, and therapeutic alliance achieved with participants.

To probe the motivational roles of hedonic gratification and social gratification in giving “Like” feedback on social media, we developed a set of novel pictures to simulate WeChat Moments. We subsequently examined how the personality trait of extraversion and stimulus content characteristics (e.g., emotional valence, personal relevance) influenced “Liking” behavior. A 2 (extraversion: extrovert group vs. introvert group) × 3 (emotional valence: positive vs. neutral vs. negative) × 2 (personal relevance: personally relevant vs. personally irrelevant)-mixed experimental design was applied to data obtained from 56 WeChat Moments users. These participants included 28 individuals with the highest extraversion scale scores (the extrovert group), and 28 individuals with the lowest extraversion scale scores (the introvert group), according to the NEO Five-Factor Inventory. Briefly, participants observed pictures on an interface similar to that of WeChat Moments and were given the option to “Like” each picture. “Like” rates and response time were then compared across groups and conditions by applying a mixed-design analysis of variance. Pearson's correlation coefficients were calculated to explore relationships between the “Like” rates under each condition and the scores for each personality trait. Compared with the neutral pictures, the positive and negative pictures were “Liked” more and less frequently, respectively (F2, 108 = 46.22, p &lt; 0.001). Compared with the poster-unrelated pictures, the personally related pictures were “Liked” more frequently (F1, 54 = 19.54, p &lt; 0.001). In the extrovert group, the frequency of “Likes” given to unrelated negative content positively associated with neuroticism (r = 0.42, p = 0.025) and negatively associated with conscientiousness (r = −0.46, p = 0.014). No correlations were observed in the introvert group. Compared with not giving “Like” feedback, participants gave “Likes” to positive and negative pictures more quickly (p = 0.035) and slowly (p &lt; 0.001), respectively.These results support the hypothesis that hedonic gratification and social gratification motivate “Like” feedback for positive content and personally related content, respectively. “Liking” behavior was not affected by extraversion, but was related to neuroticism and conscientiousness. Content-related differences in time intervals for giving “Like” feedback in this study suggest that people do not hesitate to give “Like” feedback to positive content on WeChat Moments, yet linger in deciding to give “Like” feedback to negative content.