Adolescents' secrecy is intertwined with perception of parents' behaviors as acts of privacy invasion. It is currently untested, however, how this transactional process operates at the within-person level-where these causal processes take place. Dutch adolescents (n = 244, M = 13.84, 38.50% boys) reported three times on perceived parental privacy invasion and secrecy. Cross-lagged panel models (CLPM) confirmed earlier findings. Privacy invasion predicted increased secrecy, but a reverse effect was found from increased secrecy to increased privacy invasion. Controlling for confounding positive group-level associations with a novel random intercept CLPM, negative within-person associations were found. Higher levels of secrecy predicted lower levels of privacy invasive behaviors at the within-person level. These opposing findings within- versus between-persons illustrate a Simpson's paradox.

Introduction:This study aimed at differentiating normative developmental turmoil from prodromal depressive symptoms in adolescence. Method: Negative and positive mood (daily) in different contexts (friends, home, school), and (subsequent) depressive symptoms were assessed in Dutch adolescents.Results & conclusion: Mixture modeling on one cross-sectional study, using a newly developed questionnaire (CSEQ; subsample 1a; n = 571; girls 55.9%; Mage = 14.17) and two longitudinal datasets with Experience Sampling Methods data (subsample 1b: n = 241; Mage = 13.81; 62.2% girls, sample 2: n = 286; 59.7% girls; Mage = 14.19) revealed three mood proiles: 18-24% "happy", 43-53% "typically developing", and 27-38% "at-risk". Of the "at-risk" proile between 12.5% and 25% of the adolescents scored above the clinical cut-off for depression. These mood proiles predicted later depressive symptoms, while controlling for earlier symptoms. In subsample 1b, parents were not always aware of the mental health status of their adolescent.

Background Anxiety and mood problems in adolescents often go unnoticed and may therefore remain untreated. Identifying and preventing the development of emotional problems requires monitoring and effective tools to strengthen adolescents' resilience, for example, by enhancing coping skills. Objective This study describes the developmental process, feasibility, and acceptance of Grow It!, a multiplayer serious game app for adolescents aged 12-25 years. The app consists of the experience sampling method (ESM) to monitor thoughts, behaviors, and emotions in daily life to enhance self-insight and daily cognitive behavioral therapy–based challenges to promote adaptive coping. Methods Our approach entails an iterative game design process combined with an agile method to develop the smartphone app. The incorporated game features (ie, challenges, chat functionality, and visual representation) in the Grow It! app were co-designed with adolescent end users to increase participant engagement and adherence. Results The Grow It! app was delivered for Android and iOS in May 2020. Grow It! was offered to adolescents during the COVID-19 crisis between May and December 2020. Participants of the Grow It! COVID-19 study (sample 1: N=685; mean age 16.19, SD 3.11 years; 193/685, 28.2% boys; sample 2: N=1035; mean age 18.78, SD 3.51 years; 193/1035, 18.64% boys) completed 31.5% (13.2/42) to 49.5% (10.4/21) of challenges. Compliance of ESM was suboptimal (35.1/210, 16.7% to 32.5/105, 30.9%). Follow-up questionnaires indicated an overall score of the app of 7.1 out of 10. Moreover, 72.6% (278/383) to 75.6% (487/644) would recommend the app to friends. Conclusions To our knowledge, Grow It! is the first gamified ESM app that both measures individual differences in emotional dynamics and offers an integrated cognitive behavioral therapy–based intervention. Our findings support the feasibility and acceptance, and therefore applicability, of the Grow It! app in adolescents. Further iterations of this serious game app will focus on the increase of compliance and on providing participants feedback through their personal mood profiles.

Adolescent mental health and well-being have been adversely impacted by the COVID-19 pandemic. In this preregistered longitudinal study, we evaluated whether adolescents’ well-being improved after playing the multiplayer serious game app Grow It! During the first lockdown (May–June 2020), 1282 Dutch adolescents played the Grow It! app (age = 16.67, SD = 3.07, 68% girls). During the second lockdown (December–May 2020 onwards), an independent cohort of 1871 adolescents participated (age = 18.66, SD = 3.70, 81% girls). Adolescents answered online questionnaires regarding affective and cognitive well-being, depressive symptoms, anxiety, and impact of COVID-19 at baseline. Three to six weeks later, the baseline questionnaire was repeated and user experience questions were asked (N = 462 and N = 733 for the first and second cohort). In both cohorts, affective and cognitive well-being increased after playing the Grow It! app (t = − 6.806, p < 0.001; t = − 6.77, p < 0.001; t = − 6.12, p < 0.001; t = − 5.93, p < 0.001; Cohen’s d range 0.20–0.32). At the individual level, 41–53% of the adolescents increased in their affective or cognitive well-being. Adolescents with higher risk profiles (i.e., more depressive symptoms, lower atmosphere at home, and more COVID-19 impact) improved more strongly in their well-being. Positive user evaluations and app engagement were unrelated to changes in affective and cognitive well-being. This proof-of-concept study tentatively suggests that Grow It! supported adolescents during the pandemic.