A potential association between pet ownership and mental well-being is suggested, but there is a shortage of high-quality longitudinal studies that consider probable differences among different species. We aimed to examine whether ownership of the most popular pets (dogs and cats) would predict mental well-being. The Tokyo Teen Cohort (TTC), a prospective population-based birth cohort study, had dog and cat ownership data at age 10 and mental well-being score at ages 10 and 12 from 2584 adolescents. Linear regression analysis with adjusting for covariates showed that dog ownership had a positive effect on mental well-being compared to no dog ownership, however, cat ownership had a negative effect compared to no cat ownership. Two-factor mixed-design analysis of variance showed that dog ownership predicted maintained mental well-being, while cat ownership predicted progressing decline of mental well-being. Thus, dog and cat ownership may have different effects on adolescents’ mental well-being, implying that the underlying mechanisms that are activated by these types of ownership may differ.

Problematic Internet use (PIU), hyperactivity/inattention, and depressive symptoms are comorbid problems in adolescence, but the causal relationships among these issues are unclear. To assess the relationships among PIU, hyperactivity/inattention, and depressive symptoms in adolescents in the general population. This longitudinal cohort study used data from the Tokyo Teen Cohort study in Tokyo, Japan, for two years between October 2012 and January 2015. Of the 3171 pairs of children and parents, 3007 pairs continued to participate in the second wave of the Tokyo Teen Cohort study. A total of 3007 children were included in the analysis (mean [standard deviation] age, 9.7 [0.4] years; 1418 women [47.2%]. Cross-lagged panel analysis revealed that PIU at timepoint 1 was significantly associated with hyperactivity/inattention at timepoint 2 (β = 0.03; 95% confidence interval (CI) 0.01–0.06), and hyperactivity/inattention at timepoint 1 was also significantly associated with PIU at timepoint 2 (β = 0.07; 95% CI 0.04–0.10), even after adjustments were made for depressive symptoms. Furthermore, PIU at timepoint 1 was significantly associated with depressive symptoms at timepoint 2 (β = 0.05; 95% CI 0.01–0.12), and depressive symptoms at timepoint 1 were also significantly associated with PIU at timepoint 2 (β = 0.05; 95% CI 0.02–0.07), even after adjustments were made for hyperactivity/inattention. These results support the bidirectional relationships among PIU, hyperactivity/inattention, and depressive symptoms. PIU may be a target to improve hyperactivity/inattention and depressive symptoms in adolescents.

Background: Video game loot boxes, which can typically be purchased by players or are given as reward, contain random virtual items, or loot, ranging from simple customization options for a player's avatar or character, to game-changing equipment such as weapons and armor. Loot boxes have drawn concern, as purchasing loot boxes might lead to the development of problematic gambling for adolescents. Although parental problem gambling is associated with adolescent problem gambling, no studies have evaluated the prevalence of loot box purchases in adolescents’ parents. Objective: This study investigated the association between loot box purchasing among adolescents and parents, and problem online gaming in population-based samples. Methods: In total, 1615 adolescent (aged 14 years) gamers from Japan responded to a questionnaire regarding their loot box purchasing and problem online gaming behaviors. Problem online gaming was defined as four or more of the nine addictive behaviors from the Diagnostic and Statistical Manual of Mental Disorders. The adolescents’ primary caregivers were asked about their loot box purchasing. Results: Of the 1615 participants, 57 (3.5%) reported loot box purchasing. This prevalence did not differ according to primary caregivers’ loot box purchasing, but adolescents who purchased loot boxes were significantly more likely to exhibit problem online gaming (odds ratio 3.75, 95% CI 2.17-6.48). Conclusions: Adolescent loot box purchasing is linked to problem online gaming, but not with parents’ loot box purchasing. Measures to reduce these behaviors should target reducing addictive symptoms in young video gamers.

Objective: To describe the psychosocial functioning in children with undiagnosed persistent ADHD symptoms. Method: A prospective, population-based birth cohort study was conducted among 2,945 children and their primary caregivers who lived in Tokyo, Japan, and were followed up at the age of 10 years and 12 years. Parents reported a history of ADHD diagnosis and completed the Strengths and Difficulties Questionnaire. Results: Overall, 91 participants had persistent ADHD symptoms; however, 76 (83.5%) had no history of an ADHD diagnosis. The presence of undiagnosed ADHD symptoms was significantly associated with worse psychosocial functioning for most continuous outcomes when compared with the absence of ADHD symptoms and diagnosis, including lower self-esteem (standardized mean difference [SMD] = −0.31) and higher depression (SMD = 0.36), emotional symptoms (SMD = 0.69), conduct problems (SMD = 1.26), and peer relationship problems (SMD = 0.98). Conclusion: Our findings suggest the importance of paying more attention to the possible underdiagnosis of ADHD in children.

During the COVID-19 pandemic, adolescent carers in the UK may have experienced psychological distress owing to increased caring burden and loss of a break from their caring role. This study investigated longitudinal association between adolescents' caring status and mental health outcomes from 2018/2019 to February–March 2021. The participants (n = 3,927) answered mental health questions in both the Millennium Cohort Study sweep 7 survey (age 17 years in 2018/2019) and at least one of three waves of the COVID-19 survey from May 2020 to February–March 2021. Caring status at the age of 17 years was assessed using a single question regarding whether the participant regularly looked after anyone who needed care, without being paid. Outcome measures were psychological symptoms, measured using the Kessler Distress Scale, and mental well-being, measured using the Warwick-Edinburgh Mental Well-being Scale. Compared with 3,616 noncarers, 311 (7.9%) adolescent carers reported significantly higher Kessler Distress Scale and lower Warwick-Edinburgh Mental Well-being Scale scores during the pandemic. These associations were largely explained by psychosocial risk factors. Worse outcomes were associated with poor sleep quality, attempted suicide at baseline, low social support, and a strong feeling of loneliness during the pandemic. These factors were significantly more likely to be observed among adolescent carers than noncarers. UK adolescent carers exhibited worsened mental health outcomes one year after the first national lockdown. This increased distress may be attributable to psychosocial risk factors during the pre–COVID-19 and current COVID-19 periods, and they require psychosocial support.