Clinician-guided internet-delivered cognitive behavioral therapy (iCBT) is an effective treatment for depression and anxiety disorders. However, few studies have examined the effectiveness of completely unguided iCBT. The current research investigated adherence to, and the effects of two brief unguided iCBT programs on depression and anxiety symptom severity, and psychological distress. Study 1 evaluated a four-lesson transdiagnostic iCBT program for anxiety and depression (N = 927). Study 2 then evaluated a three-lesson version of the same program (N = 5107) in order to determine whether reducing the duration of treatment would influence adherence and treatment effects. Cross-tabulations and independent t-tests were used to examine the extent to which users adhered and remitted with treatment. Linear mixed models were used to evaluate the effects of treatment in the entire sample, and stratified by gender and completer-type (e.g., users who completed some but not all lessons vs. those who completed all lessons of treatment). Among those who began treatment, 13.83% completed all four lessons in Study 1. Shortening the course to three lessons did not improve adherence (e.g., 13.11% in Study 2). In both studies, users, on average, experienced moderate to large effect size reductions in anxiety and depressive symptom severity, as well as psychological distress. This pattern of results was robust across gender and for those who did and did not complete treatment. Approximately two-thirds of those who completed treatment experienced remission. These data show that unguided iCBT programs, which have the capacity to attract large numbers of individuals with clinically significant symptoms of depression and anxiety, and psychological distress, can produce significant improvements in wellbeing.

The twenty-first century has seen the development and delivery of online programs of behavioral family intervention for disruptive child behavior. Typically, programs evaluate outcomes in terms of change in child functioning and change in parenting ability. Existing research has also articulated the importance of parent–child relational capacity and its role in facilitating change in child functioning, and the importance of parent emotion regulation in the interests of ensuring optimal child development. These factors were explored in a meta-analysis of k = 14 prospective longitudinal research studies of online parenting interventions for disruptive child behavior. Peer reviewed randomized controlled trials with inactive control groups that were published in English between 2000 and 2022 were included in the review if they were delivered online; offered parent self-directed treatment; included as participants families who were screened as having child behavioral difficulties on validated psychometric assessment measures; and assessed child treatment outcomes, parenting ability and parent treatment outcomes. The protocol for this study was pre-registered with PROSPERO (CRD42020215947). Statistical analyses employed random effects models and reported pooled effect sizes (Hedge’s g) within and between groups. Results emphasize the importance of child outcomes and parenting ability in program assessment, however, suggest that parents’ capacity to develop optimal parent–child relationships and regulate emotion may not be sufficiently reflected in program content. Identified continuous and categorical moderators of treatment outcome were also assessed. Results of the review are discussed in terms of their potential to influence the future development of online programs of behavioral family intervention and, therefore, child development.