Continuous exposure to stressors can lead to vulnerability and, in some cases, resilience. This study examined the variation in its psychological impact across the first four waves of COVID-19 in Hong Kong.

Transcripts from Open Up, an online text-based counseling service, between January 2019 and January 2021 were analyzed (N = 60 775). We identified COVID-19 mentioned sessions using keywords and further categorized them into those that also mentioned symptoms of common mental disorders (CMDs) and those that did not. Autoregressive integrated moving average models were used to analyze the associations between the severity of the outbreak and the mention of COVID-19 and CMDs.

Results revealed that the pandemic led to increased psychological distress. Compared to prior to its advent, more people sought help in the initial months of the outbreak. Furthermore, associations were found between the severity of the outbreak and the number of help-seeker mentioning the pandemic, as well as between the outbreak severity and the number of help-seekers disclosing psychological distress. However, these relationships were not uniform across the four waves of outbreaks; a dissociation between outbreak severity and help-seekers' concern was found in the fourth wave.

As the pandemic waxes and wanes, people may become habituated to its psychological toll. This may be interpreted as a form of resilience. Instead of worsening with time, the psychological impact of COVID-19 may reduce with repeated exposure.

Despite its efficacy in treating comorbid insomnia and depression, cognitive behavioral therapy for insomnia (CBT-I) is limited in its accessibility and, in many countries, cultural compatibility. Smartphone-based treatment is a low-cost, convenient alternative modality. This study evaluated a self-help smartphone-based CBT-I in alleviating major depression and insomnia.

A parallel-group randomized, waitlist-controlled trial was conducted with 320 adults with major depression and insomnia. Participants were randomized to receive either a 6-week CBT-I via a smartphone application, proACT-S, or waitlist condition. The primary outcomes included depression severity, insomnia severity, and sleep quality. The secondary outcomes included anxiety severity, subjective health, and acceptability of treatment. Assessments were administered at baseline, post-intervention (week 6) follow-up, and week 12 follow-up. The waitlist group received treatment after the week 6 follow-up.

Intention to treat analysis was conducted with multilevel modeling. In all but one model, the interaction between treatment condition and time at week 6 follow-up was significant. Compared with the waitlist group, the treatment group had lower levels of depression [Center for Epidemiologic Studies Depression Scale (CES-D): Cohen's d = 0.86, 95% CI (−10.11 to −5.37)], insomnia [Insomnia Severity Index (ISI): Cohen's d = 1.00, 95% CI (−5.93 to −3.53)], and anxiety [Hospital Anxiety and Depression Scale – Anxiety subscale (HADS-A): Cohen's d = 0.83, 95% CI (−3.75 to −1.96)]. They also had better sleep quality [Pittsburgh Sleep Quality Index (PSQI): Cohen's d = 0.91, 95% CI (−3.34 to −1.83)]. No differences across any measures were found at week 12, after the waitlist control group received the treatment.

proACT-S is an efficacious sleep-focused self-help treatment for major depression and insomnia.

ClinicalTrials.gov, NCT04228146. Retrospectively registered on 14 January 2020. https://clinicaltrials.gov/ct2/show/NCT04228146