Digital cognitive behavioral therapy for insomnia (dCBT-i) is found to be effective but is rarely used in China. Hence, the investigators developed an automated Chinese dCBT-i program and examined its feasibility, acceptability, and preliminary effectiveness in individuals with insomnia symptoms.

Inclusion Criteria:

• were aged 18 or older;
• had a positive screening result for chronic insomnia, i.e., a score of 16 or lower on the Sleep Condition Indicator (SCI);
• had stable access to the internet via a smartphone.

Exclusion Criteria:

• additional sleeping conditions except for insomnia (such as restless legs syndrome and sleep apnea);
• psychosis or mania;
• serious physical health concerns necessitating surgery or with prognosis <6 months;
• undergoing medical or psychological treatment for insomnia with a health professional;
• habitual night shift, evening, or rotating shift-workers.