Inclusion Criteria:  Chinese Hong Kong residents who are able to read Chinese; Aged 18 - 65 years; Subjective sleep complaints of having difficulties in falling asleep, difficulties in staying asleep, or early morning awakening with consequences for daily life for at least 3 months. Pittsburgh Sleep Quality Index total score of at least 5 indicating sleep disturbance with 89.6% sensitivity and 86.5% specificity; and Willing to give informed consent and comply with the trial protocol.  Exclusion Criteria:  Currently receiving psychotherapy or participating in other clinical trials for insomnia; Pregnancy; Shift workers; At significant suicidal risk as rated by the Hamilton Depression Rating Scale item on suicide (score ≥ 3); No comorbid sleep disorders primarily requiring other treatment, such as sleep apnea or narcolepsy; and Taking herbal remedies, over-the-counter medication, or psychotropic drugs that target insomnia within the 2 weeks prior to baseline.