Combined Electroacupuncture and Auricular Acupuncture for Persistent Insomnia

Inclusion Criteria: * Aged 18 years or above * Hong Kong residents * Ethnic Chinese * Meet the diagnosis criteria of presistent insomnia for at least 3 months according to Current Diagnostic and Statistical Manual of Mental Disorders (the proposed Fifth Edition) * Insomnia more than 3 nights per week for at least 3 months * Willing to give informed consent * Able to comply with trial protocol Exclusion Criteria: * Have a Hamilton Depression Rating Scale scores above 18 * Have sleep apnea or periodic limbs movement disorder detected by overnight polysomnography * Have suicidal risk as assessed by the Hamilton Depression Rating Scale suicidal risk item * Have current major depressive disorder, generalized anxiety disorders or panic disorder, manic or hypomanic episode, substance use disorders except caffeine and nicotine, organic mental disorder, schizophrenia or any other psychotic disorder * Receiving psychotropic drugs with dosage changes in the last 4 weeks prior to screening, baseline or during the study * Have valvular heart defects or bleeding disorders or were taking anticoagulant drugs * Are pregnant, breast-feeding, or woman of childbearing potential not using adequate contraception * Have any unstable psychiatric conditions or serious physical illnesses which are judged by the investigator to render unsuitable or unsafe * Have infection or abscess close to the site of selected acupoints and in the investigator's opinion inclusion is unsafe * Taking Chinese herbal medicine or over-the-counter drugs which are intending for insomnia within the last 2 weeks prior to baseline or during the study * Any acupuncture or auricular acupuncture treatment during the previous 6 months prior to baseline