The first published account of CES and chemical dependence (CD) was a study by Wen and Cheng (1973). Forty patients admitted to Kwong Wah Hospital in Hong Kong for a variety of ailments who were coincidentally addicted to opiates were engaged in a study using CES combined with acupuncure for withdrawal symptoms. The subjects had been addicted for periods ranging from 3 to 58 years. A CES device of unspecified wave patterns was used at a frequency which was gradually increased from 0 to 125 Hz at an unspecified intensity. The electrodes were attached to acupuncture needles placed in the conches of both ears.

The length of treatment varied depending on individual patient needs, averaging 1.5 hours. The number of treatments also varied widely as seen from Wen and Chang’s comments, “In the first few days of treatment, we gave the patients  two or three days, followed by one stimulation for the next four or five days.”  Outcome measures were the researchers’ clinical observations of patient improvement and the patient’s sense of well being. Neither normal treatment, no treatment, nor placebo controls were used in the study. Results showed  that 39 of the 40 subjects were discharged  to out-patient clinics non-addicted and withdrawal symptom- free after the CES acupuncture treatment. All 39 of the subjects suffered little or no withdrawal symptoms during the study. These findings received the attention of numerous clinicians and researchers throughout the world.