Pain. 1980 Jun; 8(3): 331-42.
High versus low intensity acupuncture analgesia for treatment of chronic pain: effects on platelet serotonin.
The 26 chronic pain patients were tested in a baseline plus cross-over design. Half of the subjects were first treated with high intensity acupuncture; then they were treated with low intensity acupuncture. For the other 13 subjects the treatment order was reversed. In the first treatment sequence subjects reported lower pain estimates and engaging in more activities of daily living during treatment with high intensity acupuncture--but not with low intensity acupuncture. In addition, under high intensity acupuncture (i.e. with low pain levels), subjects had higher levels of platelet serotonin; this last finding is consistent with recent research which implicates central serotonin in pain control. The results of the second treatment sequence were ambiguous.