A double-blind controlled trial of mianserin and amitriptyline in depression.

A double-blind trial was carried out in 47 patients with depression to compare the effectiveness of 30 mg mianserin, 60 mg mianserin and 50 mg sustained-release amitriptyline, each given as a single dose at night over a period of 4 weeks. Hamilton Rating Scale scores showed significant, progressive improvement from Week 1 with all three regimens. Although the differences between the groups were not significant, the greatest improvement occurred after 60 mg mianserin daily and the order of effectiveness was consistent for various Hamilton Rating Scale items. Patient self-assessment, using visual analogue scales, gave similar results to the Hamilton Rating Scale with significant, progressive improvement in all groups. Once again, a consistent order of effectiveness was evident with most of the items, the greatest improvement being noted with 60 mg mianserin daily and the least with 30 mg mianserin daily. There was a considerable reduction in the number of reports of symptoms recorded before the trial during treatment in all groups. The only increase in symptoms possible drug-related was of blurred vision in patients receiving amitriptyline.

Experimental changes in pain threshold and severe pain threshold for electrically induced pain.

Pain and severe pain thresholds were measured in groups of 15 (Experiment 1) and 20 (Experiment 2) normal volunteers. In Experiment 1, the subjects underwent a series of ten constant level, painful stimuli each of 10 sec duration at an arbitrarily chosen level between the thresholds. This level was recorded. It ranged from 14% to 81% of the difference between thresholds. The thresholds were then remeasured. For the second experiment the experimental stimulus commenced at a non-painful level and increased over a period of 5 sec to a level midway between thresholds for a series of three stimuli and again thresholds were remeasured. An overall effect was demonstrable only in Experiment 2, where the severe pain threshold was significantly reduced (p less than 0.001). There was a marked individual variation with increases and decreases in both thresholds occurring in different individuals at significance levels varying from p less than 0.05 to p less than 0.001. No subject changed the two thresholds in opposite directions. Examination of the responses in Experiment 1 suggested that for any increase in either threshold to occur it was necessary that the repeated painful stimulus should be at a level below the mid-point between the two thresholds, but that this was not a sufficient condition.

Cultural factors in clinical pain assessment.

Experimental evidence suggests that the threshold at which a given stimulus is perceived as painful is relatively constant both for an individual and between individuals. However, higher thresholds at which pain described as severe or at which particular behavioural response occurs are much more variable and appear to depend on cultural factors. Since one concern of a healing profession is to alleviate or minimize pain it would be helpful if some means of assessment of the intensity of pain experienced by other persons were available. Unfortunately no such measure exists. Distinction must be made between relief of pain which should be based on physiological principles and relief of distress in which socio-psychological factors are of much greater importance.