Is melatonin analgesia associated with improvement of the descending endogenous pain-modulating system in fibromyalgia : a phase II , randomized , double-dummy , controlled trial?
Melatonin increased the inhibitory endogenous pain-modulating system as assessed by the reduction on NPS(0-10) during the CPM-TASK. Melatonin alone or associated with amitriptyline was better than amitriptyline alone in improving pain on the VAS, whereas its association with amitriptyline produced only marginal additional clinical effects on FIQ and PPT.
The numbers with mild depression were too small to make valid conclusions. However, this group had a significantly longer length of infertility. Thus even if a more extensive study shows similar data it may well be that the length of infertility causes only mild depression rather than that depression leads to infertility. However the possibility still exists that even mild depression may to some degree impair success with infertility therapy.