What are the adverse effects of short and long-term use of melatonin?
Thirty-four studies were relevant to this question of the review. The overall quality of these studies was assessed using the Downs and Black Checklist.115 The overall quality of studies ranged from 12 to 26 on a 29-point scale; one study had a score of 12,144 13 studies had a score between 16 and 20,27 60 61 63–65 81 92 94 124 145–147 19 studies had a score between 21 and 2554 66 68 69 71 74 76 78 80 82 90 95 129 130 143 148–151 and one study had a score of 26.67 The quality of reporting ranged from five to 11 on an 11-point scale; two studies had a score of five or six,63 144 15 studies had a score between seven and nine27 61 64–66 68 76 80–82 92 94 145–147 and 17 studies had a score between 10 and 11.54 60 67 69 71 74 78 90 95 124 129 130 143 148–151 The external validity of studies ranged from zero to three; most studies had a score of one, eight studies had a score of two,63 66 74 80 82 130 145 151 four studies had a score of three,54 67 90 143 and six studies had a score of zero.
