Benefi Ts and Risks of Homoeopathy

1672 www.thelancet.com Vol 370 November 17, 2007 animal studies should be acknowledged, since some reports have suggested that rimonabant might have antidepressant or anxiolytic actions. Another observation that might provide an alternative physio logical basis for increased mood disorders seen with greatest weight-loss comes from evidence that leptin, the adipose-derived hor mone, had an antidepressant action after intrahippocampal but not hypothalamic injec tion. However, direct clinical correlates are diffi cult to draw. What is the signifi cance of the fi ndings reported by Christensen and colleagues? First, their meta-analysis has raised major questions about the safety of rimonabant in obese people, who are already at an increased risk of de pres sion, especially since the FDA review suggests that the risk of suicide is increased by use of this agent. More over, at least four other companies have CB1 antagonists in phase II or III development. The fi ndings of Christensen and colleagues’ meta-analysis suggest that phase III studies of such CB1 antagonists should monitor psychiatric complications very carefully. Second, the link between depression and this CB1-receptor blocker raises theoretical questions about a potential central role for the endocannabinoid system in both normal and clinical mood states.