Positron emission tomography measurement of cerebral metabolic correlates of tryptophan depletion-induced depressive relapse. - Bremner,J.D.; Innis,R.B.; Salomon,R.M.; Staib,L.H.; Ng,C.K.; Miller,H.L.; Bronen,R.A.; Krystal,J.H.; Duncan,J.; Rich,D.; Price,L.H.; Malison,R.; et al. (Arch Gen Psychiatry, 1997)