the pretreatment plasma ratio of tryptophan ( trp ) to other large neutral amino acids ( lnaa ) , thought to reflect brain serotonin formation , was determined in 44 inpatients with major depression , who were subsequently treated double-blind on a fixed-dose schedule for 4 weeks with the selective serotonin uptake inhibitor paroxetine ( n = 27 ) or clomipramine ( n = 17 ) .
C0039869
thought
C0006104
brain