α-[11C]Methyl-L-tryptophan trapping in the orbital and ventral medial prefrontal cortex of suicide attempters

Low serotonin neurotransmission is thought to increase vulnerability to suicidal behavior. To test this hypothesis, we measured brain regional serotonin synthesis, as indexed by PET and alpha-[C-11]methyl-L-tryptophan trapping, in 10 patients who had made a high-lethality suicide attempt and 16 healthy controls. Compared to healthy controls, suicide attempters had reduced normalized alpha-[C-11]methyl-L-tryptophan trapping in orbital and ventromedial prefrontal cortex. alpha-[C-11]Methyl-L-tryptophan trapping in these regions correlated negatively with suicide intent. Low serotonin synthesis in the prefrontal cortex might tower the threshold for suicidal behavior. (c) 2005 Elsevier B.V. and ECNP. All rights reserved.