Chronic psychosocial stress in tree shrews: effect of the substance P (NK1 receptor) antagonist L-760735 and clomipramine on endocrine and behavioral parameters.

Rationale Substance P and its preferred receptor, the neurokinin 1 receptor (NK1R), have been proposed as possible targets for new antidepressant therapies, although results of a recently completed phase III trial failed to demonstrate that the NK1R antagonist MK-869 is more effective than placebo in the treatment of depression.