Figure 3. Anxiety-related effects of drugs targeting the 5-HT, neuropeptide, glutamate and endocannabinoid systems.
Findings from experiments conducted between 1960 and 2012 are shown as the percentage of experiments that showed anxiolytic-like, anxiogenic-like and inactive effects. The number of experiments reporting anxiolytic-like effects is shown on the graph. This figure shows that although compounds modulating the 5-hydroxytryptamine (5-HT), corticotropin-releasing factor (CRF), cholecystokinin (CCK), endocannabinoid and tachykinin systems have shown variable effects, compounds acting at several glutamatergic receptors (that is, metabotropic glutamate receptor 2 (mGluR2) and mGluR5), compounds targeting neuropeptide Y (NPY) and compounds that block melanin-concentrating hormone (MCH) receptors have all produced relatively consistent anxiolytic-like effects. CB1, cannabinoid 1; FAAH, fatty acid amide hydrolase; MPEP, 2-methyl-6-(phenylethynyl)pyridine; NK1, neurokinin 1; NMDA, N-methyl-D-aspartate; NPS, neuropeptide S; SSRI, selective serotonin reuptake inhibitor.