Endocannabinoid tone
Both consequences shown here are beneficial: better mood, less anxiety. The system is designed to signal in bursts and reset; sustained heavy stimulation downregulates the receptor, which is how tolerance and the blunted-mood rebound arise. Endogenous tone raised by exercise, sleep and social contact behaves differently from the same receptors flooded from outside.
In depth
Endocannabinoid signaling — the tone-setting system that buffers stress, mood and homeostasis.
What drives it
Stress & cortisol increases it.
Stress/eCB review 2016, Neuropsychopharmacology — stress mobilizes endocannabinoid signaling (raising 2-AG at CB1, lowering anandamide), engaging the eCB system to shape and terminate the HPA stress response. PMID 26068727
Mood (serotonin) increases it.
Serotonin builds its own brake and the brake then shuts serotonin off. One receptor subtype is running both the anxiogenic CRF arm and this self-limiting endocannabinoid arm. And the endocannabinoid return arm is independently characterized: CB1 inhibition of excitatory currents onto raphe 5-HT neurons is presynaptic, shown by increased paired-pulse ratio and coefficient of variation and by inhibition of mEPSC frequency but not amplitude. doi 10.20517/and.2023.19 · PMC2766225
What it drives
It increases Motivation.
Microbiome-dependent endocannabinoid metabolites (fatty-acid amides such as OEA) made in the gut stimulate TRPV1/CB1 sensory neurons, which elevates dopamine in the ventral striatum and drives exercise motivation; blocking peripheral endocannabinoid receptors, ablating spinal afferents or blocking dopamine each abolishes the effect (Nature 2022, DOI 10.1038/s41586-022-05525-z). Mouse study — mechanism, not yet a human outcome. doi 10.1038/s41586-022-05525-z
It increases Mood.
Endocannabinoid/mood review 2012 — CB1-endocannabinoid signaling modulates emotional homeostasis; deficient signaling is associated with anxiety and depression, and enhancing it improves mood. PMID 23261685
It reduces Calm under stress.
GABA is not the only brake, and the review says so directly: many other neurotransmitters modulate anxiety responses in the amygdala, including serotonin, opioid peptides, endocannabinoids, neuropeptide Y, oxytocin and corticotropin-releasing hormone. Scope, stated plainly: the source that names endocannabinoids here explicitly declines to EXAMINE them in detail — it is an enumeration, not a demonstration. This edge is entered on the strength of that enumeration and needs its own review. The mechanism is now well evidenced in humans, and the definitive clinical trial failed. Both ARE recorded. Human randomized, double-blind, placebo-controlled: the FAAH inhibitor PF-04457845 (orally daily, 10 days; n=16 active vs 29 placebo) produced a ten-fold increase in baseline anandamide, and this was associated with potentiated recall of fear-extinction memory at 24 hours, attenuated autonomic stress reactivity measured by electrodermal activity, and protection against stress-induced negative affect measured by facial electromyography (Biol Psychiatry 2020;87:538, PMID 31590924). Human genetics agrees: people homozygous for a loss-of-function FAAH mutation show the same phenotype — the drug reproduces a natural genotype. Imaging shows the enzyme tracks the fear response: in 28 healthy people scanned with PET using the FAAH radiotracer [11C]curb, amygdala FAAH binding correlated positively with BOLD signal during processing of angry and fearful faces — more of the enzyme that destroys anandamide, more amygdala reactivity (PMC10206405). Mechanism: FAAH inhibition raises anandamide in the basolateral amygdala, increasing CB1 receptor signaling, which attenuates GABAergic transmission by long-term depression of inhibitory transmission — lifting a brake on the BLA neurons recruited to encode extinction. And here is the part that must travel with all of it: in a randomized clinical trial of 100 patients, A FAAH inhibitor did NO better than placebo at enhancing the response to exposure-based therapy in PTSD (PMC12923879). The biomarker moved ten-fold, the imaging correlated, the genetics agreed, the experimental-medicine endpoints improved — and the clinical endpoint did not. A further randomized placebo-controlled trial combining FAAH inhibition with internet-delivered CBT was run in 2025 (doi 10.1038/s41386-025-02128-w). This is the exact shape of error a mechanism-forward atlas is prone to: a beautiful pathway with a null trial at the end of it. The edge stands as mechanism; it does not support a clinical claim. doi 10.1038/s41386-025-02128-w · PMID 31590924 · PMC10206405
It reduces Mood (serotonin).
endocannabinoids suppress excitatory synaptic transmission to dorsal raphe serotonin neurons through activation of presynaptic CB1 receptors (Haj-Dahmane & Shen 2009), and serotonin release is inhibited via presynaptic CB1 receptors (Nakazi 2000). The signaling is tonic, not only evoked: both 2-AG and anandamide are constitutively released in the drn, exerting tonic control of glutamatergic transmission onto 5-HT neurons, with the magnitude set by overall network activity — silencing the network abolishes the tonic signal. And the two endocannabinoids are not interchangeable: tonic 2-AG, but not anandamide, modulates synaptic plasticity, and it does so not through canonical cannabinoid receptors but through intracellular PPAR-gamma, blocking potentiation by inhibiting the NO/sGC/pkg pathway. PMC8273699
It increases Alertness chemical.
They accelerate it: systemic administration of the CB1 agonist WIN55,212-2 increases the firing frequency of noradrenergic neurons and enhances forebrain norepinephrine release, acute intravenous WIN55212-2 or delta-9-THC raised locus coeruleus firing rate while the CB1 antagonist SR141716A had the opposite effect, and blocking anandamide breakdown with URB597 during acute swim stress increased norepinephrine release in the prefrontal cortex and basolateral amygdala. Agonist up, antagonist down — both directions tested. And a genuine tension is recorded rather than smoothed: CB1 deletion also increased LC-NE excitability and input resistance, and CB1 loss leads to enhanced age-related neuronal loss in the locus coeruleus. Acute pharmacological activation and lifelong genetic absence do not give mirror-image results, so this edge should not be read as a simple dial. doi 10.3389/fnmol.2017.00411 · PMC7792602
It reduces Calm.
10.1038/35069076 — ,depolarization-induced suppression of inhibition (dsi) is the classical and original electrophysiological example of endocannabinoid function in the central nervous system. Mechanism, and it runs backwards: depolarization raises calcium in the postsynaptic cell, which produces and releases 2-AG, which diffuses retrogradely — postsynaptic to presynaptic — to activate CB1 receptors on the incoming terminal and suppress GABA release. The receiving neuron tells its own inhibitors to back off. The constitutive activity is powerful enough to produce silent inhibitory synapses. Region decides which transmitter is targeted, which matters for an anxiety map: in cortical circuits CB1 sits mainly on CCK basket cells regulating GABA (dsi) and only to a lesser extent on pyramidal cells regulating glutamate (dse). In the central amygdala the balance inverts — the major role of CB1 there is to broadly regulate glutamatergic transmission, with CB1 activation reliably reducing excitatory currents while effects on GABAergic transmission were more variable. doi 10.1038/35069076
It increases Supports weight management.
The hypothesis came from an observation anyone could have made: appetite rises sharply when CB1 receptors are activated. It worked: a meta-analysis of four rimonabant trials showed weight loss of 4.7 kg over placebo after one year — larger than sibutramine (4.5 kg) or orlistat (2.7 kg). The mechanism is described as primarily affecting energy intake by dampening the reward aspect of feeding behavior. And it was withdrawn, because the European committee for medicinal products for human use found that rimonabant doubled the risk of psychiatric disorders — depressed mood, anxiety, irritability, insomnia and suicidality. In November 2008 all further research halted, and the clinical development of three other CB1 antagonists was terminated: taranabant, otenabant and SLV-319. The MAP already draws the Endocannabinoid Signaling → Mood (Positive Affect) link and the Endocannabinoid Signaling → Anxiety link, both on evidence that CB1 activity is protective. Rimonabant is a CB1 inverse agonist. The drug that moved weight in the desired direction moved those two nodes in the opposite one — and the psychiatric harm was not an unrelated toxicity, it was the same receptor action read at a different outcome. The atlas predicts this collision from edges evidenced independently, in different reviews. And separation looks unlikely rather than merely difficult: the therapeutic effect and the psychiatric effects occur over the same dose range, and the side effects ARE most pronounced at the most efficacious weight-reducing dose. Only about 50 percent of the benefit to triglycerides, fasting insulin and insulin resistance could be accounted for by the weight loss itself. PMC3083904
It increases Fear extinction.
Activation of CB1 receptors within the vmPFC during fear extinction induces neuronal plasticity and increases inhibition of brain areas involved in the expression of conditioned fear; intra-basolateral-amygdala CB1 agonists enhance recall of extinction learning. doi 10.1111/j.1601-183X.2012.00801.x · PMC2787650
Blends that modulate it
Each blend page names this pathway and carries the study behind its claim.
See it on the map
Open the causal map to follow this pathway upstream and downstream, arrow by arrow, each with its study.