Anandamide regulates how active neurons are, and how much neurotransmitter they release. This acts as a sort of ‘dimmer’ switch, slowing down communication between cells and keeping all the circulating chemicals on an even keel and in balance (homeostasis). Levels of the neurotransmitters, dopamine, serotonin, endorphins etc for pleasure, mood, appetite, motivation, body movement, cognition, concentration. memory, brain development etc are all kept in balance by anandamide.
But THC is much stronger and persistent. Being foreign to the body it has no enzymes to break it down, it is fat-soluble so remains in the fatty brain cells, around 50% for a week, 10% for a month, with traces for weeks afterwards, all the time giving out signals and interfering with total brain functioning.
Even one joint/month will ensure a permanent presence of THC, and as Professor Sir Robin Murray says, ‘users will be in a state of low grade intoxication most of the time’.
Anandamide is overwhelmed - the whole brain chemical signalling system is thrown into chaos. And the general excitability of the brain’s neural networks is greatly reduced.