Why Did Matt Walker Float Three Cannabidiol Sleep Routes?

On the show, Dr. Matt Walker refuses to state that CBD is beneficial for sleep, because he says nobody can make that statement now. He still lays out three candidate mechanisms he has been exploring in case CBD ends up potentially beneficial: a thermoregulatory effect, an anxiolytic effect, and a change in adenosine signaling. He calls the mechanisms tentative, says any one of them is viable, and says all three are viable together.

The first is thermoregulatory. In some animal models, CBD created a profile of hypothermia: it cools core body temperature down, and a lower core body temperature is known to be good for sleep. The second is anxiolytic, a reduction in anxiety. He says the anxiety data is quite strong, including recent functional imaging in which the amygdala, an epicenter of emotion deep within the brain, is quietened down with CBD. He calls the anxiety route a second, non-mutually exclusive possibility. The third rests on recent data suggesting CBD can alter the signaling of adenosine. Producing more adenosine is not required. He says CBD can perhaps modulate the sensitivity of the brain so the weight of the same adenosine is weightier as a brain signal and therefore creates stronger pressure for sleep.

The three routes can operate at once: cooling the body, quieting anxiety at the amygdala, and increasing the sleep pressure carried by adenosine.