Every day we are bombarded with new information, often too much at once. We try to process it all, but, we may beat ourselves up when we forget something like a friend’s birthday or a deadline at work. As we age forgetfulness seems more common. People worry that they will lose their memory with age. We have all had that moment when we walk in a room and think “why did I come in here?” Perhaps, though, there is a survival benefit to forgetting. Just like information overload, memory overload would paralyze us from functioning. Heck, if I couldn’t forget the pain of childbirth, I would never have had my second child!
I’d like to present the counter to memory lapses as a blessing in disguise: the ability to forget is what saves our sanity. Be it a school shooting, car accident, or time spent in a war zone, many people wish they could forget. Post-traumatic-stress-disorder, or PTSD, is the inability to forget (and often relive) a traumatic event. Stressful experiences are processed in the amygdala, that reptilian part of the brain that reacts primally to stimulus. It is in the amygdala that our “fight or flight” response is activated.
Until recently, scientists considered forgetting a passive biological process, but, new data have found forgetting to be an active process regulated in the brain by dopamine. Forgetting may actually be the default process; it is only when something happens to make a moment impactful that it becomes memorable. Two dopamine receptors on the same neuron regulate whether you remember or forget something; each is responsible for its own path to forgetting or remembering. Studies with this pair of receptors demonstrate that learning and forgetting can be greatly altered when the receptors are mutated and may be enhanced in some individuals such as savants or those with a photographic memory. The normal signalling of dopamine can lead to memory formation, however, over-stimulation of dopamine can lead to forgetting. This explains why when you are in a hectic situation (ex. a car accident) it is difficult to remember details of the event. Interestingly, sleep enhances memory formation by suppressing the activity of dopamine receptors that promote active forgetting.
So how does cannabis come into play with forgetting? In several ways. First, acute cannabis use is associated with memory impairment. This appears to be derived from effects at the CB1 receptor, a binding site for THC and endocannabinoids (EC). As discussed in a previous CBE article, EC and THC function through receptors to initiate cascades of events that may lead to the release of dopamine. The EC are involved with memory processing. This memory impairment may relate to the inability to retrieve memories (like looking for a file on your hard drive) and impact short-term or long-term memories. From the perspective of painful memories, this is extremely valuable. Recent inclusion of PTSD in the State of Colorado’s list of accepted medical conditions attests to this benefit. Using cannabis for PTSD management can greatly improve patients’ mental health by helping the person forget or not fixate on an event.
Secondly, the amygdala has a high concentration of CB1 receptors in it (particularly in the basolateral complex). When stressful events occur and the amygdala is activated, EC and THC may play roles in memory consolidation and release of stress hormones. Lastly, cannabis is a useful agent for sleep and anxiety. Stressful memories can greatly impact sleep quality. By including cannabis as a part of your wellness routine, you can sleep better and improve your overall health and well-being. Now, consider forgetting things in a whole new light! Thanks, cannabis!