Memory formation is a complex process that occurs diffusely within the brain, and it can be affected by several different modifiable parameters:
1. Sleep deprivation.
3. Excessive stimulant consumption.
4. Medications (antihistamines, antidepressants, antihypertensives).
5. Illicit drug use.
Memory formation continues even while we sleep, as the brain “consolidates” newly-acquired information. The average adult requires 6 to 8 hours of uninterrupted sleep each night. The risk of insomnia increases with age. Maintaining a regular exercise program and sleep schedule will minimize the risk of insomnia. Avoid taking stimulants in the evening or late afterrnoon. Do not take sleeping pills on a regular basis, as they can contribute to memory loss and “rebound insomnia” when they are discontinued. It is also important to obtain quality sleep, which can be disrupted by medical conditions such as obstructive sleep apnea. If you do not feel adequately rested after 6-8 hours of uninterrupted sleep, it might be reasonable to consult with your physician to see if you are suffering from sleep apnea or another treatable medical condition that is interfering with your sleep.
Smoking increases the risk of stroke and cerebrovascular disease in general, which can impair memory. Smoking can also impair heart and lung function over time, which indirectly impedes memory formation. Smoking can result in decreased blood flow to the brain from vasoconstriction, which can increase oxidative stress within neurons. It is unclear if smoking directly inhibits memory formation, however.
Stimulants in moderation taken early in the day (such as caffeine) can improve focus, concentration, and memory formation. However, stimulants taken in the late afternoon or evening can be counter-productive by contributing to insomnia. It is important to minimize stimulant consumption in the evening in order to obtain adequate, quality sleep for memory consolidation.
Some medications, both prescription and over-the-counter, can impair memory formation. There is some evidence that antihistamines (ie Benadryl, Claritin, Allegra, diphenhydramine, Vistaril, etc) can impair memory formation, as histamine functions as a neurotransmitter within the hypothalamus of the brain. Certain medications used to treat high blood pressure (ie captopril) and depression (ie paroxetine) are associated with memory loss. Keep in mind failure to treat severe seasonal allergies, uncontrolled hypertension, depression, and other medical problems can also negatively impact memory formation, so it is important to weigh these factors carefully by discussing them with your physician prior to discontinuing any medication.
It is a “no-brainer” (pun intended) that illicit drug use negatively impacts memory formation. Furthermore, illicit drugs can result in permanent brain injury, typically by disrupting synapse structure and function. Phencyclidine (PCP) disrupts the functioning of glutamate receptors in the brain, which is one of the most important neurotransmitters for memory formation and long-term potentiation. Lysergic acid diethylamide (LSD) is a hallucinogenic drug that activates specific serotonin receptors in the brain and can disrupt memory retrieval, sometimes permanently. Cocaine and crack block resorption of many neurotransmitters in the brain, including norepinephrine, dopamine, and serotonin. This can disrupt memory formation and retrieval, and can also result in seizures. Cocaine also induces vasoconstriction and significantly increases the risk of stroke. Heroin is converted into morphine in the brain, and activates opioid receptors. This results in sedation, which impairs memory function, and can lead to dependence and other severe health problems over time. It is safe to say that one should refrain completely from illicit drug use in order to promote optimal memory formation and function.
Memory formation is a diffuse process within the brain and is impacted by many general health conditions. As mentioned previously, insomnia, depression, uncontrolled hypertension, and smoking all negatively impact memory. An underactive thyroid gland (hypothyroidism) can also impede memory formation. Excessive stress, anxiety, and a lack of exercise can negatively impact cognitive function and memory formation. Alcohol can also impede memory formation, so it should be used only in moderation. It is important to maintain a healthy diet to optimize memory formation, and it is also important to keep learning. The more you stimulate your brain with learning, the better it will become at forming and consolidating memories. Keep in mind, the average human brain contains over 100 trillion synaptic connections, and can store over 100 terabytes of information. That is more than 10 times the volume of the US Library of Congress! The human brain is a special gift, capable of amazing things- it is up to you to optimize your brain’s health and function.