One of the reasons that opiates are so powerful is that they bind to special receptors in the brain, stimulating a cascade of events that changes the actual structure of brain pathways. Over time, repeated use of opiates such as heroin or prescription painkillers fundamentally alters the brain circuits associated with learning and memory. This causes many people with opiate dependence to suffer from memory impairment and associated problems.
Impact of Opiate Dependence and Abuse on the Learning and Memory Circuits in the Brain
The primary brain region responsible for learning and memory is called the hippocampus. Seated deep within the brain, the hippocampus makes associations between events in our lives, allowing us to recall them later. Cells in the hippocampus are covered in receptors that respond to a type of brain chemical called glutamate. Glutamate is the core molecule responsible for learning and memory processes.
Using opiates causes a significant drop in the amount of glutamate available in key brain regions. This disrupts the memory pathway, preventing the hippocampus from doing its job to create new memories. Additionally, pathways leading from the hippocampus to other brain regions may be negatively affected by opiate use. Over time, these pathways become restructured and are less effective at transmitting information. This leads to problems with learning, memory, and efficient thinking abilities.
In general, the brain cannot grow new cells to replace those that are lost during life. One of the only known exceptions to this is the hippocampus, which can create new neurons to support new memories. Unfortunately, studies in rodents suggest that using opiates disrupts this production of new neurons. Over time, this may cause the hippocampus to become smaller and less effective, further reducing memory abilities.
Individuals Affected by Opiate Abuse and Dependence Suffer from Memory Problems
Researchers have carefully studied the short and long term effects of opiate abuse and dependence on thinking abilities. Several studies have compared people with a history of opiate abuse with non-drug users. Study participants were given a set of tests designed to assess memory, abstract reasoning, mental flexibility, visuospatial skills, verbal abilities, and planning. The results showed that people who had a history of opiate dependence performed much more poorly on tasks of memory, reasoning, and planning.
This scientific evidence is consistent with many of the complaints we hear when treating patients in a clinical setting. Many people struggling with opiate dependence say that they just don’t feel as mentally “sharp” as they used to. Everyday memory problems, such as difficulty recalling whether you have taken medication or where you left your keys, are more common among people experiencing opiate addiction. These are the most common symptoms of opiate dependence.
What Can Be Done to Reverse Memory Problems Associated with Opiate Dependence
Thus far, the science about the role of opiate addiction in human learning and memory is still in the early phases. More studies are needed to determine the trajectory of decline in memory abilities and whether people’s thinking abilities will recover after treatment.
However, there is an association between length of opiate use and severity of cognitive problems. People who have been using opiates for years tend to have more problems with memory and other thinking abilities. Thus, getting treatment for opiate dependence may halt or even reverse the damage associated with long-term opiate abuse. Treatments such as rapid opiate detox cleanse the body of opiates, preventing their continued harmful effects on the hippocampus and other brain structures. Over months and years of sobriety, the brain may slowly rebuild its connections and restore its former level of functioning, resulting in improvements in learning and memory abilities.
Peters & Devries (2012). Glutamate mechanisms underlying opiate memories. Cold Spring Harbor Perspectives in Medicine. Retrieved on April 30, 2015.
Eisch et al. (2000). Opiates inhibit neurogenesis in the adult rate hippocampus. Proceedings of the National Academy of the Sciences of the United States of America, 97, 7579-84. Retrieved on April 30, 2015.
Ersche et al. (2006). Profile of executive and memory function associated with amphetamine and opiate dependence. Neuropsychopharmacology, 31, 1036-47. Retrieved on April 30, 2015