It is well known that using illicit drugs or abusing controlled substances is harmful to the body and brain; however, nearly 8,000 Americans over the age of 11 abused drugs for the first time each day in 2013. In addition, close to 25 million Americans were considered to be current illicit drug users, which means that they had used drugs within 30 days of the National Survey of Drug Use and Health (NSDUH) being conducted. Regardless of all of the negative consequences of drug abuse, drugs can make users feel good and temporarily relieve feelings of stress, depression, and other difficult emotions, which encourages people to keeping taking them. Drugs interfere with the way the brain processes motivation and pleasure, making it harder and harder to remove them from the bloodstream without professional help. Illicit drugs and controlled substances also disrupt normal cognitive functions such as decision-making, learning, and memory processes. Memory loss may be a common side effect of drug abuse.
Memory Loss, the Brain, and Drugs
The human brain is a very complex organ involved in just about every aspect of human life. The three main regions of the brain are the brain stem, cerebrum, and cerebellum. The brain stem mainly controls life-sustaining functions, such as heart rate, digestion, body temperature, and breathing, and it is located at the base of the skull. The cerebellum is involved in controlling motor functions and balance, and also cognitive functions such as language, attention, and the emotional responses to pleasure and fear, and processing and storing task-based, or procedural, memories. The cerebrum makes up 85 percent of the brain by weight and contains the cerebral cortex and the limbic system, which control decision-making and many other cognitive abilities, emotional perceptions, and the formation, processing, and storage of short-term and long-term memories. Many factors can influence memory impairment and memory loss; for example, as people age, they lose neurons in the hippocampus, which is part of the limbic system, and it may disrupt their ability to learn new things. Drug abuse also interferes with the way the brain communicates and processes memories, which can cause memory loss.
Drug abuse may go hand-in-hand with other potential contributors to memory loss, such as:
- Stress: High levels of stress due to traumatic events and chronic stress are risk factors for substance abuse and addiction, as published in the Annals of the New York Academy of Sciences. Stress can make changes in the brain that can cause memory loss or inhibit the growth of new neurons in the hippocampus, which is important for the formation of new memories.
- Poor nutrition: Drug abuse can deplete the body of healthy levels of vitamins and nutrients that are necessary for proper brain function.
- Depression: Mood disorders can create an inability to focus and a lack of attention that can disrupt memories. A third of those suffering from a major depressive disorder also meet the criteria for a substance abuse disorder, according to studies published in Current Opinion in Psychiatry.
- Unhealthy sleep patterns: A disruption of quality sleep, which is often a side effect of drug abuse, can interfere with memory functions.
Impact of Drug Use on Memory Loss
Emotions and memory are complexly intertwined. It is understood that drug abuse alters moods and interferes with the regulation of emotions and therefore with memory formation, processing, and storage. Some of these effects may only last as long as a user is intoxicated or “high,” while others may be persist longer and increase with regular abuse. Different types of drugs affect the brain in differing ways; therefore, some may be more detrimental to memory functions than others.
Marijuana comes from the Cannabis sativa plant, and it is the most commonly abused illicit drug in America, according to the National Institute on Drug Abuse (NIDA). The main active ingredient in marijuana is delta-9-tetrahydrocannabinol, or THC, which binds to cannabinoids receptors in the brain, over activating them and producing a “high” and other mind-altering effects. The hippocampus is involved in memory processing and the transferring of short-term memories into long-term ones, which is disrupted with the introduction of THC. Typically, marijuana primarily affects the formation of new short-term memories and their transference to long-term status, meaning that while someone is “high,” they may not be able to make new memories or remember what happened while they are intoxicated. Of particular concern are young marijuana users whose brains have not been fully formed. According to the Monitoring the Future survey, marijuana is the most popular illicit drug among young Americans, with close to 40 percent of high school seniors abusing it in the month leading up to the national survey. The endocannabinoid system in the brain builds and refines the connections between neurons, or synapses, during its development. When marijuana is introduced before the brain is finished forming, cognitive abilities, which may include memory functions, may be disrupted permanently. A study published by NIDA found that people who started abusing marijuana as adolescents, and used it regularly, lost an average of 8 IQ points that were unrecoverable even upon the cessation of marijuana abuse in adulthood. The shape of the hippocampus was also shown to be altered by chronic and long-term marijuana abuse in adolescents in a study published in Tech Times, and this change negatively affected long-term memory functions. Teens who smoked marijuana daily from age 16 or 17 for at least three years were tested on long-term memory functions and found to perform 18 percent lower than their peers who didn’t abuse the drug regularly. Other studies published in Pharmacology Biochemistry and Behavior indicate that marijuana abuse significantly affects short-term memory functions and attention levels while intoxicated and immediately thereafter, and continued and regular abuse may perpetuate these deficiencies in memory and attention long-term.
Heroin and Prescription Opioids
Opioids are a class of drugs including both illegal heroin and prescription narcotics like Vicodin, OxyContin, and morphine. In 2012, the NIDA published that 467,000 Americans were dependent on heroin, while another 2.1 million battled a substance abuse disorder involving opioid painkillers. Opioid drugs bind to opioid receptor sites in the brain and effectively block feelings of pain. They also stimulate the production of dopamine, which is one of the brain’s chemical messengers, or neurotransmitters, involved in feelings of pleasure within the limbic system. When normal neurotransmitter functions are disrupted, cognitive functions like short-term and long-term memory may be impaired. Heroin abuse, when perpetuated long-term, has been shown to disrupt the integrity of white matter in the brain and therefore interfere with decision-making abilities, a person’s response to stress, and emotional and mood regulation, as published in the journal Brain Research. While opioids are not thought to cause significant memory loss or disruption directly, their effects on the central nervous system, particularly on respiration, may lead to permanent brain damage, coma, or death. Opioids slow breathing functions by acting on the brain stem, which may result in a toxic overdose. The Centers for Disease Control and Prevention (CDC) cites drug overdose as the leading cause of injury death with over half of the drug-related drug overdose fatalities being related to prescription drugs, and over 70 percent of the prescription drug overdoses involving opioids in 2013. Those who survive an opioid overdose may experience impaired cognition and disrupted memory functions as a result of the brain being deprived of oxygen for a length of time.
Prescription medications such as Valium, Xanax, and Ativan are commonly abused. More than 60,000 people seeking treatment for a drug abuse or dependency issue in 2008 reported abusing benzodiazepines, as published in the Treatment Episode Data Set (TEDS) Report. These medications are prescribed to treat anxiety, insomnia, and seizures. They also may be used during a medical procedure as a part of an anesthesia regimen due to their ability to induce short-term memory loss with their amnesic properties. Benzodiazepines are central nervous system depressants, which suppress regions of the brain involved in fear, anxiety, and stress reactions. They may stimulate gamma-aminobutyric acid (GABA) production, which is a inhibitory neuron in the brain that can decrease feelings of stress and anxiety and promote sleep. Benzos may interfere with the way people process memories and the transference of short-term memories into long-term ones as well as the formation of new memories. Benzos may also interfere with episodic memories, which are memories related to recent events. In some cases, users have reported “blackouts” when taking a benzodiazepine, meaning that they engaged in an activity they had no recollection of afterwards. Sedatives and tranquilizers may leave users feeling confused, drowsy, and “fuzzy” while taking them. Benzodiazepines are prescribed for short-term relief of symptoms and when taken for too long may have many negative side effects, including difficult withdrawal symptoms when their usage is stopped suddenly. Taking or abusing benzodiazepines long-term can increase the risk of developing Alzheimer’s, a form of dementia involving memory loss and cognitive impairment. A study published by Harvard Health reported that taking a benzodiazepine for more than six months increased the risk for developing Alzheimer’s a staggering 84 percent over those who didn’t take or abuse this class of drug. The elderly population is warned against taking benzodiazepine medications as well since slowed metabolisms and interactions with other medications can cause adverse reactions and increase cognitive impairment and potential memory troubles.
Cocaine and Methamphetamine
Cocaine is a highly addictive drug derived from the coca plant that is abused in either powder or rock form (“crack”). Cocaine works to block the reabsorption of dopamine in the brain, causing a flood of this neurotransmitter and an intense euphoric effect. Cocaine is a powerful stimulant drug, and 855,000 Americans aged 12 and older were estimated to be addicted to in 2013, according to the Substance Abuse and Mental Health Services Administration (SAMHSA). The brains of cocaine-addicted individuals have been studied through magnetic resonance imaging (MRI) and show a constriction, or narrowing, of blood vessels in the brain that slows blood flow and may cause cognitive and memory impairment in chronic abusers of the drug. A publication through the University of Pittsburg also reported on a study showing how cocaine abuse not only negatively affected attention levels and the ability to focus, but also caused a disruption in abusers’ visual working memories. Visual memory refers to the processing of things you see and their storage in the brain. When you see a particular face, for instance, visual memory helps you to remember whom it belongs to and stores that information for future retrieval. Short-term verbal memory, or the memory of words and language, may also be impaired or disrupted with cocaine abuse. Prospective task-based memory can be based on either event or time-based triggers, meaning that remembering to do something is either triggered by an external cue or due to the self-awareness that it is time to do something. Cocaine abuse negatively affects the frontopolar cortex, which may produce deficits in both forms of prospective memory, PsychCentral reports. Another stimulant drug – abused by about 600,000 Americans over 11 in the month prior to the national survey published by SAMHSA – is methamphetamine, which is a synthetic drug produced in illicit laboratories around the world. Just like cocaine, methamphetamine, or meth, interferes with normal dopamine production and the natural chemical communication system within the brain. Serotonin, another chemical messenger involved in pleasure and mood regulation, is also affected by methamphetamine abuse. These disruptions in the reward center may cause both functional and structural changes in the frontal cortex of the brain, which can cause an interference with verbal learning, emotions, and memory. Stimulant drugs such as cocaine and meth also make it harder to get quality sleep, and sleep is important in healthy memory formation, processing, and storage. When we sleep, new memories are transferred into long-term memories and stored. Meth can disrupt sleep patterns and therefore stunt this process, making it more difficult for stimulant drug abusers to successfully retain short-term memories and form long-term ones.
Molly and ecstasy are street names for 3,4-methylenedioxymethamphetamine, or MDMA, which is another synthetic drug. MDMA has both stimulant and hallucinogenic properties and is commonly referred to as a “club” or “party” drug.Similar to other stimulant drugs, ecstasy increases the levels of dopamine and serotonin in the brain as well as stimulates production of norepinephrine. This flood of “happy cells” makes users feel good, but chronic abuse can actually make it harder to feel happiness without the drug, as natural production of these neurotransmitters may be stunted. A study published in the journal Addiction reported that MDMA selectively affects the executive working memory and visual recall functions in the hippocampus related to learning and memory. Executive memory is the ability to remember instructions, make plans and decisions, control impulses, and manage multiple tasks simultaneously. In men, cognitive flexibility, or the ability to make changes to behavior as outside influences dictate them, is also impaired by MDMA abuse, according to the journal of Pharmacology Biochemistry and Behavior. Ecstasy abusers are often aware that they are suffering memory lapses or impairment. Negative effects of MDMA on memory may be reversed when users stop abusing the drug and maintain a period of abstinence.
Hallucinogens (LSD, PCP)
Drugs that alter the way people perceive things and produce mind-altering effects are called hallucinogens. LSD and PCP are examples of hallucinogen drugs, which are illegal in the United States. These drugs commonly affect serotonin and dopamine levels, inducing mood swings, and also distort reality and alter a user’s sensory perceptions. PCP, with the street name of “angel dust,” directly affects production of the neurotransmitter glutamate, which is important for the regulation of emotions as well as learning and memory functions. Acid, or LSD, may cause a user to experience “flashbacks” months or even years after abusing the drug and may cause mood disturbances and long-term memory loss. Hallucinogens are less understood, and long-term effects may not be as fully documented as long-term effects of other drugs.
Research is ongoing as the exact effects drug abuse and addiction may have on the brain and its memories. Multiple drugs at a time may be abused in one sitting, making it harder to quantify the exact ramifications of a singular drug on the brain. Additionally, some people may have underlying brain abnormalities or dysfunctions that may interfere with research results on a particular drug’s effects on the brain and memory loss. It is generally accepted that many of the negative consequences of drug abuse may be reversible when they are removed from the system, and the brain is allowed a chance to recover without the influence of illicit or controlled substances. Many drugs should not be stopped “cold turkey,” however, if the user is emotionally and physically dependent on them. Medical and mental health services may be necessary during detox and throughout a drug treatment program while the brain heals and restores its natural and healthy balance without the presence and chemical disruption of drugs. The sooner a drug abuse or dependency is managed professionally, the less lasting brain damage may be. Utilizing evidence-based treatment models rooted in neuroscience and cutting-edge treatment methods, medical and mental health professionals at Futures of Palm Beach provide supportive and compassionate care plans to treat addiction, mental illness, and co-occurring disorders. Call now to learn more.