Substance Use & Abuse on Brain Health

by Women's Brain Health Initiative:Substance abuse is commonly considered a problem that affects younger adults, but research has shown that substance use, abuse, and addiction are not limited to a specific age. Historically, older adults have not demonstrated high rates of alcohol or other drug use compared with their younger counterparts or presented in large numbers to substance abuse treatment programs.These facts have helped to create and perpetuate a misconception that older adults do not use substances and/or do not use substances problematically. However,A SUBSTANTIAL AND GROWING PERCENTAGE OF OLDER ADULTS KNOWINGLY OR UNKNOWINGLY MISUSE ALCOHOL, MEDICATIONS, AND ILLEGAL SUBSTANCES.It is estimated that the number of people aged 50 and over who require treatment for illicit drug problems in the U.S. may increase by as much as 300% by 2020, compared to 2001.The number of older adults engaged in substance abuse is rising in part because the aging baby boomer population (those born between 1946 and 1964) is simply increasing the number of older people dramatically. But, among the baby boomer cohort, rates of substance abuse tend to be higher than any previous generation, further amplifying the growth in numbers of elderly persons with substance abuse problems.Alcohol and prescription drugs are the most commonly abused substances among older adults, but illicit drugs are used as well. The types of illicit drugs used by those 50 and older tend to mirror the ones frequently used amongst the general population.Cannabis is the most commonly used “illicit” drug in the world, with 192.2 million people reported as past-year users in 2016, according to the most recent World Drug Report published by the United Nations Office on Drugs and Crime. (“Illicit” has been used in quotation marks to highlight that cannabis is illegal in many places around the world, but not all.) Opioids are the next most commonly-used type of drug, with 34.3 million past-year users, followed by amphetamines and prescription stimulants (34.2 million), ecstasy (20.6 million), and cocaine (18.2 million).The World Drug Report further indicates that an estimated one in nine people who use drugs (11%) suffer from “drug use disorders,” meaning that their drug use is harmful to the point where they may experience drug dependence and/or require treatment. As of 2016, there were 30.5 million people worldwide who suffer from this disorder. Opioids cause the most harm, accounting for 76% of drug abuse-related deaths.There are, of course, numerous negative health impacts related to the abuse of prescription and illicit drugs, including the potential to die from an overdose. This article focuses specifically on the impacts to the brain and cognitive function. According to an Alzheimer’s Australia fact sheet,ALL SUBSTANCES OF ABUSE DISRUPT NORMAL NEUROTRANSMISSION AND CAN CHANGE THE STRUCTURE OF THE BRAIN, POTENTIALLY INCREASING THE RISK OF DEVELOPING DEMENTIA.The Impact of OpioidsOpioids are drugs used primarily to provide relief from pain (both physical and emotional), but can also be used as a treatment for other conditions such as cough and diarrhea suppression. Some opioids are prescribed drugs, some are over-the-counter medications, and others are considered illicit. When used properly, prescription and over-the-counter opioids can be helpful. However, all types of opioids can induce feelings of euphoria (i.e. feeling high), so they have the strong potential to be misused. It is important to note, though, that only a minority of individuals who use opioids develop an addiction.Research has shown that opioid misuse can affect the physical structure of the brain. Researchers S.N. Ramage and colleagues conducted post-death examinations of the brains of 34 intravenous drug abusers, who had mainly used heroin and methadone. The brains of 16 additional non-drug users were also examined for comparison (i.e. the control group). The average age across both groups was 26 years old.The researchers discovered that the drug abusers had a level of brain damage usually seen only in much older adults. In fact,THE BRAIN DAMAGE WAS SIMILAR TO THAT OBSERVED IN THE EARLY STAGES OF ALZHEIMER’S DISEASE.Damaged nerve cells were found in key areas of the brain that are involved in learning, memory, and emotional well-being. Those in the drug abuse group were up to three times more likely to have suffered brain damage than those in the control group. These findings were published in Neuropathology and Applied Neurobiology in 2005.Opioid misuse has also been linked to negative changes in cognitive function. A meta-analysis of research findings about the neuropsychological consequences of chronic opioid use published between 1964 and 2010 was undertaken by Dr. Alexander Baldacchino and colleagues, with the results published in Neuroscience & Biobehavioral Reviews in 2012.“Our analysis revealed that chronic opioid exposure is associated with deficits across a range of different neuropsychological domains,” explained Dr. Baldacchino, Chair in Medicine at the University of St. Andrews in the U.K. “However, the only domains where robust impairment was found were working memory, cognitive impulsivity (risk taking), and cognitive flexibility (verbal fluency).”A confounding variable is a factor that a researcher failed to control or eliminate, thus damaging the validity of the experiment and limiting the conclusions that can be drawn. Studies of human opioid users can have various confounding variables, though, making it challenging to determine the effects of opioids alone. In other words, there may be other elements at play that affect chronic opioid users’ brains and cognitive function. For example, they might use multiple types of drugs or there may be predisposing factors (e.g. some brain abnormalities and functional deficits may have been present before a person started taking drugs, and perhaps made him or her vulnerable to developing an addiction).Research conducted by Dr. Karen Ersche and colleagues – published in Science in 2012 – discovered evidence of such predisposing factors. “Since brain structure is largely inherited and drug dependence runs in families, we wondered if there might be a genetic or epigenetic influence on addiction,” said Dr. Ersche, “and we found that might indeed be the case.”The researchers compared brain structure and ability to regulate behaviour in 50 biological sibling pairs. Within each pair, one sibling was dependent on stimulant drugs and the other had no history of chronic drug or alcohol abuse. These sibling pairs were also compared with 50 unrelated, age- and intelligence-matched healthy volunteers. “Our research revealed that impairments and brain abnormalities frequently seen in the siblings with drug addiction were also seen in their non-addicted siblings, suggesting that these impairments had been there before drug use began,” Dr. Ersche explained.The Impact of CocaineCocaine is a stimulating drug derived from the coca plant that causes an intense euphoric effect. It is used in either powder or rock form (“crack”), and is highly addictive. Cocaine use is known to cause physical structure changes in the brain, as well as to have a negative impact on cognitive function.A recent academic review by Dr. Kirsten Frazer and colleagues examined the research published about the relationship between cocaine and cognition between the years 1999 and 2016. The majority of studies they reviewed reported statistically significant differences between cocaine users and non-drug-using controls in brain structure, blood-oxygen-level dependent signals, and brain metabolism.The researchers found differences in cognitive performance between the two groups as well, but limited to just a couple of measures (namely, executive function and working memory). They did not find evidence that chronic cocaine use is associated with broad cognitive deficits. These findings were published in 2018 in Behavioural Brain Research.An example of a study that found cocaine use to be linked with alterations in brain structure was written by Dr. Karen Ersche and colleagues, and published in 2013 in Molecular Psychiatry. In that study, the researchers explored whether cocaine dependence is a “fast-track for brain ageing.” They concluded that it might be, after reviewing brain scans of 120 participants aged 18 to 50 years old. Half of the participants were addicted to cocaine and the other half had no history of substance misuse.“We looked for differences in gray matter volume between the two groups,” explained Dr. Ersche, a lecturer in the Department of Psychiatry at University of Cambridge in the U.K. “We discovered that all participants showed a reduction of gray matter volume in cortical and subcortical regions as they aged, but the annual rate of gray matter volume loss in cocaine-dependent individuals was twice the rate of the healthy participants.” The accelerated decline in brain volume was most prominent in the prefrontal and temporal cortex – important regions of the brain associated with attention, decision-making, and self-regulation, as well as memoryCannabis in CanadaCannabis became legal in Canada on October 17, 2018. Prior to this date, only prescribed medical marijuana use was legal (as opposed to recreational use).In the fifth issue of Mind Over Matter®, we examined the research to date on cannabis and its impacts on brain health. Despite its legalization, Health Canada continues to warn the public about the short- and long-term negative effects of cannabis on the brain, particularly for individuals who begin using it at a young age, use it frequently, and over long periods of time.While it is true that recreational uses of cannabis affect cognitive function, research suggests that some types of cannabis use (for instance, medical marijuana or small doses of isolated components) may have a positive impact on the brain – acting as a neuroprotectant and anti-inflammatory, helping prevent, stop or reverse brain disease. Cannabis may also be helpful in treating symptoms of Alzheimer’s disease such as agitation, aggression, and pain. More research is needed, though, to fully understand the association between cannabis and the brain, and how best to use cannabis for therapeutic effect.Opioids & Opiates: What’s the Difference?Some people carefully distinguish between the terms “opiates” and “opioids,” while others use the terms interchangeably or have a preference for one or the other. The latest trend, among journalists and politicians in particular, is to use the term “opioids” to encompass all of these types of drugs.For those who differentiate between the two terms, the difference lies in how the drugs are made. Opiates is the term used to refer to drugs that have been extracted or refined from natural plant matter (for instance, poppy sap and fibers). Opium, morphine, codeine, and heroin are all examples of opiates.Opioids, on the other hand, is the term used to refer to drugs that are synthesized or made in a laboratory, as opposed to derived from natural plant matter. Some of these drugs may be partially synthesized from components of opium (such as hydrocodone, hydromorphone, and oxycodone), while others are completely designed and constructed in laboratories.The pharmaceutical industry has created hundreds of different opioid molecules. Some of the more widely-used opioids include the following:

• Dextromethorphan (e.g. in over-the-counter products like NyQuil, Robitussin, TheraFlu, and Vicks);
• Loperamide (e.g. in the over-the-counter drug Imodium);
• Hydrocodone (e.g. Vicodin);
• Oxycodone (e.g. Oxycontin and Percocet);
• Methadone (e.g. Dolophine); and
• Fentanyl/fentanil (e.g. Ultiva and Sublimaze).

Source: MIND OVER MATTER V7