With all the medical marvels that research scientists have been able to create, and with intense focus on prevention, treatment and recovery for the increasing numbers of people addicted to illicit substances, prescription drugs used nonmedically, and process addictions, it’s logical to conclude that there must be a way to somehow just turn off addiction. But is it really possible now? Is it only a matter of time? Or is such a thing merely wishful thinking? Let’s look at where science is today relative to turning off or curing specific types of addiction.
Obesity
A study conducted by researchers from Scripps Research Institute has shown that the same molecular mechanisms that cause people to become addicted to drugs are also behind the compulsion to overeat, pushing people into obesity. Results of the study were published in Nature Neuroscience in March 2010 and received a great deal of attention following a preliminary abstract was presented at a Society for Neuroscience meeting in October. News media articles around the world seized on the point that obese patients have been saying for years: that compulsive or binge eating of junk food, just like other addictions, is extremely difficult for the individual to stop.
The study goes even deeper than the abstract, however, and took three years to complete. In the study, using rat models, researchers were able to show that the rats developed obesity coincident with the progressive deterioration of the chemical balance in the brain’s reward circuitries. What happened, in essence, is that as the rats’ pleasure centers in their brains became less and less responsive, they consumed more and more high-calorie food to the point where they became obese. These exact changes occur in rats that overconsume heroin or cocaine and are believed by researchers to play an important role in the development of compulsive drug use or addiction.
After demonstrating the rats that were obese had addiction-like food seeking behavior, the researchers then investigated the molecular mechanisms underlying such behavior. They focused on the dopamine D2 receptor, already well-known to play an important part in vulnerability to drug addiction and obesity. The D2 receptor responds to dopamine, a neurotransmitter released in the brain by pleasurable experiences like sex, eating food, and doing cocaine. In the example of cocaine abuse, the drug alters the dopamine flow by blocking its retrieval, thus flooding the brain and overstimulating receptors. Over time, this leads to physical changes in the manner in which the brain responds to the drug. The same thing happens with addiction to junk food. Summing up, the D2 receptor levels were significantly reduced in the obese rats.
Another interesting finding was that when researchers injected a specialized virus into test rats that knocked down the receptors, they immediately developed addiction-like eating behavior.
What does this study have to do with being able to turn off addiction? In order to get to the point where medications or treatments can be developed to help stop addition, researchers first have to know how the addiction develops. Discovering the molecular mechanisms in the brain that underlie addiction is the first step. And it is a promising one – whether it’s for searching for a way to turn off addiction to cocaine or heroin or compulsive sex or compulsive overeating.
Cocaine Addiction
Another study, again conducted by Scripps Research Institute, explored various pharmacological strategies for reducing cocaine dependence in rats that self-administered the drug. The study may have implications for how doctors may be able to one day treat cocaine dependence in humans. This study focused on glutamate, the primary excitatory neurotransmitter in the brain, which has been linked with addiction. Glutamate is an important neurotransmitter that is involved in memory and learning. Metabotropic glutamate receptors (mGluRs) represent a family of G-protein coupled receptors that modulate the transmission of glutamate. These receptors are promising targets for development of drugs that may eventually be used to treat a number of neurologic and psychiatric disorders, including addiction to drugs.
What researchers found is that using certain agonist and antagonist medications on two specific G-protein receptors produced results that appeared to be effective with different stages of cocaine abuse. Without getting too technical, use of one of them, an agonist for mGlu2/3, may be a promising target for severely-addicted cocaine users, while the other, mGluR5, an antagonist, may be useful only for treatment of the early stages of cocaine abuse.
Bottom line importance of this study: All types cocaine use may not be alike. Different exposure to cocaine may produce different adaptations in the brain. The profiles of the two study metabotropic glutamate receptors should stimulate additional research and may one day result in medications that can reduce or eliminate cocaine addiction.
Brain Plasticity
Researchers in Bordeaux, France studying the correlation between synaptic plasticity and the transition to addiction found that the brains of addicted rats had a permanent loss of the capacity to produce a form of plasticity known as long term depression (or LTD). LTD, which refers to the ability of synapses (region of communication between neurons) to reduce their activity under the effect of certain stimulation, plays a major role in the development of new memory and in flexible behavior. In essence, short-term cocaine usage does not result in modification of LTD, but long-term cocaine use results in LTD deficits in all users.
Why is plasticity of the brain important? Researchers say that without this plasticity, which allows new learning to occur, a person’s behavior becomes increasingly more rigid, possibly leading to the development of compulsive consumption of drugs. And, since addiction exhibits many similarities in men and rodents – and, in particular, the fact that only a small number of consumers of drugs (men or rodents) become addicted – these discoveries may have important implications for developing new treatments for addiction. It is important to note that researchers say that these discoveries probably won’t mean they’ll be able to find new therapies trying to understand the modifications caused by a drug in the brains of drug addicts – because those brains already are anaplastic (suffering loss of plasticity). It’s more in the brains of non-addicted drug users that scientists may find a key to effective addiction therapy treatment.
Bottom line: Researchers may be onto a way to understanding the biological mechanisms which enable adaptation to a drug and help the user maintain a controlled consumption, and then developing effective tools to combat the loss of plasticity that leads to addiction.
Workaholism
A new study in Spain has resulted in the development of a new scale, the DUWAS (Dutch Work Addiction Scale), for measuring addiction to work, or workaholism. Work addiction is characterized primarily by two features – working compulsively and working excessively. People are only workaholics if they not only work excessively, but they also work compulsively, and they feel anxious and guilt-ridden when they are not working.
How widespread is work addiction? The prevalence varies from country to country. In countries such as Japan, for example, work addiction is estimated to be 20 percent, while in Spain the prevalence is between 11.3 and 12 percent. Experts say that spending more than 50 hours per week working could be a determining factor in work addiction.
Addiction to work is characterized by extreme activity at and devotion to work (working outside normal working hours, working nights and weekends and holidays), compulsion to work (inability to delegate tasks to others), relating self-esteem to work, and focusing on work to the point where it interferes with their interpersonal communications.
Work addiction risk factors include fear of losing a job, competition in the job market; financial, family and social pressures; need to achieve a certain level of success; high levels of personal efficiency; fear of overbearing, threatening or demanding bosses; and lack of personal affection leading the individual to make up for this deficiency by working harder and longer.
People who are workaholics also tend to take illegal substances to enable them to work harder, increase their productivity and performance, and overcome tiredness and the need for sleep.
Bottom line: The development of a more effective scale to evaluate work addiction will prove more beneficial in helping identify affected individuals and getting them into effective treatment to overcome such addiction. It can also help identify individuals who are in the early stages of workaholism and provide them with healthier coping mechanisms.
Use of Supervised Injection Facilities Aids in Quitting Injection Drugs
A study conducted in British Columbia found that the use of supervised injection facilities, such as Insite in Vancouver, which connects its clients with addiction treatment programs, leads to a greater likelihood of such clients eventually quitting injection drug use for at least six months. The study results were reported in September 2010 in Drug and Alcohol Dependence, a peer-reviewed journal. It was the first to show a causal link between the use of a supervised injection facility with the cessation of injection.
There had already been extensive research showing the increase in admission to drug treatment by clients who used supervised injection facilities, but none that studied the subsequent cessation of drug injection. What the new study found is that clients who had been going regularly to Insite and then went into drug treatment were more likely to have had contact with on-site addiction counselors. It was this group that was most likely to subsequently stop injecting drugs.
Addiction is recognized as a chronic relapsing condition, and the definition of “injection cessation,” for the purposes of this study, was restricted to a period of six months.
Bottom line: Anything that can get injection drug users into treatment is a positive step. Repeated access to addiction counselors at a supervised injection facility site helps clients become motivated to enter treatment and, based on the results of this study, more likely to remain free of injecting drugs for a period of six months following completion of treatment.
Brain Training to Think Ahead of Drug Use Consequences
People who are vulnerable to addiction lack an ability to see past their immediate desire for drug seeking and drug use. This is a process called “delay discounting,” which is a tendency to devalue future rewards and punishments. Delay discounting may be parallel to “reward myopia,” which is a tendency to opt for something more immediately stimulating, such as drugs. Delay discounting is a cognitive function involving the brain’s frontal cortex. It builds on working memory, that is temporarily storing and managing information to reason and guide behavior.
What happens in people vulnerable to addiction – who know that drug use is harmful – tend to discount or devalue this information and instead are drawn to the immediately rewarding affect they get with drug use. In a new article published in Biological Psychiatry, researchers studied this process using an approach they borrowed from rehabilitation of traumatic brain injury and stroke patients.
Researchers had stimulant abusers repeatedly perform a task involving working memory, basically exercising their brains to promote functional enhancement of the underlying cognitive circuits. The result was that such training improved working memory and had the added benefit of reducing discounting of delayed rewards.
Researchers found that myopic view of immediate pleasures and delayed punishments isn’t a fixed feature of addiction and postulate that cognitive training may be one tool clinicians may use to end the so-called hijacking of imagination by drugs of abuse.
Bottom line: While this study needs to be replicated and extended, it may provide a new target for drug abuse treatment and a new method to help intervene in addiction.
Genes Associated with Binge Drinking Identified
Binge drinking – defined as achieving blood alcohol content (BAC) of 0.8 g percent in a two-hour period (the legal limit in many states) – is a serious problem in America. This is a pattern of behavior seen often among college students on spring break as well as hard-partying adults. Binge drinking doesn’t meet the classic definition of alcoholism – characterized by dependence and a long period of drinking followed by withdrawal – but it carries many of the same serious health risks as excessive drinking. These include heart disease, cancer, and motor vehicle accidents, among many others.
University of Maryland researchers identified two genes associated with binge drinking that may lead to new, more effective ways of treating excessive drinking. The researchers manipulated to brain receptors, GABA receptors and toll-like receptor 4 (TLR4), that resulted in significant binge drinking reduction for two weeks in rats that had been bred and trained to drink alcohol excessively.
What the researchers found is that treatments that manipulate both of these receptors have the potential to reduce anxiety and control cravings – with little to no risk for addiction. Partial funding for the study came from the National Institute on Alcohol Abuse and Alcoholism (NIAAA), part of the National Institutes of Health (NIH).
There are compounds that exist that would stimulate receptors in the same way scientists did in this study. Down the line, these compounds could become new therapies for binge drinking. In essence, they would act as a substitute for alcohol, in much the same way as methadone acts as a substitute for heroin. The compounds would help alcoholics stop drinking, reduce cravings for alcohol, and reduce the anxiety they try to alleviate by drinking.
Bottom line: Further investigation of the role of TLR4 and GABA receptors is required. But the discovery of the involvement of TLR4 in the pathway with GABA is remarkable in that it provides a new understanding of what each is all about. Future treatments could target one or both, depending on what scientists find.
Promising New Treatment for Heroin Dependency
Heroin addiction is commonly treated today with methadone or Subutex, two substances that resemble morphine and are addictive, but reduce heroin use and criminality among patients. A new treatment in a Norwegian study using naltrexone implants is targeted toward people who wish to overcome addiction to heroin without using other addictive substances.
What happens is that naltrexone works by completely blocking the effects of heroin and other morphine substances. This not only reduces the likelihood of overdose, but also physical dependency and other drug cravings.
Although it was a small-scale study (56 heroin-dependent patients who were already detoxed and motivated to stop using heroin), after six months, more than half of the naltrexone implant group (11 out of 23) compared with 5 out of 26 (in the control group), managed to remain drug-free (of heroin or other morphine substances).
Researchers found that the findings were clear-cut and are seeking to obtain a more detailed documentation of the effects of naltrexone in order to provide a basis for approval from the Norwegian Medicines Agency to include naltrexone implant as one of the treatment options available to heroin-dependent patients in Norway.
Bottom line: It is through research such as this that scientists may be able to find a way to turn off addiction to heroin and other morphine substances.
Hope for the Future
While the above-mentioned studies – which are only the tip of the iceberg in the hundreds of studies currently in progress — point to some promising discoveries, there is, as of yet, no absolute way of turning off addiction. Much further investigation needs to be done, replicated, verified, and then work begun to develop treatments that may prove effective in either preventing addiction or treating it so that it doesn’t return – or both.
In answer to the question, is it possible to just turn off addiction – the truth is that scientists are making a great deal of progress, but there’s still a long way to go. There is hope for the future.
http://www.addictiontreatmentmagazine.com/addiction/is-it-possible-to-just-turn-off-addiction/