Addiction causes – Genetic variability related to attention, impulsivity, and drug use.

It will probably come as no surprise to at least most of you that addiction is closely linked to problems of self-regulation (like ADD and ADHD). This is one of the main reasons that professionals view addiction as a disease, and not a choice.

This post is pretty advanced, but it should leave you knowing a lot more about the relationship between attention, self-regulation, impulsivity, and addiction. Also, when I use the term “Addiction causes” I have to stress that the link to date has been one of association, NOT causation. We don’t truly know what causes addiction.

What is self-regulation?

Self-regulation is the ability to control one’s actions in ways that are appropriate to specific situations. Having to do with the most advanced aspects of cognition, self-regulation is considered to be the prime example of human executive functioning. It’s this aspect of thought and brain function that is thought to truly separate humans from other animals.

Being this important for our functioning, you can probably imagine how complex and interactive the brain systems that control executive functioning are. You’d be right.

These systems, centered in the Prefrontal Cortex (PFC), the part of the brain nestled right behind your forehead, are connected to essentially every other brain system, including vision, hearing, motor control, emotion, etc. It’s the PFC that controls these systems and tells the brain what brain impulses should actually be acted on.

And impulses is a great word for it. Given how complex the system is, there are many things that can affect its function. There are genetic factors, some that have to do with early development, and others that are affected by behavior, including the ingestion of drugs.

In this post, I would like to focus on the genetic influences, later on, I’ll talk about the developmental influences and the effects of drugs and other behavior on these systems.

Genetic influences on executive function:

There are a host of genes that affect different aspects of executive function. Some of these, like those impacting genes related to DAT, DRD4, and COMT functioning, have an effect on dopamine function that has been correlated with personality traits like sensation seeking and impulsivity.

Hyperactivity

As I’d mentioned earlier, these personality traits themselves, and the genes that affect them, have been found to be associated with addiction as well as several other conditions and syndromes that are related (such as ADD and ADHD).

Just to be clear, we all have these genes, but there are different version of them (called alleles). Some of these versions are more common than others, and some are associated with the conditions I mentioned earlier.

For instance: There are 2 versions of the COMT gene. This gene codes for a chemical in the brain that breaks down DA (this breakdown is important for brain function as I’d mentioned in an earlier post). One of these versions (named MET) breaks dopamine more slowly while the other (VAL) breaks it down quickly. The VAL allele actually breaks the dopamine down so fast that it interferes with dopamine’s ability to properly get its message across. That’s why this allele has been linked to attention and impulsivity issues. Each of these alleles has a 50% prevalence in society, which means that 1 out of 2 people have the VAL allele. Obviously its effect is not enormous, but along with many other factors, it has a significant impact on dopamine functioning.

Similar issues come up with one of the versions of the DRD4 gene, which codes for a specific type of dopamine receptor; and with the DAT gene, which codes for the DAT transporter I talked about in the cocaine post mentioned earlier.

Again, while the effects of each of these genetic variants is small, these can add up along with other genetic influences and environmental factors (especially during early development) to overall affect a person’s ability to control impulses.

Obviously, those who have a more difficult time controlling their impulses would have a more difficult time making appropriate choices. These difficulties can lead some to be more likely to start behaviors that are detrimental, including the use of drugs. The drugs themselves can then further exacerbate the problem (as we’ll see in a future post), and can do other things to make users more likely to keep using them.

In short, while genes don’t make people use drugs, they can definitely make it more likely for certain people to engage in risky behavior, including trying drugs in the first place…

Question of the day:
Did any of the people you know who have developed drug use/abuse problem show problems with impulsivity before their drug use?

Addiction brain effects : Opiate addiction – Heroin, oxycontin and more

Okay, we’ve talked about crystal meth and cocaine and how they affect the brain during drug use. As I mentioned, both cocaine and meth interfere with the way the brain stores and cleans up important neurotransmitters, including, most importantly, Dopamine and Norepinephrine.

opiates-morphine & heroinThe class of drugs known as opiates, which includes morphine, heroin, codeine, and all their derivatives (including oxycontin), acts on the brain in a completely different manner. Since our goal at All About Addiction is to explain drug use and abuse as comprehensively as possible, let’s turn our attention to this opiate addiction next.

Heroin, morphine, oxycontin, vicodin and other opiates

While cocaine and crystal meth work by disrupting the normal functioning of molecules responsible for cleaning up released neurotransmitters, opiates work by activating actual receptors that naturally occuring neurotransmitters activate. Substance like this are known as agonists; they perform the same action (identically as, to a lesser, or greater extent) as a substance the body already manufactures.

In the case of morphine, heroin, and most other opiates, the most important receptors activated are knownOpiate Receptors as µ-opioid receptors. Activation of the µ-opioid receptors is associated with analgesia (suppression of pain), sedation, and euphoria, which makes sense given the relaxing, pleasure inducing effects of opiates.

Natural opioids (also called endogenous opioids), which include endorphins, are used by the body to relieve pain and increase relaxation, especially during periods of extreme stress. These are the chemicals that make sure we can function during accidents, like after breaking our leg…

Opioids and dopamine

Opioids also increase the amount of dopamine in the brain indirectly. As I mentioned in the earlier posts, dopamine is thought to be the reward indicator in the brain. Unlike crystal meth and cocaine, heroin and its relatives increase the activity of dopamine neurons by releasing the hold that other neurons (that use GABA) have on them. Think of this as the release of pressure on a hose spraying water on a lawn. When the pipe is pinched, only so much water can get through, but once the clasp is released, water can flow in greater quantity; this is essentially what opiates do.

Heroin addiction and long term opiate use

Like I said before, this doesn’t sound so bad, does it? All we’re talking about here is the increasing of the functioning of system that already exists in the brain. The problem isn’t so much in the process, the problem starts when this system gets activated for long periods of time.

HeroinHeroin addicts, and other frequent users of opiates complain about the extreme discomfort they feel when they stop using the drugs. This discomfort has been described as the worse case of the flu you could imagine. Doesn’t sound too appealing, does it? In fact, withdrawal symptoms associated with stopping opiate use are at least one of the main reasons many users return to the drug after trying to clean up. This in addition to all the other effects of the drug on the brain to make wanting to stop so much harder.

The reason for the pains and aches? Given the overactivation of its pain suppression system, the body not only reduces its own supply of opioids, but it also turns up the sensitivity on its pain receptors. Heroin users notice this as an increase in tolerance, but they compensate for it by simply using more. However, when they stop, they’re left with a body unable to suppress its own, hyper sensitive pain system. The results are more than uncomfortable, they’re simply excruciating…

Another common complaint of addicts is diarrhea. This, again, is simply the reversal of the constipation caused earlier by heroin’s actions on opioid receptors that are present in the peripheral system (outside the central nervous system).

I’ve heard addicts speak online about the slow recovery from opiate addiction and I want to dispell a myth here:

Opiates DO NOT stay in your system for weeks or months – The drug itself is gone from the body within days. The reason for the continued suffering is the slow adjustment of your brain and body back to the way things were before the drugs. Think of how long the tolerance took to develop… Now play the tape back in reverse. That’s what happening to you. You can help relieve the pain, but know that if you use anything in the opiate family, you’re making the process last much longer…

So, in summary: As usual, the actions of opiates on the body and brain are not all the severe, extreme, or inappropriate. Opiates are still used in medicine for pain suppression, not only because they work, but because the potential for abuse when used in this way are minimal to non-existent. However, as with all drugs, continued, chronic, abusive use of opiates will change the way your body functions in ways that will produce the exact opposite effects of those users like so much. This leaves people not only with possible addiction problems, but also with a terrifyingly uncomfortable return back to normal functioning.

Addiction help

If you need help finding treatment for your own, or a loved one’s addiction, make sure to give our Rehab-Finder a try: It’s the only evidence-based, scientifically created, tool for finding rehab anywhere in the United States!

More CPDD Addiction research: Addiction, exercise, recovery!

Okay, this is probably the last addiction research update I will give focusing on the Reno conference. The rest of the stuff I learned will be incorporated into future posts.

I’ve written before about the relationship between exercise and recovery (see here) and I will surely write more since for me, it was a big part of the equation.

two separate studies at CPDD reaffirmed my belief that exercise can be a very useful tool in addiction recovery.

The first study, conducted in humans, examined the effect of incorporating an extensive exercise routine into a residential, as well as intensive outpatient, addiction treatment program. Their findings showed improved outcomes for participants in the short, as well as long run. These included length of sobriety, subjective assessment of well being, and more. In talking to the researcher, she seemed to believe that at least part of the effect was due to the relief of cravings achieved by allowing patients to focus on something that took effort, rather than simply sitting around.

The second, and to my mind even more interesting, study examined the effect of exercise on cocaine self-administration in rats. Researchers assigned half of their rats to a cage that had a running wheel while the others were assigned to a regular cage. the rats with the running wheel used the device to run an average of 12 kilometers a day! After a week of simply resting in their cages, when transferred to another cage for 2 hours a day, the rats who had the wheel in their cage took less than half as much cocaine as the rats who didn’t have a wheel. the “wheel-rats” were also found to run less after they began the cocaine portion of the experiment, but their cocaine-taking never got near that of the non-exercising rats. It seems that having the exercise did something to reduce the reinforcing power of cocaine.

I have a feeling that future research will show that these finding hold true for other drugs (like crystal meth, heroin, marijuana, cigarettes, and alcohol) and possibly even for behavioral addictions like food addiction, gambling, and sex addiction.

All in all, research seems to be supporting the notion that exercise can play a significant role in recovery from addiction. Whether it be for boredom relief or an actual internal change in the motivating power of drugs, it looks to me as if Addiction + Exercise = Recovery !

Links of the week

Guess what? It’s that time again. Here are some posts by other writers that offer good help for addicts. I know I’ve been slacking on these, but I’ve simply had too many of my own cents to add. It happens often.

Trudging the gentle path: Being an atheist in recovery

Spiritual River: A new recovery eBook

Stop eating disorders: How to stop a binge

About.com: Signs of a relpase (I don’t necessarily agree with all of these, but it’s a good article)

Addiction Recovery Basics: Sign of addiction

That’s it for now, enjoy!

And don’t forget to click the title of the post for related articles on allaboutaddiction.com that offer addiction help!

Latest drug addiction research from CPDD: Drug use patterns among adults

I’m currently attending the annual meeting of the College on Problems of Drug Dependence (CPDD) in Reno, NV.

Since there’s so much drug addiction research being presented here, I figured I would post a daily update with some of the things I found most interesting. There’s absolutely no way for me to see all the presentations I’m interested in, so what I get to see is what you get to hear about.

One of the interesting presentations today had to do with a broad study of drug use patterns among adults who are not drug addicts. The study, conducted by researchers at the University of Alabama (who ran the CARDIA study), looked at the drug use patterns of adults enrolled in a Coronary Artery Risk study over many years. It’s important to note that drug use in this case does not include smoking, drinking alcohol, or marijuana use. The researchers also didn’t distinguish between use of different drugs for the purpose of this study.

The researchers found 4 common drug use patterns:

  1. No current use – Over 80% of the participants reported no use within a month of any of the follow-up dates. More than half of those people said they’d used at least one drug at some point in their life, but their use was not common enough to ever fall within a month of their check-ups.
  2. Early use, low frequency – About 12% of people used drugs with some frequency at an early age but then reduced their use throughout the follow-up period.
  3. Persistent use, low – These users continued to use drugs throughout the study period, but their use did not escalate.
  4. Early, persistent, use – These users started early, used a lot, and though their use tapered off, it remained higher than any other group throughout the study.

I personally think that these findings are encouraging. They show that at least within this population, only a small proportion of individuals engage in what we would consider chronic, dangerous, drug use.

I reported similar findings regarding relapse in alcoholics in another post a while back (see here), and I’m glad that statistical techniques are being used to uncover larger patterns of drug use and abuse in a more general population.

More addiction research to come. There’s almost too much to report!

The brain-addiction connection: Cocaine, dopamine, and more

Okay, so we’ve covered how the brain’s neurons communicate with one another normally; now let’s learn about how drugs mess things up to produce their specific effects. Since the brain-addiction relationship is different for different drugs, we’ll do this one by one, starting with cocaine:

Cocaine

One of the most commonly abused drugs, cocaine interrupts a molecule in the brain that’s responsible for clearing away the dopamine that is released during normal functioning (it’s called DAT). Like I’d said before, neurons talk to each other by releasing these neurotransmitter molecules to transmit impulses from one to another.

Imagine for a second that every time you spoke, the sound of your voice would continue on, reverberating endlessly. By the time each of us would be done uttering our first sentence, the world would be a mess of unintelligible sounds, echoing forever. This wouldn’t make for a very effective way of communicating.

Sound loses energy as it travels through air, eventually having so little energy that it no longer moves enough air to be audible. This keeps each word distinct and meaningful. In the brain, the individual messages between neurons are similarly kept distinct up by a number of processes.

These include dissipation, chemical breakdown, and reuptake.

Let’s learn more about these processes

Dissipation is a process similar to the story with air and sound, as the molecules move around, their concentration gets lower, and they become less likely to activate anything.

Chemical breakdown does is exactly what it sounds like, chemicals breaking the neurotransmitters down so they can no longer activate anything.

Reuptake is a more complicated process of recycling. Instead of letting all those precious chemicals go to waste, the brain recycles them so they can be used again later. Cocaine blocks the molecule that makes this reuptake process (for dopamine) possible. It’s a small molecule that carries the cocaine back into the cell that released it. Cocaine wedges itself in place of the dopamine (see picture below) and therefore deactivates it.

Dopamine Transport Molecule

What does cocaine’s action result in?

The result is that since it can’t be as efficiently cleaned up, dopamine ends up hanging around the brain for longer than it’s supposed to. Because dopamine is one of the brain’s main “pleasure”, or “positive” signaling molecules, users of cocaine feel better than they would otherwise as a result of this extra dopamine.

This doesn’t sound like such a bad thing, does it? Reuptake is a small price to pay for feeling a high that is almost “naturally produced” (some of the brain’s own dopamine hanging around for longer than it should). The problem is, that like in anything else, for every action, there’s a reaction…

What happens when cocaine in taken for a long time?

Faced with increasing amounts of dopamine, the brain starts adjusting in these ways:

  • It starts out by producing and releasing less dopamine, because as far as it’s concerned, the balance has been interrupted.
  • The number of receptors available to bind with dopamine is also reduced.
  • Next, it starts turning up brain systems that are supposed to counteract the actions of dopamine in order to once again, adjust for the increased levels.

Overall, these are some of the reasons for the “come down” or, after effects of a heavy night of cocaine use.

Over time, many of these changes become long lasting, resulting in a whole set of undesirable effects for the user, including withdrawal, mood problems, as well as some serious problems with thinking and control over behavior.

Not to be ignored are the effects that cocaine use, and the good feelings it initially brings along, have on motivation and normal reward functioning and learning in the brain; but we’ll get to that in another lesson…

Question of the day:
Does the above explanation of how cocaine works help you make sense of the effects it has? Could you see how these effects would possibly bring about addictive, rather than recreational, use?

About addiction: Meth, pregnancy, codependency, and ADD

Here’s a new set of articles about addiction that are worth taking the time to read. As usual, don’t forget that if you click the title of this post, you’ll get a list of posts on our site that are related to this week’s links (below the post).

Breaking The Cycles: To Talk or Not To talk – A great post about a topic we’ve already mentioned on here

PhysOrg: Crystal Meth during pregnancy

Addiction Today: Families and marijuana use

Science Blogs Select: Poppy tea can kill you

ADD ADHD Blog – Nascar and ADD – I’ve long thought that there was a relationship between impulse control problems and other conditions that are more acceptable than drug addiction…

That’s it for now, enjoy!