Physical addiction or psychological addiction – Is there a real difference?

This is another one of the basic questions I get regarding addiction.

It seems that people think about physical addiction and psychological addiction as somehow separate processes. I think this distinction makes no sense. Even if people really meant what they were saying, the brain is undoubtedly part of the body, and therefore, psychological addictions are also physical.

The “Physical Addiction” Vs. “Psychological Addiction” truth

blackboardWhat people are really referring to when they make this comparison is the distinction between physical withdrawal symptoms and the addictive process in the brain. There’s no doubt that some substances, like alcohol, opiates, and the likes, leave long term users with horrible withdrawal symptoms that are terrible to watch, and even worse to go through. In fact, early addiction theories asserted that it was this horrible withdrawal syndrome that made people go back to drugs. This was called the Tolerance-withdrawal addiction theory.

The Tolerance-withdrawal addiction theory fell apart when addictions to substances that didn’t display such withdrawal effects became obvious (like cocaine addiction), and when getting people through the difficult withdrawal proved insufficient to cure their addiction (naltrexone was thought to be the magic cure once upon a time).

In one of my previous posts about marijuana addiction, a reader suggested that since marijuana does not produce horrible withdrawal symptoms, it can not be physically addictive. While withdrawal from marijuana, cocaine, methamphetamine, nicotine, and numerous other drugs does not result in the stereotypical “opiate-withdrawal-flu-like-syndrome,” there is no doubt that real withdrawal from these substances exists for long term users and it sucks: Fatigue, depression, anxiety, sleep disturbances, and trouble eating are only some of the symptoms that tend to show up.

Withdrawal – The real physical addiction

Withdrawal symptoms occur because the body is attempting to counteract the stoppage of drug ingestion. Just like tolerance builds as the body adjusts to chronic drug use, withdrawal occurs as the body reacts to its cessation.

As crystal meth increases the amount of dopamine present in the brain, the body reacts by producing less dopamine and getting rid of dopamine receptors. When a user stops putting meth in their body, the low production of dopamine must increase and additional receptors must be inserted. Like tolerance, the process of withdrawal, even past the initial, obvious, symptoms, is a long and complicated one. For crystal meth addicts, the initially low levels of dopamine result in what is known as anhedonia, or an almost complete lack of pleasure in anything. There’s no mystery as to why: Dopamine is one of the major “pleasure” neurotransmitters. No dopamine, no pleasure.

The process of addiction in the brain

So, if we’re going to try to dissect which drugs cause what effects on the body, it’s important that we understand the underlying causes for those effects and that we use the proper language. Withdrawal, tolerance, and addiction are different, though obviously related topics. Their interplay is key for understanding the addiction process, but their more subtle points can often be lost on those observing addicts unless they are well trained.

As I’d mentioned in earlier posts, our current best notions about addiction are that the process involves some obvious physical and psychological processes and some much more subtle effects on learning that are still being studied. A study I’m currently conducting is meant to test whether drugs interfere with some of the most basic learning processes that are meant to limit the amount of control that rewards have over behavior. Such fine distinctions are no doubt the result of the ways in which drugs alter the neurochemical reactions that take place in our brain. Such basic changes can not possibly be seen as any less important than physical withdrawal symptoms.

All in all, the only way to look at Addiction is as both a psychological addiction AND a physical addiction that are inextricably liked through our psyche’s presence in the brain, a physical part of the body. It may seem like a small thing, but this distinction makes many users feel as if their problem is less, or more, sever than that of other addicts. As far as I’m concerned, if you have a behavior that is making your life miserable and which you can’t seem to stop, it doesn’t matter if you’re throwing up during withdrawal or not. It’s an issue and you need help.

Addiction-brain effects – Tolerance, sensitization, and withdrawal

If you’ve been with us for any length of time, you’ve already read about the addiction-brain effects for specific drugs. I think it’s important to understand some of the more general changes that occur in the addicted brain regardless of the specific drugs used.

One of the most common effects of long term drug use is something called tolerance, or the reduced effect of a drug dose. A lot of people know about this one, especially if they’re users and have found themselves needing to use more and more to get the same effect. However, while this is the most known, it is not the only change in the body, or brain’s, response to drugs with repeated use. The other effect, known as sensitization, is characterized by the exact opposite reaction – an increase in the response to the drug.

Tolerance & Withdrawal in the addicted brain

toleranceThe exact mechanism by which tolerance occurs is different for each drug, but the overall concept is the same. With repeated drug administrations, the body adjusts its internal processes in an attempt to return to its initial level of functioning. Drug use normally causes greater quantities of neurotransmitters like dopamine, serotonin, the opioids, and adrenaline to be present in the drug user’s synapses (see here for a review). The body counters this by reducing its own release of these chemicals, reducing the numbers of receptors that can be activated by the neurotransmitters, and increasing functions known as “opponent processes” that are meant to counter their activity.

The interesting thing about tolerance is that by reducing the level of these important neurotransmitters, addicts are left with another, possibly more important effect, which is the loss of the addicted brain’s ability to respond to any reward, including natural ones like food, sex, enjoying a good football game, or anything else. Essentially, this sort of cross-tolerance leaves the addict less able to respond to rewards in general.

The reduced response to drugs, and the corresponding changes in the body and brain’s own functioning, have long been thought to be a major cause of addiction. The withdrawal that results once drug taking stops is closely linked to the development of tolerance. Still, we now know that tolerance and withdrawal are not necessary, and certainly not sufficient for the development of addiction. Nevertheless, they are referred to as the physical dependence portion of addiction and are often are part of the overall picture.

Sensitization

Sensitization is the term used for an increased response to the same dose of a drug. That might sound a little oxymoronic after the tolerance discussion we just had, but bare with me.

Tolerance commonly develops when drug use is constant, or ongoing. It’s an aspect of chronic, long-term, use. On the other hand, sensitization is likely to occur when a user engages in intermittent, binge-like, drug use happening either once daily, or with even greater spacing (as in once every few days) and in large quantities. When you combine chronic use with binge behavior, you can actually get both responses.

Sensitization to drugs has been shown for physiological responses like heart-rate, blood pressure, and movement in animals and humans. More importantly, sensitization plays a part in increasing the motivation for drug use. Just like sensitization increases the physical response to drugs, there is a corresponding increased response in the addicted brain in areas important for motivation (like the NAc and VTA for instance). If an addict responds more to their drug of choice after repeated use, it should come as no surprise that sensitization has also been hypothesized to play an important role in the addiction process.

Drugs cause brain changes that drive addiction

opponent processesWhen both tolerance and sensitization develop in someone who has been using drugs, they’re left with a reward system that is less responsive to rewards in general while being more responsive to the drugs they’ve been binging on and to cues (or triggers) that are associated with those drugs. If that sounds like a recipe for disaster, it is. If you’re an addict yourself, you don’t have to imagine this, you’ve lived it – A state where nothing seems rewarding without being high.

The problem is that both tolerance and sensitization are examples of changes in response to drugs that are completely outside of the control of the user. There’s no doubt that the average drug user doesn’t think about, or even recognize, that as they continue to use drugs, their body adjusts in multiple ways that can make it that much harder for them to stop use at a later point. It should be clear that this is not an issue for everyone – both tolerance and sensitization require repeated administration of drugs that are pretty close together. But they don’t require hundreds of uses, a few days with continuous, or intermittent use, are often enough to bring about these changes in the addicted brain.

We often hear that even the first hit of a drug can cause someone to be addicted. While there’s little doubt that even a single drug administration can change brain response in important ways, I can say with absolute certainty that using a drug repeatedly cause long-lasting changes in the brain chemistry that make future drug use more likely.

Obesity, drug addiction, and dopamine

Eating junk-food can be addictive, and apparently, it causes brain changes that look eerily similar to drug addiction. That’s the message not only from the rapidly fattening waistlines of Americans everywhere, but also from the Johnson and Kenny labs at the Scripps Institute.

Food and drug addiction

The idea that obesity is caused by a compulsive pattern of eating, and that there could be a similarity between such compulsive eating and drug addiction isn’t super new. In fact, Dr. Volkow from NIDA seemed to make research into this association her goal when taking  the helm of the addiction research kingdom.

When you think about it, the notion isn’t far-fetched: Drug addicts continue to take drugs, in increasing amounts, even though they’d often like to stop (at some point) and in the face of negative consequences and the common loss of other important life functions (like family, work, etc.). Obese individuals are quite the same, eating more and more food regardless of their desire to adopt a healthier diet and in-spite of ridicule, low self-esteem, and decreased functioning that often accompanies extreme weight gain.

The research by Johnson and Kenny examined whether exposure to the kind of high-fat, super high-calorie foods that floods the junk-food market are responsible for creating food-addicts in a similar way to drugs that alter the brain in ways that make stopping more difficult.

Dopamine, reward, and junk-food

The study took three groups of rats and gave them either the regular chow diet lab animals are used to or the worse kind of birthday party food: bacon, sausage, cheesecake, pound cake, frosting and chocolate. You can imagine the party going on in the rat cages that got to eat that! Of the two groups that got to eat the crazy-fat food, one had unlimited access while the other got to binge for only one hour a day.

The bottom line: Only the rats that got unlimited access to the fat-party food developed compulsive eating habits that resulted in roughly twice the weight gain of the other two groups and the ability to continue eating even in the face of signals for punishment (a light that they were trained to associate with shocks).

When the researchers looked deeper, they found that the brains of these rats suffered a significant reduction in the density of a specific kind of dopamine receptor (D2) in a brain part known as the striatum, the same kind of reduction common in drug addicted people and obese individuals. This receptor type is often thought to be important for regulation of impulses, both physical and otherwise. It therefore makes sense that losing this type of function would cause uncontrollable eating or drug taking.

Are drug- and food-addictions the same?

While this research isn’t saying that compulsive eating, or obesity, are the same as drug addiction, it does strongly suggest that there are common mechanisms in both. More importantly, it reveals a common process that unfolds when over-exposure to the reward, in this case food, occurs. This tells us that there can likely be common pathways to these different addictive disorders, though whether any specific person ended up a food- or drug-addict because of this kind of process is still an open question. I wonder if we’ll see something like this with sex addiction soon…

Citation:

Johnson and Kenny (2010) Dopamine D2 receptors in addiction-like reward dysfunction and compulsive eating in obese rats. Nature neuroscience, 13, 635-641.

Steven Tyler deals with pain killer addiction by checking into rehab

After the recent death of Michael Jackson, and possibly Brittany Murphy, due to prescription drug overdoses, Steven Tyler, the lead singer of the mega-band Aerosmith, has checked himself into rehab for pain-killer addiction.

Many pain killers commonly used are opiates (which are very similar to heroin), and many chronic-pain sufferers resolve to taking such drugs in high quantities and for many years. Such use can easily lead to dependence and serious withdrawal symptoms.

We wish Tyler all the best in his rehabilitation efforts. Stay strong Steven!

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!