Originally posted on Psychology Today:

One of the biggest problems with addiction is that we never know who is truly an addict. Yes, we have tests and notions, interviews and criteria, but all of those are simply tools we’ve used to get around the problem of not knowing. Well, a recent study by a couple of researchers at Florida State University may help us get a little closer (before you get too excited, read the limitations at the end). My take-home message from this post is familiar: Addiction is a disease, not a question of morality.

Am I An addict? Testing for addiction

One of the major reasons for the push to find the ‘alcoholic gene’ was the hope that, once found, it would let us say, with certainty, who is (and who isn’t) an addict. All those people who simply use drugs and other addictions as an excuse for their horrible behavior would be revealed and all those who truly need help could be identified. But it didn’t quite work out that way.

There is no alcoholic gene. There are a whole bunch of genes that are associated with, and most likely contribute to, the risk of someone becoming an addict. But they vary for different drugs, require some pretty serious testing, and contribute very little (individually) to our ability to categorize people. The same genes that are linked to addiction are also linked to ADHD, anxiety disorders, depression, and on and on…

But wouldn’t it be great if we had a conclusive test? Something that worked to really help us tell the difference between addicts and the rest?

Skin response testing

Electrodermal response modulation (ERM; a fancy name for measuring skin conductance) is a measure of how skin conductance changes in response to predictable versus unpredictable stress.

The connection between addiction and skin response might seem a stretch, but hey, dilated pupils are a sign for sexual attraction so… The idea is that the more prepared the overall system is to deal with predictable stress, the better equipped a person is to handle life stressors. Bad responsivity would mean that the person’s system is not adjusting well to stressors that are predictable, producing too much arousal and discomfort to events they should be prepared for.

So for this study, high ERM good, low ERM bad, got it?

To make a long story short, this recent research shows that low ERM was more common among individuals with addiction than among controls (people with no major mental health issues) and even among individuals with personality disorders.

The good news is that this finding is promising in terms of possible future identification of people who are likely to develop addiction problems. But of course, there are some issues.

Limitations of the study

Since the study used people who were already addicted, it’s impossible for us to know if low ERM exists before addiction develops. If it does, we may be able to identify potential addicts before they become addicted, but if not, it would still be useful to have a test to distinguish current addicts from non-addicts.

Of course, at the moment the test only works by comparing addicted to non-addicted groups – we don’t have norms or cutoff points to tell us on an individual basis who is or isn’t an addict. A lot more research will be required before that would be possible.

This is not the first test that has shown promise in terms of a quick identification test for addiction. There is quite a bit of research showing a relationship between a specific brain wave (called P300) and addiction. the problem is that P300 turned out to be pretty generally associated with what are known as externalizing disorders (like illegal activity, high risk sexual behavior, aggression, etc.). I personally believe that as behavioral addictions (like sex addiction that involves high risk sexual behavior) become more commonly understood, many of those externalizing disorders may be reclassified, making P300 possibly more popular as an addiction measure.

The Bottom Line: So can we tell?

It’s too early to know if ERM will turn out to be a really good marker for addiction, but I’m sure people are hard at work trying to figure that out, so let’s give them some time. Years ago I heard a presentation about people with low variability in heart rate which seemed to suggest something very similar, so I’m hopeful. But to me, there’s a more important take home message:

Once again, this study shows that there are physiological factors to addiction that are far beyond anyone’s actual control. I don’t personally know anyone who can change their skin conductance, and so I’m pretty comfortable saying that addiction is an actual medical condition in so far as it has physical symptoms and some promising treatments.

But then again, I am a scientist…