BLOG No. THIRTY ONE

Welcome back my blog on anxiety and depression. In my last blog, number 30, we talked about the decreased number of D2 dopamine receptors in the ventral tegmental area (VTA) of the brain (part of the basal ganglia) and how that was related to addictive behavior.

But what is it mean to have addictive behavior?

Webster defines addiction as a compulsive, chronic psychological or physiological need for a habit-forming substance and/or a strong inclination to do, use, or indulge in something repeatedly. But I think we can drill down a little bit deeper—and better.

Scientists talk about addiction as an impulsive act, where patients will choose a lesser award given to them quickly, versus waiting patiently for a larger reward. Also, impulsivity, which drives addiction, will choose a quicker reward, even though the patient knows that in the end it will come with higher losses. For instance, the gambler will risk quick rewards, even though it may mean a greater loss—the loss of his family and friends…and mortgage payment.

So what in the brain goes on in these impulsive decisions that drive addiction? Why do addicts choose immediate rewards, knowing that in the end that they will face punishment—be at the legal ramifications, or or the loss of a connection with people they love.

I have two friends with addictions. One friend Mike, is addicted to drinking brake fluid! But of course, he says he can stop anytime. I have another friend Joanna who has been addicted for a long time to snorting detergent. But she’s clean now.

We spoke in blog 30 about low levels of D2 receptors in the VAT and how that causes an increase in impulsive behavior. And remember from that blog, when the VAT is stimulated, it produces type one dopamine (D1), which flows to the nucleus accumbens (NA), and produces the sensation of pleasure. And there is nothing wrong with pleasure.

But when a patient tries to capture that pleasure and it leads to damaging a person’s health and relationships, the patient suffers.

And why would someone do that?

Well, when the D1 dopamine stimulates the NA, and the pleasure is created, there is a period of time necessary between the D1 stimulations to create the same kind of pleasure. And if that time has not elapsed, neurochemically, the pleasure, or high, is not the same as before. I’m sure that you have heard addicts’ comments that say, “The second high will never be the same as the first.” Imagine eating a perfectly cooked steak…and then eating it night after night.

And, of course, certain substances that cause the pleasure we all seek, will down regulate (decrease) the number of D1 receptors on the neuron more than other substances. (i.e. illicit drugs). When the number of receptors is decreased, more of the stimulating substance is needed. (Look back, if needed to the target example in blog 30). More stimulation of the receptor is need for the same effect! And when you add D2 impulsivity to D1 down regulation, you begin to understand addiction.

It should also be noted that motivation is the opposite of impulsivity: it is the ability to resist a temptation to gain an award, to later on gain a better award. For example, you resist the quick high of a cute boy’s come on, to maintain your current lover.

And I confess, that the whole subject of addiction is much more complex than what I presented, but I did not want to bore my readers with esoteric facts. The above is complex enough. Hopefully I have done my job.

Well, my wife just asked me where I put the wine stopper. Such a silly girl! Until next time this is Dr. G saying, keep the faith!