Biology Plays A Major Role In Addiction – CapeNews.net

At a recent meeting, the subject of rampant drug addiction on the Cape came up. One of the men there shared that his grown daughter had died of a drug overdose. In addition to his sadness, he radiated profound guilt because he had been unable to rescue her. Why do our loving pleas so often fall on deaf ears when dealing with addiction? Part of the problem is that our brains are biologically wired in ways that make drugs both seductive and gripping. Not only may the addict have a genetic makeup that makes them more likely to abuse drugs, but their experience with the drug changes their brain in a way that drives intense craving, and difficulty stopping drug use even when the consequences are catastrophic.

The molecules in our brains that underlie nervous system function and determine our behavior are invisible to us. Yet, they are critical to all our decisions, including drug-taking. Addiction has a biological basis. Habit-forming drugs, including opiates, alcohol, nicotine, cocaine, and others often act by mimicking our naturally-occurring hormones or neurotransmitters. They physically attach to the target receptor for naturally-occurring neurotransmitters.

While the details vary between different drugs of abuse, the consequences of this attachment are similar for all of them. They cause alterations in electrical activity and release of dopamine (a neurotransmitter) in the reward pathway (also called the pleasure center) within the brain. This release of dopamine contributes to an intensely pleasurable high. Why are we so powerless in our attempts to rescue our loved one from their compulsive search for this high?

Part of the answer lies in the phenomenon known as homeostasis: the tendency of biological systems to maintain relatively constant conditions in the internal environment while continuously interacting with and adjusting to changes originating within or outside the system. For example, when healthy, we maintain a steady body temperature, steady heart rate, steady levels of blood electrolytes, et cetera. To the dismay of many of us, for example, it is difficult to lose weight permanently because our body fights to bring it back to our individual biological set point.

Similarly when we alter brain activity with a drug of abuse, our neurons battle to resist and compensate for this alteration. When the drug is on board, alarms go off in our brain.Somethings not right.initiate corrective action! The brains strategy for corrective action is very intuitive: modify the sensitivity and number of drug-responsive molecules in brain neurons.

In my own laboratory, we studied a compelling example of this strategy in response to alcohol (yes, alcohol is a drug of abuse). We focused on a molecule (called an ion channel) in the brain that controls the electrical activity of neurons. We found that alcohol activated these channels, which changed the electrical activity in the reward pathway. The surface (called the membrane) of neurons is studded with these alcohol-sensitive ion channels. Importantly, they can influence the electrical activity in the brains neurons only when they are on the membrane.

With repetitive exposure to alcohol, two things happened. First, the channels were modified in a way that made them less sensitive to alcohol. Second, just to be doubly sure to protect from the actions of alcohol, the channels were shuttled off the membrane and into the interior of the neurons. There, they could not influence brain activity. While this means that the experienced drinker can drink more without immediate consequence, it also can lead to abuse, addiction, and overdose.

The process of homeostasis has left the addict with brain neurons modified to respond less powerfully to the drug. This reduction in the potency of the drug is known as drug tolerance. In an addict, tolerance drives the path to dependency, which results in symptoms of withdrawal when the drug is absent. Moreover, the addict requires ever higher doses of the drug to alleviate craving.

These changes in ion channels can be observed in the microscope, as well as in electrical recordings from brain cells. I have found that viewing our microscope slides showing a physical change in the ion channels in brain neurons provides users with confirmation that addiction is a disease.

Although we cannot yet quantitate addiction with diagnostic numbers, as with blood sugar in diabetes, or blood pressure in hypertension, we have moved beyond a mysterious and nebulous attribution to lack of will power. And with this new realization, the user becomes more likely to seek treatment, and more hopeful that they will be able to quit.

Love and caring are invaluable parts of the success stories of recovery. But sometimes they are not enough, in spite of the true desire of the addict to stop using. We are understanding more and more of the molecular mechanisms underlying drug tolerance, and as this understanding grows, we come closer to finding a universally effective pharmacological treatment to reduce craving. For now, our best line of attack is to prevent the first drug use, and public health experts are working hard to educate the public.

But after extensive drug use, our task (and those of addiction care providers) is a difficult one. While there are many success stories, the failures will generate grief. But maybe we can feel a little less guilt, knowing the strong biological forces that the addict or alcoholic is battling in this devastating disease. Maybe the knowledge of how easily biology plays into compulsive drug use will serve as a deterrent to kids or adults tempted to start down the path.

Read the original:
Biology Plays A Major Role In Addiction - CapeNews.net