Built into all of our brains is an elaborate collection of physical and chemical structures that make up our Reward System. The reward system is nature's design to regulate and control behavior by rewarding pleasurable experiences that promote the continued well-being and survival of the individual on the micro level, and the proliferation of the species on the macro level. Eating is an example of an individual survival imperative, and one that can be both practical and pleasurable. Shelter-seeking may not come to mind as something pleasurable, but being warm, dry and safe, the benefits of having shelter, are both practical (they increase the odds of survival) and pleasurable (a reward for shelter-seeking). Sex is not necessary for the survival of an individual but it is absolutely essential for survival of a species. Engaging in sex, then, offers great rewards in terms of physical pleasure (for humans and higher primates) and social status (humans and other mammals).
Central to the functioning of this reward system are an array of chemical neurotransmitters that relay information between the cells of the brain, with two of particular importance, dopamine and serotonin. When an individual is engaged in something causing pleasure, i.e. eating, sex, play, etc. there is a boost in the levels of these two chemicals in the brain. Increasing the level of dopamine and serotonin rewards the brain and creates an overall sense of emotional contentment and well-being in the moment, and a likeliness of returning to the activity later to duplicate the feelings associated with it.
To illustrate, many Law Enforcement Officers are dedicated to outdoor sports such as hunting, fishing, skiing, etc. Maybe you or a close colleague is. Take the hunter who thoroughly enjoys the excitement and strategy of the hunt while in the midst of it, and who leaves the field with a deep sense of contentment and well-being afterward. Both are the rewards system at work and ensure the hunters eventual return to the field.
Trouble in Paradise, or When the Reward System Goes Awry
Although the reward system is designed to reward the individual for engaging in appropriate and productive activities that increase well-being, there are really no safeguards against misappropriating it, and not everything that can give pleasure and boost dopamine and serotonin are good for us. Searching for a buzz by fermenting grains and fruit for consumption, or harvesting certain non-food crops for creative ingestion, is certainly nothing new in human history. Alcohol, tobacco, cannabis, opiates and coca have been used by humans for thousands of years of recorded human history, and probably tens of thousands before that. All of these, and more modern intoxicants, offer very dramatic boosts to our reward system that maybe far greater than what it is typically asked to manage. The intensity of the pleasure they offer is so great, and the corresponding chemical bump is as well, that they can begin to rewire the reward system.
Remember, the reward from the neurochemical boost reinforces the behavior that caused it and subsequently prompts us to seek it again. A big reward and our brain wants more of the same, so naturally we replicate the behavior. Do it enough and behavior begets repetitive pleasure-seeking begets habit begets addiction.
Doctors Wilkie Wilson and Cynthia Kuhn describe addiction as a hijacking of the brain's reward system. The addiction overrides its normal function, rewiring it and altering the essential chemistry. Remove what the body wants and dopamine and serotonin levels drop depriving the brain of what it craves to feel well. Food, sex, and other normal pursuits that should provide the chemical boost become inadequate, at least in normal amounts, and only the desired drug can provide relief. Think of an opiate addict you have known or worked with in the middle of a serious Jones. It is not necessarily even the high they are looking for anymore, they need their dope just to feel normal. Their reward system has been hijacked.
Like the man whose overeating behavior has led to heart disease, a maladaptive physical change in his body, the addicts behavior has led to a maladaptive physical change in his brain. His addiction has become a disease.
A New Definition of Drug
Maybe you are asking yourselves But what has this got to do with cops? Sure, I might know a few that drink too much, but drugs..? Much has been learned about the science and nature of addiction and its physical impact. We are going to ask you to shift your thinking on the definition of drug. To truly understand addiction, as it relates to our reward systems, definitions must be broadened to include a far wider array of drugs, some of which you cannot drink, smoke, snort or shoot. They are every bit as addictive - and destructive - as those you can, and almost all are completely legal.