16 Aug Addictions
Our addictions exert a long and powerful influence on the brain that manifests in three distinct ways: craving for the object of addiction, loss of control over its use, and continuing involvement with it despite adverse consequences. The brain registers all pleasures in the same way, and pleasure has a distinct signature: the release of the neurotransmitter dopamine. Dopamine release is so consistently tied with pleasure that it’s classed as the brain’s pleasure centre. All addictions cause a particularly powerful surge of dopamine. The likelihood that participation in a rewarding activity will lead to addiction is directly linked to the speed with which it promotes dopamine release, the intensity of that release, and the reliability of that release. Dopamine not only contributes to the experience of pleasure, but also plays a role in learning and memory, two key elements in the transition from liking something to becoming addicted to it.
Dopamine interacts with another neurotransmitter, glutamate, to take over the brain’s system of reward-related learning. This system has an important role in sustaining life because it links activities needed for human survival with pleasure and reward. The reward circuit in the brain includes areas involved with motivation and memory as well as with pleasure. Addictive behaviour’s stimulates the same circuit, and then overloads it. Repeated exposure to addictive behaviour causes nerve cells to communicate in a way that couples liking something with wanting it, in turn driving us to go after it. That is, this process motivates us to take action to seek out the source of pleasure. Over time, the brain adapts in a way that actually makes the sought-after substance or activity less pleasurable. In nature, rewards usually come only with time and effort.
Addictive behaviour’s provide a shortcut, flooding the brain with dopamine and other neurotransmitters. Our brains do not have an easy way to withstand the onslaught. In a person who becomes addicted, brain receptors become overwhelmed. The brain responds by producing less dopamine or dopamine receptors becoming desensitised. As a result, dopamine has less impact on the brain’s reward centre. People who develop an addiction typically find that, in time, the desired substance no longer gives them as much pleasure. They have to take more of it to obtain the same dopamine “high” because their brains have adapted, and this is an effect known as tolerance. At this point, compulsion takes over. The pleasure associated with an addictive drug and yet the memory of the desired effect and the need to recreate it (the wanting) persists.
It’s as though the normal mechanism of motivation is no longer functioning. The learning process also comes into play. Information is stored regarding environmental cues associated with the desired substance, so that it can be located again. These memories help create a conditioned response, intense craving whenever the person encounters those environmental cues. Conditioned learning helps explain why people who develop an addiction risk relapse even after years of abstinence.
How do you know if you’re addicted?
Do you use more of the substance or engage in the behaviour more often than in the past?
Do you have withdrawal symptoms when you don’t have the substance or engage in the behaviour?
Have you ever lied to anyone about your use of the substance or extent of your behaviour?