Dopamine: The "rewarding" neurotransmitter

Dopamine is a neurotransmitter that most of us have heard of. We’ve heard the term ‘dopamine hit’ as a descriptor of how euphoria takes place in the brain in response to illicit drug use, such as cocaine for example. Dopamine is the neurotransmitter in the brain associated with pleasure and associated with re-wiring the brain to crave the pleasure or repeat a behavior in response to reward.

Dopamine relates to depression in that a major indicator of depression is ‘anhedonia’: anhedonia refers to not only a loss of pleasure, but also a loss of motivation to repeat rewarding behaviors (i.e. Eating, seeing friends, doing well at work etc.) This generally happens, once a significant amount of emotional pressure is imposed on the brain, and pathways start to rewire in such a way that decreases the release of dopamine from nerve cells in the brain. This was the reason behind the creation of anti-depressants such as Bupropion (Wellbutrin) that target dopamine.

Bupropion (Wellbutrin/Zyban): The dual use DNRI anti-depressant

We briefly touched on the role of dopamine in craving as well as in repetitive behaviours. We also discussed dopamine’s role in pleasure in relation to depression. However, we haven’t thoroughly discussed its’ role in addiction. When people use drugs like cocaine, amphetamines and other stimulants, they are raising dopamine levels in the brain. This is the reason they feel pleasure or euphoria. How then, can a drug like Bupropion (Zyban) be used in smoking cessation?

Interestingly, it is those with genetically low baseline levels of dopamine that are most prone to addiction (that’s a conversation for another article). The reason for this is that when they use drugs that promote dopamine release or engage in other pleasurable behaviours such as binge eating, sex, smoking or gambling, they experience a greater measure of euphoria than those with normal baseline levels. This pronounced euphoria, leads to a more pronounced desire/craving to repeat the behaviour.

 When a medication such as Bupropion is used to prevent the return of dopamine back to its’ originating nerve cell, there is more dopamine available in an individual’s brain, rewiring dopamine to normal levels associated with pleasure, craving, motivation and reward. When one has normal baseline levels of dopamine, the amount of euphoria achieved from ‘addictive’ behaviors is dampened as is the desire to seek out or repeat the behaviour. Bupropion is also said to be able to block nicotine receptors, which is why it is so commonly used in smoking cessation, to dampen the pleasure associated with nicotine.