One of the reasons why it’s difficult for drug addicts to stay clean is that their substance abuse has a major effect on the structure of their brains. Here is some background on why the brain reacts to drug use:
Dopamine is one of the chemicals in your brain that makes you feel good. The use of drugs releases more dopamine that acts on the brain.
Dopamine attaches to neurons in the “reward center” section of your brain, This is what makes drug use feel pleasurable to drug users.
The tricky thing about dopamine and the reward center is that repeated exposure to high levels of dopamine can alter the structure. Drugs release extremely high levels of dopamine in the brain, and the brain has to learn to accommodate them. This causes several changes in the brain structure and the way it reacts to dopamine release in the future.
D2 receptors are the receptors on the brain that react to dopamine. They allow dopamine molecules to bind to the brain and take effect. When a drug user experiences rushes of dopamine from the drugs they consume, the brain reacts by decreasing the number of dopamine receptors in the brain, giving the drug user less sensitivity to dopamine.
Dendrites, or dendritic spines, are small attachments on the neurons, where dopamine attaches and acts on the reward center. You can think of these as little antennae that search for molecules in the brain, and allow them to bind to the reward center. The dendrites get longer and begin to make even more connections in the brain. This has some major effects, as we’ll see below.
Now that the brain is wired for strong levels of dopamine stimulation, it begins to crave the drugs. A decrease in dopamine receptors means that a drug addicts every day life experiences won’t be able to stimulate the brain strongly enough to give a good dopamine rush to the brain. The only thing that can satisfy the brain’s high requirements for dopamine stimulation is the drugs. But, since this is a vicious cycle, repeated drug use only further decreases dopamine receptors in the brain.
Along with this, the increase in dendrite receptors can have unwanted effects on other systems of the brain and further the mental symptoms of the drug user. In some areas the connections grow stronger, and in others they are weaker; this strange altering of the brain structure can cause problems for brain health.
The brain is altered from the first time that you use drugs. Many drug addicts and first time users may not be aware of how they are affecting their brains, leading to unexpected addiction. The changes are, unfortunately, irreversible. But since the physical changes in the brain only get worse with repeated use, the symptoms may be manageable with treatment from the outset. The most recommended method of treatment is professional care from an inpatient addiction treatment facility.