Irreversible Addiction

Why do people let addictions take over their life? Why do they continue to take the drugs that seemingly destroyed their relationships, caused them to lose their job and often absorbed all their money? Logically, with all these terrible repercussions, you would think it would be easy to ditch the drugs and fix your life. However, it is not quite that simple. After taking drugs, they seem to rewire the brain and make it impossible to forget about the drugs and the positive feelings they cause in the body.


Dopamine is a neurotransmitter in the brain that is involved in the reward pathway. Normally, the reward pathway is activated during activities like eating or sex. The release of dopamine during these activities is what makes us enjoy them. When drugs are taken they activate this reward pathway which causes a release of dopamine. The neurotransmitter binds to D1 receptors which causes a direct reward response in the body. Dopamine can also bind to D2 receptors which inhibits a punishment response, further increasing the reward response. When drugs are present, they block the dopamine reuptake proteins. This allows the dopamine signaling to potentiate for longer and cause a larger reward response. Because of this reaction, it causes the body’s response to normal rewards to lessen. Therefore, the same response can only be obtained by taking drugs.

This is the release of dopamine into the synaptic cleft and shows that cocaine is capable of blocking the reuptake transporter. This allows the dopamine signal to potentiate longer and cause a larger response in the body.

Long Term Potentiation

Long Term potentiation or LTP is important in learning and memory because as a signaling pathway is used more often, the strength of the pathway gets stronger with the release of the same number of neurotransmitters. This helps us in learning and memory because it causes the pathways we use the most to become prominent in our brains. This is bad when drugs are involved because as the dopamine reward pathway is activated the signal becomes stronger and the body essentially remembers the pathway better. Therefore, when a person who had a drug addiction is exposed to cues that remind them of the drug, the body remembers the reward pathway, releases dopamine and causes the addict to want more drugs. Therefore, an addict can never truly forget this reward pathway and always has the opportunity to relapse as the brain is changed permanently from drugs.


The dopamine reward pathway is responsible for causing drug addiction to last for a lifetime. Regardless of treatment, the cues and rewards for taking drugs will always be prevalent especially because the reward pathway is no longer as strong for normal reward triggers. There is no perfect solution to this problem other than a very strong will and a good support system. However, every addict is not fortunate to have these two things making it very easy to relapse. We need to understand that after taking drugs, the brain is rewired and permanently changed. It will probably never go back to normal, so it is not completely the addicts fault for continuing to use drugs. They need support to change their ways.

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For more information on addiction and dopamine receptors see article: