Research has revealed that the drugs most commonly used by humans, such as opiates, alcohol, nicotine, amphetamines and cocaine, can cause a neurochemical reaction that significantly increases the amount of dopamine released by neurons in the brain's reward center. There are many activities that can stimulate dopamine production, including sex, exercise, nicotine and recreational drugs. While sex promotes natural dopamine release, medications can trigger an abundant amount of dopamine, leading to a euphoric sense of pleasure. However, when you're on a dopamine wave, you have to fall lower when that wave decreases, resulting in the shock that many drug users experience when their euphoria wears off.
People who are addicted to drugs or alcohol may find it difficult to stop using these substances, but treatment can help and has worked for thousands of people with substance problems. Drugs can alter important areas of the brain that are necessary for life-sustaining functions and may drive compulsive drug use, which marks addiction. At the same time, another area of the brain becomes more sensitive to feelings of withdrawal, such as anxiety and irritability, as the effects of drugs wear off and you'll try to use drugs for another reason to ease this discomfort. Known as the “wellness hormone”, dopamine is a chemical messenger that transmits signals between brain cells. It used to be thought that the surges of dopamine produced by drugs directly caused euphoria, but scientists now think that dopamine has more to do with causing us to repeat pleasurable activities (reinforcement) than with directly producing pleasure. Dopamine agonists are a broad category of drugs that mimic the actions of dopamine in the body to alleviate symptoms related to low dopamine levels.
For the brain, the difference between normal rewards and drug rewards can be compared to the difference between someone who whispers in your ear and someone who shouts into a microphone. A high level of drug dependence, concurrent medical or mental health disorders, multiple drug abuse, a family history of addiction, high levels of stress, the experience of trauma and a low level of support at home may contribute to the onset of addiction. Even if they can resist drug or alcohol use for a while, at some point the constant desire caused by these factors can erode their determination and cause a return to substance use or a relapse. Dopamine agonists are prescription drugs that can be used alone or in combination with other medications to treat a variety of conditions that result from dopamine loss. Depression, anxiety, insomnia, irritability, restlessness, problems with memory and cognitive functions, difficulties in regulating moods and problems controlling cravings can occur without drug interactions. If you have an allergic reaction to a dopamine agonist drug (swelling of the tongue, difficulty breathing or rash), call 911 right away and seek medical attention. Many of the side effects of medications on brain chemistry can be reversed when drugs are processed outside the body after a period of time.
However, some medications may have a longer lasting effect. Drugs such as methamphetamine can damage up to half of the dopamine-producing cells (and perhaps even more of the serotonin-containing nerve cells) in the brain with chronic exposure. This damage may only be partially reversible as chronic methamphetamine users may suffer from memory problems, learning problems, psychosis, aggression, emotional dysfunction and even develop Parkinson's disease as a result of functional and structural changes in the brain that may persist for years later.