After repeated drug use, the brain begins to adapt to dopamine surges. Neurons may begin to reduce the number of dopamine receptors or simply produce less dopamine. The result is less dopamine signaling in the brain, such as lowering the volume of the dopamine signal. addiction affects the brain on many levels.
Chemical compounds in stimulants, nicotine, opioids, alcohol and sedatives enter the brain and bloodstream after use. Once a chemical enters the brain, it can cause people to lose control of their impulses or want to consume a harmful substance. Drugs interfere with the way neurons send, receive, and process signals through neurotransmitters. Some drugs, such as marijuana and heroin, can activate neurons because their chemical structure resembles that of a natural neurotransmitter in the body.
This allows drugs to attach to neurons and activate them. Although these drugs mimic brain chemicals, they don't activate neurons in the same way as a natural neurotransmitter and cause abnormal messages to be sent over the network. These scans show us that several different regions and pathways within the brain are affected by addiction. From an increase in neurotransmitters such as dopamine to reduced or increased activity in certain regions of the brain, addiction has a direct impact on the structure, functioning and health of the brain.
Chronic overstimulation of the brain (such as that which occurs in addiction) interferes with maintaining this balance (homeostasis). When the brain has difficulty maintaining homeostatic balance, the wonderfully adaptive brain makes adjustments. It does this by creating a new balanced set point. The creation of a new equilibrium is called allostasis.
All addictive drugs affect the brain pathways involving reward, that is, the dopamine system in the reward pathway. However, glutamate exerts its effects, it plays an increasingly prominent role in the history of addiction. Addictive drugs take over amygdala and hippocampal cells to build intense emotional memories of drug experiences. These memories link the powerful pleasures of drug addicts to people, places, and the paraphernalia associated with them.
From then on, these associations can by themselves trigger cravings. In fact, one way that alcohol and drug treatment programs help users abstain is by trying to break these associations, creating a new social circle and new, supportive and abstinent friends, as a substitute for their former drinking buddies or drug users. Scientists once believed that the experience of pleasure alone was enough to entice people to continue searching for an addictive substance or activity. And perhaps a big, perhaps because addiction experts are divided on this point, the path also figures in “addictions that do not involve drugs”, for example, the compulsive and destructive search to eat, exercise, gamble or have sex.
Additional research has also been initiated to discover the structural changes that occur in the brain during addiction, which can help scientists and medical professionals to devise new methods of treatment. These may include avoiding people, places, and situations associated with addictive behavior, as well as finding new ways to manage disturbing or difficult emotions or life circumstances. Addiction involves longing for something intensely, losing control over its use, and continuing to engage with it despite adverse consequences. Although important for understanding addiction, it does not seem likely that the dopamine pathway itself will produce promising new drugs or other treatments for addiction.
On dopamine transporter knockouts, Haney observes: “I don't think Caron's study alone denies the theory of dopamine addiction; there's too much data to back it up. Addiction researchers have investigated the role of cAMP in several brain regions, including the nucleus accumbens, where chronic exposure to morphine accelerates activity in the cAMP pathway. Detoxification can take several days to several weeks, depending on the substance and how long a person has struggled with addiction. Identifying what happens in the brain when a drug is inhaled, injected or eaten, why it leads to compulsive drug searching and learning to interrupt that process seems to be the last best hope for a permanent solution to addiction.
The likelihood that the use of a drug or participation in a rewarding activity will lead to addiction is directly related to the speed with which it promotes the release of dopamine, the intensity of that release, and the reliability of that release. Repeated exposure to an addictive substance or behavior causes the nerve cells of the nucleus accumbens and the prefrontal cortex (the area of the brain involved in task planning and execution) to communicate in a way that couples who like something want it, in turn, leads us to pursue it. This is not a total loss of autonomy: addicted people are still responsible for their actions, but they are much less able to nullify the powerful urge to seek relief from abstinence provided by alcohol or drugs. Many addiction experts suggest that by moving away from your typical environment and its “triggers”, it's easier to stay sober and stay sober.
In this way, while brain scans can show us the damage caused by addiction, they can also point us to potential proactive solutions to help people recover and find effective treatments for ongoing addictive behaviors. . .