Most drugs have a negative effect on the brain's reward circuit, causing euphoria along with floods of dopamine. A properly functioning reward circuit motivates people to engage in the activities that help them thrive. Dopamine increases in the reward circuit reinforce harmful behaviors such as drug addiction, causing people to repeat the same action over and over.
The brain adjusts to drugs by decreasing the response capacity of the reward circuit as the user continues to use them. The individual's experience of high is diminished relative to what they experienced when they first tried the drug. This phenomenon is called tolerance. They may try to get the exact same high by taking more of the drug. These brain adaptations often make it difficult for people to get pleasure from things that they used to like food or sex.
Why do some people develop a tolerance for drugs while others are able to avoid this fate? There is no one characteristic that can reliably forecast whether a person would develop a dependency on drugs. The likelihood of developing an addiction is determined by a number of different factors. The more predisposing characteristics a person possesses, the higher the probability that using drugs would result in addiction to those drugs.
Biology. About half of a person's propensity toward addiction is determined by the genes that they inherit from their parents. Other factors that may increase the likelihood of drug abuse and addiction include gender, ethnicity, and the existence of other mental problems.
Environment. The environment that a person is surrounded by consists of a variety of various effects, some of which include their family, friends, economic standing, and overall quality of life. Peer pressure, physical and sexual abuse, early exposure to drugs, stress, and parental supervision are all factors that can have a significant impact on a person's chance of engaging in drug use and developing an addiction to drugs.
Development. The risk of addiction is determined by a complex interaction between a person's genes, their environment, and key developmental phases throughout their lifetime. It is possible to get addicted to drugs at any age; however, the earlier in life that drug usage begins, the greater the risk that it may ultimately result in addiction. This presents a unique set of challenges for teenagers. Teenagers' brains are still growing, and this may make them more prone to engaging in dangerous activities, such as experimenting with drugs. These behaviours include poor decision-making, poor judgement, and a lack of self-control.