Long-term use also alters other chemical systems and neural circuits in the brain, which can affect a number of cognitive and behavioural functions, including learning, judgement, decision-making, stress, memory, and behaviour. Due to the nature of addiction, many drug users continue to use despite being aware of the possible negative effects of their actions.
Dopamine is a chemical messenger that floods the brain with chemicals. Most drugs can cause pleasure. A functioning reward system encourages people to do the things they need to survive, such as eating or spending time with their loved ones. The reward circuit encourages people to engage in harmful, but enjoyable, behaviors like drug abuse.
No one factor can indicate whether a person would become addicted to drugs. A mix of genetic, environmental, and developmental variables impacts susceptibility for addiction. The more risk factors a person possesses, the greater the likelihood that consuming drugs might lead to addiction.