Substance use disorder is a complex disease of the brain and body characterised by the compulsive misuse of one or more substances despite serious health and social consequences. Substance Use Disorder disrupts the regions of the brain that are responsible for reward, motivation, learning, judgment, and memory.
1. CHANGES TO THE BRAIN
Substance dependence rewires the structure and alters the operation of the brain. Substances interfere with the brain's communication system, preventing nerve cells from sending, receiving, and processing information.
For example. the brain's reward system is activated when we engage in activities, such as eating our favourite food, hanging out with friends, or going for a run. The chemical dopamine represents this reward. The release of dopamine is also induced by substance misuse.
2. GENETIC FACTORS
Some individuals are genetically more prone to substance dependency than others. Genetic factors account for almost 50% of the risk of substance dependence. This means that a person is more likely to develop substance dependence themselves if there is a history of substance dependence in their family. This line of thinking implies that brain chemistry, brain structure, and genetic abnormalities that influence human behaviour are associated with the familial susceptibility to substance dependence.
3. BEHAVIORAL FACTORS
Many individuals who experiment with substances do so at a young age. They may also be misusing substances to manage other symptoms of a mental illness. Following the onset of substance dependence, behavioural features and brain changes occur. Loss of control is one of the most characteristic signs of substance dependence. If a person decides to reclaim control, they will be confronted with behavioural elements that might complicate the situation. Oftentimes, withdrawal symptoms are so excruciating that a person relapses to escape the traumatic experience.