An addiction is the act or condition of being physically and mentally dependent on a particular substance or activity. The two main types of addiction are behavioral addictions, such as gambling, and addictive substance addiction, and they are both influenced by many different factors. In the UK, statistics from the National Drug Treatment Monitoring System show that in 2011-2012, 197,110 people aged 18 and over were in treatment for drug abuse and addiction. An addiction can not only affect and ruin an individual's health and quality of life, but has more far-reaching effects, as the individual may be seen as a burden or threat to his or her family and friends, as well as to the healthcare system and the surrounding society. This report will focus on substance addiction, primarily drugs and alcohol, and the risk factors that make people more susceptible to it. In this report I will ask and address the following questions: Are there genetic, environmental, or neurobiological factors that make some people particularly vulnerable to drug or alcohol addiction? And how do these factors interact? Although I will mainly cover genetic, neurobiological, and some environmental factors in detail explaining why some people are more likely to develop addictions than others, I will briefly mention some other risk factors and explain how they can lead to addiction. Substance addicts no longer find pleasure in taking the substance they are addicted to and only take it to avoid the harsh withdrawal symptoms. The table below illustrates the different risk factors that influence addiction and briefly explains how they are related to addiction. Risk Factors Link to Addiction Genetics Hereditary Genes The answers g...... in the center of the document ......link them with memories. The buildup of dopamine in the nucleus accumbens (NAc) of the limbic system produces powerful feelings of pleasure because cocaine causes the formation of an unnaturally large number of complex dopamine receptors in the NAc. There are two important memory centers in this system located in the hippocampus and the amygdala. Under the influence of cocaine, these memory centers are imprinted with memories of pleasure, people, places, and other things associated with the cocaine experience. When you encounter these signals again, it can trigger a desire to repeat the experience. This can lead to compulsive behavior that drives you to continue taking cocaine. The frontal cortex of the limbic system can stop other regions of the limbic regions from creating the desire to take cocaine, however if this is compromised, it is unlikely to overcome the desire to abuse cocaine..