The causes of addiction vary somewhat with the substance abused. The current opioid epidemic has some connection to prescriptions for pain killers, both over prescription and patient misuse, and nicotine addiction has a relationship to stress.
One major set of causes relates to psychology and to mood disorders such as anxiety and depression. People who experience anxiety in social situations may turn to alcohol to boost their self-confidence. A major loss, such as the death of a spouse or the loss of a job can lead to depression, and to the use of alcohol or other substances to improve moods. Traumatic events may lead directly or indirectly to an addiction. People coping with the consequences of such events as violent crime, accidents, or wartime experiences may turn to alcohol, antidepressants and other drugs.
There is also a strong correlation between mental illness and addiction. People who have been diagnosed as having a mental health disorder at some point in their lives account for a sizable majority of the abusers of nicotine, cocaine and alcohol. Prescription medications can lead to abuse, particularly prescription pain killers. Physicians may overprescribe pain killers, or oblige patients coping with long-term pain. Longer term use of addictive pain killers can result in the body developing an increasing tolerance, meaning stronger medication is required, upping the chance of addition.
There are also some environmental factors. Substance abuse may occur in social groups associated with drug use, such as college students and alcohol. Athletes who have used performance enhancing drugs are also at increased risk for addiction. Family history is also an element in addiction. If one or both parents has had an addiction problem, the likelihood of their children also having an addiction is several times higher than in the general population. It is unclear if this connection is genetic, or that children may follow their parent’s social trajectory. Abusive or neglectful families may also be related in that they may result in depression, anxiety or PTSD.