Mental abnormalities, the need to respond to the environmental changes, and individual thoughts and feelings are the common causes of addition. However, psychologists have developed different theories to explain the causes of addiction, notes Aroostook Mental Health Center.
There is a connection between how the human brain responds to pleasure and the repeated use of an addictive substance. Once the brain registers regular use of an addictive substance, a person develops an urge for it. Alcohol and some drugs cause physical changes in the nerve cells, which communicate the urge for more of the addictive substance. Repeated use of an additive substance increases tolerance over time, and the user has to increase his dose to experience the same pleasure, explains Medical News Today.