An addiction is a disorder that is extremely complex, and the thoughts and mental processes involved are extensive. The physical and psychological effects of each substance may be different but the process that results in an addiction are the same in every case. All drugs that are commonly abused and also alcohol cause changes in the way that the brain functions, and when the substance is used repeatedly these changes become more pronounced. The neurotransmitter in the brain called dopamine increases when substances are abused for recreational purposes. This provides the feeling of euphoria or being high, and the cells in the brain remember this as a pleasant experience. This can cause the individual to want to use the drug or alcohol again and it starts a downward spiral that is very destructive.
When your brain is under the influence of drugs or alcohol the brain changes that occur interfere with your ability to think normally or to function properly. As addiction develops your gray matter starts to equate using the substance with basic survival, and you may feel that you can not continue without the substance any more than you can go without eating, breathing, or sleep. Eventually it becomes impossible to feel normal without the substance of choice, and the substance abuse continues even if your loved ones turn away or you find yourself in legal trouble as a result. When the urge to use becomes strong you may find yourself trying to rationalize your behavior or come up with reasons why you need to continue the drug or alcohol abuse, even if you realize deep down that this activity is destroying your life and family.