Drug addiction is a brain disease which can develop over time. Though initial use is voluntary, control over consumption is gradually eroded. Common signs of addiction include drug hunger, compulsive use, and loss of control. Addictive drug use ordinarly results in damage to level of function, personal relationships, and role in society.
Drug use can modify a person’s mood, perception, memory and emotional states. When drugs are used regularly over a sustained period, there may be changes in brain functioning and structure. These changes can persist long after the drug use stops, and may distort and disrupt the drug user’s emotional and cognitive functioning. The brain prioritizes a compulsion to use drugs — the essence of drug addiction.
Brain function depends on neurotransmission, or messages sent from one neuron (a specialized brain cell) to another. Beginning with an electrical signal, the message crosses the gap between cells (the synapse) through release of a neurotransmitter substance such as dopamine or norephinephrine. The neurotransmitter may bind with the second cell at a receptor site to produce a reaction.
Psychoactive drugs make use of this system of neurotransmission. By facilitating or interfering with the binding of the neurotransmitter at the receptor, certain drugs materially alter the way brains cells communicate. Overall brain levels of dopamine or serotonin may change, affecting behavior. Increased levels of dopamine, for example, are strongly associated with pleasure, and serve as a powerful reinforcer for further drug use.
Drug Delivery Systems and the Brain
Some methods of drug use create a more powerful effect than others. For instance, smoking cocaine delivers the drug to the brain through the mucus membranes of the lungs, and far more quickly than inhalation or even than injection. That’s a reason that smoking crack seems ‘more addictive’ than snorting it. The more rapidly the substance is delivered to the brain, the more potent its effects may seem.
The Persistence of Abnormal Brain Function
The brain is constantly ‘learning’ from its interaction with the environment. Using drugs over time leads to adaptation to allow the brain to function in the presence of the drug. When drug use stops, the brain doesn’t easily return to its pre-use state. Adaptive changes persist. This suggests that some important aspects of brain function remain unchanged, and might help to explain why even addicts who have been ‘clean’ for extended periods are unable to return to drug use without further problems.
Understanding the brain’s response to addiction can help build a more stable recovery.
About the Author
Tim Stoddart is a founder and owner of Sober Nation. He specializes in Social Media Marketing, SEO and developing content to help people who have been afflicted with the disease of addiction. Tim currently lives in south Florida. You can follow him on Twitter as @Sober_Nation.
— April 12, 2013 @ 
