Addiction is a Disease of the Brain

People do not start drinking or using drugs with hopes of becoming addicted. They do it because, to them, it feels good. Addiction, unfortunately, is covert and creeps up after prolonged use; what we call the 'oops phenomenon'. It happens when occasional use becomes continuous and persistent, until it becomes daily use. Ultimately, it reaches a point where the individual cannot function without consuming large quantities of alcohol or drugs – the point of addiction.

It is now known that prolonged alcohol or drug abuse alters the structure and function of the brain. Scientists have a more complete idea of the kinds of changes involved, thanks to advances in technology. For instance, there is now insight into the role of heredity in addiction. This could eventually lead to being able to identify people at risk of addiction – enabling early preventative measures to be taken.

Long-term alcohol abuse causes the brain, quite literally, to shrink. With the use of MRI, PET and CT scans, researchers have been able to observe this amongst living alcoholics. The same technology has revealed the damage that drugs can cause to brain cells. For example, it has been discovered that methamphetamines addiction ('speed') damages cells in the brain that produce dopamine, a chemical that causes the feeling of euphoria. This damage can lead to aptosis, whereby cells in the brain self-destruct.

Research indicates that up to 75% of long term alcoholic abusers have some sort of cognitive impairment – even after detox and rehab. The National Institute on Alcohol Abuse and Alcoholism states, "alcoholic dementia is the second leading cause of adult dementia in the United States, exceeded only by Alzheimer’s Disease".

The human body has an elaborate system of nerve cells, called neurons. These neurons extend from the brain and spinal cord, running throughout the body, to the extremities of the hands and feet; not unlike electrical wires behind the walls of a house. However, in our bodies, the ‘wires’ are not continuous. Interspaced between the neurons are small gaps called synapses. Chemicals called neurotransmitters carry messages from the brain throughout the vast network of neurons, across the synapses, directing thought, feelings and behavior.

Addiction causes an anarchic exchange of neurotransmitters. It can:

• Flood the brain with excess neurotransmitters.
• Stop the brain from making neurotransmitters.
• Bind to receptors in place of neurotransmitters.
• Block neurotransmitters from entering or leaving neurons.
• Empty neurotransmitters from parts of the cells where they're normally stored, causing the neurotransmitters to be destroyed.
• Increase the number of receptors for certain neurotransmitters.
• Make some receptors more sensitive to certain neurotransmitters.
• Make other receptors less sensitive to neurotransmitters (leading to tolerance).
• Interfere with the re-uptake system by preventing neurotransmitters from returning to the sending neuron.

If the above is too scientific and boring, the main point is that addiction totally disrupts the function of the brain.

Take, for example, dopamine, which was mentioned earlier. Alcohol, nicotine, opiates, and cocaine all increase dopamine levels, causing a temporary feeling of pleasure. Ironically, these excessive levels have a long-term detrimental effect on the brains chemistry. Here’s why. The brain seeks to maintain a constant level of cell activity and dopamine production. This enables the body to experience the normal pleasures of life. With drugs and alcohol, the body is subjected to artificially high levels of dopamine. The brain, in turn, tries to compensate by limiting its natural supply of this neurotransmitter. Therefore, the brain becomes dependent upon the drug/alcohol to function normally.

When the extra dopamine supplied by the drugs is missing, the addict feels less pleasure. Depression, fatigue and more extreme withdrawal symptoms typically ensue. To relieve these symptoms, the addict turns to the drugs, only worsening the problem.

These cravings eventually become so powerful that they rule the life of the individual. He or she is unable to function without a constant source of artificial dopamine. This is due, in part, to changes to a specific path of neurons in the brain known as 'the pleasure system' or 'reward circuit'. To an individual using alcohol or drugs to repeatedly stimulate this 'reward circuit', the idea of abstaining from using these chemicals is as alien as the idea of becoming an astronaut. The use of alcohol or drugs thus takes over the will of the user – converting what was a voluntary behavior into an obligatory compulsion.

Remember, not everyone who drinks or is an occasional drug user will become addicted. Research has thus far failed to prove why some people can be social drinkers or drug users, without experiencing these changes in brain structure and function; although it is widely accepted that heredity plays a partial role.

Each of us has a unique chemical blueprint that shapes every aspect of who we are, from height and weight to personality and behavior. This blueprint is created by structures called chromosomes (which contain our genes). Occasionally, mutations in genes can produce various hereditary diseases. Disorders such as cystic fibrosis and Huntington's Chorea result from a change in a single gene. And some success has been achieved in isolating the exact location of those genes in developing treatments.

Unlike, for example, cystic fibrosis, addiction stems from changes in many genes. Additionally, the genes involved vary from individual to individual. This makes it almost impossible to locate the genes that influence addiction.

Nevertheless, the evidence pointing to addiction being hereditary is considerable. Identical twins born to alcoholic parents are more likely to become alcoholics than fraternal twins born to alcoholic parents. This is because identical twins share identical genes while fraternal twins do not. Also, adopted children of alcoholic parents are more often affected by alcoholism than adopted children of non-alcoholic parents. The same is true when children with alcoholic birth parents are raised by non-alcoholic foster parents.

A promising development in this area has emerged from studies by Professor Henri Begleiter, PhD, a professor of psychiatry and neuroscience at the State University of New York. Begleiter discovered a possible trend in the brainwaves of people from alcoholic families. His studies have been replicated by various researchers who have reached the same conclusions.

Brain waves can be recorded and printed out as an electroencephalogram (EEG). In Begleiter’s experiments, volunteers subjected to a significant stimulus, such as a loud sound, responded 300 to 500 milliseconds afterwards. This resulted in a characteristic peak on the EEG called the P3 amplitude. The P3 amplitude was found to be significantly lower in alcoholics – even those who had a record of long-term abstinence. Interestingly, this lowered P3 amplitude was discovered in non-alcoholic relatives of alcoholics, suggesting that the unusual brain wave pattern is inherited. Professionals hope that this may help doctors to predict whether or not individuals at risk will become alcoholics. Those at risk could therefore be educated early on to stay away from drugs. This knowledge could also further the development of medications to reduce cravings. Some examples of these medications include: Methadone for heroin addicts, Naltrexone for alcoholics and Bupropion for nicotine addicts.

The old-school idea that addicts are simply weak no longer holds true. Addiction takes more than willpower to overcome and is scientifically recognized as a disease, requiring treatment and therapy.