Substance use disorders, as addictions are now called, develop when alcohol and a wide variety of substances alter normal brain function by directly altering normal brain chemistry. Current research indicates that process addictions can produce some of the same brain alterations.
Brain Changes Associated With Physical Addiction
Human brains are essentially huge collections of individual nerve cells (neurons) that sit very close to each other but don’t actually touch. In order to communicate with others of its kind, each neuron produces chemical messengers called neurotransmitters, then sends these messengers across the small gap that separates the neuron from its nearest neighbor. When a neurotransmitter reaches another neuron, it triggers electrical changes that increase or decrease activity levels within that cell; highly active neurons maintain or increase communication by rapidly sending messages to additional cells, while less active neurons slow communication down or bring it to a halt.
Dozens of different chemicals act as neurotransmitters and trigger specific changes inside the brain. For instance, the neurotransmitter dopamine activates the brain’s pathways for reward and pleasure, while the neurotransmitter serotonin helps keep your mood stable. The neuro-transmitting chemical glutamate helps keep your brain alert and receptive to change, while the chemical norepinephrine helps trigger your brain’s innate “fight-or-flight” response. Epinephrine (adrenaline) also helps trigger fight-or-flight responses, while the neurotransmitter oxytocin influences your ability to feel jealousy or love.
Commonly abused drugs such as opioid narcotics, cocaine or methamphetamine, or alcohol alter normal levels of key neurotransmitters such as dopamine, glutamate, serotonin, and norepinephrine. Alteration of dopamine levels in the brain’s pleasure centers is particularly associated with both physical dependence on a substance and the eventual onset of addiction. Physical dependence is a reliance on the presence of a given substance for feelings of “normalcy.” Addiction means there are ongoing cravings for that substance, as well as compulsive behaviors geared toward satisfying those cravings.
Brain Changes Associated With Substance Addiction
Alcoholics and drug addiction rarely start using their substance of choice with the intention of developing an active addiction. Instead, they engage in activities that seem relatively harmless, then gradually lose control as brain changes turn voluntary substance use into an involuntary, compulsive activity.
Brain Changes Associated with Process Addiction
Process or behavior addiction begins in roughly the same way, either through involvement in universal, essential human activities-such as eating or having sex-or through involvement in other activities commonly found in contemporary society, such as shopping, gambling, looking at pornographic material or surfing the Internet.
Since engagement in any of these activities can produce some sort of reward (a full belly, sexual satisfaction, new clothes, money, etc.), it tends to increase brain levels of dopamine and trigger feelings of pleasure. In most people, these pleasurable feelings have their place among a wide range of emotional reactions to life. However, in certain people, these feelings gradually take on an increasing importance that’s out of balance with other life experiences. Conditions or circumstances that can potentially trigger this kind of shift in emphasis include depression, ongoing stress or anxiety, significant childhood trauma, self-esteem problems, or any source of ongoing emotional pain.
By consciously or unconsciously seeking to habitually reward themselves through their activities, people developing process addictions start to alter their dopamine pathways in much the same way as substances alter the dopamine pathways of habitual alcohol and drug users. Classic features of chronic dopamine alteration (in both process addicts and substance addicts) include gradually decreasing feelings of pleasure for any given level of behavior/substance use; an increased frequency of behavior/substance use that’s designed to offset the drop in pleasurable feelings; and an eventual decrease or loss of the ability to experience pleasure from any source, including the person’s behavior/substance of choice. As with alcoholics and drug addicts, the end result of these changes in process is a compulsive, fruitless search for some sort of sustainable sense of release, or “high.”