For the past five years, I have had the privilege of being one of the treatment team members at New Found Life and provide psychiatric consultations for patients. There are many psychiatric conditions, such as depression, that may prompt an individual to find relief with alcohol or drugs of abuse, and evaluation and treating these conditions is one of the reasons I care for patients at New Found Life
As with depression and other psychiatric conditions, neuroscience research has allowed a better understanding on how these conditions exert their effects and offered more specific and effective treatments. Addiction has also benefited from breakthroughs in neuroscience, and incorporating what is now known about the neuroscience of addiction is one of the reasons I evaluate every patient who comes through New Found Life.
Below, I will briefly describe brain function in addiction and describe a common drug of abuse, cocaine.
Addiction is marked by compulsive substance use, in spite of psychological, social, and health problems, that is coupled with episodes of substance craving. The key concept in substance abuse is that, followed over the long-term, it has a chronic course marked by symptoms that wax and wane. Addiction can be best thought of and treated as a brain disease. For example, if you have a family history of diabetes, you then have a greater chance to become diabetic. You did not decide this, it is just a susceptibility passed on from your parents. If you are diabetic and do not follow a diet, the diabetes will run its course and you will have complications that will affect almost every organ system in your body. Analogously, if you have a family history of substance abuse, you then have a greater chance to become an addict. You did not decide this, it is just a susceptibility passed on from your parents. If you use substances of abuse, the disease will run its course and you will have complications that will affect almost every organ system in your body.
Why people initially decide to try tobacco, alcohol, or illicit drugs is complex, though, for the most part, the decision to use a substance that affects one’s mental state is an attempt to change the current state one is in and no one ingests or injects something he or she thinks will make him or her worse than he or she already is. Once an individual has made this choice, the degree of addiction is decided by the inherent nature of the substance, the person’s predisposition for addiction and the environment that surrounds the individual.
To understand the motivation that addicts endure in their addiction, it is necessary to outline the specific areas of the brain that characterize the “reward” and “craving” that are involved in the disease. Once an individual has been sensitized to a substance of abuse the brain areas involved are powerful. To appreciate the power of the brain it is best to conceptualize brain function as following a sequential order of importance. The brain keeps important functions simple, so they are not easily disrupted. (This is in contrast to relatively non-important functions, such as deciding which shirt to wear in the morning, in which higher areas of the brain that are very complicated are utilized.) An example of something simple for the brain to orchestrate is breathing. It is a simple act that is very important, and it needs to be done constantly. The brain centers that control simple important acts tend to be primitive, i.e., they are found in most animals and have persisted through evolution. The medical term to describe evolutionary history is “phylogenesis” and the phylogenically old structure that controls breathing is the brain stem.
Right above the brain stem is another phylogenically old structure called the midbrain. Housed in the midbrain are the origins of brain cells that utilize the neurotransmitter dopamine. These cells project throughout the brain and the role of dopamine has been implicated in many brain functions and diseases, for example, Parkinson’s disease is due to loss of dopaminergic brain cells housed in the midbrain. Stimulation of these dopaminergic neurons in the midbrain causes a release of dopamine in a certain small area, approximately 1 centimeter, of the brain called the nucleus accumbens. The nucleus accumbens can be thought of as the “pleasure center” of the brain and is used to reward behaviors. Natural behaviors such as sex and eating utilize this reward pathway. How this pathway relates to addiction is that most, if not all, substances that are abused by individuals tap into this primitive pathway. This pathway reinforces the drug seeking behaviors and craving that characterize addiction. Since this pathway is old and relatively simple, it is difficult to disrupt. Hence, the nature of addiction, which is marked by continued substance abuse in the face of self-destructive behavior.
An interesting finding concerning addiction is, as the addiction progresses, increasingly more of the substance of abuse is needed to produce the reward in the brain. This occurrence is called tolerance. Tolerance drives addicts to use more, and contributes greatly to the toxicity of abuse.
Even though the addicted brain is a powerful force, there are other aspects to the phenomena of addiction. The mind and environment play an important role in the course of the disease. Interventions that utilize these other aspects are imperative in treating addiction, and hence a comprehensive multi-disciplinary treatment team approach is used at New Found Life.
Cocaine is a chemical derived from the Erythroxylum coca tree, which is found in western South America. Though is sometimes associated with the cocoa bean or the kola nut in the lay press, it is not related to these plants. It may be administered intranasally, intravenously, or orally (smoked). Since 1971, the Federal government has been surveying the population annually to estimate the numbers of individuals that use illicit drugs, alcohol, and tobacco. The latest data from the Substance Abuse and Mental Health Services Administration reveal that there are 1.9 million current cocaine users aged 12 or older, comprising 0.7 percent of the population
In susceptible individuals, cocaine is one of the most addicting drugs. Cocaine taps into the brain reward system directly by targeting the nucleus accumbens. Cocaine increases dopamine levels in the nucleus accumbens and this action accounts for the intense euphoria experienced with the drug and also the craving sensations after the drug has been eliminated from the body.
Cocaine also enhances the release of other neurotransmitters in the brain and throughout the body. Simply, the end result of the release of these neurotransmitters is to stimulate, and this accounts for the desired effects of cocaine. Acutely, cocaine induces an intense euphoria, increased self-confidence, talkativeness, and increased libido. As the cocaine leaves the body, the euphoria decreases and anxiety increases. The craving for more cocaine steadily increases. This reinforces the need to ingest more of the drug. Interestingly, the first time cocaine is used yields the most satisfying effects. Subsequent episodes of cocaine use produce less intense euphoria, but the detrimental effects continue. This phenomenon lends credence to the power of cocaine addiction.
There is only one indication for the medical use of cocaine. Cocaine is used as a local anesthetic in surgery. The amounts of cocaine used in surgery are minuscule and do not enter the brain.
There are many adverse physical and psychological effects of cocaine. Acutely, cocaine decreases appetite, prevents sleep and induces muscle contraction and sweating. At higher doses, paranoia and auditory, as well as visual, hallucinations occur. Other acute effects of cocaine are seizures, cardiac arrest, and, due to increased blood pressure, stroke.
For those who try cocaine and become chronic users, the long-term effects are miserable. Chronic administration of cocaine disrupts the normal chemistry of the brain, and patients can develop symptoms that mimic psychiatric disorders. Profound depression, paranoid delusions and constant auditory hallucinations are common long-term effects. Physically, chronic cocaine use causes impotence, tremors and extreme weight loss, and there is the potential chance of death due to intoxication.
While these adverse effects are significant they can be alleviated with medications and other treatments. Moreover, that cocaine hijacks the brain reward circuitry can be used as a method of treatment. Medications that modulate dopamine function can relieve some of the craving found in cocaine addiction and assist the patient in his or her pursuit of abstinence.