Drug abuse costs the United States economy hundreds of billions of dollars in increased health care costs, crime, and lost productivity.
The total costs of drug abuse and addiction due to use of tobacco, alcohol and illegal drugs are estimated at $524 billion a year. Illicit drug use alone accounts for $181 billion in health care, productivity loss, crime, incarceration and drug enforcement.
The effects of drug abuse are wide ranging and affect people of all ages. Besides addiction, drug abuse is linked to a variety of health problems, including HIV/AIDS, cancer, heart disease, and many more. It is also linked to homelessness, crime, and violence. Thus, addiction is costly to both individuals and society.
Addiction can be defined as the abnormal fixation and craving and using of any substance, dispite negative consequences.
The words drug addiction call up many different images and powerful emotions.
Any discussion about psychoactive drugs, particularly drugs like nicotine and marijuana, inevitably moves to the question is it really addicting.
Addiction is a complex disease. It is a brain disease. It is characterized by compulsive, at times uncontrollable, drug craving, seeking, and use that persist even in the face of extremely negative consequences. This issue revolves around whether or not dramatic physical withdrawal symptoms occur when an individual stops taking the drug, what is called a "physical dependence."
According to the definition of the American Society of Addiction Medicine, these drugs are known to cause addiction:
Drug craving and the other compulsive behaviors are the essence of drug addiction. They are extremely difficult to control, much more difficult than any physical dependence. They are the principal target symptoms for most drug treatment programs. Drug seeking becomes compulsive, in large part as a result of the effects of prolonged drug use on brain functioning and, thus, on behavior. For most addicts, drug use becomes chronic, with relapses possible even after long periods of abstinence.
Drug addiction is widely considered a pathological state. If a person is compulsively seeking and using a drug despite negative consequences, such as loss of job, debt, physical problems brought on by drug abuse, or family problems, then he or she is an addict.
The physical signs of being an addict can vary depending on the person and the drug being abused.
For example, someone who abuses marijuana may have a chronic cough or worsening of asthmatic conditions. THC, the chemical in marijuana responsible for producing its effects, is associated with weakening the immune system which makes the user more vulnerable to infections, such as pneumonia.
Each drug has short-term and long-term physical effects; stimulants like cocaine increase heart rate and blood pressure, whereas opioids like heroin may slow the heart rate and reduce respiration.
One important example is the use of opiates, like morphine, to treat cancer pain. In most circumstances, opiates are addicting. However, when administered for pain, although morphine treatment can produce physical dependence - which now can be easily managed after stopping use - it typically does not cause compulsive, uncontrollable morphine seeking
and use, addiction as defined here. This is why so many cancer physicians find it acceptable to prescribe opiates for cancer pain. An opposite example is marijuana, and whether it is addicting. There are some signs of physical dependence or withdrawal in heavy users, and withdrawal has been demonstrated in studies on animals.
For an addict, there is no motivation more powerful than drug craving. The addict's entire life becomes centered on getting and using the drug. Virtually nothing seems to outweigh drug craving as a motivator. People have committed all kinds of crimes and even abandoned their children just to get drugs. Focusing on drug addiction as compulsive, uncontrollable drug use should help clarify everyone's perception of the nature of drug addiction and of potentially addicting drugs.
For the addict and the clinician, this more accurate definition forces the focus of treatment away from simply managing physical withdrawal symptoms and toward dealing with the more meaningful and powerful, concept of uncontrollable drug seeking use. The task of treatment is to regain control over drug craving, seeking and use. Rethinking drug addiction also affects which drugs we worry about and the nature of our concerns. The message from modern science is that in deciding which drugs are addicting and require what kind of societal attention, we should focus primarily on whether taking those causes uncontrollable drug seeking and use.
Drugs are chemicals. They work in the brain by tapping into the brain's communication system and interfering with the way nerve cells normally send, receive, and process information.
Some drugs, such as marijuana and heroin, can activate neurons because their chemical structure mimics that of a natural neurotransmitter.
This similarity in structure "fools" receptors and allows the drugs to lock onto and activate the nerve cells. Although these drugs mimic brain chemicals, they don't activate nerve cells in the same way as a natural neurotransmitter, and they lead to abnormal messages being transmitted through the network.
Other drugs, such as amphetamine or cocaine, can cause the nerve cells to release abnormally large amounts of natural neurotransmitters or prevent the normal recycling of these brain chemicals. This disruption produces a greatly amplified message, ultimately disrupting communication channels. The difference in effect can be described as the difference between someone whispering into your ear and someone shouting into a microphone.
All drugs of abuse directly or indirectly target the brain's reward system by flooding the circuit with dopamine. Dopamine is a neurotransmitter present in regions of the brain that regulate movement, emotion, cognition, motivation, and feelings of pleasure. The overstimulation of this system, which rewards our natural behaviors, produces the euphoric effects sought by people who abuse drugs and teaches them to repeat the behavior.
Our brains are wired to ensure that we will repeat life-sustaining activities by associating those activities with pleasure or reward. Whenever this reward circuit is activated, the brain notes that something important is happening that needs to be remembered, and teaches us to do it again and again, without thinking about it. Because drugs of abuse stimulate the same circuit, we learn to abuse drugs in the same way.
When some drugs of abuse are taken, they can release 2 to 10 times the amount of dopamine that natural rewards do. In some cases, this occurs almost immediately (as when drugs are smoked or injected), and the effects can last much longer than those produced by natural rewards. The resulting effects on the brain's pleasure circuit dwarfs those produced by naturally rewarding behaviors such as eating and sex. The effect of such a powerful reward strongly motivates people to take drugs again and again. This is why scientists sometimes say that drug abuse is something we learn to do very, very well.
Just as we turn down the volume on a radio that is too loud, the brain adjusts to the overwhelming surges in dopamine (and other neurotransmitters) by producing less dopamine or by reducing the number of receptors that can receive and transmit signals. As a result, dopamine's impact on the reward circuit of a drug abuser's brain can become abnormally low, and the ability to experience any pleasure is reduced. This is why the abuser eventually feels flat, lifeless, and depressed, and is unable to enjoy things that previously brought them pleasure. Now, they need to take drugs just to bring their dopamine function back up to normal. And, they must take larger amounts of the drug than they first did to create the dopamine high an effect known as tolerance.
We know that the same sort of mechanisms involved in the development of tolerance can eventually lead to profound changes in neurons and brain circuits, with the potential to severely compromise the long-term health of the brain. For example, glutamate is another neurotransmitter that influences the reward circuit and the ability to learn. When the optimal concentration of glutamate is altered by drug abuse, the brain attempts to compensate for this change, which can cause impairment in cognitive function. Similarly, long-term drug abuse can trigger adaptations in habit or unconscious memory systems. Conditioning is one example of this type of learning, whereby environmental cues become associated with the drug experience and can trigger uncontrollable cravings if the individual is later exposed
to these cues, even without the drug itself being available. This learned "reflex" is extremely robust and can emerge even after many years of abstinence.
Chronic exposure to drugs of abuse disrupts the way critical brain structures interact to control behavior - behavior specifically related to drug abuse. Just as continued abuse may lead to tolerance or the need for higher drug dosages to produce an effect, it may also lead to addiction, which can drive an abuser to seek out and take drugs compulsively. Drug addiction erodes a person's self-control and ability to make sound decisions, while sending intense impulses to take drugs.
