Tolerance and Dependence
When a person’s body is exposed to any type of substance for a regular period of time, the substance throws off this sense of balance or homeostasis. The person’s internal system attempts to maintain homeostasis by using counter-regulatory processes to establish a new state of balance based on the presence of the drug in the system. These include modifying the levels of certain neurotransmitters, hormones, and other substances/processes in the body to adjust for the presence of the drug in the system. This may be an ongoing process. For instance, tolerance to a substance occurs when chronic use of the drug produces changes in the system so that more amounts of the drug are needed to produce the same effects that were once achieved at lower doses. The body keeps adjusting its set point for homeostasis, as an individual uses more and more of the drug. This leads to increased levels of tolerance.
When the person stops using the drug, the state of homeostasis in the body that has been developed as a result of regularly getting the drug is suddenly thrown off. This results in a state of imbalance that includes a number of issues with levels of hormones, neurotransmitters, and imbalances in other systems that result in what most people think of as withdrawal symptoms. People feel sick, psychologically thrown out of balance, and may even develop severe and potentially dangerous symptoms, such as seizures, depending on the type of drug they were using.
When people have developed both tolerance and withdrawal symptoms, they have become physically dependent on the drug. This means that they need regular exposure to the drug in order for their system to maintain its new level of homeostasis. Drug levels in the tissues will decrease if drug use is not continued. In addition, anyone experiencing withdrawal symptoms as a result of stopping a certain drug has assuredly developed some level of tolerance to it. The person’s system bases its set point on a certain level of the drug in its tissues. When this level drops, the system becomes unbalanced.
Physical dependence occurs with many drugs, including drugs that are taken for medicinal purposes only. The syndrome of physical dependence may be a symptom of addiction, but physical dependence is neither necessary nor sufficient for an individual to be addicted to a drug. Addiction represents the nonmedical use of drugs that results in negative consequences for the individual. People who continue to use drugs under the supervision of a physician for medical reasons may develop physical dependence on them, but they have not developed the disorder of addiction.
The American Psychiatric Association lists the diagnostic criteria for withdrawal from a number of different substances, including alcohol, stimulants, opioids, etc. These diagnostic criteria differ according to the class of drug. While the formal diagnostic criteria for withdrawal from each class of drug will not be listed here, a general description of the withdrawal syndrome for several classes of commonly abused drugs follows. Readers interested in learning more about specific withdrawal symptoms can refer to the American Psychiatric Association or other professional sources, such as Kaplan and Sadock’s Synopsis of Psychiatry or The Principles of Addiction Medicineby the American Society of Addiction Medicine.
- Alcohol withdrawal: Withdrawal from alcohol consists of a number of physical and emotional/psychological symptoms. Alcohol has a high potential for the development of physical dependence. Individuals who chronically abuse alcohol may develop a minor withdrawal syndrome that results in issues with nausea, vomiting, shakiness, headache, and other flulike symptoms, or if they have a history of chronic, heavy use, they may also be vulnerable to developing a severe withdrawal syndrome that includes the potential to develop hallucinations, seizures, marked confusion, and a syndrome known as delirium tremens. Individuals who develop seizures or delirium tremens during withdrawal from alcohol are at serious risk for death and need close medical supervision.
- Benzodiazepine withdrawal: Benzodiazepines are a class of drugs that are primarily used in the treatment of anxiety disorders and for seizure control. These drugs include familiar drugs such as Xanax, Valium, Ativan, Klonopin, and a number of others. Like alcohol, they have the potential to cause serious physical dependence when abused, and withdrawal from them produces a similar syndrome to that noted in alcohol withdrawal. There is a potential to develop seizures from withdrawal from benzodiazepines, and individuals withdrawing from them require strict medical supervision.
- Withdrawal from narcotic (opioid) medications/drugs: Narcotic drugs include large number of drugs used for the treatment of chronic pain and other issues, and several illicit drugs. This class includes familiar drugs like morphine, Vicodin, and OxyContin, and the illicit drug heroin and opium derivatives. The withdrawal syndrome associated with this class of drugs is not generally considered to be potentially physically dangerous or fatal; however, individuals will usually experience severe physical and emotional discomfort. This can include nausea, vomiting, mood swings, and depression or anxiety. Some of these individuals may be at risk for self-harm, such as suicide attempts or accidents due to poor judgment.
- Withdrawal from stimulant medications/drugs: Stimulants include a number of drugs used for medicinal purposes, such as Ritalin and Adderall, diet aids, caffeine, and illicit substances like cocaine and methamphetamine (crystal meth). Tolerance to these drugs develops rather quickly; however, the withdrawal syndrome associated with these drugs is believed to be primarily emotional and psychological. It is not comprised of symptoms that suggest severe physical. In addition, the withdrawal syndrome for stimulants drugs varies significantly, depending on the type of stimulant a person has used (e.g., think caffeine withdrawal compared to withdrawal from cocaine or crystal meth). Serious complications can occur with withdrawal from certain stimulant medications, such as cocaine or methamphetamine, that include hallucinations, paranoia, and the development of seizures. Many of these drugs are associated with a severe psychological “crash” when discontinued that consists of severe depression, insomnia, fatigue, and cravings for the drug. Others, such as caffeine, produce mild withdrawal symptoms that include headaches, irritability, nervousness, and mild insomnia.
- Withdrawal from nicotine: People trying to quit smoking are familiar with the severe cravings and symptoms of nicotine withdrawal. Many of these symptoms are primarily psychological in nature; however, there is a mild level of physical dependence associated with chronic use of nicotine. These withdrawal symptoms include dizziness, mild headache, potential nausea, feeling jittery or shaky, anxiety, depression, and severe cravings. The withdrawal process from nicotine is not considered to be potentially physically dangerous, but individuals may experience relatively moderate or even severe emotional and psychological distress.
- Withdrawal from cannabis: Cannabis withdrawal is now a recognized clinical syndrome. The symptoms are primarily psychological and include irritability, mild anxiety, issues with sleep, appetite loss, and depression. The symptoms are not considered to be dangerous.
Other withdrawal syndromes are recognized. Interested readers may wish to refer to the sources mentioned above regarding potential withdrawal symptoms associated with other substances not mentioned here.
Treatment for Withdrawal
Of course, any person can attempt a “cold turkey” approach to withdrawal. In some cases, such as with alcohol or benzodiazepine withdrawal, this could lead to a potentially dangerous situation. Given the current advances in medicine and the understanding of substance use disorders, there is no reason for anyone to attempt this approach these days.
Medically assisted treatment exists for the withdrawal process from many of the above-mentioned substances. In some instances, this may require a tapering strategy where a physician administers increasingly lower doses of the substance to an individual on a fixed schedule along with professional supervision and treatment in order to slowly detoxify the person from the substance. In other cases, such as withdrawal from narcotics, medications that are designed specifically to assist in the withdrawal process from these drugs can be given and tapered on a similar schedule. In many cases, medically assisted treatment will use other drugs to control cravings, to reduce the symptoms of withdrawal, and, in cases of alcohol or benzodiazepine withdrawal, to avoid serious symptoms such as seizures.
Medically assisted withdrawal procedures should only be performed by a licensed physician who is certified in addiction medicine or psychiatry and has experience treating the particular withdrawal syndrome in question.
Individuals who are not trained and certified in addiction medicine attempting to mimic professional medically assisted withdrawal treatment protocols on their own are creating a potentially dangerous and possibly fatal situation.