18.1 Introduction
This chapter discusses patients who abuse substances that affect the central nervous system (CNS). It examines systems of substance classification, concepts related to the etiology and dynamics of substance abuse and dependency, physical and behavioral changes that occur in people who abuse and become dependent on substances, and interdisciplinary treatment interventions.
These disorders are seen across many educational, treatment, and counseling settings. They are often, but not always, seen in conjunction with another major mental health problem. Problems occur on a spectrum from use to dependence, and it is important to understand the entire spectrum to properly diagnose, prevent progression of, and treat these disorders. The treatment of these disorders is a complex specialty area of mental health.
18.2 Terminology of Substance Abuse and Dependence
Substance abuse is a maladaptive pattern of substance use leading to impairment, distress, and recurrent significant negative consequences. These adverse consequences can occur in medical, psychosocial, or legal domains. Individuals who abuse licit or illicit substances often engage in situations that are physically hazardous.
Substance dependence is the compulsive use of a substance, accompanied by tolerance and withdrawal. A diagnosis of substance dependence (once called “addiction”) pre-empts a diagnosis of abuse, as tolerance, compulsive use and withdrawal are generally not present in substance abuse. In both instances, DSM specifies that the behaviors will have occurred in the past year. The major differences are outlined in Table 18.1. Since tolerance and withdrawal require a sustained period of use, and these manifestations of substance dependence may not typically begin until the individual is in the twenties or thirties. However, some older adolescents may meet the criteria for substance dependence by age 18.
Table 18.1 Substance abuse versus substance dependence.
| Abuse (1 out of 4 in past year) | Dependence (3 out of 7 in past year) |
| Recurrent use resulting in failure to fulfill major roles | Tolerance |
| Recurrent use in situations that are physically hazardous | Withdrawal |
| Recurrent substance-related legal problems | Substance taken in larger amounts and/or for a longer period than was intended |
| Continued use despite having persistent and social problems due to use | Unsuccessful attempts to cut down or control use |
| Great deal of time spent in activities necessary to obtain substance or recover from its effects | |
| Important social, occupational, or recreational activities given up because of use | |
| Substance use continues despite knowledge that medical or psychological problems are due to use |
Prolonged heavy ingestion of a substance results in physical tolerance and more of the drug is needed to achieve the desired effect. When physical tolerance develops, the person may experience withdrawal or an abstinence syndrome after cessation or a decrease in consumption.
All drugs of abuse and dependency share certain factors, while some factors are specific to each drug. The commonalities underlying these disorders is that the core problem is the abuse of, or dependency on, a substance, although the manifestations or functional disturbances resulting from the problem may differ. The words “addiction” and “dependence” are frequently confused. There is little consensus on what addiction actually means and it is not a DSM term. Addiction usually refers to a behavioral pattern of drug abuse characterized by overwhelming involvement with use of a drug (compulsive use) and with the securing of its supply, and by a high tendency to relapse after discontinuation. Addiction is often used when dependence is what is meant.
The use and abuse of substances happen in fads, but the most commonly abused substances include alcohol, opioids the stimulants, such as cocaine and the amphetamines, and the cannabinoids. Prescription sedative abuse and dependence have become problematic among psychiatric and other patients.
Owing to the sheer volume of material available on scores of drugs of abuse, this chapter will highlight those that are most commonly encountered in clinical practice. The remainder are presented in a table with their intoxication manifestations, health effects, and withdrawal symptoms.
18.3 Recreational Use of Substances
Recreational use of drugs and alcohol has become an increasingly part of Western culture. Only the use of tobacco and alcohol is endorsed legally, but (with some exceptions) recreational use of other substances is overlooked by authorities. Some users are apparently unharmed, using substances episodically and in small doses and avoiding toxicity and tolerance. Recreational drugs and substances are taken orally or inhaled, their use is often accompanied by rituals, and they are rarely ingested alone. It is important for the clinician to be aware of recreational drug and alcohol use and patterns in that such use can interfere with therapeutics and has the potential to turn into more serious use.
An estimated 20% of people in the United States have used prescription drugs for nonmedical reasons. This is called “prescription drug abuse” and is a growing problem. Prescription drugs that are abused or used for nonmedical reasons can lead to dependence. Commonly abused classes of prescription drugs include opioids, CNS depressants, and stimulants.
A study in 2007 showed that 2.7% of eighth-graders, 7.2% of tenth-graders, and 9.6% of twelfth-graders had abused hydrocodone, and 1.8% of eighth-graders, 3.9% of tenth-graders, and 5.2% of twelfth-graders had abused oxycodone, for nonmedical purposes at least once in the year prior to being surveyed.
Approximately 22% of US adults have a substance abuse disorder. In 2008, an estimated 20.1 million of the population aged 12 years or older were current (past month) illicit drug users, meaning they had used an illicit drug during the month prior to the survey interview. This estimate represents 8.0% of the population aged 12 years or older. Illicit drug use is higher among males than females. Further statistics on substance abuse and dependence can be found on the SAMHSA website at http://www.oas.samhsa.gov/nhsda.htm.
18.5 Etiology of Drug and Alcohol Dependence
Commonly used psychoactive drugs vary in their potential for creating dependence. Drug dependence develops in a way that is both complex and unclear. The process is influenced by the properties of the psychoactive drugs, genetic predispoisition, cultural and social settings.
Heritability or genetic vulnerability may be important in the development of drug and alcohol dependence. Epidemiological studies of twins suggest that, while both genetic and environmental factors play a role in twin concordance of drug use, concordance of abuse and dependence are more influenced by genetic factors. While no single gene has been definitively linked to any substance use disorder, certain alleles may play a role in their development and/or clinical manifestations.
Research has focused on the effects of illicit drugs on reward pathways in the brain. The most prevalent reward pathway involves several sequential parts of the brain: the ventral tegmental area, the nucleus accumbens, and the prefrontal cortex. When the brain perceives a pleasure stimulus, the neurotransmitter dopamine normally sends the stimulus along this pathway. Drugs of abuse interfere with this normal neurotransmission by binding themselves to dopamine receptors sites, thus replacing the normal effect of dopamine with the drug’s effect. The result is the stimulation of receiving neurons by the substance, resulting in the initial mood-altering effect of the drug (depression or euphoria). With continued presence of the addictive drug, dopamine levels either drop or the pleasure pathway is destroyed, reducing normal neurotransmission of pleasure experiences. The physiologic dependence and addiction to a substance is characterized when the person experiences cravings for stimulation of the pleasure pathway, often leading to engagement in compulsive behavior to obtain the chemicals of stimulation. The craving for the stimulus eventually becomes stronger than the reward.
Environment and the presence and availability are also critical factors in the development of substance use. Experimentation can only occur when substances of abuse are accessible. The development of substance use and dependence disorders depends on a myriad of risk factors, which are listed in Table 18.2.
Table 18.2 Risk factors for substance use disorders.
| Genetic factors | Studies have found rates of substance dependence 3–4 times higher in identical twins than in dizygotic twins |
| Psychologic factors | High rates of depressive disorders and sensation seeking |
| Social and environmental factors | Peer and family influences |
| Biologic factors | Repeated exposure to the substance results in neural adaptation that perpetuates the dependence cycle |
The “gateway” drug use hypothesis, in which experimentation with drugs evolves into more serious drug use, was described over three decades ago. The natural history of substance abuse and dependence typically follows a chronic relapsing pattern, although many youths experiment with drugs and never progress to dependence.
18.6 Comorbidity and Dual Diagnoses
One of the emerging issues from the Healthy People 2010 midcourse review was co-occurring mental health and substance abuse disorders and the outcomes resulting from this combination. About 50% of adults who have a diagnosable mental disorder will also have a substance abuse disorder at some point during their lifetime. Co-occurring disorders tend to be more chronic and disabling than either disorder alone. Individuals with co-occurring disorders are more likely to experience a chronic course or to require more services than people with either type of disorder alone.
The terms comorbidity and dual diagnosis describe a patient with coexisting substance abuse or dependency and a major psychiatric disorder. The disorders are unrelated and meet the DSM-IV-TR criteria.
Reports estimate that dual diagnoses in chronically mentally ill patients range from 30% to 40% of outpatients and from 60% to 80% of inpatients. Traditional methods of treatment for major psychiatric disorders and substance dependency (i.e., substance dependency programs) have not been successful in treating patients with dual diagnoses. Ongoing research on the identification, treatment, and rehabilitation of patients with dual diagnoses is needed.
18.7 Alcohol Use and Dependence
18.7.1 Pharmacology and Effects
Alcohol (ethanol) is a legal chemical having pharmacologic properties that produce mind- and mood-altering effects. It is a CNS depressant. Alcohol-containing beverages include beer, wine, and distilled spirits. In contrast to some other drugs that produce their effects from small quantities, alcohol usually requires large quantities used over a period of time to cause physical dependence.
As the dose of alcohol increases, a pattern of effects emerge: sedation, impaired mental and motor functioning, deepening stupor with a decrease in stimulation response (including painful stimulus response), coma, and eventually death from respiratory and circulatory collapse. The physical and behavioral manifestations of the effects of alcohol on the CNS are related directly to the level of alcohol in the blood and the concentration of alcohol in the brain. The blood’s alcohol level is expressed as milligrams of alcohol per milliliter of blood (mg/mL). Alcohol concentration in the blood depends on the rate of absorption, transportation to the CNS, redistribution to other parts of the body, metabolism, and elimination. Alcohol is absorbed through the mouth, stomach, and small intestine. It is absorbed unchanged into the blood and circulates throughout the body, including the brain. It also crosses the placenta into fetal circulation. Intoxication occurs when the circulating alcohol interferes with the normal functioning of brain nerve cells.
The rate of absorption of alcohol into the blood varies and depends on the rate of ingestion, substances in the beverage (e.g., carbonation can increase absorption), food in the stomach, and the drinker’s physical or emotional state.
Body size affects the concentration of alcohol in the blood. The same amount of alcohol ingested by a small person results in greater blood alcohol concentration than in a big person, because the latter has more blood volume in which the alcohol is diluted. A person’s body chemistry and cultural influences also may alter the behavioral effects of alcohol.
Oxidation, which occurs mainly in the liver, eliminates 90% of the alcohol absorbed by the body. The other 10% is eliminated unchanged through body fluids such as breath, sweat, and urine. The rate of drinking may vary, but the excretion of alcohol from the body remains at a fixed rate. A healthy liver metabolizes about one ounce of alcohol per hour.
18.7.2 Tolerance
Alcohol-tolerant individuals may also be cross-tolerant to other CNS depressants. The drinking history of alcoholics often reveals the ability to increase tolerance and to maintain this increase for long periods. Frequently, an irreversible drop in tolerance follows this increased tolerance; the person becomes intoxicated with smaller amounts of alcohol.
18.7.3 Intoxication
Intoxication occurs after drinking excessive amounts of alcohol and is evidenced in maladaptive behavior such as fighting, impaired judgment, or interference with social or occupational functioning. Physiologic signs such as slurred speech, incoordination, unsteady gait, and flushed face may accompany intoxication. Psychologic signs may be observed, such as mood change, irritability, talkativeness, or impaired attention.
18.7.4 Abuse and Dependence
Alcohol abuse refers to a maladaptive pattern of episodic drinking resulting in failure ot fulfill obligations, exposure to physically hazardous situations, legal problems or social and interpersonal problems without evidence of dependence. Alcohol dependence refers to frequent consumption of large amounts of alcohol over time, resulting in tolerance, physical and psychologic dependence, and withdrawal syndrome. People who abuse or who are dependent on alcohol often experience serious social consequences from their drinking. They can also experience serious medical and neurological conditions. These are briefly described below.
18.7.4.1 Alcoholic Hallucinosis
Alcoholic hallucinosis usually occurs within 48 hours after cessation of, or a reduction in, drinking. Vivid, perhaps threatening, auditory hallucinations may develop, but clouding of consciousness does not occur.
18.7.4.2 Alcoholic Amnestic Disorder
The alcoholic amnestic disorder results from heavy, prolonged drinking and is thought to be related to poor nutrition. Amnesia consists of impairment in the ability to learn new information (short-term memory) and to recall remote information (long-term memory). Other neurologic signs, such as neuropathy, unsteady gait, or myopathy, may be present.
Amnestic disorders related to thiamine deficiency include Wernicke’s encephalopathy, a mild to severe decrease in mental functioning characterized by ataxia, nystagmus, ophthalmoplegia, and mental status changes. These symptoms improve with thiamine replacement. Korsakoff’s psychosis also results from thiamine deficiency and involves gait disturbance, short-term memory loss, disorientation, delirium, confabulation, and neuropathy. Korsakoff’s psychosis is not reversed by thiamine replacement therapy. Wernicke–Korsakoff syndrome is the coexistence of Wernicke’s encephalopathy and Korsakoff’s psychosis.
18.7.4.3 Alcoholic Dementia
Alcoholic dementia is associated with prolonged, chronic alcohol dependence. Signs of dementia include loss of intellectual ability that is severe enough to interfere with social or occupational functioning and impairment in memory, abstract thinking, and judgment. The degree of impairment may range from mild to severe.
18.7.5 Associated Medical Conditions
Heavy consumption of alcohol adversely affects most body systems. Gastrointestinal problems occur as a result of the irritating effects of alcohol on the GI tract, resulting in gastritis or gastric ulcers. Acute or chronic pancreatitis may occur. Esophagitis may result from the direct toxic effects of alcohol on the esophageal mucosa, increased acid production in the stomach, or frequent vomiting. Cardiovascular problems such as mild to moderate hypertension, cardiomyopathy, or arrhythmias result from the direct toxic effects of the substance and malnutrition.
The liver is highly susceptible to the damaging effects of alcohol because it is the primary organ that metabolizes the substance. Alcohol is toxic to the liver, regardless of the person’s nutritional status. Alcoholic hepatitis is a serious condition involving inflammation and necrosis of the liver cells and sometimes is reversible. Cirrhosis of the liver, in which the liver cells are destroyed and replaced by scar tissue, is the most serious condition and is irreversible. A high risk of cancer, especially of the mouth, pharynx, larynx, esophagus, pancreas, stomach, and colon, is associated with alcoholism.
Hematopoietic complications include decreased white blood cell production, decreased granulocyte adherence, and thrombocytopenia, leading to compromised immune function. Nonspecific indicators of regular alcohol use include elevated levels of mean corpuscular volume, gamma-glutamyltransferase, and carbohydrate-deficient transferrin. While other conditions such as nonalcoholic liver disease, hyperthyroidism, and use of anticonvulsants also can elevate the gamma-glutamyltransferase level, this combination of findings should raise suspicion of regular alcohol consumption of 6–8 ounces a day.
18.7.6 Other Complications of Alcohol Consumption
Among pregnant women aged 15–44, an estimated 10.6% reported current alcohol use, 4.5% reported binge-drinking, and 0.8% reported heavy drinking. This is a troubling statistic in that such activity can lead to fetal alcohol syndrome. FAS is a serious syndrome characterized by a group of congenital birth defects caused by chronic drinking while pregnant. These include prenatal and postnatal growth deficiency, facial malformations (small head circumference, flattened and elongated groove between nose and upper lip, flattened midface, sunken nasal bridge), CNS dysfunction, and varying degrees of major organ system malfunction. FAS is associated with poor academic performance and behavioral difficulties in children and it is the leading cause of mental retardation.
18.7.7 Alcohol Withdrawal
Alcohol withdrawal, also referred to as “abstinence syndrome,” occurs after a reduction in, or a cessation of, prolonged heavy drinking. Earliest signs of withdrawal include irritability and impatient behavior. A coarse tremor of hand, tongue, and eyelids may follow, as may nausea and vomiting, general malaise or weakness, autonomic nervous system hyperactivity (e.g., increased blood pressure and pulse), headache, paroxysmal sweats, anxiety, a depressed or irritable mood, and orthostatic hypotension. Sleep disturbances, insomnia, nightmares, or hallucinations also may occur during withdrawal. Alcohol withdrawal is often assessed using the Clinical Institute Withdrawal Assessment of Alcohol Scale – Revised (CIWA-AR).
Related posts:
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
