▪ Substance Abuse Disorders



▪ Substance Abuse Disorders





Use and abuse of alcohol and narcotics have occurred throughout history. Indeed, until recently their use to alleviate pain was one of the few effective medical therapies. Advances in chemistry led, particularly during the 19th and 20th centuries, to the formulation of more potent preparations as active ingredients were identified and then used to search for other agents. At one time, cocaine and the opiates were widely prescribed and readily available, often being included in various elixirs and tonics. By 1924, an awareness of the potential for abuse led to federal regulation so that opiates and cocaine could only be prescribed by physicians. Similarly, the advent of Prohibition meant that alcohol was no longer freely available; as a result (until repeal in 1933), there was an extensive black market in alcohol as there now is other substances (see Musto, 1999, for an historical review). Over time, the federal government has taken an increasingly active role in the regulation of medications and substances with abuse potential. State governments do, however, continue to be the primary regulators in some areas, e.g., for alcohol sales.

Advances in understanding the pharmacology and mechanisms of action (e.g. using animal models) have advanced our knowledge of brain processes and the mechanisms that may underlie substance abuse. Until recently, most of the work on substance abuse and substance dependence has come from work with adults. There has been less research on children and adolescents. Clearly, adolescents who abuse drugs or alcohol have sure risk for developing dependence in adulthood. Among adolescents, substance abuse is significantly more common than dependence (probably by about two to one), and abuse of multiple substances is fairly common. There is some suggestion (Hopfer & Riggs, 2007) that in contrast to adults, the distinction currently made between abuse and dependency may be more artificial in adolescents.




EPIDEMIOLOGY AND DEMOGRAPHICS

There have been major changes in the use of drugs over the past decade in adolescents in the United States. As noted in Figure 15.1, there have been some fluctuations in patterns of substance abuse, although the most consistently used substances in adolescents have included alcohol, tobacco, and marijuana. About one-third of high school seniors report use of some illegal substance (apart from marijuana) at some point in their lives. Variations in patterns of substance abuse are noteworthy but not always well understood. There has been a noteworthy increase in the use of hydrocodone in adolescents.

Age-related data from publicly funded substance abuse treatment programs are presented in Table 15.1. For younger adolescents, marijuana is most frequently cited as the primary substance of abuse, but for the oldest adolescents and young adults, marijuana combined with alcohol continues to be a major problem along with a variety of other substances. There is a steady increase in prevalence of substance use and disorders of substance use over the course of adolescence with about 25% of older adolescents meeting criteria for abuse and 20% for disorder.







FIGURE 15.1. Trends in prevalence of twelfth grade lifetime drug use. (Adapted from Johnson, L. D., O’Malley, P. M., Bachman, J. G., & Schulenberg, J. E. (2005). Monitoring the Future: National Survey Results on Drug Use, 1975-2004. Volume 1: Secondary School Students. Bethesda, MD: National Institute on Drug Abuse; 680. NIH Publication No. 05-5727.)

Boys and young men are more likely to engage in substance abuse and also are more likely to meet criteria for dependence in late adolescence, particularly for alcohol and marijuana. Girls and young women are more likely to report nicotine dependence. Rates of substance use disorders are high in a mental health setting and even more so in juvenile justice setting, where a majority of individuals meet lifetime criteria for substance use disorders.

Risk appears to increase with early onset of substance use. It remains unclear why this is so, although animal studies have suggested greater potential for vulnerability to drug sensitization during the adolescent period. It may also be that early use of substances arises as a result of more general risk factors.


ETIOLOGY

Various risk factors are associates with substance abuse disorders in adolescents (see Whitmore & Riggs, 2006). Obviously, development of these disorders depends on ready access to substances of abuse. However, even when these substances are widely available, only a small number of adolescents develop substance use disorders. Attempts have been made to understand genetic and environmental factors using twin and adoption studies. Genetic factors become more apparent if environments support their expression. Genetic mechanisms can be complex (e.g., there may be a direct impact on the ability to metabolize or react to substances). Effects may also be more indirect (e.g., by impacting other aspects of development or behavior). It is clear that family history of substance abuse or dependence is a powerful predictor of risk.

Risk for substance and abuse and dependence is increased in association with a number of other conditions. For example, the various externalizing disorders are a major risk factor (Crowley & Riggs, 1995). Because of their frequent association with each other, disentangling contributions of these conditions is complicated, but it is clear that conduct disorder is a major risk factor and the less severe oppositional defiant disorder (ODD) and even attentiondeficit/hyperactivity disorder (ADHD) also appear to increase risk.









TABLE 15.1 PRIMARY ADMITTING SUBSTANCE OF ABUSE (% OF TOTAL ADMISSIONS), BY AGE FROM THE TREATMENT EPISODE DATA SET























































































































Substance


Age (years)


12-14 %


15-17 %


18-20 %


None


8.3


2.2


0.9


Alcohol


17.7


19.9


30.6


Crack or cocaine


1.2


2.4


6.3


Marijuana or hashish


66.7


66.9


37.9


Heroin


0.2


1.2


9.8


Nonprescription methadone


0


0


0.1


Other opiates and synthetics


0.4


0.6


2.5


PCP


0.1


0.1


0.4


Hallucinogens


0.1


0.3


0.4


Methamphetamine


2.1


4


8.4


Other amphetamines


0.6


0.9


1.4


Other stimulants


0.2


0.1


0.1


Benzodiazepines


0.2


0.2


0.4


Other tranquilizers


0.1


0.1


0


Barbiturates


0


0


0


Other sedatives or hypnotics


0.2


0.1


0.2


Inhalants


0.9


0.2


0.1


Over-the-counter medications


0.2


0.2


0.1


Other


0.9


0.6


0.5


Total percent


100


100


100


(Total N)


(24,911)


(123,496)


(119,138)


PCP, phencyclidine.


From TEDS: Treatment Episode Data Set. (2003). Highlights. National Admissions to Substance Abuse Treatment Services, DASIS Series: S-27. Rockville, MD: Services DoHaH. DHHS Publication No. SMA 05-4043, with permission.

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Aug 1, 2016 | Posted by in PSYCHIATRY | Comments Off on ▪ Substance Abuse Disorders
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