9.1 Tolerance and Addiction

9-1 What are substance use disorders, and what roles do tolerance, withdrawal, and addiction play in these disorders?

psychoactive drug a chemical substance that alters perceptions and moods.

substance use disorder continued substance craving and use despite signifi cant life disruption and/or physical risk.

Chemical substances that change our perceptions and moods are termed psychoactive drugs, and most of us manage to use such substances, which include caffeine and alcohol, in moderation and without disrupting our lives. But some of us develop a self-harming substance use disorder (TABLE 9.1). A drug’s overall effect depends not only on its biological effects but also on the user’s expectations, which vary with social and cultural contexts (Gu et al., 2015; Ward, 1994). If one culture assumes that a particular drug produces euphoria (or aggression or sexual arousal) and another does not, each culture may find its expectations fulfilled. We’ll take a closer look at these interacting forces in the use and potential abuse of particular psychoactive drugs. But first, let’s consider how our bodies react to the ongoing use of psychoactive drugs.

Table 3.3: TABLE 9.1
When Is Drug Use a Disorder? According to the American Psychiatric Association, a person may be diagnosed with substance use disorder when drug use continues despite significant life disruption. Resulting brain changes may persist after quitting use of the substance (thus leading to strong cravings when exposed to people and situations that trigger memories of drug use). The severity of substance use disorder varies from mild (two to three of these indicators) to moderate (four to five indicators) to severe (six or more indicators).
Diminished Control

  1. Uses more substance, or for longer, than intended.

  2. Tries unsuccessfully to regulate use of substance.

  3. Spends much time acquiring, using, or recovering from effects of substance.

  4. Craves the substance.
Diminished Social Functioning

  1. Use disrupts commitments at work, school, or home.

  2. Continues use despite social problems.

  3. Causes reduced social, recreational, and work activities.
Hazardous Use

  1. Continues use despite hazards.

  2. Continues use despite worsening physical or psychological problems.
Drug Action

  1. Experiences tolerance (needing more substance for the desired effect).

  2. Experiences withdrawal when attempting to end use.
(Source: American Psychiatric Association, 2013.)

tolerance the diminishing effect with regular use of the same dose of a drug, requiring the user to take larger and larger doses before experiencing the drug’s effect.

addiction compulsive craving of drugs or certain behaviors (such as gambling) despite known adverse consequences.

withdrawal the discomfort and distress that follow discontinuing an addictive drug or behavior.

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Figure 3.15: FIGURE 9.1 Drug tolerance

Why might a person who rarely drinks alcohol get buzzed on one can of beer while a long-term drinker shows few effects until the second six-pack? The answer is tolerance. With continued use of alcohol and some other drugs (but not marijuana), the user’s brain chemistry adapts to offset the drug effect (a process called neuroadaptation). To experience the same effect, the user requires larger and larger doses (FIGURE 9.1). Ever-increasing doses of most psychoactive drugs may lead to addiction: The person craves and uses the substance despite its adverse consequences. (See Thinking Critically About: Addiction.) The World Health Organization (2008b) has reported that, worldwide, 90 million people suffer from such problems related to alcohol and other drugs. Regular users often try to fight their addiction, but abruptly stopping the drug may lead to the undesirable side effects of withdrawal.

THINKING CRITICALLY ABOUT

Addiction

9-2 How has the concept of addiction changed?

In recent years, the concept of addiction has been extended to cover many behaviors formerly considered bad habits or even sins. Psychologists debate whether the concept has been stretched too far, and whether addictions are really as irresistible as commonly believed. For example, “even for a very addictive drug like cocaine, only 15 to 16 percent of people become addicted within 10 years of first use,” observed Terry Robinson and Kent Berridge (2003).

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A social-networking addiction?
David Horsey/Seattlepi.com

Addictions can be powerful, and many addicts do benefit from therapy or group support. Alcoholics Anonymous has supported millions in overcoming their alcohol addiction. But viewing addiction as an uncontrollable disease can undermine people’s self-confidence and their belief that they can change. And that, critics say, would be unfortunate, for many people do voluntarily stop using addictive drugs, without any treatment. Most ex-smokers, for example, have kicked the habit on their own (Newport, 2013).

The addiction-as-disease-needing-treatment idea has been offered for a host of driven, excessive behaviors—eating, gambling, work, sex, and accumulating wealth. However, critics suggest that “addiction” can become an all-purpose excuse when used not as a metaphor (“I’m a science fiction addict”) but as reality. Moreover, they note that labeling a behavior doesn’t explain it. Attributing serial adultery to a “sex addiction” does not explain the sexual impulsiveness (Radford, 2010).

Sometimes, though, behaviors such as gambling, video gaming, or online surfing do become compulsive and dysfunctional, much like abusive drug-taking (Gentile, 2009; Griffiths, 2001; Hoeft et al., 2008). Thus, psychiatry’s manual of disorders now includes behavior addictions such as “gambling disorders,” and proposes Internet gaming disorder for further study (American Psychiatric Association, 2013). Studies in Asia, Europe, and North America estimate gaming addiction rates of from 3 to 12 percent of players (Anderson et al., 2012; Ferguson et al., 2011). Some Internet users display an apparent inability to resist logging on and staying on, even when this excessive use impairs their work and relationships (Ko et al., 2005). But there is hope. One research review found both psychological and drug therapies for Internet addiction “highly effective” (Winkler et al., 2013).

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RETRIEVE IT

Question

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ANSWER: With repeated exposure to a psychoactive drug, the user's brain chemistry adapts and the drug's effect lessens. Thus, it takes bigger doses to get the desired effect.