Abnormal Psychology

420 CHAPTER 9

expectationsabout the effects of taking a substance and his or her willingness to

try the substance or continue to use it (psychological factor). And once a person has

tried a drug, its specifi c neurological effects and other consequences of its use—such

as whether the experience of taking the drug is reinforced and how friends respond

to the drug use (psychological and social factors)—will affect how likely the per-

son is to continue using it. For instance, the Beatles took Preludin because they

were handed the pills and everyone around them was taking them (social factor).

Once they took the pills, they found that they could play longer and stay up later

(neurological factor), which was reinforcing (psychological factor). In turn, the

band members developed expectations about Preludin’s effects and were motivated

to take it again (psychological factor).

Once someone’s drug use reaches a level where tolerance and withdrawal occur,

the unpleasant consequences of withdrawal and cravings (neurological and psycho-

logical factors) increase the risk of continued dependence. And when a former abuser

goes into a social situation in which he or she previously abused drugs, the cues of that

environment—the people, the bar, the drug paraphernalia—trigger cravings for the

drug. What’s more, larger social forces (such as economic stressors or family or

community violence) can act to heighten the negatively reinforcing aspects of sub-

stance abuse as a way to cope with diffi cult circumstances.

Key Concepts and Facts About Other Abused Substances

• Narcotic analgesics, also called opioids, can dull pain and de-
  crease awareness. Continued opioid use quickly leads to tol-
  erance and withdrawal, as well as compulsive drug-related
  behaviors. Heroin is an opioid. Opioids activate the dopamine
  reward system. They also depress the central nervous system
  and decrease endorphin production, thereby reducing the
  body’s inherent ability to relieve pain. Using an opioid and a de-
  pressant at the same time is potentially lethal.


• Hallucinogens include LSD, mescaline, psilocybin, and mari-
  juana. Hallucinogens have unpredictable effects, which depend
  in part on the user’s expectations and the context in which the
  drug is taken. People can have a “bad trip” when using LSD and
  can experience fl ashbacks long after the drug wears off. LSD af-
  fects serotonin functioning.


• Although the effects of marijuana are more subtle, abuse of or
  dependence on this hallucinogen affects motivation, learning,
  and memory. The active ingredient in marijuana—THC—appears
  to have an effect on the brain similar to that of cannabinoids,
  and activates the dopamine reward system. Chronic marijuana
  users may develop withdrawal.


• Dissociative anesthetics (sometimes referred to as “club drugs”)
  are so named because they induce a sense of dissociation and
  cause anesthesia. They depress the central nervous system and
  affect glutamate activity. Dissociative anesthetics include PCP
  and ketamine. Use and abuse of this type of drug impairs cogni-
  tive functioning and can lead to violent behavior.


• Genes may predispose some people to develop abuse of or de-
  pendence on these substances.
  
  
  • Psychological factors related to substance use disorders include ob-
    servational learning of what to expect from taking the drugs and of
    using the drugs as a coping strategy. Classical conditioning of stimuli
    related to drug use can lead to cravings and can play a role in build-
    ing tolerance (and hence overdoses are more likely when those cues
    are not present). In addition, the disorders may arise in part from op-
    erant conditioning (reinforcement of the effects of the drug).
  
  
  • Social factors related to substance use disorders include the in-
    dividual’s relationships with family members, peers’ use of sub-
    stances, cultural norms and perceived norms about appropriate
    and inappropriate use of substances, and socioeconomic factors.
  
  
  • These factors form feedback loops: Genes infl uence tempera-
    ment, which in turn influences an individual’s choice of peer
    group and willingness to experiment with (and continue to use)
    drugs. The relationship also works the other way: Social factors
    can infl uence what peer groups are available to an individual,
    which in turn infl uences the models he or she observes of how
    to cope and of the perceived norms of substance use. These
    factors then affect an individual’s substance use, which leads
    to specifi c neurological effects (including tolerance and with-
    drawal), which further infl uence substance use behavior.
  
  
  
  

Making a Diagnosis

• Reread Case 9.6, and determine whether or not the young man’s
  symptoms meet the criteria for abuse of or dependence on PCP.
  Specifi cally, list which criteria apply and which ones do not. If you
  would like more information to determine whether he is depen-
  dent on PCP, what information—specifi cally—would you want,
  and in what ways would the information infl uence your decision?