Abnormal Psychology

Schizophrenia and Other Psychotic Disorders 555

an underlying vulnerability to schizophrenia (Walker & Diforio, 1997). The key

idea is that vulnerable people are biologically predisposed either to produce too

much stress hormones or to be too sensitive to the effects of such hormones when

they encounter a stressful event (van Os & Delespaul, 2003). The excess hormones

or the excessive sensitivity to them can activate certain dopamine pathways too

strongly, which then exacerbates schizophrenia symptoms. The social withdrawal

common among people with schizophrenia may thus be an attempt to decrease

stress (Walker & Diforio, 1997). Consistent with this view, people with schizo-

phrenia who took part in a stress management program had fewer hospital admis-

sions 1 year later (Norman et al., 2002). Moreover, as this model predicts, people

with schizophrenia have higher baseline levels of cortisol, as do people at risk for

schizophrenia. And antipsychotic medications lower the high cortisol levels in

people with schizophrenia.

In addition, the neurocognitive defi cits that accompany schizophrenia leave

these patients with fewer cognitive resources to cope with stressful events. For ex-

ample, their lack of insight and impaired theory of mind make it diffi cult for them

to plan adequately. Cognitive defi cits give rise to cognitive distortions, which can

give rise to delusions that ultimately lead to social withdrawal (Beck & Rector,

2005). And the distorted ways of thinking about self and the world create stress,

which produces higher levels of cortisol as a result of the hyperactivation of the

hypothalamic-pituitary-adrenal (HPA) axis, which leads to a cascade of neurologi-

cal events that further decreases cognitive functioning.

The Genain quads illustrate the effects of these feedback loops. A family history

of schizophrenia as well as prenatal complications made the quads neurologically

vulnerable to developing schizophrenia. They were socially isolated, were teased

by other children, and experienced physical and emotional abuse. Had the Genain

quads grown up in a different home environment, with parents who treated them

differently, it is possible that some of them might not have developed schizophrenia

and those who did might have suffered fewer relapses.

Key Concepts and Facts About Understanding Schizophrenia

• A variety of neurological factors are associated with
  schizophrenia:
  
  
  • Abnormalities in brain structure and function have been
    found in the frontal and temporal lobes, the thalamus, and
    the hippocampus. Moreover, certain brain areas do not
    appear to interact with each other properly. People with
    schizophrenia are more likely to have enlarged ventricles
    than are other people. The brain abnormalities give rise to
    biological markers in some individuals.
  
  
  • These brain abnormalities appear to be a result of, at least
    in some cases, maternal malnourishment or illness during
    pregnancy or to fetal oxygen deprivation.
  
  
  • Schizophrenia is associated with abnormalities in dopamine,
    serotonin, and glutamate activity, as well as a heightened
    stress response and increased cortisol production.
  
  
  • Less than 15% of people with schizophrenia have a fi rst-
    degree relative (who is not a twin) who also has the dis-
    order, but genetics is still the strongest predictor that
    a given individual will develop schizophrenia. Genetics
  
  
  
  

alone, though, cannot explain why a given individual

develops the disorder.

• Psychological factors that are associated with schizophrenia
  and shape the symptoms of the disorder include:
  
  
  • cognitive deficits in attention, memory, and executive
    functioning;
  
  
  • dysfunctional beliefs and attributions; and
  
  
  • diffi culty recognizing and conveying emotions.
  
  
  
  


• Various social factors are also associated with schizophrenia:
  
  
  • an impaired theory of mind, which makes it diffi cult to under-
    stand other people’s behavior, which in turn means that that
    other people’s behavior routinely appears to be unpredictable;
  
  
  • a stressful home environment, such as being raised in an
    orphanage or by a parent with schizophrenia;
  
  
  • the stresses of immigration—particularly for people likely to
    encounter discrimination—and economic hardship; and
  
  
  • the individualist nature of the culture, which is associated
    with lower recovery rates for people with schizophrenia.