538 CHAPTER 12
possible reasons for this fi nding in the Understanding Schizophrenia section on
social factors.
Table 12.5 provides a summary of facts about schizophrenia.Prognosis
In general, the long-term prognosis for schizophrenia follows the rule of thirds:- one third of patients improve signifi cantly;
- one third basically stay the same, having episodic relapses and some permanent
defi cits in functioning, but able to hold a “sheltered” job—a job designed for
people with mild to moderate disabilities; and - one third become chronically and severely disabled by their illness.
Table 12.6 summarizes factors associated with a better prognosis in Western coun-
tries. However, this table does not indicate a crucial fact about the prognosis for
people with schizophrenia: Over the course of their lives, people with schizophrenia
are more likely than others to die by suicide or to be victims of violence. Let’s exam-
ine these risks in greater detail.Table 12.5 • Schizophrenia Facts at a Glance
Prevalence- Approximately 1% of people worldwide have schizophrenia (Gottesman, 1991; Tandon,
Keshavan, & Nasrallah, 2008).
Comorbidity- Over 90% of people with schizophrenia also have another disorder. The most frequent
comorbid disorders are mood, anxiety, and substance-related disorders.
Onset- Men are more likely to develop the disorder between 18 and 25, whereas women are more
likely to develop it between 26 and 45 years old.
Course- About two thirds of people who have had one episode will go on to have subsequent episodes.
- About a third of people with schizophrenia become chronically ill, without much reduction of
symptoms; for most others, the symptoms subside.
Gender Differences- Schizophrenia affects men more frequently than women (1.4:1 male-to-female ratio; McGrath,
2006), and—as noted above—women tend to develop the disorder at older ages than do men. - Women have fewer negative symptoms than do men.
Cultural Differences- Schizophrenia is more common among those living in urban areas and those from lower
socioeconomic groups (Freeman, 1994; Mortensen et al., 1999; Saha et al., 2005). - In non-Western countries, people with schizophrenia generally function better in society than
do those in Western countries (Hopper et al., 2007). - In a given country, immigrants are almost twice as likely to develop schizophrenia as are
native-born residents (Saha et al., 2005). - Within the United States, Latinos and Whites are less likely to develop schizophrenia than are
Blacks (Zhang & Snowden, 1999).
Source: Unless otherwise noted, citations for above table are: American Psychiatric Association, 2000.