Table 1

Suggested addition to DSM-IV diagnostic criteria for schizophrenia

B. Social/occupational/cognitive* dysfunction: For a significant portion of the time since the onset of the disturbance, one or more major areas of functioning such as work, interpersonal relations, self-care, or cognitive functioning are markedly below the level achieved prior to the onset (or when the onset is in childhood or adolescence, failure to achieve expected level of interpersonal, academic, or occupational achievement). In adults, if cognitive impairment was present premorbidly and has not deteriorated since the onset of the disturbance, then cognitive function should be markedly below normal or expected levels.
Cognitive impairment in schizophrenia is defined as marked impairment of 2 or more of the following 3 domains of cognitive function:

  1. attention or vigilance (sustained attention)

  2. memory (ability to learn new information or to recall previously learned information)

  3. executive functioning (abstract reasoning, problem solving, planning, initiating, organizing, response inhibition, ability to shift cognitive set, sequencing, evaluating, or working memory, i.e., ability to manipulate information held in immediate memory).

These deficits may occur against a background of generalized or global intellectual impairment (e.g., subaverage IQ) and reduced capacity for information processing.jpn_29_2_87.rtf

  • Note: IQ = intelligence quotient.

  • ↵* Italicized text is the proposed addition to the Diagnostic and statistical manual of mental disorders, 4th edition (DSM-IV), p. 285.3