88 Schizophrenia Spectrum and Other Psychotic Disorders
(hypnopompic ) are considered to be within the rang e of normal experience. Hallucinations
may be a normal part of religious expe rience in certain cultural contexts. 
Disorganized Thinking (Speech)
Disorganized thinking  (formal thought disorder ) is typically inferred from the individual’s
speech. The individual may switch from one topic to another ( derailment or loose associa-
tions ). Answers to questions may be oblique ly related or completely unrelated ( tangential-
ity). Rarely, speech may be so severely disorgan ized that it is nearly incomprehensible and
resembles receptive aphasia in its linguistic disorganization ( incoherence  or “word salad”).
Because mildly disorganized speech is common and nonspecific, the symptom must be se-
vere enough to substantially impair effective communication. The severity of the impair-
ment may be difficult to evaluate if the person making the diagnosis comes from a
different linguistic background than that of the person being examin ed. Less severe dis-
organized thinking or speech may occur du ring the prodromal and residual periods of
schizophrenia.
Grossly Disorganized or Abnormal Motor Behavior 
(Including Catatonia)
Grossly disorganized or abnormal motor behavior  may manifest itself in a variety of ways,
ranging from childlike “silliness” to unpred ictable agitation. Problems may be noted in
any form of goal-directed behavior, leading to difficulties in performing activities of daily
living.
Catatonic behavior  is a marked decrease in reactivity to the environment. This ranges
from resistance to  instructions ( negativism ); to maintaining a rigid, inappropriate or bi-
zarre posture; to a complete lack  of verbal and motor responses ( mutism  and stupor ). It can