Speaking of Schizophrenia
In schizophrenia, speech and language disturbance have been recognized as core components of the disorder since the fledgling days of modern psychiatry. In his canonical description of dementia praecox, which is often credited as the first modern characterization of schizophrenia, Emil Kraepelin, MD, described both positive (eg, incoherence, derailment, stereotypy, neologisms) and negative symptoms (eg, mutism) associated with speech.
“Incoherence of the train of thought…is usually distinctly noticeable in the conversation of the patients. The most different ideas follow one another with most bewildering want of connection, even when patients are quite quiet. A patient said ‘Life is a dessert-spoon,’ another, ‘We are already standing in the spiral under a hammer,’ a third, ‘Death will be awakened by the golden dagger.’” – Emil Kraepelin, MD (1919).
Moreover, it was observed that speech abnormalities in schizophrenia were not limited to content, but extended to prosody and vocal qualities: “The cadence often lacks the risings and fallings, the melodies of speech.”1 Kraepelin and others extrapolated these speech and language disturbances to indicate not only an impairment in communication, but also fundamentally disordered thought—at times derailment or loosening of associations, at times a poverty of thought.1,2
Nancy Andreasen, MD, PhD, was among the first to formalize the assessment and measurement of thought disorder with her 1986 Scale for the Assessment of Thought Language and Communication (TLC).3 The TLC standardized definitions and provided anchors for clinician ratings of 18 items of speech disturbances, each focused on the content of speech. Items measure negative thought disorder (eg, poverty of speech, poverty of content of speech) and positive thought disorder (eg, derailment, pressure of speech, incoherence, etc). With the TLC and subsequent scales, Andreasen and other researchers were able to quantify speech disturbance in patients with schizophrenia. They found that many features were shared with speech from patients in manic episodes, although mania was associated with greater positive thought disorder and schizophrenia with greater negative thought disorder.
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