Speech Analysis Can Predict Risk of Psychosis

Researchers say an automated speech analysis program can determine the risk of a young person developing psychosis.

In a new study, scientists at Columbia University Medical Center, New York State Psychiatric Institute, and the IBM T. J. Watson Research Center found that a computerized analysis program correctly differentiated between at-risk young people who developed psychosis over a two and a half year period and those who did not.

Researchers say the proof-of-principle study found that the computerized analysis provided a more accurate classification than clinical ratings. The study appears in NPJ-Schizophrenia.

Experts explain that about one percent of the population between the age of 14 and 27 is considered to be at clinical high risk (CHR) for psychosis. CHR individuals have symptoms such as unusual or tangential thinking, perceptual changes, and suspiciousness.

About 20 percent will go on to experience a full-blown psychotic episode. Identifying who falls in that 20 percent category before psychosis occurs has been an elusive goal. Early identification could lead to intervention and support that could delay, mitigate, or even prevent the onset of serious mental illness.

Interestingly, speech provides a unique window into the mind, giving important clues about what people are thinking and feeling. Participants in the study took part in an open-ended, narrative interview in which they described their subjective experiences.

These interviews were transcribed and then analyzed by computer for patterns of speech, including semantics (meaning) and syntax (structure).

Researchers explain that the software established each patient’s semantic coherence (how well he or she stayed on topic), and syntactic structure, such as phrase length and use of determiner words that link the phrases.

A clinical psychiatrist may intuitively recognize these signs of disorganized thoughts in a traditional interview, but a machine can augment what is heard by precisely measuring the variables.

The participants were then followed for two and a half years.

Investigators found key speech features were predictive of future mental problems. Specifically, speech characteristics that predicted psychosis onset included breaks in the flow of meaning from one sentence to the next, and speech that was characterized by shorter phrases with less elaboration.

The speech classifier tool developed in this study to mechanically sort these specific, symptom-related features achieved 100 percent accuracy. That is, the computer analysis correctly differentiated between the five individuals who later experienced a psychotic episode and the 29 who did not.

Investigators believe these results suggest that this method may be able to identify thought disorder in its earliest, most subtle form, years before the onset of psychosis. Thought disorder is a key component of schizophrenia, but quantifying it has proved difficult.

For the field of schizophrenia research, and for psychiatry more broadly, the approach opens the possibility that new technology can aid in prognosis and diagnosis of severe mental disorders, and track treatment response.

Automated speech analysis is inexpensive, portable, fast, and non-invasive. It has the potential to be a powerful tool that can complement clinical interviews and ratings.

Nevertheless, investigators say that additional research with a second, larger group of at-risk individuals is needed to see if this automated capacity to predict psychosis onset is both robust and reliable.

This research can also facilitate additional diagnostic interventions as automated speech analysis could be used in conjunction with neuroimaging to obtain a better understanding of early thought disorder(s) and new approaches for treatment.

Source: Columbia University Medical Center/EurekAlert