Washington: An automated speech analysis programme can spot at-risk young people who may go on to develop psychosis, scientists say.
The programme correctly differentiated between at-risk young people who developed psychosis over a two-and-a-half year period and those who did not, researchers said.
In a proof-of-principle study, researchers at Columbia University Medical Center, New York State Psychiatric Institute, and the IBM Thomas J Watson Research Center found that the computerised analysis provided a more accurate classification than clinical ratings.
About one per cent 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 per cent will go on to experience a full-blown psychotic episode. Identifying who falls in that 20 per cent 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.
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 analysed by computer for patterns of speech, including semantics (meaning) and syntax (structure).
The analysis 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 recognise these signs of disorganised 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.
The speech features that predicted psychosis onset included breaks in the flow of meaning from one sentence to the next, and speech that was characterised by shorter phrases with less elaboration.
The speech classifier tool correctly differentiated between the five individuals who later experienced a psychotic episode and the 29 who did not.
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, this opens the possibility that new technology can aid in prognosis and diagnosis of severe mental disorders, and track treatment response.
Automated speech analysis has the potential to be a powerful tool that can complement clinical interviews and ratings, researchers said.
