Partners:
Everis, Spain
ETH, Switzerland
UZH, Switzerland
Freiburg, Germany
MA Systems, UK
Bristol, UK
Xiwrite, Italy
Ultrasis, UK
Jaume, Spain
Valencia, Spain
Lanzhou, China
EU-Grant (FP7):
248544
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Monitoring the Time Course of Recovery by Voice Analysis
Investigations into antidepressant drug response are generally based on observer ratings and
self-ratings. Therefore, the question arises as to the extent to which the respective results
primarily reflect the expectations of raters and patients. To address this question, we
conducted a study of 43 hospitalized depressive patients and assessed the time course of
recovery at 3-day intervals throughout the first two weeks of treatment plus a final
assessment at hospital release. Our sample included 17 mild cases (HAMD-17 baseline score <22),
13 moderately depressed patients (HAMD-17 baseline score 22-27), and 13 severely depressed
patients (HAMD-17 baseline score >27). The patients’ psychopathology was assessed on the
basis of the HAMD rating scale immediately after the speech recordings. All patients were
treated with antidepressants.
Onset of Improvement
The onset of improvement (20% sustained baseline score reduction) occurred in the great majority
of patients (79.1%) within the first 12 days of study, virtually independent of the severity of
depression at baseline. Early improvement was highly predictive of later outcome as 67.6%
of the patients showing improvement within the first 12 days were responders (50% sustained
baseline score reduction) by the end of the observation period. Inversely, 92% of the
responders at the end of the observation period exhibited an onset of improvement within the
first 12 days. Early improvement could not be attributed to a few HAMD items, because score
reductions included all items throughout all stages of treatment.
Speaking Behavior and Voice Sound Characteristics
The analysis of the patients’ speaking behavior and voice sound characteristics yielded, in
62.8% of the cases, an essentially parallel development over time for the HAMD scores on the
one hand, and acoustic variables on the other (see Figures). The time course of
improvement thus appeared to have a strong biological component and was unlikely to be
attributable to the expectations of doctors and patients. Specifically, the Figures
demonstrate that (1) the time course of recovery varies from patient to patient and may
include deterioration, recovery can even be incomplete; and (2) speech parameters follow
the psychopathology score changes very closely in either direction. A configuration of
15 speech parameters enabled discrimination between patients and controls at an overall
performance of 75% correctly classified subjects.
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Time course of a patient’s recovery from depression as reflected by
HAMD-17 scores (green square points) assessed at two-day intervals over an observation
period of two weeks, plus a final assessment at the time of discharge from hospital
("day63"). The corresponding change over time of the speech parameter "F0-amplitude"
is also shown (red circle points) to demonstrate the close relationship
between the two courses of development (all but one of the chosen patients responded
to therapy).
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