Emotional speech markers of psychiatric disturbance in Huntington's disease

Abstract

Introduction: Psychiatric disorders and difficulties in emotional expression represent a major problem in the management of Huntington's Disease (HD). To improve patient follow-up, we propose to investigate the link between emotional expression and psychiatric symptoms, measured by the Problem Behaviors Assessment (PBA) scale. To this aim we developed the first emotional/psychiatric speech corpus, emoHD.

Methods: We included 102 HD gene carriers and 35 healthy controls (HC). Psychiatric symptoms were assessed using PBA sub-scales for Depression, Irritability/aggressivity, Apathy, and Obsessive/compulsive symptoms. Speech was annotated using three emotional descriptors: primary emotions, affective phenomena, and activation levels. Affective phenomena labels were selected based on PBA statements by external participants unaware of the study's aims. We analyzed (1) emotional descriptors' relationships, (2) emotional expression differences between HD and HC, and (3) the associations between emotions and psychiatric symptoms.

Results: HD patients showed reduced emotional expressiveness than HC with more neutral activation levels (=0). Only the primary emotion "angry" was less expressed in HD compared to HC. In contrast they expressed more affective phenomena states like apathetic, confused, "depressed", "disoriented", "frustrated", and "pessimistic" than HC, whereas they expressed less "other" and "irritable" than HC. Expressed emotions were congruent with psychiatric symptoms (e.g., "anxious" and "nervous" are positively associated with Depression PBA sub-scale; "frustrated" with Irritability/aggressivity PBA sub-scale).

Conclusion: We showed that speech is a promising marker for emotional/psychiatric symptoms in HD, supporting future remote monitoring and personalized care strategies.

Keywords: Huntington’s disease; emotional expression; psychiatric symptoms; remote monitoring; speech analysis.

Figure 1

Overview of the emoHD corpus. Participants in the emoHD corpus were Huntington’s Disease (HD) gene carriers’ and healthy controls (HC). They underwent psychiatric evaluation (pathway C) by certified neurologists (orange box) using the Problem Behaviors Assessment (PBA) sub-scales, constituting the clinical database of emoHD. Independently, participants’ speech was recorded by neuropsychologists (green box), constituting the speech database of emoHD. Recordings were emotionally annotated (pathway B) by speech therapists (green box) which included three emotional descriptors: (1) primary emotions for coarse-grain characterization; affective phenomena to capture emotional manifestations specific to Huntington’s disease — these labels were selected by external participants (grey box) to maintain all steps independent and blind to each other (pathway A); and (3) activation levels to indicate the emotional excitation expressed. Researcher (LC) was blind to the participants’ status, and ran the statistical analysis.

Figure 2

Distribution in seconds of primary emotions, affective phenomena and activation levels across the speech tasks. Distribution of primary emotions (A) and activation levels (B) across speech tasks. The distribution of affective phenomena is displayed separately for scaling reasons: neutral and other affective phenomena [Panel (C) right] and all other affective phenomena [Panel (C) left].

Figure 3

Heatmap of adjusted p-values of pairwise Fisher’s exact tests with Bonferroni multiple comparison correction. (A) Mapping between primary emotions and affective phenomena labels; (B) Mapping between primary emotions and activation levels labels; (C) Mapping between activation levels and affective phenomena labels. Significant adjusted p-values are displayed by *,**,*** corresponding to p-values equal to 0.05, 0.005, ≤0.001.

Figure 4

Proportion of primary emotions in Huntington’s disease gene carriers and controls. Healthy controls (HC) and Huntington’s disease (HD) gene carriers’ distributions of primary emotions proportions. The proportions range from 0-1. Significant group differences are displayed by *,**,*** corresponding to permutation p-values equal to 0.05, 0.005, ≤0.001.

Figure 5

Proportions of affective phenomena in Huntington’s disease gene carriers and controls. Healthy controls (HC) and Huntington’s disease (HD) gene carriers’ distributions of affective phenomena (AP) proportions. The proportions range from 0-1. Significant group differences are displayed by *,**,*** corresponding to permutation p-values equal to 0.05, 0.005, ≤0.001.

Figure 6

Proportion of activation levels in Huntington’s disease gene carriers and controls. Healthy control (HC) and Huntington’s disease (HD) gene carriers’ distributions of activation levels proportions. The proportions range from 0-1. Significant group differences are displayed by *,**,*** corresponding to permutation p-values equal to 0.05, 0.005, ≤0.001.

Figure 7

Multilinear regressions after a stepwise bidirectional approach for PBA sub-scales. Healthy controls (HC) and Huntington’s Disease (HD) gene carriers grouped according to the Integrating Staging System (ISS). The figure displays the results of the multilinear regressions with stepwise bidirectional approach, evaluating the associations between the different emotional descriptors (primary emotions, affective phenomena, and activation levels) and the Depression, Irritability/aggressivity, Apathy and Obsessive/compulsive Problem Behaviors Assessment (PBA) sub-scales. An increase in PBA sub-scales characterizes worst psychiatric symptoms. The Depression sub-scale ranges from 0 to 48, Irritability/aggressivity and Obsessive/compulsive sub-scales from 0 to 32, and Apathy from 0 to 16. The emotional descriptors are expressed in proportions normalizing total speech duration. The bidirectional stepwise approach selected the emotional descriptors that best fit the PBA sub-scales, and displaying the significantly associated ones by a filled dot and by *,**,*** corresponding to p-values equal to 0.05, 0.005, ≤0.001.