Thibaut Dondaine, PhD; Pierre Philippot, PhD; Jean-Marie Batail, MD; Florence Le Jeune, MD, PhD; Paul Sauleau, MD, PhD; Sophie Drapier, MD; Marc Vérin, MD, PhD; Bruno Millet, MD, PhD; Dominique Drapier, MD, PhD; Gabriel Robert, MD, PhD
Background: Within the heterogeneity of schizophrenia, apathy constitutes an independent cluster of negative symptoms associated with poor outcomes. Attempts to identify an emotional deficit in patients who have schizophrenia with negative symptoms have yielded mixed results, and studies that focus on the relationship between apathy and emotional disorders are lacking.
Methods: We set out to remedy this shortcoming using a validated battery of film excerpts to induce positive and negative emotions in patients with chronic schizophrenia with (n = 20) or without (n = 20) apathy, and in controls (n = 20) comparable for age, sex and socioeconomic status. We assessed emotions using an innovative but validated technique to evaluate tonic and phasic electrodermal activity and subjective feelings using a standardized visual analogue scale.
Results: Using a qualitative measure of apathy, we did not find a specific decrease in tonic activity during the induction of positive emotions. However, we did observe that patients with apathy showed reduced tonic activity independent of valence (i.e., for both positive and negative emotions) compared with controls and patients without apathy. Moreover, the quantitative measure of apathy (Apathy Evaluation Scale) was the only significant factor, explaining 24% of the variance in tonic activity during induction of positive emotions after controlling for confounding factors.
Limitations: Electrodermal activity was the only physiologic measure we acquired. We induced several emotions sequentially that might have overlapped with each other, but we added an emotional “washout” period and randomized the order of each film excerpt to limit this possibility.
Conclusion: Taken together, these results suggest that apathy in schizophrenia could impair tonic activity during positive emotions. Treatments aimed at enhancing positive emotions may help alleviate apathy in schizophrenia.
Submitted Aug. 29, 2017; Revised Jan. 10, 2018; Revised May 14, 2018; Accepted May 22, 2018; Published online Oct. 2, 2018
Acknowledgments: The authors would like to thank Dr. Gabrielle Guinard and Dr. Laurine Mégret for their help with recruiting patients. They also thank Stéphane Brousse and Jacques Soulabaille for their help with recruiting healthy controls. This work is dedicated to the memory of Nicolas Hervé, who passed away during the preparation of this work. He contributed to the analysis of EDA data. He will be missed by all his colleagues from the Guillaume Régnier Hospital in Rennes.
Affiliations: From the University Department of Psychiatry, Guillaume Régnier Hospital, Rennes, France (Batail, D. Drapier, Robert); University of Lille, Inserm, CHU Lille, U1171, Degenerative and Vascular Cognitive Disorders, F-59000, Lille, France (Dondaine); Behaviour and Basal Ganglia Laboratory (EA 4712), University of Rennes, Rennes, France (Batail, Le Jeune, Sauleau, S. Drapier, Vérin, D. Drapier, Robert); Eugène Marquis Centre, Rennes, France (Le Jeune); Neurophysiology Department, Rennes University Hospital, Rennes, France (Sauleau); Movement Disorders Unit, Rennes University Hospital, Rennes, France (S. Drapier, Vérin); Psychiatry Department, Pitié-Salpêtrière Hospital, Paris, France (Millet); University of Louvain-la-Neuve, Louvain-la-Neuve, Belgium (Philippot).
Funding: This work was supported by an internal grant promoted by the Guillaume Régnier Hospital.
Competing interests: None declared.
Contributors: T. Dondaine, J.-M. Batail, F. Le Jeune, S. Drapier, B. Millet, D. Drapier and G. Robert designed the study. T. Dondaine acquired and analyzed the data, which P. Philippot, P. Sauleau, M. Vérin, D. Drapier and G. Robert analyzed. T. Dondaine wrote the article, which all authors reviewed. All authors approved the final version to be published and can certify that no other individuals not listed as authors have made substantial contributions to the paper.
Correspondence to: T. Dondaine, Faculté de Médecine, Pôle Recherche, Service de Pharmacologie Clinique, 1, place de Verdun, 59045 Lille CEDEX, France; firstname.lastname@example.org