title: Voice analysis as an objective state marker in bipolar disorder.
abstract: Changes in speech have been suggested as sensitive and valid measures of depression and mania in bipolar disorder. The present study aimed at investigating (1) voice features collected during phone calls as objective markers of affective states in bipolar disorder and (2) if combining voice features with automatically generated objective smartphone data on behavioral activities (for example, number of text messages and phone calls per day) and electronic self-monitored data (mood) on illness activity would increase the accuracy as a marker of affective states. Using smartphones, voice features, automatically generated objective smartphone data on behavioral activities and electronic self-monitored data were collected from 28 outpatients with bipolar disorder in naturalistic settings on a daily basis during a period of 12 weeks. Depressive and manic symptoms were assessed using the Hamilton Depression Rating Scale 17-item and the Young Mania Rating Scale, respectively, by a researcher blinded to smartphone data. Data were analyzed using random forest algorithms. Affective states were classified using voice features extracted during everyday life phone calls. Voice features were found to be more accurate, sensitive and specific in the classification of manic or mixed states with an area under the curve (AUC)=0.89 compared with an AUC=0.78 for the classification of depressive states. Combining voice features with automatically generated objective smartphone data on behavioral activities and electronic self-monitored data increased the accuracy, sensitivity and specificity of classification of affective states slightly. Voice features collected in naturalistic settings using smartphones may be used as objective state markers in patients with bipolar disorder.
authors.affiliation: Psychiatric Center Copenhagen, Rigshospitalet, Copenhagen, Denmark.
authors.forename: M
authors.initials: M
authors.lastname: Faurholt-Jepsen
authors.affiliation: DTU Compute, Technical University of Denmark (DTU), Lyngby, Denmark.
authors.forename: J
authors.initials: J
authors.lastname: Busk
authors.affiliation: The Pervasive Interaction Laboratory, IT University of Copenhagen, Copenhagen, Denmark.
authors.forename: M
authors.initials: M
authors.lastname: Frost
authors.affiliation: Psychiatric Center Copenhagen, Rigshospitalet, Copenhagen, Denmark.
authors.forename: M
authors.initials: M
authors.lastname: Vinberg
authors.affiliation: Psychiatric Center Copenhagen, Rigshospitalet, Copenhagen, Denmark.
authors.forename: E M
authors.initials: EM
authors.lastname: Christensen
authors.affiliation: DTU Compute, Technical University of Denmark (DTU), Lyngby, Denmark.
authors.forename: O
authors.initials: O
authors.lastname: Winther
authors.affiliation: DTU Compute, Technical University of Denmark (DTU), Lyngby, Denmark.
authors.forename: J E
authors.initials: JE
authors.lastname: Bardram
authors.affiliation: Psychiatric Center Copenhagen, Rigshospitalet, Copenhagen, Denmark.
authors.forename: L V
authors.initials: LV
authors.lastname: Kessing
mesh_terms: D000328:Adult; D000339:Affect; D000927:Anticonvulsants / Q000627:therapeutic use; D000928:Antidepressive Agents / Q000627:therapeutic use; D018692:Antimanic Agents / Q000627:therapeutic use; D014150:Antipsychotic Agents / Q000627:therapeutic use; D001714:Bipolar Disorder / Q000188:drug therapy / Q000503:physiopathology* / Q000523:psychology; D003625:Data Collection; D003863:Depression / Q000188:drug therapy / Q000503:physiopathology* / Q000523:psychology; D005260:Female; D006801:Humans; D018020:Lithium Compounds / Q000627:therapeutic use; D008297:Male; D010045:Outpatients; D057566:Self Report; D000068997:Smartphone; D013689:Telephone; D060145:Text Messaging; D014831:Voice; D055815:Young Adult
chemical_list: D000927:Anticonvulsants; D000928:Antidepressive Agents; D018692:Antimanic Agents; D014150:Antipsychotic Agents; D018020:Lithium Compounds