title: Psychometric properties of the Affective Lability Scale (54 and 18-item version) in patients with bipolar disorder, first-degree relatives, and healthy controls.
abstract: BACKGROUND
  The aim of this study was to investigate the psychometric properties of the original 54 item version (ALS-54) and the short 18 item version (ALS-18) of the Affective Lability Scale (ALS) in patients with bipolar disorders, their first-degree relatives and healthy controls. Internal Consistency and Confirmatory Factor Analysis were performed, comparing clinical and non-clinical group comparisons on ALS scores.
  
  
  METHODS
  A total of 993 participants (patients with bipolar disorders [n=422], first-degree relatives [n=201] and controls [n=370]) were recruited from France and Norway. Diagnosis and clinical characteristics were assessed using the Structured Clinical Interview for DSM-IV Axis I disorders (SCID-I), or the Diagnostic Interview for Genetic Studies (DIGS). Affective lability was measured using the ALS-54 and ALS-18.
  
  
  RESULTS
  Both ALS-54 and ALS-18 showed high internal consistency, but the subdimensions of both versions were highly inter-correlated. From confirmatory factor analysis both versions revealed acceptable to good model fit. Patients had significantly higher ALS scores compared to controls, with affected first-degree relatives presenting intermediate scores.
  
  
  CONCLUSIONS
  Both the original ALS-54 version and the short ALS-18 version showed good psychometric properties. They also discriminated between patients with a bipolar disorder (high ALS), first degree relatives (intermediate ALS), and healthy controls (low ALS). A high correlation between ALS items for both versions was observed. Our study supports reducing the scale from 54 to 18 items.
authors.affiliation: NORMENT, KG Jebsen Center for Psychosis Research, Institute of Clinical Medicine, University of Oslo, Norway; NORMENT, Division of Mental Health and Addiction, Oslo University Hospital, Oslo, Norway. Electronic address: monica.aas@medisin.uio.no.
authors.forename: Monica
authors.initials: M
authors.lastname: Aas
authors.affiliation: NORMENT, KG Jebsen Center for Psychosis Research, Institute of Clinical Medicine, University of Oslo, Norway; NORMENT, Division of Mental Health and Addiction, Oslo University Hospital, Oslo, Norway.
authors.forename: Geir
authors.initials: G
authors.lastname: Pedersen
authors.affiliation: AP-HP, Hôpital H. Mondor - A. Chenevier, DHU Pepsy, Pôle de Psychiatry, Créteil 94000, France; Université Paris Est, Faculté de médecine, Créteil 94000, France; Inserm, U955, Créteil 94000, France; Fondation Fondamental, Créteil, France; ENBREC, European Network of Bipolar Research Expert Centres (ENBREC), Paris, France.
authors.forename: Chantal
authors.initials: C
authors.lastname: Henry
authors.affiliation: NORMENT, Division of Mental Health and Addiction, Oslo University Hospital, Oslo, Norway.
authors.forename: Thomas
authors.initials: T
authors.lastname: Bjella
authors.affiliation: Inserm, U955, Créteil 94000, France; Fondation Fondamental, Créteil, France; AP-HP, GH Saint-Louis - Lariboisière - Fernand Widal, Pôle Neurosciences, Paris 75010, France; Université Paris 7, Denis Diderot, Paris, France; ENBREC, European Network of Bipolar Research Expert Centres (ENBREC), Paris, France.
authors.forename: Frank
authors.initials: F
authors.lastname: Bellivier
authors.affiliation: AP-HP, Hôpital H. Mondor - A. Chenevier, DHU Pepsy, Pôle de Psychiatry, Créteil 94000, France; Université Paris Est, Faculté de médecine, Créteil 94000, France; Inserm, U955, Créteil 94000, France; Fondation Fondamental, Créteil, France; ENBREC, European Network of Bipolar Research Expert Centres (ENBREC), Paris, France.
authors.forename: Marion
authors.initials: M
authors.lastname: Leboyer
authors.affiliation: Fondation Fondamental, Créteil, France; Service de Psychiatrie et Psychologie Clinique, Université de Lorraine et CHU de Nancy, Hôpitaux de Brabois, Vandoeuvre Les Nancy 54500, France.
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Kahn
authors.affiliation: Fondation Fondamental, Créteil, France; Service de Psychiatrie et Psychologie Clinique, Université de Lorraine et CHU de Nancy, Hôpitaux de Brabois, Vandoeuvre Les Nancy 54500, France.
authors.forename: Renaud F
authors.initials: RF
authors.lastname: Cohen
authors.affiliation: Fondation Fondamental, Créteil, France; Hôpital Charles Perrens, Centre Expert Trouble Bipolaire, Service de psychiatrie adulte, Pôle 3-4-7, Bordeaux 33000, France.
authors.forename: Sebastien
authors.initials: S
authors.lastname: Gard
authors.affiliation: NORMENT, KG Jebsen Center for Psychosis Research, Institute of Clinical Medicine, University of Oslo, Norway; Department of Specialized Inpatient Treatment, Division of Mental Health Services, Akershus University Hospital, 1478 Lørenskog, Norway.
authors.forename: Sofie R
authors.initials: SR
authors.lastname: Aminoff
authors.affiliation: NORMENT, Division of Mental Health and Addiction, Oslo University Hospital, Oslo, Norway.
authors.forename: Trine V
authors.initials: TV
authors.lastname: Lagerberg
authors.affiliation: NORMENT, KG Jebsen Center for Psychosis Research, Institute of Clinical Medicine, University of Oslo, Norway; NORMENT, Division of Mental Health and Addiction, Oslo University Hospital, Oslo, Norway; ENBREC, European Network of Bipolar Research Expert Centres (ENBREC), Paris, France.
authors.forename: Ole A
authors.initials: OA
authors.lastname: Andreassen
authors.affiliation: NORMENT, KG Jebsen Center for Psychosis Research, Institute of Clinical Medicine, University of Oslo, Norway; NORMENT, Division of Mental Health and Addiction, Oslo University Hospital, Oslo, Norway.
authors.forename: Ingrid
authors.initials: I
authors.lastname: Melle
authors.affiliation: AP-HP, Hôpital H. Mondor - A. Chenevier, DHU Pepsy, Pôle de Psychiatry, Créteil 94000, France; Inserm, U955, Créteil 94000, France; Fondation Fondamental, Créteil, France; ENBREC, European Network of Bipolar Research Expert Centres (ENBREC), Paris, France.
authors.forename: Bruno
authors.initials: B
authors.lastname: Etain
mesh_terms: D000328:Adult; D000339:Affect; D001714:Bipolar Disorder / Q000523:psychology*; D016022:Case-Control Studies; D005163:Factor Analysis, Statistical; D005190:Family; D005260:Female; D005602:France; D006801:Humans; D008297:Male; D009664:Norway; D011569:Psychiatric Status Rating Scales; D011594:Psychometrics; D015203:Reproducibility of Results
keywords: ALS original 54 item version (ALS-54); ALS short 18 item version (ALS-18); Bipolar disorders; First-degree relatives; Healthy controls; Psychometric properties