title: Mood instability is a common feature of mental health disorders and is associated with poor clinical outcomes.
abstract: OBJECTIVE
  Mood instability is a clinically important phenomenon but has received relatively little research attention. The objective of this study was to assess the impact of mood instability on clinical outcomes in a large sample of people receiving secondary mental healthcare.
  
  
  METHODS
  Observational study using an anonymised electronic health record case register.
  
  
  METHODS
  South London and Maudsley NHS Trust (SLaM), a large provider of inpatient and community mental healthcare in the UK.
  
  
  METHODS
  27,704 adults presenting to SLaM between April 2006 and March 2013 with a psychotic, affective or personality disorder.
  
  
  METHODS
  The presence of mood instability within 1 month of presentation, identified using natural language processing (NLP).
  
  
  METHODS
  The number of days spent in hospital, frequency of hospital admission, compulsory hospital admission and prescription of antipsychotics or non-antipsychotic mood stabilisers over a 5-year follow-up period.
  
  
  RESULTS
  Mood instability was documented in 12.1% of people presenting to mental healthcare services. It was most frequently documented in people with bipolar disorder (22.6%), but was common in people with personality disorder (17.8%) and schizophrenia (15.5%). It was associated with a greater number of days spent in hospital (β coefficient 18.5, 95% CI 12.1 to 24.8), greater frequency of hospitalisation (incidence rate ratio 1.95, 1.75 to 2.17), greater likelihood of compulsory admission (OR 2.73, 2.34 to 3.19) and an increased likelihood of prescription of antipsychotics (2.03, 1.75 to 2.35) or non-antipsychotic mood stabilisers (2.07, 1.77 to 2.41).
  
  
  CONCLUSIONS
  Mood instability occurs in a wide range of mental disorders and is not limited to affective disorders. It is generally associated with relatively poor clinical outcomes. These findings suggest that clinicians should screen for mood instability across all common mental health disorders. The data also suggest that targeted interventions for mood instability may be useful in patients who do not have a formal affective disorder.
authors.affiliation: Department of Psychosis Studies, King's College London, Institute of Psychiatry, Psychology & Neuroscience, London, UK.
authors.forename: Rashmi
authors.identifier: http://orcid.org/0000-0002-9259-8788
authors.initials: R
authors.lastname: Patel
authors.affiliation: Department of Psychosis Studies, King's College London, Institute of Psychiatry, Psychology & Neuroscience, London, UK.
authors.forename: Theodore
authors.initials: T
authors.lastname: Lloyd
authors.affiliation: Department of Psychological Medicine, King's College London, Institute of Psychiatry, Psychology & Neuroscience, London, UK.
authors.forename: Richard
authors.initials: R
authors.lastname: Jackson
authors.affiliation: Department of Psychological Medicine, King's College London, Institute of Psychiatry, Psychology & Neuroscience, London, UK.
authors.forename: Michael
authors.initials: M
authors.lastname: Ball
authors.affiliation: South London and Maudsley NHS Foundation Trust, Biomedical Research Centre Nucleus, London, UK.
authors.forename: Hitesh
authors.initials: H
authors.lastname: Shetty
authors.affiliation: South London and Maudsley NHS Foundation Trust, Biomedical Research Centre Nucleus, London, UK.
authors.forename: Matthew
authors.initials: M
authors.lastname: Broadbent
authors.affiliation: Department of Psychiatry, University of Oxford, Oxford, UK.
authors.forename: John R
authors.initials: JR
authors.lastname: Geddes
authors.affiliation: Department of Psychological Medicine, King's College London, Institute of Psychiatry, Psychology & Neuroscience, London, UK.
authors.forename: Robert
authors.initials: R
authors.lastname: Stewart
authors.affiliation: Department of Psychosis Studies, King's College London, Institute of Psychiatry, Psychology & Neuroscience, London, UK.
authors.forename: Philip
authors.initials: P
authors.lastname: McGuire
authors.affiliation: Department of Psychosis Studies, King's College London, Institute of Psychiatry, Psychology & Neuroscience, London, UK.
authors.forename: Matthew
authors.initials: M
authors.lastname: Taylor
mesh_terms: D000293:Adolescent; D000328:Adult; D000339:Affect; D000368:Aged; D014150:Antipsychotic Agents / Q000627:therapeutic use*; D001714:Bipolar Disorder / Q000150:complications* / Q000188:drug therapy; D005260:Female; D006760:Hospitalization; D006801:Humans; D007902:Length of Stay; D008297:Male; D008603:Mental Health; D008875:Middle Aged; D019964:Mood Disorders / Q000453:epidemiology / Q000209:etiology*; D016017:Odds Ratio; D010343:Patient Admission; D010554:Personality Disorders / Q000150:complications* / Q000188:drug therapy; D011618:Psychotic Disorders / Q000150:complications* / Q000188:drug therapy; D012559:Schizophrenia / Q000150:complications* / Q000188:drug therapy; D016896:Treatment Outcome; D006113:United Kingdom / Q000453:epidemiology; D055815:Young Adult
chemical_list: D014150:Antipsychotic Agents
keywords: Clinical Record Interactive Search (CRIS); electronic health record (EHR); mood instability; natural language processing (NLP); text mining