Jouko Miettunen University of Oulu, Finland Prevalence of alcohol use disorders in schizophrenia – A systematic review and meta-analysis Jouko Miettunen University of Oulu, Finland

Disclosure I have no financial relationships to disclose I will not discuss off label use and/or investigational use in my presentation.

Introduction Previous systematic reviews have found a wide range of rates (12-55%) of alcohol use disorder in schizophrenia samples Previous studies published between the years 1960-89 were reviewed by Mueser et al. and those from the years 1990-2001 by Cantor-Graae et al. Mueser et al. Schizophr Bull 1990;16:31-55 Cantor-Graae et al. Schizophr Res 2001;48:69-82

Population lifetime prevalence of alcohol abuse or dependence Reference (country) Male Female Ross 1995 (Canada) 19.2 % 4.8 % Chen et al 1993 (Hong Kong) 8.9 % 0.6 % Wittchen et al 1992 (Germany) 21.0 % 5.1 % Wells et al 1989 (New Zealand) 32.0 % 6.1 % Bland et al 1988 (Canada) 29.3 % 6.7 % Canino et al 1987 (USA) 24.6 % 2.0 % Somers et al. Can J Psychiatry 2004;49:373-84

Schizophrenia and alcohol Schizophrenia patients with alcohol use disorders have more psychotic symptoms and more severe depressive symptoms (less negative symptoms?) poorer treatment compliance increased somatic morbidity risk for violence, criminality and suicides more negative psychosocial events e.g. divorce and unemployment more admissions and longer hospitalization periods Potvin et al. Psychol Med 2006;36:431-440; Potvin et al. Aust N Z J Psychiatry 2007;41:792-799; Drake & Mueser. Alcohol Health Res World 1996;20:87-93; Dixon. Schizophr Res 1999;35(suppl.):93-100; Gregg et al. Clin Psychol Rev 2007;27:494-510.

Aim Our aim is to present recent studies of alcohol use disorders (AUDs) in schizophrenia, estimate overall prevalence, and characteristics affecting the prevalence of AUDs

Methods We conducted a search using three literature databases and a manual search on articles published in 1996-2008 Metaregression was used to study how prevalence is affected by different study characteristics Articles that reported diagnoses according to DSM or ICD diagnostic systems were included We compared results with those of cannabis use disorders

Alcohol use disorders in schizophrenia Altogether 60 studies met our criteria median of current AUD prevalence was 9.4% (IQR = 4.6-19.0, 18 studies) median of lifetime AUD prevalence 20.6% (IQR = 12.0-34.5, 47 studies)

Prevalence of alcohol use disorders in schizophrenia patients by type of alcohol use diagnosis Number of studies Mean (%) Median (%) Inter-Quartile Range Range Lifetime - abuse 19 17.0 13.5 5.9-24.0 1.5-47.1 - dependence 10 22.3 18.7 12.0-32.4 3.8-46.9 - abuse or dependence 29 24.5 20.6 13.5-35.9 1.3-57.0 - total 47 23.4 12.0-35.9 Current 9 10.6 4.6 2.1-14.9 1.1-38.8 4 13.0 11.4 6.4-19.7 5.9-23.4 8 12.8 10.5 6.3-21.5 1.1-24.5 18 12.4 9.4 4.6-19.0 Total 60 20.9 17.8 9.7-28.6 1.1-57.0

Comparison of studies 1996-2008 Alcohol use disorders Cannabis use disorders Current diagnosis Number of studies 18 10 Median (IQR) % 9.4 (4.6-19.0) 16.0 (8.6-28.6) Lifetime diagnosis 47 28 20.6 (12.0-34.5) 27.1 (12.2-38.5)

Comparison of studies 1996-2008 Current alcohol vs. cannabis use disorders (7) 2 younger (mean age < 30 years) samples with more cannabis 5 older (mean age > 30 years) samples with more alcohol Lifetime alcohol vs. cannabis use disorders (24) 8 studies with more cannabis 14 studies with more alcohol 2 with no difference

Diagnostic criteria ICD-10 vs. DSM-IV Alcohol use that causes either physical or mental damage in the absence of dependence is categorized in ICD-10 as harmful This category highlights the somatic problems related to alcohol use more than abuse in DSM-IV This may lead to lower rate of abuse in younger populations in ICD-10 Kaczynski Pollock et al. J Stud Alcohol 2000;61:439–46. Hiller. Eur Arch Psychiatry Neurol Sci 1989;239:101–8.

Conclusion Approximately every fifth schizophrenia patient had lifetime AUD diagnosis The decrease seen in prevalence estimates may be explained by stricter AUD criteria in diagnostic systems

Conclusion Alcohol and cannabis use disorder are both common schizophrenia Alcohol use disorders were more common in older than in younger schizophrenia patient samples When contrasted to the most recent review there might be a descending trend in AUD prevalence in schizophrenia patients

Koskinen J, Löhönen J, Koponen H, Isohanni M, Miettunen J Koskinen J, Löhönen J, Koponen H, Isohanni M, Miettunen J. Prevalence of alcohol use disorders in schizophrenic psychoses – A systematic review and meta-analysis. Acta Psychiatr Scand 2009; doi: 10.1111/j.1600-0447.2009.01385.x Koskinen J, Löhönen J, Koponen H, Isohanni M, Miettunen J. Rate of cannabis use disorders in clinical samples of patients with schizophrenia: A meta-analysis. Schizophr Bull 2009; doi:10.1093/schbul/sbp031 www.joukomiettunen.net

Research Group Koskinen Johanna, MD Isohanni Matti, MD, PhD Department of Psychiatry, University of Oulu, Finland Koskinen Johanna, MD Isohanni Matti, MD, PhD Löhönen Johanna, MA Miettunen Jouko, PhD Department of Psychiatry, University of Kuopio, Finland Koponen Hannu, MD, PhD This study has been supported by the Academy of Finland