Coffee and cigarette use: association with suicidal acts in 352 Sardinian bipolar disorder patients

Authors

  • Christopher Baethge,

    1. Department of Psychiatry and Psychotherapy, University of Cologne Medical School, Cologne, Germany
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  • Leonardo Tondo,

    1. Department of Psychiatry and Neuroscience Program, Harvard Medical School, and McLean Division of Massachusetts General Hospital, Boston, MA, USA
    2. Department of Psychology, University of Cagliari, Sardinia
    3. Lucio Bini Mood Disorders Research Center, Cagliari, Italy
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  • Beatrice Lepri,

    1. Department of Psychology, University of Cagliari, Sardinia
    2. Lucio Bini Mood Disorders Research Center, Cagliari, Italy
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  • Ross J Baldessarini

    1. Department of Psychiatry and Neuroscience Program, Harvard Medical School, and McLean Division of Massachusetts General Hospital, Boston, MA, USA
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  • LT has received research support from Janssen and Eli Lilly & Co.; and has served as a consultant to GlaxoSmithKline and Merck. RJB was recently (≥ 5 years) a consultant or investigator-initiated research collaborator with AstraZeneca, Auritec, Biotrofix, Janssen, JDS-Noven, Eli Lilly & Co., Luitpold, NeuroHealing, Novartis, Pfizer, and SK-BioPharmaceutical. CB and BL have no conflicts of interest with regard to this research. None of the authors has other financial relations or equity holdings with pharmaceutical or biomedical corporations.

Corresponding author:
Christopher Baethge, M.D.
Department of Psychiatry and Psychotherapy
University of Cologne Medical School
Kerpener Strasse 62
50924 Cologne, Germany
Fax: +49 2234 7011 140
e-mail: christopher.baethge@web.de

Abstract

Objective:  Abuse of illicit drugs and alcohol is prevalent in bipolar disorder (BPD) patients, and is an adverse prognostic factor. Much less is known about correlates of nicotine and caffeine consumption, but tobacco smoking is tentatively associated with suicidal behavior.

Methods:  Retrospective analysis of demographic and clinical factors among 352 longitudinally assessed DSM-IV types I and II BPD patients contrasted patients with versus without consumption of nicotine or caffeine, based on univariate comparisons and multiple regression modeling.

Results:  Current smoking (46%) and coffee drinking (74% of cases) were common, and significantly and independently associated with suicidal acts [coffee: odds ratio (OR) = 2.42, 95% confidence interval (CI): 1.15–5.09; smoking: OR = 1.79, CI: 1.02–3.15; both p < 0.001]. Risk increased with more smoking (cigarettes/day; rs = 0.383; p < 0.0001) and greater coffee consumption (cups/day; rs = 0.312; p = 0.008). Neither intake was related to yearly rates of all episodes, depressions, or manias.

Conclusions:  This is the first report to associate suicidal acts with coffee consumption in BPD patients, and it confirmed an association with smoking. Pending further evidence, the findings underscore the importance of monitoring use of even legal and mildly psychotropic substances by BPD patients.

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