Are "social drugs" (tobacco, coffee and chocolate) related to the bipolar spectrum?

Background: Across all ages and cultures, mankind has always used substances in order to induce pleasurable sensations or desirable psychophysical states. These substances, notably caffeine, tobacco, alcohol and chocolate, can be labeled 'social drugs'. Methods: We analyzed the social drug habits of 562 patients suffering from mood disorders, according to DSM-IV-R criteria (major depressive episode, recurrent depression, bipolar type I and II disorders and depression not otherwise specified). The sample was also divided into bipolar and non-bipolar according to Hypomania Check-list 32 (HCL-32), which proposes a broader concept of hypomania and soft bipolarity, comprising the spectrum of bipolar disorders proper, along with other, "softer" expressions of bipolarity intermediate between bipolar disorder and normality. Results: Using HCL-32 criteria, but DSM-IV-R criteria, a link was confirmed between bipolar spectrum and substance use including social drugs such as tobacco and coffee. Limitation: Observational correlational study. Conclusion: This study is in support of earlier theoretical formulations within the framework of the Pisa-San Diego collaboration.