Prevalence and diagnostic distribution of medically unexplained painful somatic symptoms across 571 major depressed outpatients

Abstract

Michele Fornaro1, Icro Maremmani2,3, Pier Luigi Canonico4, Paolo Carbonatto5, Claudio Mencacci6, Giovanni Muscettola7, Luca Pani8, Riccardo Torta9, Claudio Vampini10, Fabio Parazzini11, Arina Dumitriu12, Giulio Perugi2,31Department of Neurosciences, Section of Psychiatry, University of Genova, Genoa, Italy; 2Dipartimento di Psichiatria Università di Pisa, Pisa, Italy; 3Institute of Behavioural Sciences "G. De Lisio", Pisa, Italy; 4Università di Novara, Novara, Italy; 5Societa' Italiana di Medicina Generale (SIMG) Turin, Italy; 6Ospedale Fatebenefratelli, Milan, Italy; 7Università di Napoli, Naples, Italy; 8Istituto di Neurogenetica e Neurofarmacologia, CNR, Cagliari, Italy; 9Ospedale Molinette, Turin, Italy; 10Ospedale Maggiore, Verona, Italy; 11GPA net, Milan, Italy; 12Boehringer Ingelheim S.p.A., Milan, ItalyObjective: To assess the prevalence and distribution of medically unexplained painful somatic symptoms (PSSs) versus nonpainful somatic symptoms (NPSSs) in patients diagnosed with major depressive episode (MDE).Method: A total of 571 outpatients diagnosed with MDE according to DSM-IV-TR criteria were consecutively enrolled into a cross-sectional, multicentric, observational study over a period of 7 months. Subjects were evaluated by means of the ad hoc validated 30-item Somatic Symptoms Checklist (SSCL-30) and Zung's questionnaires for depression and anxiety. The 32-item Hypomania Checklist (HCL-32) was also administered in order to explore any eventual association of PSSs or NPSSs with sub-threshold (DSM-IV-TR [Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision] not recognized) bipolar disorder (BD).Results: In our sample, just 183 patients (32%) did not report painful somatic symptoms (NPSSs). Of these, 90 patients (15.76%) had no somatic symptoms at all. The remaining 388 (68%) had at least one PSS being subdivided as follows: 248 (43%) had one or two PSSs, while 140 (25%) experienced two or more. Patients with at least one PSS also reported a greater number of nonpainful somatic symptoms than NPSS. Bipolar patients (associated with higher HCL-32 scores) were less represented across PSS cases than NPSS subjects. Conversely, females were more prone to having a higher number of total somatic symptoms (and bipolar features).Conclusion: PSSs are common in patients with MDE, especially among those patients reporting fewer somatic symptoms in general as opposed to those patients who exhibit more somatic symptoms (both PSSs and NPSSs) with lower relative number of PSSs. A major therapeutic implication is that antidepressant monotherapy could be used with more confidence in unexplained PSS patients than in NPSS patients because of the latter group's lower frequency of (sub)-threshold bipolar features.Keywords: major depressive episode, MDE, bipolar disorder, BD