title: Prevalence and clinical features associated to bipolar disorder-migraine comorbidity: a systematic review.
abstract: BACKGROUND
  The prevalence and clinical features associated with bipolar disorders (BDs)-migraine comorbidity have been reported inconsistently across different studies, therefore warranting a systematic review on the matter.
  
  
  METHODS
  A systematic review was conducted in accordance with the PRISMA statement searching major electronic databases for documents indexed between January, 2000 and July, 2014. Eligible studies were those including quantitative data on prevalence rates and clinical features associated to BD-migraine comorbidity; case reports excluded. Three authors independently conducted searches, quality assessment of the studies and data extraction.
  
  
  RESULTS
  Several cross-sectional studies, and a handful of retrospective follow-up studies or non-systematic reviews assessed the prevalence and/or the clinical correlates of migraine-BD comorbidity. High prevalence rates and a significant burden of BD-migraine comorbidity were common findings, particularly in case of BD-II women (point-prevalence rates up to 77%), migraine with aura (up to 53%) and/or cyclothymic temperament (up to 45% of the cases).
  
  
  CONCLUSIONS
  Some of the biases encountered in a few studies accounted by the present review may nonetheless have hampered the generalizability of the overall conclusions drawn herein.
  
  
  CONCLUSIONS
  BD-migraine comorbidity may comprise of a sub-phenotype of BDs requiring patient-tailored therapeutic interventions to achieve an optimal outcome. Specifically, additional studies including longitudinal follow-up studies are aimed in order to shed further light on the actual prevalence rates and clinical features associated to BD-migraine comorbidity, with a special emphasis towards the clinically suggestive potential connection between mixed features, bipolar depression, migraine, and increased risk for suicidality. PROSPERO registration number: CRD42014009335.
authors.affiliation: Department of Education Science, University of Catania, Catania, Italy. Electronic address: dott.fornaro@gmail.com.
authors.forename: Michele
authors.initials: M
authors.lastname: Fornaro
authors.affiliation: National Health Service, Department of Mental Health, Psychiatric Service of Diagnosis and Treatment, Hospital "G. Mazzini", ASL 4, Teramo, Italy. Electronic address: dodebera@aliceposta.it.
authors.forename: Domenico
authors.initials: D
authors.lastname: De Berardis
authors.affiliation: Department of Education Science, University of Catania, Catania, Italy. Electronic address: depasqua@unict.it.
authors.forename: Concetta
authors.initials: C
authors.lastname: De Pasquale
authors.affiliation: Department of Education Science, University of Catania, Catania, Italy. Electronic address: luisa.indelicato@hotmail.it.
authors.forename: Luisa
authors.initials: L
authors.lastname: Indelicato
authors.affiliation: Service for Monitoring and early Intervention against psychoLogical and mEntal suffering in young people" (SMILE), L'Aquila University, Italy. Electronic address: rocco.pollice@cc.univaq.it.
authors.forename: Rocco
authors.initials: R
authors.lastname: Pollice
authors.affiliation: Hermanas Hospitalarias, Villa San Giuseppe Hospital, 63100 Ascoli Piceno, Italy. Electronic address: a.valchera@ospedaliere.it.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Valchera
authors.affiliation: Department of Clinical Neuroscience, Villa San Benedetto Menni, Hermanas Hospitalarias, Albese con Cassano, Como, Italy. Electronic address: pernagp@gmail.com.
authors.forename: Giampaolo
authors.initials: G
authors.lastname: Perna
authors.affiliation: Department of Neuroscience, Reproductive Sciences and Odontostomatology, University "Federico II" of Naples, Via Pansini 5, 80131 Naples, Italy. Electronic address: felix_ias@hotmail.com.
authors.forename: Felice
authors.initials: F
authors.lastname: Iasevoli
authors.affiliation: Department of Neuroscience, Reproductive Sciences and Odontostomatology, University "Federico II" of Naples, Via Pansini 5, 80131 Naples, Italy. Electronic address: carmine.tomasetti@gmail.com.
authors.forename: Carmine
authors.initials: C
authors.lastname: Tomasetti
authors.affiliation: Department of Neurosciences and Imaging, University "G. d'Annunzio" of Chieti, 66013 Chieti, Italy. Electronic address: giovanni.martinotti@gmail.com.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Martinotti
authors.affiliation: St. John's National Academy of Health Sciences, Bangalore, India. Electronic address: ann007sarah@gmail.com.
authors.forename: Ann Sarah
authors.initials: AS
authors.lastname: Koshy
authors.affiliation: Department of Clinical Medicine, Section for Psychiatry, University of Bergen, Bergen, Norway. Electronic address: ole.fasmer@kliniskmedisin.uib.no.
authors.forename: Ole Bernt
authors.initials: OB
authors.lastname: Fasmer
authors.affiliation: Department of Psychiatry, University of Bergen, Bergen, Norway. Electronic address: ketil.odegaard@helse-bergen.no.
authors.forename: Ketil Joachim
authors.initials: KJ
authors.lastname: Oedegaard
mesh_terms: D001714:Bipolar Disorder / Q000150:complications* / Q000453:epidemiology / Q000523:psychology; D015897:Comorbidity; D003430:Cross-Sectional Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008881:Migraine Disorders / Q000150:complications* / Q000453:epidemiology / Q000523:psychology; D020325:Migraine with Aura / Q000150:complications / Q000453:epidemiology / Q000523:psychology; D015995:Prevalence; D012737:Sex Factors