title: Authors' reply.
authors.affiliation: Liz Forty, Nick Craddock (on behalf of the authors), Institute of Psychological Medicine and Clinical Neurosciences, Cardiff University, UK. Email: craddockn@cardiff.ac.uk.
authors.forename: Liz
authors.initials: L
authors.lastname: Forty
authors.affiliation: Liz Forty, Nick Craddock (on behalf of the authors), Institute of Psychological Medicine and Clinical Neurosciences, Cardiff University, UK. Email: craddockn@cardiff.ac.uk.
authors.forename: Nick
authors.initials: N
authors.lastname: Craddock
mesh_terms: D001714:Bipolar Disorder; D002908:Chronic Disease; D005260:Female; D006801:Humans; D008297:Male