{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,16]],"date-time":"2026-09-16T11:37:45Z","timestamp":1789558665328,"version":"build-2803163510"},"reference-count":0,"publisher":"Cambridge University Press (CUP)","issue":"6","license":[{"start":{"date-parts":[[2004,8,31]],"date-time":"2004-08-31T00:00:00Z","timestamp":1093910400000},"content-version":"unspecified","delay-in-days":0,"URL":"https:\/\/www.cambridge.org\/core\/terms"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Psychol. Med."],"published-print":{"date-parts":[[2005,6]]},"abstract":"<jats:p><jats:bold>Background.<\/jats:bold> Few epidemiological studies have investigated incidence by age or age at onset distributions for mania or bipolar disorder. The current study aimed to determine these in a defined area in south-east London, over a 35-year period.<\/jats:p><jats:p><jats:bold>Method.<\/jats:bold> All cases of first-episode mania presenting to psychiatric services in Camberwell, south-east London, between 1965 and 1999 were identified. Incidence rates by age, using 5-year age-at-onset bands, were estimated and the structure of the age-at-onset distribution for first-episode mania was investigated using finite mixture distributions (admixture analysis).<\/jats:p><jats:p><jats:bold>Results.<\/jats:bold> The incidence of DSM-IV bipolar I disorder (BP I), first manic episode peaked in early adult life (16\u00b738\/100000 population per year in the 21\u201325 years band) with a much smaller peak in mid-life. A two-component normal mixture distribution fitted age at onset better than either a single normal distribution or a three-component mixture, implying the existence of early and later onset subgroups. The early onset group had a stronger family history of bipolar disorder, and showed more acute, severe and atypical symptoms during their first manic episode.<\/jats:p><jats:p><jats:bold>Conclusions.<\/jats:bold> The incidence of mania peaks in early adult life but there is clear evidence of early and later onset subgroups which may represent different forms of disorder.<\/jats:p>","DOI":"10.1017\/s0033291704003307","type":"journal-article","created":{"date-parts":[[2005,5,23]],"date-time":"2005-05-23T11:41:45Z","timestamp":1116848505000},"page":"855-863","source":"Crossref","is-referenced-by-count":96,"title":["Incidence and distribution of first-episode mania by age: results from a 35-year study"],"prefix":"10.1017","volume":"35","author":[{"given":"N.","family":"KENNEDY","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"B.","family":"EVERITT","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"J.","family":"BOYDELL","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"J.","family":"VAN OS","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"P. B.","family":"JONES","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"R. M.","family":"MURRAY","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"56","published-online":{"date-parts":[[2004,8,31]]},"container-title":["Psychological Medicine"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.cambridge.org\/core\/services\/aop-cambridge-core\/content\/view\/S0033291704003307","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2019,4,9]],"date-time":"2019-04-09T20:45:46Z","timestamp":1554842746000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.cambridge.org\/core\/product\/identifier\/S0033291704003307\/type\/journal_article"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2004,8,31]]},"references-count":0,"journal-issue":{"issue":"6","published-print":{"date-parts":[[2005,6]]}},"alternative-id":["S0033291704003307"],"URL":"https:\/\/doi.org\/10.1017\/s0033291704003307","relation":{},"ISSN":["0033-2917","1469-8978"],"issn-type":[{"value":"0033-2917","type":"print"},{"value":"1469-8978","type":"electronic"}],"subject":[],"published":{"date-parts":[[2004,8,31]]}}}