{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,11]],"date-time":"2026-04-11T23:37:40Z","timestamp":1775950660408,"version":"3.50.1"},"reference-count":27,"publisher":"Wiley","issue":"5","license":[{"start":{"date-parts":[[2020,1,22]],"date-time":"2020-01-22T00:00:00Z","timestamp":1579651200000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"funder":[{"DOI":"10.13039\/501100003243","name":"Ministerstvo Zdravotnictv\u00ed Cesk\u00e9 Republiky","doi-asserted-by":"publisher","award":["16\u201032696A"],"award-info":[{"award-number":["16\u201032696A"]}],"id":[{"id":"10.13039\/501100003243","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100003243","name":"Ministerstvo Zdravotnictv\u00ed Cesk\u00e9 Republiky","doi-asserted-by":"publisher","award":["16\u201032791A"],"award-info":[{"award-number":["16\u201032791A"]}],"id":[{"id":"10.13039\/501100003243","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100000024","name":"Canadian Institutes of Health Research","doi-asserted-by":"publisher","award":["142255"],"award-info":[{"award-number":["142255"]}],"id":[{"id":"10.13039\/501100000024","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100000874","name":"Brain and Behavior Research Foundation","doi-asserted-by":"publisher","id":[{"id":"10.13039\/100000874","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Bipolar Disorders"],"published-print":{"date-parts":[[2020,8]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:sec><jats:title>Background<\/jats:title><jats:p>Seasonal peaks in hospitalizations for mood disorders and schizophrenia are well recognized and often replicated. The within\u2010subject tendency to experience illness episodes in the same season, that is, seasonal course, is much less established, as certain individuals may temporarily meet criteria for seasonal course purely by chance.<\/jats:p><\/jats:sec><jats:sec><jats:title>Aims<\/jats:title><jats:p>In this population, prospective cohort study, we investigated whether between and within\u2010subject seasonal patterns of hospitalizations occurred more frequently than would be expected by chance.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>Using a compulsory, standardized national register of hospitalizations, we analyzed all admissions for mood disorders and schizophrenia in the Czech Republic between 1994 and 2013. We used bootstrap tests to compare the observed numbers of (a) participants with seasonal\/regular course and (b) hospitalizations in individual months against empirical distributions obtained by simulations.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>Among 87\u00a0184 participants, we found\u00a0uneven distribution of hospitalizations, with hospitalization peaks for depression in April and November (X<jats:sup>2<\/jats:sup>(11)\u00a0=\u00a0363.66, <jats:italic>P<\/jats:italic>\u00a0&lt;\u00a0.001), for mania in August (X<jats:sup>2<\/jats:sup>(11)\u00a0=\u00a050.36, <jats:italic>P<\/jats:italic>\u00a0&lt;\u00a0.001) and for schizophrenia in June (X<jats:sup>2<\/jats:sup>(11)\u00a0=\u00a070.34, <jats:italic>P<\/jats:italic>\u00a0&lt;\u00a0.001). Significantly more participants than would be expected by chance, had two subsequent rehospitalizations in the same 90\u00a0days in different years (7.36%, bootstrap <jats:italic>P<\/jats:italic>\u00a0&lt;\u00a0.01) or after a regular, but non\u2010seasonal interval (6.07%, bootstrap <jats:italic>P<\/jats:italic>\u00a0&lt;\u00a0.001). The proportion of participants with two consecutive hospitalizations in the same season was below chance level (7.06%).<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusions<\/jats:title><jats:p>Psychiatric hospitalizations were unevenly distributed throughout the year (cross\u2010sectional seasonality), with evidence for regularity, but not seasonality of hospitalizations within subjects. Our data do not support the validity of seasonal pattern specifier. Season may be a general risk factor, which increases the risk of hospitalizations across psychiatric participants.<\/jats:p><\/jats:sec>","DOI":"10.1111\/bdi.12884","type":"journal-article","created":{"date-parts":[[2019,12,28]],"date-time":"2019-12-28T06:11:18Z","timestamp":1577513478000},"page":"508-516","update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":17,"title":["Cross\u2010sectional and within\u2010subject seasonality and regularity of hospitalizations: A population study in mood disorders and schizophrenia"],"prefix":"10.1111","volume":"22","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-4672-4923","authenticated-orcid":false,"given":"Eduard","family":"Bakstein","sequence":"first","affiliation":[{"name":"National Institute of Mental Health Klecany Czech Republic"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Karol\u00edna","family":"Mlad\u00e1","sequence":"additional","affiliation":[{"name":"National Institute of Mental Health Klecany Czech Republic"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Eva","family":"F\u00e1rkov\u00e1","sequence":"additional","affiliation":[{"name":"National Institute of Mental Health Klecany Czech Republic"},{"name":"3rd School of Medicine Charles University Prague Czech Republic"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Marian","family":"Koleni\u010d","sequence":"additional","affiliation":[{"name":"National Institute of Mental Health Klecany Czech Republic"},{"name":"3rd School of Medicine Charles University Prague Czech Republic"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Filip","family":"\u0160paniel","sequence":"additional","affiliation":[{"name":"National Institute of Mental Health Klecany Czech Republic"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Denisa","family":"Mankov\u00e1","sequence":"additional","affiliation":[{"name":"National Institute of Mental Health 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