Hostname: page-component-5d84bcc8dc-cszgk Total loading time: 0 Render date: 2026-09-12T23:24:31.165Z Has data issue: false hasContentIssue false
  • English
  • Français

Gender, age at onset, and duration of being ill as predictors for the long-term course and outcome of schizophrenia: an international multicenter study

Published online by Cambridge University Press:  09 August 2021

Konstantinos N. Fountoulakis Open the ORCID record for Konstantinos N. Fountoulakis [Opens in a new window] ,
Elena Dragioti ,
Antonis T. Theofilidis ,
Tobias Wiklund ,
Xenofon Atmatzidis ,
Ioannis Nimatoudis ,
Erik Thys ,
Martien Wampers ,
Luchezar Hranov  and
Trayana Hristova
...Show all authors
Konstantinos N. Fountoulakis*
Affiliation:
3rd Department of Psychiatry, Faculty of Medicine, School of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece
Elena Dragioti
Affiliation:
Department of Medical and Health Sciences (IMH), Faculty of Health Sciences, Linköping University, Linköping, Sweden Hallunda Psychiatric Outpatient Clinic, Stockholm Psychiatric Southwest Clinic, Karolinska Huddinge University Hospital, Huddinge, Sweden
Antonis T. Theofilidis
Affiliation:
3rd Department of Psychiatry, Faculty of Medicine, School of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece
Tobias Wiklund
Affiliation:
Department of Medical and Health Sciences (IMH), Faculty of Health Sciences, Linköping University, Linköping, Sweden Hallunda Psychiatric Outpatient Clinic, Stockholm Psychiatric Southwest Clinic, Karolinska Huddinge University Hospital, Huddinge, Sweden
Xenofon Atmatzidis
Affiliation:
Department of Medical and Health Sciences (IMH), Faculty of Health Sciences, Linköping University, Linköping, Sweden Hallunda Psychiatric Outpatient Clinic, Stockholm Psychiatric Southwest Clinic, Karolinska Huddinge University Hospital, Huddinge, Sweden
Ioannis Nimatoudis
Affiliation:
3rd Department of Psychiatry, Faculty of Medicine, School of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece
Erik Thys
Affiliation:
University Psychiatric Center, Katholieke Universiteit Leuven, Kortenberg, Belgium
Martien Wampers
Affiliation:
University Psychiatric Center, Katholieke Universiteit Leuven, Kortenberg, Belgium Department of Neurosciences, Katholieke Universiteit Leuven, Leuven, Belgium
Luchezar Hranov
Affiliation:
University Multiprofile Hospital for Active Treatment in Neurology and Psychiatry “Sveti Naum”, Sofia, Bulgaria
Trayana Hristova
Affiliation:
University Multiprofile Hospital for Active Treatment in Neurology and Psychiatry “Sveti Naum”, Sofia, Bulgaria
Daniil Aptalidis
Affiliation:
University Multiprofile Hospital for Active Treatment in Neurology and Psychiatry “Sveti Naum”, Sofia, Bulgaria
Roumen Milev
Affiliation:
Department of Psychiatry, Queen’s University, Providence Care Hospital, Kingston, Ontario, Canada
Felicia Iftene
Affiliation:
Department of Psychiatry, Queen’s University, Providence Care Hospital, Kingston, Ontario, Canada
Filip Spaniel
Affiliation:
National Institute of Mental Health, Klecany, Czech Republic
Pavel Knytl
Affiliation:
National Institute of Mental Health, Klecany, Czech Republic
Petra Furstova
Affiliation:
National Institute of Mental Health, Klecany, Czech Republic
Tiina From
Affiliation:
Department of Psychiatry, University of Turku, Turku, Finland
Henry Karlsson
Affiliation:
Department of Psychiatry, University of Turku, Turku, Finland
Maija Walta
Affiliation:
Department of Psychiatry, University of Turku, Turku, Finland
Raimo K. R. Salokangas
Affiliation:
Department of Psychiatry, University of Turku, Turku, Finland
Jean-Michel Azorin
Affiliation:
Department of Psychiatry, Sainte Marguerite University Hospital, Marseille, France Timone Institute of Neuroscience, Marseille, France
Justine Bouniard
Affiliation:
Department of Psychiatry, Sainte Marguerite University Hospital, Marseille, France Timone Institute of Neuroscience, Marseille, France
Julie Montant
Affiliation:
Department of Psychiatry, Sainte Marguerite University Hospital, Marseille, France Timone Institute of Neuroscience, Marseille, France
Georg Juckel
Affiliation:
Department of Psychiatry, Ruhr University Bochum, Bochum, Germany
Ida S. Haussleiter
Affiliation:
Department of Psychiatry, Ruhr University Bochum, Bochum, Germany
Athanasios Douzenis
Affiliation:
2nd Department of Psychiatry, National and Kapodistrian University of Athens, Athens, Greece
Ioannis Michopoulos
Affiliation:
2nd Department of Psychiatry, National and Kapodistrian University of Athens, Athens, Greece
Panagiotis Ferentinos
Affiliation:
2nd Department of Psychiatry, National and Kapodistrian University of Athens, Athens, Greece
Nikolaos Smyrnis
Affiliation:
Department of Psychiatry, National and Kapodistrian University of Athens School of Medicine, Eginition Hospital, Athens, Greece
Leonidas Mantonakis
Affiliation:
Department of Psychiatry, National and Kapodistrian University of Athens School of Medicine, Eginition Hospital, Athens, Greece
Zsófia Nemes
Affiliation:
Nyírő Gyula Hospital, Budapest, Hungary
Xenia Gonda
Affiliation:
Department of Psychiatry and Psychotherapy, Semmelweis University, Budapest, Hungary
Dora Vajda
Affiliation:
Department of Psychiatry and Psychotherapy, Semmelweis University, Budapest, Hungary
Anita Juhasz
Affiliation:
Department of Psychiatry and Psychotherapy, Semmelweis University, Budapest, Hungary
Amresh Shrivastava
Affiliation:
Western University, London, Ontario, Canada
John Waddington
Affiliation:
Department of Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, Dublin, Ireland
Maurizio Pompili
Affiliation:
Department of Neurosciences, Mental Health and Sensory Organs, Suicide Prevention Center, Sant’Andrea Hospital, Sapienza University of Rome, Rome, Italy
Anna Comparelli
Affiliation:
Department of Neurosciences, Mental Health and Sensory Organs, Suicide Prevention Center, Sant’Andrea Hospital, Sapienza University of Rome, Rome, Italy
Valentina Corigliano
Affiliation:
Department of Neurosciences, Mental Health and Sensory Organs, Suicide Prevention Center, Sant’Andrea Hospital, Sapienza University of Rome, Rome, Italy
Elmars Rancans
Affiliation:
Department of Psychiatry and Narcology, Riga Stradins University, Riga, Latvia
Alvydas Navickas
Affiliation:
Department of Clinic of Psychiatric, Faculty of Medicine, Vilnius University, Vilnius, Lithuania Department of Psychosocial Rehabilitation, Vilnius Mental Health Center, Vilnius, Lithuania Department for Psychosis Treatment, Vilnius Mental Health Center, Vilnius, Lithuania
Jan Hilbig
Affiliation:
Department of Clinic of Psychiatric, Faculty of Medicine, Vilnius University, Vilnius, Lithuania Department of Psychosocial Rehabilitation, Vilnius Mental Health Center, Vilnius, Lithuania Department for Psychosis Treatment, Vilnius Mental Health Center, Vilnius, Lithuania
Laurynas Bukelskis
Affiliation:
Department of Clinic of Psychiatric, Faculty of Medicine, Vilnius University, Vilnius, Lithuania Department of Psychosocial Rehabilitation, Vilnius Mental Health Center, Vilnius, Lithuania Department for Psychosis Treatment, Vilnius Mental Health Center, Vilnius, Lithuania
Lidija I. Stevovic
Affiliation:
Clinical Department of Psychiatry, Clinical Centre of Montenegro, Podgorica, Montenegro Department of Psychiatry, School of Medicine, University of Montenegro, Podgorica, Montenegro Clinical Department of Neurology, Clinical Centre of Montenegro, Podgorica, Montenegro
Sanja Vodopic
Affiliation:
Clinical Department of Psychiatry, Clinical Centre of Montenegro, Podgorica, Montenegro Department of Psychiatry, School of Medicine, University of Montenegro, Podgorica, Montenegro Clinical Department of Neurology, Clinical Centre of Montenegro, Podgorica, Montenegro
Oluyomi Esan
Affiliation:
Department of Psychiatry, College of Medicine, University of Ibadan, Ibadan, Nigeria
Oluremi Oladele
Affiliation:
Department of Psychiatry, College of Medicine, University of Ibadan, Ibadan, Nigeria
Christopher Osunbote
Affiliation:
Department of Psychiatry, College of Medicine, University of Ibadan, Ibadan, Nigeria
Janusz K. Rybakowski
Affiliation:
Department of Adult Psychiatry, Poznan University of Medical Sciences, Poznan, Poland
Pawel Wojciak
Affiliation:
Department of Adult Psychiatry, Poznan University of Medical Sciences, Poznan, Poland
Klaudia Domowicz
Affiliation:
Department of Adult Psychiatry, Poznan University of Medical Sciences, Poznan, Poland
Maria L. Figueira
Affiliation:
Department of Psychiatry and Mental Health, Santa Maria University Hospital, Lisbon, Portugal
Ludgero Linhares
Affiliation:
Department of Psychiatry and Mental Health, Santa Maria University Hospital, Lisbon, Portugal
Joana Crawford
Affiliation:
Department of Psychiatry and Mental Health, Santa Maria University Hospital, Lisbon, Portugal
Anca-Livia Panfil
Affiliation:
University of Medicine and Pharmacy of Târgu Mureş, Târgu Mureș, Romania
Daria Smirnova
Affiliation:
Department of Psychiatry, Samara Psychiatric Hospital, Inpatient Unit, Samara State Medical University, Samara, Russia
Olga Izmailova
Affiliation:
Department of Psychiatry, Samara Psychiatric Hospital, Inpatient Unit, Samara State Medical University, Samara, Russia
Dusica Lecic-Tosevski
Affiliation:
Institute of Mental Health, Belgrade, Serbia Serbian Academy of Sciences and Arts, Belgrade, Serbia
Henk Temmingh
Affiliation:
Department of Psychiatry and Mental Health, University of Cape Town, Cape Town, South Africa
Fleur Howells
Affiliation:
Department of Psychiatry and Mental Health, University of Cape Town, Cape Town, South Africa
Julio Bobes
Affiliation:
Department of Psychiatry, University of Oviedo and Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Oviedo, Spain
Maria P. Garcia-Portilla
Affiliation:
Department of Psychiatry, University of Oviedo and Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Oviedo, Spain
Leticia García-Alvarez
Affiliation:
Department of Psychiatry, University of Oviedo and Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Oviedo, Spain
Gamze Erzin
Affiliation:
Psychiatry Department, Diskapi Yildirim Beyazit Training and Research Hospital, Ankara, Turkey
Hasan Karadağ
Affiliation:
Psychiatry Department, Diskapi Yildirim Beyazit Training and Research Hospital, Ankara, Turkey
Avinash De Sousa
Affiliation:
Department of Psychiatry, Lokmanya Tilak Municipal Medical College, Mumbai, India
Anuja Bendre
Affiliation:
Department of Psychiatry, Lokmanya Tilak Municipal Medical College, Mumbai, India
Cyril Hoschl
Affiliation:
National Institute of Mental Health, Klecany, Czech Republic
Cristina Bredicean
Affiliation:
University of Medicine and Pharmacy of Timisoara, Timisoara, Romania
Ion Papava
Affiliation:
University of Medicine and Pharmacy of Timisoara, Timisoara, Romania
Olivera Vukovic
Affiliation:
Institute of Mental Health, School of Medicine, University of Belgrade, Belgrade, Serbia
Bojana Pejuskovic
Affiliation:
Department of Psychiatry, Royal College of Surgeons in Ireland, Beaumont Hospital, Dublin, Ireland
Vincent Russell
Affiliation:
Department of Psychiatry, Royal College of Surgeons in Ireland, Beaumont Hospital, Dublin, Ireland
Loukas Athanasiadis
Affiliation:
1st Department of Psychiatry, Faculty of Medicine, School of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece
Anastasia Konsta
Affiliation:
1st Department of Psychiatry, Faculty of Medicine, School of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece
Nikolaos K. Fountoulakis
Affiliation:
Faculty of Medicine, Medical University, Sofia, Bulgaria
Dan Stein
Affiliation:
MRC Unit on Risk and Resilience in Mental Disorders, Department of Psychiatry and Mental Health, University of Cape Town, Cape Town, South Africa
Michael Berk
Affiliation:
IMPACT Strategic Research Centre, School of Medicine, Barwon Health, Deakin University, Geelong, Victoria, Australia Orygen, The National Centre of Excellence in Youth Mental Health, Parkville, Victoria, Australia Centre for Youth Mental Health, The Florey Institute for Neuroscience and Mental Health, Parkville, Victoria, Australia Department of Psychiatry, University of Melbourne, Parkville, Victoria, Australia
Olivia Dean
Affiliation:
IMPACT Strategic Research Centre, School of Medicine, Barwon Health, Deakin University, Geelong, Victoria, Australia Orygen, The National Centre of Excellence in Youth Mental Health, Parkville, Victoria, Australia Centre for Youth Mental Health, The Florey Institute for Neuroscience and Mental Health, Parkville, Victoria, Australia Department of Psychiatry, University of Melbourne, Parkville, Victoria, Australia
Rajiv Tandon
Affiliation:
Department of Psychiatry, University of Florida, Gainesville, Florida, USA
Siegfried Kasper
Affiliation:
Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria
Marc De Hert
Affiliation:
University Psychiatric Center, Katholieke Universiteit Leuven, Kortenberg, Belgium Department of Neurosciences, Katholieke Universiteit Leuven, Leuven, Belgium Antwerp Health Law and Ethics Chair-AHLEC University, Antwerpen, Belgium
*
*Author for correspondence: Konstantinos N. Fountoulakis Email: kfount@med.auth.gr
Get access Rights & Permissions [Opens in a new window]

Abstract

Background

The aim of the current study was to explore the effect of gender, age at onset, and duration on the long-term course of schizophrenia.

Methods

Twenty-nine centers from 25 countries representing all continents participated in the study that included 2358 patients aged 37.21 ± 11.87 years with a DSM-IV or DSM-5 diagnosis of schizophrenia; the Positive and Negative Syndrome Scale as well as relevant clinicodemographic data were gathered. Analysis of variance and analysis of covariance were used, and the methodology corrected for the presence of potentially confounding effects.

Results

There was a 3-year later age at onset for females (P < .001) and lower rates of negative symptoms (P < .01) and higher depression/anxiety measures (P < .05) at some stages. The age at onset manifested a distribution with a single peak for both genders with a tendency of patients with younger onset having slower advancement through illness stages (P = .001). No significant effects were found concerning duration of illness.

Discussion

Our results confirmed a later onset and a possibly more benign course and outcome in females. Age at onset manifested a single peak in both genders, and surprisingly, earlier onset was related to a slower progression of the illness. No effect of duration has been detected. These results are partially in accord with the literature, but they also differ as a consequence of the different starting point of our methodology (a novel staging model), which in our opinion precluded the impact of confounding effects. Future research should focus on the therapeutic policy and implications of these results in more representative samples.

Keywords

Genderage at onsetdurationlong-term courseoutcomeschizophrenia

Information

Type
Original Research
Information
CNS Spectrums , Volume 27 , Issue 6 , December 2022 , pp. 716 - 723
Copyright
© Cambridge University Press 2021

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Article purchase

Temporarily unavailable

References

Fountoulakis, KN, Dragioti, E, Theofilidis, AT, et al. Staging of schizophrenia with the use of PANSS: an international multi-center study. Int J Neuropsychopharmacol. 2019;22(11):681–697.10.1093/ijnp/pyz053CrossRefGoogle ScholarPubMed
Fountoulakis, KN, Dragioti, E, Theofilidis, AT, et al. Modeling psychological function in patients with schizophrenia with the PANSS: an international multi-center study. CNS Spectr. 2021;26(3):290–298.10.1017/S1092852920001091CrossRefGoogle ScholarPubMed
Kay, SR. Positive–negative symptom assessment in schizophrenia: psychometric issues and scale comparison. Psychiatr Q. 1990;61(3):163–178.CrossRefGoogle ScholarPubMed
Kay, SR, Fiszbein, A, Opler, LA. The Positive and Negative Syndrome Scale (PANSS) for schizophrenia. Schizophr. Bull. 1987;13(2):261–276.10.1093/schbul/13.2.261CrossRefGoogle ScholarPubMed
Kay, SR, Opler, LA, Lindenmayer, JP. Reliability and validity of the Positive and Negative Syndrome Scale for schizophrenics. Psychiatry Res. 1988;23(1):99–110.CrossRefGoogle ScholarPubMed
Kay, SR, Sandyk, R. Experimental models of schizophrenia. Int J Neurosci. 1991;58(1–2):69–82.10.3109/00207459108987184CrossRefGoogle ScholarPubMed
Kay, SR, Sevy, S. Pyramidical model of schizophrenia. Schizophr Bull. 1990;16(3):537–545. doi:10.1093/schbul/16.3.537.CrossRefGoogle ScholarPubMed
APA. Diagnostic and Statistical Manual of Mental Disorders: DSM-5. American Psychiatric Association, Arlington, VA; 2013.Google Scholar
APA. Diagnostic and Statistical Manual of Mental Disorders: Fourth Edition Text Revision DSM-IV-TR. American Psychiatric Association, Arlington, VA; 2000.Google Scholar
Davis, J, Eyre, H, Jacka, FN, et al. A review of vulnerability and risks for schizophrenia: beyond the two hit hypothesis. Neurosci Biobehav Rev. 2016;65:185–194. doi:10.1016/j.neubiorev.2016.03.017.CrossRefGoogle ScholarPubMed
Schizophrenia Working Group of the Psychiatric Genomics Consortium. Biological insights from 108 schizophrenia-associated genetic loci. Nature. 2014;511(7510):421–427. doi:10.1038/nature13595.CrossRefGoogle Scholar
Angermeyer, MC, Kuhn, L. Gender differences in age at onset of schizophrenia. An overview. Eur Arch Psychiatry Neurol Sci. 1988;237(6):351–364.10.1007/BF00380979CrossRefGoogle ScholarPubMed
Hambrecht, M, Maurer, K, Hafner, H, Sartorius, N. Transnational stability of gender differences in schizophrenia? An analysis based on the WHO study on determinants of outcome of severe mental disorders. Eur Arch Psychiatry Clin Neurosci. 1992;242(1):6–12.CrossRefGoogle Scholar
Hambrecht, M, Maurer, K, Hafner, H. Gender differences in schizophrenia in three cultures. Results of the WHO collaborative study on psychiatric disability. Soc Psychiatry Psychiatr Epidemiol. 1992;27(3):117–121. doi:10.1007/bf00788756.CrossRefGoogle Scholar
Messias, EL, Chen, CY, Eaton, WW. Epidemiology of schizophrenia: review of findings and myths. Psychiatr Clin North Am. 2007;30(3):323–338. doi:10.1016/j.psc.2007.04.007.CrossRefGoogle ScholarPubMed
Morgan, C, John, S, Esan, O, et al. The incidence of psychoses in diverse settings, INTREPID (2): a feasibility study in India, Nigeria, and Trinidad. Psychol Med. 2016;46(9):1923–1933. doi:10.1017/S0033291716000441.CrossRefGoogle ScholarPubMed
Ochoa, S, Usall, J, Cobo, J, Labad, X, Kulkarni, J. Gender differences in schizophrenia and first-episode psychosis: a comprehensive literature review. Schizophr Res Treatment. 2012;2012:916198.10.1155/2012/916198CrossRefGoogle ScholarPubMed
Kraepelin, E. Psychiatrie ein Lehrbuch für Studierende und Ärzte. 8 Aufl. Leipzig, Germany: Johann Ambrosius Barth; 1909-1915.Google Scholar
Kilicaslan, EE, Erol, A, Zengin, B, Cetinay Aydin, P, Mete, L. Association between age at onset of schizophrenia and age at menarche. Noro Psikiyatr Ars. 2014;51(3):211–215. doi:10.4274/npa.y6675.Google ScholarPubMed
Hafner, H. From onset and prodromal stage to a life-long course of schizophrenia and its symptom dimensions: how sex, age, and other risk factors influence incidence and course of illness. Psychiatry J. 2019;2019:9804836.10.1155/2019/9804836CrossRefGoogle ScholarPubMed
Gattaz, WF, Behrens, S, De Vry, J, Hafner, H. Ostradiol hemmt dopamin-vermittelte verhaltensweisen bei ratten—ein tiermodell zur untersuchung der geschlechtsspezifischen unterschiede bei der schizophrenie [Estradiol inhibits dopamine mediated behavior in rats—an animal model of sex-specific differences in schizophrenia]. Fortschr Neurol Psychiatr. 1992;60(1):8–16.CrossRefGoogle Scholar
Häfner, H, Behrens, S, De Vry, J, Gattaz, WF. Oestradiol enhances the vulnerability threshold for schizophrenia in women by an early effect on dopaminergic neurotransmission. Eur Arch Psychiatry Clin Neurosci. 1991;241(1):65–68.10.1007/BF02193758CrossRefGoogle ScholarPubMed
Hafner, H, Ehrenreich, H, Gattaz, W, Louza, M, Riecher-Rossler, A, Kulkarni, J. Oestrogen—a protective factor in schizophrenia? Curr Psychiatry Rev. 2006;2(3):339–352.10.2174/157340006778018120CrossRefGoogle Scholar
Akhondzadeh, S, Nejatisafa, AA, Amini, H, et al. Adjunctive estrogen treatment in women with chronic schizophrenia: a double-blind, randomized, and placebo-controlled trial. Prog Neuropsychopharmacol Biol Psychiatry. 2003;27(6):1007–1012.10.1016/S0278-5846(03)00161-1CrossRefGoogle ScholarPubMed
Kulkarni, J, Castella, A, Downey, M, et al. Results of two controlled studies on estrogen: avenue to neuroprotection in schizophrenia. In: Hafner, H, ed. Risk and Protective Factors in Schizophrenia. Darmstadt, Germany: Steinkopff; 2002:271–282.10.1007/978-3-642-57516-7_23CrossRefGoogle Scholar
Kulkarni, J, de Castella, A, Fitzgerald, PB, et al. Estrogen in severe mental illness: a potential new treatment approach. Arch Gen Psychiatry. 2008;65(8):955–960.CrossRefGoogle ScholarPubMed
Kulkarni, J, Gavrilidis, E, Hayes, E, Heaton, V, Worsley, R. Special biological issues in the management of women with schizophrenia. Expert Rev Neurother. 2012;12(7):823–833.CrossRefGoogle ScholarPubMed
Kulkarni, J, Gavrilidis, E, Wang, W, et al. Estradiol for treatment-resistant schizophrenia: a large-scale randomized-controlled trial in women of child-bearing age. Mol Psychiatry. 2015;20(6):695–702.CrossRefGoogle ScholarPubMed
Gureje, O. Gender and schizophrenia: age at onset and sociodemographic attributes. Acta Psychiatr Scand. 1991;83(5):402–405.10.1111/j.1600-0447.1991.tb05564.xCrossRefGoogle ScholarPubMed
Hafner, H, Riecher-Rossler, A, An Der Heiden, W, Maurer, K, Fatkenheuer, B, Loffler, W. Generating and testing a causal explanation of the gender difference in age at first onset of schizophrenia. Psychol Med. 1993;23(4):925–940.10.1017/S0033291700026398CrossRefGoogle ScholarPubMed
Hafner, H, Riecher, A, Maurer, K, Loffler, W, Munk-Jorgensen, P, Stromgren, E. How does gender influence age at first hospitalization for schizophrenia? A transnational case register study. Psychol Med. 1989;19(4):903–918.CrossRefGoogle ScholarPubMed
Hafner, H, Hambrecht, M, Loffler, W, Munk-Jorgensen, P, Riecher-Rossler, A. Is schizophrenia a disorder of all ages? A comparison of first episodes and early course across the life-cycle. Psychol Med. 1998;28(2):351–365.CrossRefGoogle Scholar
Eranti, SV, MacCabe, JH, Bundy, H, Murray, RM. Gender difference in age at onset of schizophrenia: a meta-analysis. Psychol Med. 2013;43(1):155–167.10.1017/S003329171200089XCrossRefGoogle ScholarPubMed
Murthy, GV, Janakiramaiah, N, Gangadhar, BN, Subbakrishna, DK. Sex difference in age at onset of schizophrenia: discrepant findings from India. Acta Psychiatr Scand. 1998;97(5):321–325.CrossRefGoogle ScholarPubMed
Gangadhar, BN, Panner Selvan, C, Subbakrishna, DK, Janakiramaiah, N. Age-at-onset and schizophrenia: reversed gender effect. Acta Psychiatr Scand. 2002;105(4):317–319. doi:10.1034/j.1600-0447.2002.1153.x.CrossRefGoogle ScholarPubMed
Iacono, WG, Beiser, M. Are males more likely than females to develop schizophrenia? Am J Psychiatry. 1992;149(8):1070–1074.Google ScholarPubMed
Kirkbride, JB, Fearon, P, Morgan, C, et al. Heterogeneity in incidence rates of schizophrenia and other psychotic syndromes: findings from the 3-center AeSOP study. Arch Gen Psychiatry. 2006;63(3):250–258.10.1001/archpsyc.63.3.250CrossRefGoogle ScholarPubMed
McGrath, J, Saha, S, Welham, J, El Saadi, O, MacCauley, C, Chant, D. A systematic review of the incidence of schizophrenia: the distribution of rates and the influence of sex, urbanicity, migrant status and methodology. BMC Med. 2004;2(1):13.CrossRefGoogle ScholarPubMed
Thorup, A, Waltoft, BL, Pedersen, CB, Mortensen, PB, Nordentoft, M. Young males have a higher risk of developing schizophrenia: a Danish register study. Psychol Med. 2007;37(4):479–484.10.1017/S0033291707009944CrossRefGoogle ScholarPubMed
van der Werf, M, Hanssen, M, Kohler, S, et al. Systematic review and collaborative recalculation of 133,693 incident cases of schizophrenia. Psychol Med. 2014;44(1):9–16.CrossRefGoogle ScholarPubMed
Goldstein, JM, Tsuang, MT, Faraone, SV. Gender and schizophrenia: implications for understanding the heterogeneity of the illness. Psychiatry Res. 1989;28(3):243–253.CrossRefGoogle ScholarPubMed
Gureje, O, Bamidele, RW. Gender and schizophrenia: association of age at onset with antecedent, clinical and outcome features. Aust N Z J Psychiatry. 1998;32(3):415–423.CrossRefGoogle ScholarPubMed
Immonen, J, Jaaskelainen, E, Korpela, H, Miettunen, J. Age at onset and the outcomes of schizophrenia: a systematic review and meta-analysis. Early Interv Psychiatry. 2017;11(6):453–460.CrossRefGoogle ScholarPubMed
Clemmensen, L, Vernal, DL, Steinhausen, HC. A systematic review of the long-term outcome of early onset schizophrenia. BMC Psychiatry. 2012;12:150.10.1186/1471-244X-12-150CrossRefGoogle ScholarPubMed
Asarnow, JR. Children at risk for schizophrenia: converging lines of evidence. Schizophr Bull. 1988;14(4):613–631. doi:10.1093/schbul/14.4.613.CrossRefGoogle ScholarPubMed
Asarnow, JR, Tompson, MC, McGrath, EP. Annotation: childhood-onset schizophrenia: clinical and treatment issues. J Child Psychol Psychiatry. 2004;45(2):180–194.CrossRefGoogle ScholarPubMed
Eggers, C, Bunk, D. The long-term course of childhood-onset schizophrenia: a 42-year follow-up. Schizophr Bull. 1997;23(1):105–117.10.1093/schbul/23.1.105CrossRefGoogle Scholar
Kendhari, J, Shankar, R, Young-Walker, L. A review of childhood-onset schizophrenia. Focus. 2016;14(3):328–332.CrossRefGoogle ScholarPubMed
Hafner, H, Maurer, K, an der Heiden, W. ABC Schizophrenia study: an overview of results since 1996. Soc Psychiatry Psychiatr Epidemiol. 2013;48(7):1021–1031.CrossRefGoogle ScholarPubMed
van Os, J, Howard, R, Takei, N, Murray, R. Increasing age is a risk factor for psychosis in the elderly. Soc Psychiatry Psychiatr Epidemiol. 1995;30(4):161–164.CrossRefGoogle ScholarPubMed
Häfner, H, Maurer, K, Löffler, W, et al. The ABC schizophrenia study: a preliminary overview of the results. Soc Psychiatry Psychiatr Epidemiol. 1998;33(8):380–386.Google ScholarPubMed