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Published in: BMC Psychiatry 1/2010

Open Access 01-12-2010 | Research article

Effects of age of onset on clinical characteristics in schizophrenia spectrum disorders

Authors: Yu-Chen Kao, Yia-Ping Liu

Published in: BMC Psychiatry | Issue 1/2010

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Abstract

Background

Over the last few decades, research regarding the age of onset of schizophrenia and its relationship with other clinical variables has been incorporated into clinical practices. However, reports of potential differences in demographic and clinical characteristics between early- and adult-onset schizophrenia spectrum disorders have been controversial. Thus, this study aims to assess differences in demographic and clinical characteristics correlated with age of illness onset in schizophrenia spectrum disorders.

Methods

Data were collected from 104 patients with schizophrenia and schizoaffective disorder. Diagnosis was made via structured clinical interviews. Assessments of psychiatric symptoms and social and global functioning were completed. The effect of age of onset on demographic and clinical variables was examined using correlation analyses and binary logistic regression models. We chose 17 years of age as the cut-off for early-onset schizophrenia spectrum disorders based on a recent clinical consensus. We further investigated differences in the severity of psychopathology and other clinical variables between the early- and adult-onset groups.

Results

The binary logistic regression analysis showed that age of onset was significantly related to the cognitive component of the Positive and Negative Syndrome Scale (PANSS) (odds ratio, OR = 0.58; 95% confidence interval, CI = 0.872-0.985; p < 0.001) and Barratt Impulsiveness Scale (BIS) score (OR = 0.94; 95% CI = 0.447-0.744; p = 0.015). Patients with early onset of schizophrenia spectrum disorders had significantly greater levels of cognitive impairment and higher impulsivity. There were significant differences between several demographic and clinical variables, including the negative symptom component of the PANSS (p < 0.001), cognitive component of the PANSS (p < 0.001), BIS score (p = 0.05), and psychological domain of quality of life (QOL) (p = 0.05), between patients with early- and adult-onset schizophrenia spectrum disorders, having controlled for the effect of the current age and duration of illness.

Conclusions

Our findings support the hypothesis of an influence of age of onset on illness course in patients with schizophrenia spectrum disorders. This finding may in fact be part of a separate domain worthy of investigation for the development of interventions for early symptoms of schizophrenia.
Literature
1.
go back to reference Altamura AC: A multidimensional (pharmacokinetic and clinical-biological) approach to neuroleptic response in schizophrenia. With particular reference to drug resistance. Schizophr Res. 1992, 8: 187-198. 10.1016/0920-9964(93)90017-D.CrossRef Altamura AC: A multidimensional (pharmacokinetic and clinical-biological) approach to neuroleptic response in schizophrenia. With particular reference to drug resistance. Schizophr Res. 1992, 8: 187-198. 10.1016/0920-9964(93)90017-D.CrossRef
2.
go back to reference Conley RR, Buchannan RW: Evaluation of treatment-resistant of schizophrenia. Schizophr Bull. 1997, 23: 663-674.CrossRefPubMed Conley RR, Buchannan RW: Evaluation of treatment-resistant of schizophrenia. Schizophr Bull. 1997, 23: 663-674.CrossRefPubMed
3.
go back to reference Aleman A, Kahn RS, Selten JP: Sex differences in the risk of schizophrenia: evidence from meta-analysis. Arch Gen Psychiatry. 2003, 60 (6): 565-571. 10.1001/archpsyc.60.6.565.CrossRefPubMed Aleman A, Kahn RS, Selten JP: Sex differences in the risk of schizophrenia: evidence from meta-analysis. Arch Gen Psychiatry. 2003, 60 (6): 565-571. 10.1001/archpsyc.60.6.565.CrossRefPubMed
4.
go back to reference Hafner H, Hambrecht M, Loffler W, Munk-Jorgensen P, Riecker-Rossler A: Is schizophrenia a disorder of all age? A comparison of first episode and early course across the life-cycle. Psychol Med. 1998, 28 (2): 351-365. 10.1017/S0033291797006399.CrossRefPubMed Hafner H, Hambrecht M, Loffler W, Munk-Jorgensen P, Riecker-Rossler A: Is schizophrenia a disorder of all age? A comparison of first episode and early course across the life-cycle. Psychol Med. 1998, 28 (2): 351-365. 10.1017/S0033291797006399.CrossRefPubMed
5.
go back to reference Lindstorm LH: Clinical and biological markers for outcome in schizophrenia. A review of a longitudinal follow-up study in Uppsala. Schizophr Res. 1996, 14: 23-26. Lindstorm LH: Clinical and biological markers for outcome in schizophrenia. A review of a longitudinal follow-up study in Uppsala. Schizophr Res. 1996, 14: 23-26.
6.
go back to reference Ciompi L: Learning from outcome studies. Toward a comprehensive biological psychosocial understanding of schizophrenia. Schizophr Res. 1988, 1: 373-384. 10.1016/0920-9964(88)90018-7.CrossRefPubMed Ciompi L: Learning from outcome studies. Toward a comprehensive biological psychosocial understanding of schizophrenia. Schizophr Res. 1988, 1: 373-384. 10.1016/0920-9964(88)90018-7.CrossRefPubMed
7.
go back to reference Tamminga CA, Buchanan RW, Gold JM: The role of negative symptoms and cognitive dysfunction in schizophrenia outcome. Int Clin Psychopharmacol. 1998, 13 (suppl 3): S21-S26. 10.1097/00004850-199803003-00004.CrossRefPubMed Tamminga CA, Buchanan RW, Gold JM: The role of negative symptoms and cognitive dysfunction in schizophrenia outcome. Int Clin Psychopharmacol. 1998, 13 (suppl 3): S21-S26. 10.1097/00004850-199803003-00004.CrossRefPubMed
8.
go back to reference Ho BC, Nopoulos P, Flaum M, Arndt S, Andreasen NC: Two-year outcome in first episode schizophrenia: predictive value of symptoms for quality of life. Am J Psychiatry. 1998, 155 (9): 1196-1201.CrossRefPubMed Ho BC, Nopoulos P, Flaum M, Arndt S, Andreasen NC: Two-year outcome in first episode schizophrenia: predictive value of symptoms for quality of life. Am J Psychiatry. 1998, 155 (9): 1196-1201.CrossRefPubMed
9.
go back to reference Eaton WW, Thara R, Federman E, Tien A: Remission and relapse in schizophrenia: the Madras Longitudinal Study. J Nerv Ment Dis. 1998, 186 (6): 357-363. 10.1097/00005053-199806000-00006.CrossRefPubMed Eaton WW, Thara R, Federman E, Tien A: Remission and relapse in schizophrenia: the Madras Longitudinal Study. J Nerv Ment Dis. 1998, 186 (6): 357-363. 10.1097/00005053-199806000-00006.CrossRefPubMed
10.
go back to reference Robison D, Woerner MG, Alvir JM: Predictors of relapse following response from a first episode of schizophrenia or schizoaffective disorder. Arch Gen Psychiatry. 1999, 56 (3): 241-247. 10.1001/archpsyc.56.3.241.CrossRef Robison D, Woerner MG, Alvir JM: Predictors of relapse following response from a first episode of schizophrenia or schizoaffective disorder. Arch Gen Psychiatry. 1999, 56 (3): 241-247. 10.1001/archpsyc.56.3.241.CrossRef
11.
go back to reference De Quardo JR: Pharmacologic treatment of first-episode schizophrenia: early intervention is the key to the outcome. J Clin Psychiatry. 1998, 59 (19): 9-17. De Quardo JR: Pharmacologic treatment of first-episode schizophrenia: early intervention is the key to the outcome. J Clin Psychiatry. 1998, 59 (19): 9-17.
12.
go back to reference APA: Diagnostic and statistical Manual of Mental Disorders, Fourth Edition. 1994, Washington (DC): American Psychiatric Press, 4 APA: Diagnostic and statistical Manual of Mental Disorders, Fourth Edition. 1994, Washington (DC): American Psychiatric Press, 4
13.
go back to reference Kendler KS, MacLean CJ: Estimating familial effects on age at onset and liability to schizophrenia. I. Results of a large sample family study. Gen Epidemiol. 1990, 7: 409-417. 10.1002/gepi.1370070603.CrossRef Kendler KS, MacLean CJ: Estimating familial effects on age at onset and liability to schizophrenia. I. Results of a large sample family study. Gen Epidemiol. 1990, 7: 409-417. 10.1002/gepi.1370070603.CrossRef
14.
go back to reference Sham PC, Jones P, Russell Al: Age at onset, sex, and familial psychiatric morbidity in schizophrenia. Camberwell Collaborative Psychosis Study. Br J Psychiatry. 1994, 165: 466-473. 10.1192/bjp.165.4.466.CrossRefPubMed Sham PC, Jones P, Russell Al: Age at onset, sex, and familial psychiatric morbidity in schizophrenia. Camberwell Collaborative Psychosis Study. Br J Psychiatry. 1994, 165: 466-473. 10.1192/bjp.165.4.466.CrossRefPubMed
15.
go back to reference Rapoport JL, Giedd JN, Blumenthai J: Progressive cortical change during adolescence in childhood-onset schizophrenia: a longitudinal magnetic resonance imaging study. Arch Gen Psychiatry. 1999, 56: 649-654. 10.1001/archpsyc.56.7.649.CrossRefPubMed Rapoport JL, Giedd JN, Blumenthai J: Progressive cortical change during adolescence in childhood-onset schizophrenia: a longitudinal magnetic resonance imaging study. Arch Gen Psychiatry. 1999, 56: 649-654. 10.1001/archpsyc.56.7.649.CrossRefPubMed
16.
go back to reference Loranger AW: Sex difference in age of onset of schizophrenia. Arch Gen Psychiatry. 1984, 41: 157-161.CrossRefPubMed Loranger AW: Sex difference in age of onset of schizophrenia. Arch Gen Psychiatry. 1984, 41: 157-161.CrossRefPubMed
17.
go back to reference Vourdas A, Pipe R, Corrigal R, Frangous S: Increased developmental deviance and premorbid dysfunction in early onset schizophrenia. Schizophr Res. 2003, 62: 13-22. 10.1016/S0920-9964(02)00429-2.CrossRefPubMed Vourdas A, Pipe R, Corrigal R, Frangous S: Increased developmental deviance and premorbid dysfunction in early onset schizophrenia. Schizophr Res. 2003, 62: 13-22. 10.1016/S0920-9964(02)00429-2.CrossRefPubMed
18.
go back to reference Kravariti E, Morris RG, Rabe-Hesketh S, Murray RM, Frangou S: The maudsley early onset schizophrenia study: Cognitive function in adolescents with recent onset schizophrenia. Schizophr Res. 2003, 61: 137-148. 10.1016/S0920-9964(02)00291-8.CrossRefPubMed Kravariti E, Morris RG, Rabe-Hesketh S, Murray RM, Frangou S: The maudsley early onset schizophrenia study: Cognitive function in adolescents with recent onset schizophrenia. Schizophr Res. 2003, 61: 137-148. 10.1016/S0920-9964(02)00291-8.CrossRefPubMed
19.
go back to reference Nicolson R, Lenane M, Singaracharlu S: Premorbid speech and language impairments in childhood-onset of schizophrenia: Association with risk factors. Am J Psychiatry. 2000, 157: 794-800. 10.1176/appi.ajp.157.5.794.CrossRefPubMed Nicolson R, Lenane M, Singaracharlu S: Premorbid speech and language impairments in childhood-onset of schizophrenia: Association with risk factors. Am J Psychiatry. 2000, 157: 794-800. 10.1176/appi.ajp.157.5.794.CrossRefPubMed
20.
go back to reference Hoff AL, Harris D, Faustman WO: A neuropsychological study of early onset schizophrenia. Schizophr Res. 1996, 20: 21-28. 10.1016/0920-9964(95)00065-8.CrossRefPubMed Hoff AL, Harris D, Faustman WO: A neuropsychological study of early onset schizophrenia. Schizophr Res. 1996, 20: 21-28. 10.1016/0920-9964(95)00065-8.CrossRefPubMed
21.
go back to reference Hollis O: Adult outcomes of child- and adolescent-onset schizophrenia: Diagnostic stability and predictive validity. Am J Psychiatry. 2000, 157: 1652-1659. 10.1176/appi.ajp.157.10.1652.CrossRefPubMed Hollis O: Adult outcomes of child- and adolescent-onset schizophrenia: Diagnostic stability and predictive validity. Am J Psychiatry. 2000, 157: 1652-1659. 10.1176/appi.ajp.157.10.1652.CrossRefPubMed
22.
go back to reference Goodwin FK, Jamison KR: Manic-depressive illness. 2007, New York: Oxford University Press, 2 Goodwin FK, Jamison KR: Manic-depressive illness. 2007, New York: Oxford University Press, 2
23.
go back to reference Maj M, Pirozzi R, Formicola AM, Bartoli P: Reliability and validity of the DSM-IV diagnostic category of schizoaffective disorder: preliminary data. J Affect Disord. 2000, 57: 95-98. 10.1016/S0165-0327(99)00059-2.CrossRefPubMed Maj M, Pirozzi R, Formicola AM, Bartoli P: Reliability and validity of the DSM-IV diagnostic category of schizoaffective disorder: preliminary data. J Affect Disord. 2000, 57: 95-98. 10.1016/S0165-0327(99)00059-2.CrossRefPubMed
24.
go back to reference Craddock N, O'Donovan MC, Owen MJ: Genes for schizophrenia and bipolar disorder ? Implications for psychiatric nosology. Schizophr Bull. 2006, 32: 9-16. 10.1093/schbul/sbj033.CrossRefPubMed Craddock N, O'Donovan MC, Owen MJ: Genes for schizophrenia and bipolar disorder ? Implications for psychiatric nosology. Schizophr Bull. 2006, 32: 9-16. 10.1093/schbul/sbj033.CrossRefPubMed
25.
go back to reference Ongur D, Lin L, Cohen BM: Clinical characteristics influencing age at onset in psychotic disorders. Compr Psychiatry. 2009, 50: 13-19. 10.1016/j.comppsych.2008.06.002.CrossRefPubMed Ongur D, Lin L, Cohen BM: Clinical characteristics influencing age at onset in psychotic disorders. Compr Psychiatry. 2009, 50: 13-19. 10.1016/j.comppsych.2008.06.002.CrossRefPubMed
26.
go back to reference Hollis C: Adolescent schizophrenia. Adv Psychiatry. 2000, 6: 83-92. 10.1192/apt.6.2.83.CrossRef Hollis C: Adolescent schizophrenia. Adv Psychiatry. 2000, 6: 83-92. 10.1192/apt.6.2.83.CrossRef
27.
go back to reference Marks KA, Fastenau PS, Lysaker PH, Bond GR: Self-Appraisal of Illness Questionnaire (SAIQ): relationship to researcher-rated insight and neuropsychological function in schizophrenia. Schizophr Res. 2000, 45: 203-211. 10.1016/S0920-9964(99)00208-X.CrossRefPubMed Marks KA, Fastenau PS, Lysaker PH, Bond GR: Self-Appraisal of Illness Questionnaire (SAIQ): relationship to researcher-rated insight and neuropsychological function in schizophrenia. Schizophr Res. 2000, 45: 203-211. 10.1016/S0920-9964(99)00208-X.CrossRefPubMed
28.
go back to reference Kay SR, Fiszbei A, Vital-Herne M, Silva-Fuentes L: The Positive and Negative Syndrome Scale-Spanish adaptation. J Ner Ment Dis. 1990, 178: 510-517.CrossRef Kay SR, Fiszbei A, Vital-Herne M, Silva-Fuentes L: The Positive and Negative Syndrome Scale-Spanish adaptation. J Ner Ment Dis. 1990, 178: 510-517.CrossRef
29.
go back to reference Evenden J: Impulsivity: a discussion of clinical and experimental findings. J Psychopharmacol. 1999, 13: 180-192. 10.1177/026988119901300211.CrossRefPubMed Evenden J: Impulsivity: a discussion of clinical and experimental findings. J Psychopharmacol. 1999, 13: 180-192. 10.1177/026988119901300211.CrossRefPubMed
30.
go back to reference Li CH, Ko HC, Weng LJ, Liau LC, Lu RB: The development of an impulsiveness scale: psychometric properties and related to antisocial personality disorder. Chinese J Psychol. 2002, 44 (1): 109-119. Li CH, Ko HC, Weng LJ, Liau LC, Lu RB: The development of an impulsiveness scale: psychometric properties and related to antisocial personality disorder. Chinese J Psychol. 2002, 44 (1): 109-119.
31.
go back to reference Beck AT, Steer RA: Manual for the Revised Beck Depression Inventory. San Antonio, Tex, Psychological Corp. 1987 Beck AT, Steer RA: Manual for the Revised Beck Depression Inventory. San Antonio, Tex, Psychological Corp. 1987
32.
go back to reference Beck AT, Epstein N, Brown G, Steer RA: An inventory for measuring clinical anxiety: Psychometric properties. J Consult Clin Psychol. 1988, 56: 893-897. 10.1037/0022-006X.56.6.893.CrossRefPubMed Beck AT, Epstein N, Brown G, Steer RA: An inventory for measuring clinical anxiety: Psychometric properties. J Consult Clin Psychol. 1988, 56: 893-897. 10.1037/0022-006X.56.6.893.CrossRefPubMed
33.
go back to reference Beck AT, Steer RA: Manual for the Beck Hopelessness Scale. 1988, San Antonio, Tex, Psychological Corp Beck AT, Steer RA: Manual for the Beck Hopelessness Scale. 1988, San Antonio, Tex, Psychological Corp
34.
go back to reference Beck AT, Kovacs M, Weissman A: Assessment of suicidal intent: the Scale for Suicide Ideation. J Consult Clin Psychol. 1979, 47: 343-352. 10.1037/0022-006X.47.2.343.CrossRefPubMed Beck AT, Kovacs M, Weissman A: Assessment of suicidal intent: the Scale for Suicide Ideation. J Consult Clin Psychol. 1979, 47: 343-352. 10.1037/0022-006X.47.2.343.CrossRefPubMed
35.
go back to reference WHOQOL-Taiwan Group: Development and manual of the World Health Organization WHOQOL-Taiwan quality of life assessment. 2001 WHOQOL-Taiwan Group: Development and manual of the World Health Organization WHOQOL-Taiwan quality of life assessment. 2001
36.
go back to reference Yao G, Chung CH, Yu CF, Wang JD: Development and verification of validity and reliability of the WHOQOL-BREF Taiwan version. J Formos Med Assoc. 2002, 101: 342-351.PubMed Yao G, Chung CH, Yu CF, Wang JD: Development and verification of validity and reliability of the WHOQOL-BREF Taiwan version. J Formos Med Assoc. 2002, 101: 342-351.PubMed
37.
go back to reference Motto: An integrated approach to estimating suicide risk. Assessment and Prediction of Suicide. Edited by: Maris R, Berman L, Maltzberger T, Yufit R. 1992, New York, Guilford Press, 635-639. Motto: An integrated approach to estimating suicide risk. Assessment and Prediction of Suicide. Edited by: Maris R, Berman L, Maltzberger T, Yufit R. 1992, New York, Guilford Press, 635-639.
38.
go back to reference Malla AK, Norman RMG, Manchanda R: One year outcome in first episode psychosis: influence of DUP and other predictors. Schizophr Res. 2002, 54: 231-242. 10.1016/S0920-9964(01)00254-7.CrossRefPubMed Malla AK, Norman RMG, Manchanda R: One year outcome in first episode psychosis: influence of DUP and other predictors. Schizophr Res. 2002, 54: 231-242. 10.1016/S0920-9964(01)00254-7.CrossRefPubMed
39.
go back to reference Eggers C: Schizoaffective psychoses in childhood: a follow-up study. J Autism Dev Disord. 1989, 19: 327-343. 10.1007/BF02211850.CrossRefPubMed Eggers C: Schizoaffective psychoses in childhood: a follow-up study. J Autism Dev Disord. 1989, 19: 327-343. 10.1007/BF02211850.CrossRefPubMed
40.
go back to reference Werry JS, McClellan JM: Predicting outcome in child and adolescent (early onset) schizophrenia and bipolar disorder. J Am Acad Child Adolesc Psychiatry. 1992, 31: 147-150. 10.1097/00004583-199201000-00022.CrossRefPubMed Werry JS, McClellan JM: Predicting outcome in child and adolescent (early onset) schizophrenia and bipolar disorder. J Am Acad Child Adolesc Psychiatry. 1992, 31: 147-150. 10.1097/00004583-199201000-00022.CrossRefPubMed
41.
42.
go back to reference Cowell PE, Kostianovsky DJ, Gur RC, Turetsky BI, Gur RE: Sex differences in neuroanatomical and clinical correlations in schizophrenia. Am J Psychiatry. 1996, 153: 799-805.CrossRefPubMed Cowell PE, Kostianovsky DJ, Gur RC, Turetsky BI, Gur RE: Sex differences in neuroanatomical and clinical correlations in schizophrenia. Am J Psychiatry. 1996, 153: 799-805.CrossRefPubMed
43.
go back to reference Leung A, Chue P: Sex differences in schizophrenia, a review of the literature. Acta Psychiatr. Scand Suppl. 2000, 401: 3-38. 10.1111/j.0065-1591.2000.0ap25.x. Leung A, Chue P: Sex differences in schizophrenia, a review of the literature. Acta Psychiatr. Scand Suppl. 2000, 401: 3-38. 10.1111/j.0065-1591.2000.0ap25.x.
44.
go back to reference Hoff A, Riordan MA, O'Donnell DW, Morris L, De Lisi le : Neuropsychological functioning of first episode schizophreniform patients. Am J Psychiatry. 1992, 149 (7): 898-903.CrossRefPubMed Hoff A, Riordan MA, O'Donnell DW, Morris L, De Lisi le : Neuropsychological functioning of first episode schizophreniform patients. Am J Psychiatry. 1992, 149 (7): 898-903.CrossRefPubMed
45.
go back to reference Suvisaari JM, Haukka J, Tanskanen A: Age at onset and outcome in schizophrenia are related to the degree of familial loading. Br J Psychiatry. 1998, 173: 494-500. 10.1192/bjp.173.6.494.CrossRefPubMed Suvisaari JM, Haukka J, Tanskanen A: Age at onset and outcome in schizophrenia are related to the degree of familial loading. Br J Psychiatry. 1998, 173: 494-500. 10.1192/bjp.173.6.494.CrossRefPubMed
46.
go back to reference Bell MD, Lysaker PH, Milstein RM, Beam-Goulet JL: Concurrent validity of the cognitive component of schizophrenia: Relationship of PANSS scores to neuropsychological assessments. Psychiatry Res. 1994, 54: 51-58. 10.1016/0165-1781(94)90064-7.CrossRefPubMed Bell MD, Lysaker PH, Milstein RM, Beam-Goulet JL: Concurrent validity of the cognitive component of schizophrenia: Relationship of PANSS scores to neuropsychological assessments. Psychiatry Res. 1994, 54: 51-58. 10.1016/0165-1781(94)90064-7.CrossRefPubMed
47.
go back to reference Heinrichs RW, Zakzanis KK: Neurocognitive deficit in schizophrenia: a quantitative review of the evidence. Neuropsychiatry. 1998, 12: 426-445. Heinrichs RW, Zakzanis KK: Neurocognitive deficit in schizophrenia: a quantitative review of the evidence. Neuropsychiatry. 1998, 12: 426-445.
48.
go back to reference Heaton RK, Gladsio JA, Palmer BW, Kuck J, Marcotte TD: Stability and course of neuropsychological deficits in schizophrenia. Arch Gen Psychiatry. 2001, 58: 24-32. 10.1001/archpsyc.58.1.24.CrossRefPubMed Heaton RK, Gladsio JA, Palmer BW, Kuck J, Marcotte TD: Stability and course of neuropsychological deficits in schizophrenia. Arch Gen Psychiatry. 2001, 58: 24-32. 10.1001/archpsyc.58.1.24.CrossRefPubMed
49.
go back to reference Iacono WG, Malone SM, McGue M: Substance use disorders, externalizing psychopathology, and P300 event-related potential amplitude. Int J Psychophysiol. 2003, 48 (2): 147-178. 10.1016/S0167-8760(03)00052-7.CrossRefPubMed Iacono WG, Malone SM, McGue M: Substance use disorders, externalizing psychopathology, and P300 event-related potential amplitude. Int J Psychophysiol. 2003, 48 (2): 147-178. 10.1016/S0167-8760(03)00052-7.CrossRefPubMed
50.
go back to reference Jeon YW, Polish J: Meta-analysis of P300 and schizophrenia: patients, paradigms, and practical implications. Psychopathology. 2003, 40 (5): 684-701. Jeon YW, Polish J: Meta-analysis of P300 and schizophrenia: patients, paradigms, and practical implications. Psychopathology. 2003, 40 (5): 684-701.
51.
go back to reference Cohen J: Statistical power analysis for the behavioural science. 1988, New York: Erlbaum Hillsdale, 2 Cohen J: Statistical power analysis for the behavioural science. 1988, New York: Erlbaum Hillsdale, 2
52.
go back to reference Howard R, Castle D, Wessely S, Murray R: A comparative study of 470 cases of early-onset and late-onset schizophrenia. Br J Psychiatry. 1993, 157: 172-178. Howard R, Castle D, Wessely S, Murray R: A comparative study of 470 cases of early-onset and late-onset schizophrenia. Br J Psychiatry. 1993, 157: 172-178.
53.
go back to reference Lay B, Blanz B, Hartmann M: The psychosocial outcome of adolescent-onset schizophrenia: a 12-year follow-up. Schizophr Bull. 2000, 26 (4): 801-816.CrossRefPubMed Lay B, Blanz B, Hartmann M: The psychosocial outcome of adolescent-onset schizophrenia: a 12-year follow-up. Schizophr Bull. 2000, 26 (4): 801-816.CrossRefPubMed
54.
go back to reference Schultz SK, Ho BC, Andreasen NC: Clinical features characterizing young-onset and intermediate-onset schizophrenia. J Neuropsychiatry Clin Neurosci. 2000, 12: 502-505.CrossRefPubMed Schultz SK, Ho BC, Andreasen NC: Clinical features characterizing young-onset and intermediate-onset schizophrenia. J Neuropsychiatry Clin Neurosci. 2000, 12: 502-505.CrossRefPubMed
55.
go back to reference Atkinson M, Zibin S, Chuang H: Characterizing quality of life among patients with chronic mental illness: a critical examination of the self-report methodology. Am J Psychiatry. 1996, 154: 99-105. Atkinson M, Zibin S, Chuang H: Characterizing quality of life among patients with chronic mental illness: a critical examination of the self-report methodology. Am J Psychiatry. 1996, 154: 99-105.
56.
go back to reference Voruganti L, Heslegrave R, Awad AG, Seeman MV: Quality of life measurement in schizophrenia: reconciling the quest for subjectivity with the question of reliability. Psychol Med. 1998, 28: 165-172. 10.1017/S0033291797005874.CrossRefPubMed Voruganti L, Heslegrave R, Awad AG, Seeman MV: Quality of life measurement in schizophrenia: reconciling the quest for subjectivity with the question of reliability. Psychol Med. 1998, 28: 165-172. 10.1017/S0033291797005874.CrossRefPubMed
57.
go back to reference Hafner H: Onset and early course as determinants of the further course of schizophrenia. Acta Psychiatr Scand. 2000, 102: 44-48. 10.1034/j.1600-0447.2000.00008.x.CrossRef Hafner H: Onset and early course as determinants of the further course of schizophrenia. Acta Psychiatr Scand. 2000, 102: 44-48. 10.1034/j.1600-0447.2000.00008.x.CrossRef
58.
go back to reference Bender S, Muller B, Oades RD: Conditioned blocking and schizophrenia, a replication and study of the role of symptoms, age, onset-age of psychosis and illness-duration. Schizophr Res. 2001, 49: 157-170. 10.1016/S0920-9964(00)00040-2.CrossRefPubMed Bender S, Muller B, Oades RD: Conditioned blocking and schizophrenia, a replication and study of the role of symptoms, age, onset-age of psychosis and illness-duration. Schizophr Res. 2001, 49: 157-170. 10.1016/S0920-9964(00)00040-2.CrossRefPubMed
59.
go back to reference Larsen EB, Gerlach J: Subjective experience of treatment, side-effects, mental state and quality of life in schizophrenic outpatients treated with depot neuroleptics. Acta Psychiatr Scand. 1996, 96: 381-388. 10.1111/j.1600-0447.1996.tb10664.x.CrossRef Larsen EB, Gerlach J: Subjective experience of treatment, side-effects, mental state and quality of life in schizophrenic outpatients treated with depot neuroleptics. Acta Psychiatr Scand. 1996, 96: 381-388. 10.1111/j.1600-0447.1996.tb10664.x.CrossRef
60.
go back to reference Howard R, Rabins PV, Seeman MV, Jeste DV: International Late-Onset Schizophrenia Group. Late-onset schizophrenia and very late-onset schizophrenia-like psychosis: an international consensus. Am J Psychiatry. 2000, 157: 172-178. 10.1176/appi.ajp.157.2.172.CrossRefPubMed Howard R, Rabins PV, Seeman MV, Jeste DV: International Late-Onset Schizophrenia Group. Late-onset schizophrenia and very late-onset schizophrenia-like psychosis: an international consensus. Am J Psychiatry. 2000, 157: 172-178. 10.1176/appi.ajp.157.2.172.CrossRefPubMed
61.
go back to reference Larsen TK, Joahnnessen JO, Opjordsmoen S: First-episode schizophrenia with long duration of untreated psychosis. Pathway to care. Br J Psychiatry. 1998, 172 (33): 45-52. Larsen TK, Joahnnessen JO, Opjordsmoen S: First-episode schizophrenia with long duration of untreated psychosis. Pathway to care. Br J Psychiatry. 1998, 172 (33): 45-52.
Metadata
Title
Effects of age of onset on clinical characteristics in schizophrenia spectrum disorders
Authors
Yu-Chen Kao
Yia-Ping Liu
Publication date
01-12-2010
Publisher
BioMed Central
Published in
BMC Psychiatry / Issue 1/2010
Electronic ISSN: 1471-244X
DOI
https://doi.org/10.1186/1471-244X-10-63

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