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Cognitive behavioural therapy for psychosis prevention: a systematic review and meta-analysis

Published online by Cambridge University Press:  22 March 2013

P. Hutton  and
P. J. Taylor
P. Hutton*
Affiliation:
Greater Manchester West Mental Health NHS Foundation Trust, UK University of Manchester, UK
P. J. Taylor
Affiliation:
University of Manchester, UK
*
*Address for correspondence: Dr P. Hutton, Psychosis Research Unit, Psychology Department, Greater Manchester West Mental Health NHS Foundation Trust, Bury New Road, Prestwich, Manchester M25 3BL, UK. (Email: paulhutton@nhs.net)
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Abstract

Background

Clinical equipoise regarding preventative treatments for psychosis has encouraged the development and evaluation of psychosocial treatments, such as cognitive behavioural therapy (CBT).

Method

A systematic review and meta-analysis was conducted, examining the evidence for the effectiveness of CBT-informed treatment for preventing psychosis in people who are not taking antipsychotic medication, when compared to usual or non-specific control treatment. Included studies had to meet basic quality criteria, such as concealed and random allocation to treatment groups.

Results

Our search produced 1940 titles, out of which we found seven completed trials (six published). The relative risk (RR) of developing psychosis was reduced by more than 50% for those receiving CBT at every time point [RR at 6 months 0.47, 95% confidence interval (CI) 0.27–0.82, p = 0.008 (fixed-effects only: six randomized controlled trials (RCTs), n = 800); RR at 12 months 0.45, 95% CI 0.28–0.73, p = 0.001 (six RCTs, n = 800); RR at 18–24 months 0.41, 95% CI 0.23–0.72, p = 0.002 (four RCTs, n = 452)]. Heterogeneity was low in every analysis and the results were largely robust to the risk of an unpublished 12-month study having unfavourable results. CBT was also associated with reduced subthreshold symptoms at 12 months, but not at 6 or 18–24 months. No effects on functioning, symptom-related distress or quality of life were observed. CBT was not associated with increased rates of clinical depression or social anxiety (two studies).

Conclusions

CBT-informed treatment is associated with a reduced risk of transition to psychosis at 6, 12 and 18–24 months, and reduced symptoms at 12 months. Methodological limitations and recommendations for trial reporting are discussed.

Keywords

At-risk mental statecognitive behavioural therapyprodromal psychosissubthreshold symptoms
Type
Review Article
Information
Psychological Medicine , Volume 44 , Issue 3 , February 2014 , pp. 449 - 468
Copyright
Copyright © Cambridge University Press 2013 

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References

Adams, CE, Awad, G, Rathbone, J, Thornley, B (2007). Chlorpromazine versus placebo for schizophrenia. Cochrane Database of Systematic Reviews. Issue 18, Art. No. CD000284.Google Scholar
Addington, J, Epstein, I, Liu, L, French, P, Boydell, KM, Zipursky, RB (2011). A randomized controlled trial of cognitive behavioral therapy for individuals at clinical high risk of psychosis. Schizophrenia Research 125, 54–61.Google Scholar
Amminger, GP, Schafer, MR, Papageorgiou, K, Klier, CM, Cotton, SM, Harrigan, SM, Mackinnon, A, McGorry, PD, Berger, GE (2010). Long-chain omega-3 fatty acids for indicated prevention of psychotic disorders: a randomized, placebo-controlled trial. Archives of General Psychiatry 67, 146–154.Google Scholar
Bechdolf, A, Müller, H, Stützer, H, Wagner, M, Maier, W, Lautenschlager, M, Heinz, A, de Millas, W, Janssen, B, Gaebel, W, Michel, TM, Schneider, F, Lambert, M, Naber, D, Brüne, M, Krüger-Özgürdal, S, Wobrock, T, Riedel, M, Klosterkötter, J; PREVENT study group (2011). Rationale and baseline characteristics of PREVENT: a second-generation intervention trial in subjects at-risk (prodromal) of developing first-episode psychosis evaluating cognitive behavior therapy, aripiprazole, and placebo for the prevention of psychosis. Schizophrenia Bulletin 37 (Suppl. 2), S111–S121.Google Scholar
Bechdolf, A, Puetzfeld, V, Gross, S, Guettgemanns, J (2010). Cognitive Behavioural Therapy in People at Risk of Psychosis. Huber: Bern, Switzerland.Google Scholar
Bechdolf, A, Wagner, M, Ruhrmann, S, Harrigan, S, Putzfeld, V, Pukrop, R, Brockhaus-Dumke, A, Berning, J, Janssen, B, Decker, P, Bottlender, R, Maurer, K, Moller, HJ, Gaebel, W, Hafner, H, Maier, W, Klosterkotter, J (2012). Preventing progression to first-episode psychosis in early initial prodromal states. British Journal of Psychiatry 200, 22–29.Google Scholar
Bechdolf, A, Wagner, M, Veith, V, Ruhrmann, S, Pukrop, R, Brockhaus-Dumke, A, Berning, J, Stamm, E, Janssen, B, Decker, P, Bottlender, R, Moller, HJ, Gaebel, W, Maier, W, Klosterkotter, J (2007). Randomized controlled multicentre trial of cognitive behaviour therapy in the early initial prodromal state: effects on social adjustment post treatment. Early Intervention in Psychiatry 1, 71–78.Google Scholar
Beck, AT, Grant, PM, Huh, GA, Perivoliotis, D, Chang, NA (2013). Dysfunctional attitudes and expectancies in deficit syndrome schizophrenia. Schizophrenia Bulletin 39, 43–51.CrossRefGoogle ScholarPubMed
Bentall, RP, Morrison, AP (2002). More harm than good: the case against using antipsychotic drugs to prevent severe mental illness. Journal of Mental Health 11, 351–365.Google Scholar
Bowie, CR, McLaughlin, D, Carrion, RE, Auther, AM, Cornblatt, BA (2012). Cognitive changes following antidepressant or antipsychotic treatment in adolescents at clinical risk for psychosis. Schizophrenia Research 137, 110–117.Google Scholar
Broome, MR, Woolley, JB, Johns, LC, Valmaggia, LR, Tabraham, P, Gafoor, R, Bramon, E, McGuire, PK (2005). Outreach and support in south London (OASIS): implementation of a clinical service for prodromal psychosis and the at risk mental state. European Psychiatry 20, 372–378.CrossRefGoogle ScholarPubMed
Bushe, CJ (2011). Systematic reviews – a perspective on benefits and concerns in 2011. Safe, sound and sorted? International Journal of Clinical Practice 65, 921–922.Google Scholar
Carpenter, WT (2009). Anticipating DSM-V: should psychosis risk become a diagnostic class? Schizophrenia Bulletin 35, 841–843.Google Scholar
Carpenter, WT, van Os, J (2011). Should attenuated psychosis syndrome be a DSM-5 diagnosis? American Journal of Psychiatry 168, 460–463.Google Scholar
Chuma, J, Mahadun, P (2011). Predicting the development of schizophrenia in high-risk populations: systematic review of the predictive validity of prodromal criteria. British Journal of Psychiatry 199, 361–366.CrossRefGoogle ScholarPubMed
Corcoran, CM, First, MB, Cornblatt, B (2010). The psychosis risk syndrome and its proposed inclusion in the DSM-V: a risk-benefit analysis. Schizophrenia Research 120, 16–22.CrossRefGoogle ScholarPubMed
Dubitsky, GM, Harris, R, Laughren, T, Hardeman, S (2002). Abilify (aripiprazole) tablets, medical review. US Food and Drug Administration Centre for Drug Evaluation and Research. (http://www.accessdata.fda.gov/drugsatfda_docs/nda/2002/21-436_Abilify.cfm). Accessed 17 June 2010.Google Scholar
Faber, G, Smid, HG, van Gool, AR, Wiersma, D, van den Bosch, RJ (2012). The effects of guided discontinuation of antipsychotics on neurocognition in first onset psychosis. European Psychiatry 27, 275–280.Google Scholar
French, P, Morrison, AP (2004). Early Detection and Cognitive Therapy for People at High Risk of Developing Psychosis: A Treatment Approach. Wiley: London.CrossRefGoogle Scholar
French, P, Morrison, AP, Walford, L, Knight, A, Bentall, RP (2003). Cognitive therapy for preventing transition to psychosis in high risk individuals: a case series. Behavioural and Cognitive Psychotherapy 31, 53–68.Google Scholar
Fusar-Poli, P, Bonoldi, I, Yung, AR, Borgwardt, S, Kempton, MJ, Valmaggia, L, Barale, F, Caverzasi, E, McGuire, P (2012 a). Predicting psychosis: meta-analysis of transition outcomes in individuals at high clinical risk. Archives of General Psychiatry 69, 220–229.Google Scholar
Fusar-Poli, P, Byrne, M, Badger, S, Valmaggia, LR, McGuire, PK (2012 b). Outreach and support in South London (OASIS), 2001–2011: ten years of early diagnosis and treatment for young individuals at high clinical risk for psychosis. European Psychiatry. Published online: 5 11 2012 . doi:10.1016/j.eurpsy.2012.08.002.Google Scholar
Fusar-Poli, P, Yung, AR (2012). Should attenuated psychosis syndrome be included in DSM-5? Lancet 379, 591–592.Google Scholar
Grant, PM, Beck, AT (2009). Defeatist beliefs as a mediator of cognitive impairment, negative symptoms, and functioning in schizophrenia. Schizophrenia Bulletin 35, 798–806.CrossRefGoogle ScholarPubMed
Grant, PM, Huh, GA, Perivoliotis, D, Stolar, NM, Beck, AT (2012). Randomized trial to evaluate the efficacy of cognitive therapy for low-functioning patients with schizophrenia. Archives of General Psychiatry 69, 121–127.Google Scholar
Haefner, H, Bechdolf, A, Klosterkoetter, J, Maurer, K (2011). Early Detection and Intervention in Psychosis. A Practice Handbook. Schattauer: Stuttgart.Google Scholar
Hamer, RM, Simpson, PM (2009). Last observation carried forward versus mixed models in the analysis of psychiatric clinical trials. American Journal of Psychiatry 166, 639–641.CrossRefGoogle ScholarPubMed
Higgins, JP, Altman, DG, Gotzsche, PC, Juni, P, Moher, D, Oxman, AD, Savovic, J, Schulz, KF, Weeks, L, Sterne, JA (2011 a). The Cochrane Collaboration's tool for assessing risk of bias in randomised trials. British Medical Journal 343, d5928.Google Scholar
Higgins, JPT, Green, S (eds) (2011 b). Cochrane Handbook for Systematic Reviews of Interventions. The Cochrane Collaboration, 2011 (www.cochrane-handbook.org).Google Scholar
Ho, BC, Andreasen, NC, Ziebell, S, Pierson, R, Magnotta, V (2011). Long-term antipsychotic treatment and brain volumes: a longitudinal study of first-episode schizophrenia. Archives of General Psychiatry 68, 128–137.CrossRefGoogle ScholarPubMed
Hutton, P (2012). Cognitive behavioural therapy for people at high-risk of developing psychosis and not taking antipsychotic medication: a systematic review and exploratory meta-analysis. PROSPERO 2012:CRD42012002260 (www.crd.york.ac.uk/PROSPERO/display_record.asp?ID=CRD42012002260).Google Scholar
Hutton, P, Bowe, S, Parker, S, Ford, S (2011). Prevalence of suicide risk factors in people at ultra-high risk of developing psychosis: a service audit. Early Intervention in Psychiatry 5, 375–380.Google Scholar
Ioannidis, JP, Evans, SJ, Gotzsche, PC, O'Neill, RT, Altman, DG, Schulz, K, Moher, D (2004). Better reporting of harms in randomized trials: an extension of the CONSORT statement. Annals of Internal Medicine 141, 781–788.Google Scholar
Ioannidis, JP, Trikalinos, TA (2007). The appropriateness of asymmetry tests for publication bias in meta-analyses: a large survey. Canadian Medical Association Journal 176, 1091–1096.Google Scholar
Joy, CB, Adams, CE, Lawrie, SM (2006). Haloperidol versus placebo for schizophrenia. Cochrane Database of Systematic Reviews. Issue 18, Art. No. CD003082.Google Scholar
Klingberg, S, Herrlich, J, Wiedemann, G, Wolwer, W, Meisner, C, Engel, C, Jakobi-Malterre, UE, Buchkremer, G, Wittorf, A (2012). Adverse effects of cognitive behavioral therapy and cognitive remediation in schizophrenia: results of the treatment of negative symptoms study. Journal of Nervous and Mental Disease 200, 569–576.Google Scholar
Klingberg, S, Wittorf, A, Meisner, C, Wolwer, W, Wiedemann, G, Herrlich, J, Bechdolf, A, Muller, BW, Sartory, G, Wagner, M, Kircher, T, Konig, HH, Engel, C, Buchkremer, G (2010). Cognitive behavioural therapy versus supportive therapy for persistent positive symptoms in psychotic disorders: the POSITIVE Study, a multicenter, prospective, single-blind, randomised controlled clinical trial. Trials 11, 123.CrossRefGoogle ScholarPubMed
Klosterkotter, J, Ruhrmann, S, Schultze-Lutter, F, Salokangas, RK, Linszen, D, Birchwood, M, Juckel, G, Morrison, A, Vazquez-Barquero, JL, Hambrecht, M, von Reventlow, H (2005). The European Prediction of Psychosis Study (EPOS): integrating early recognition and intervention in Europe. World Psychiatry 4, 161–167.Google ScholarPubMed
Leucht, S, Arbter, D, Engel, RR, Kissling, W, Davis, JM (2009). How effective are second-generation antipsychotic drugs? A meta-analysis of placebo-controlled trials. Molecular Psychiatry 14, 429–447.Google Scholar
Leucht, S, Heres, S, Hamann, J, Kane, JM (2008). Methodological issues in current antipsychotic drug trials. Schizophrenia Bulletin 34, 275–285.Google Scholar
Leucht, S, Hierl, S, Kissling, W, Dold, M, Davis, JM (2012). Putting the efficacy of psychiatric and general medicine medication into perspective: review of meta-analyses. British Journal of Psychiatry 200, 97–106.CrossRefGoogle ScholarPubMed
Lingjaerde, O, Ahlfors, UG, Bech, P, Dencker, SJ, Elgen, K (1987). The UKU side effect rating scale. A new comprehensive rating scale for psychotropic drugs and a cross-sectional study of side effects in neuroleptic-treated patients. Acta Psychiatrica Scandinavica. Supplementum 334, 1–100.CrossRefGoogle Scholar
Mallett, S, Clarke, M (2002). The typical Cochrane review. How many trials? How many participants? International Journal of Technology Assessment in Health Care 18, 820–823.Google Scholar
Marshall, M, Rathbone, J (2011). Early intervention for psychosis. Cochrane Database of Systematic Reviews. Issue 15, Art. No. CD004718.CrossRefGoogle Scholar
McGlashan, TH, Zipursky, RB, Perkins, D, Addington, J, Miller, T, Woods, SW, Hawkins, KA, Hoffman, RE, Preda, A, Epstein, I, Addington, D, Lindborg, S, Trzaskoma, Q, Tohen, M, Breier, A (2006). Randomized, double-blind trial of olanzapine versus placebo in patients prodromally symptomatic for psychosis. American Journal of Psychiatry 163, 790–799.Google Scholar
McGlashan, TH, Zipursky, RB, Perkins, D, Addington, J, Miller, TJ, Woods, SW, Hawkins, KA, Hoffman, R, Lindborg, S, Tohen, M, Breier, A (2003). The PRIME North America randomized double-bind clinical trial of olanzapine versus placebo in patients at risk of being prodromally symptomatic for psychosis. I. Study rationale and design. Schizophrenia Research 61, 7–18.Google Scholar
McGorry, PD, Hickie, IB, Yung, AR, Pantelis, C, Jackson, HJ (2006). Clinical staging of psychiatric disorders: a heuristic framework for choosing earlier, safer and more effective interventions. Australian and New Zealand Journal of Psychiatry 40, 616–622.Google Scholar
McGorry, PD, Nelson, B, Phillips, LJ, Yuen, HP, Francey, SM, Thampi, A, Berger, GE, Amminger, GP, Simmons, MB, Kelly, D, Thompson, AD, Yung, AR (2012). Randomized controlled trial of interventions for young people at ultra-high risk of psychosis: twelve-month outcome. Journal of Clinical Psychiatry. Published online: 27 11 2012 . doi:10.4088/JCP.12m07785.CrossRefGoogle Scholar
McGorry, PD, Yung, AR, Phillips, LJ, Yuen, HP, Francey, S, Cosgrave, EM, Germano, D, Bravin, J, McDonald, T, Blair, A, Adlard, S, Jackson, H (2002). Randomized controlled trial of interventions designed to reduce the risk of progression to first-episode psychosis in a clinical sample with subthreshold symptoms. Archives of General Psychiatry 59, 921–928.Google Scholar
Miller, TJ, McGlashan, TH, Rosen, JL, Cadenhead, K, Cannon, T, Ventura, J, McFarlane, W, Perkins, DO, Pearlson, GD, Woods, SW (2003 a). Prodromal assessment with the structured interview for prodromal syndromes and the scale of prodromal symptoms: predictive validity, interrater reliability, and training to reliability. Schizophrenia Bulletin 29, 703–715.Google Scholar
Miller, TJ, Zipursky, RB, Perkins, D, Addington, J, Woods, SW, Hawkins, KA, Hoffman, R, Preda, A, Epstein, I, Addington, D, Lindborg, S, Marquez, E, Tohen, M, Breier, A, McGlashan, TH (2003 b). The PRIME North America randomized double-blind clinical trial of olanzapine versus placebo in patients at risk of being prodromally symptomatic for psychosis. II. Baseline characteristics of the ‘prodromal’ sample. Schizophrenia Research 61, 19–30.Google Scholar
Mitchell, AJ, Vancampfort, D, de Herdt, A, Yu, W, de Hert, M (2012). Is the prevalence of metabolic syndrome and metabolic abnormalities increased in early schizophrenia? A comparative meta-analysis of first episode, untreated and treated patients. Schizophrenia Bulletin. Published online: 27 08 2012 . doi:10.1093/schbul/sbs082.CrossRefGoogle Scholar
Miyar, J, Adams, CE (2012). Content and quality of 10,000 controlled trials in schizophrenia over 60 years. Schizophrenia Bulletin 39, 226–229.Google Scholar
Moncrieff, J, Leo, J (2010). A systematic review of the effects of antipsychotic drugs on brain volume. Psychological Medicine 40, 1409–1422.Google Scholar
Morrison, AP, Barratt, S (2010). What are the components of CBT for psychosis? A Delphi study. Schizophrenia Bulletin 36, 136–142.Google Scholar
Morrison, AP, Bentall, RP, French, P, Walford, L, Kilcommons, A, Knight, A, Kreutz, M, Lewis, SW (2002). Randomised controlled trial of early detection and cognitive therapy for preventing transition to psychosis in high-risk individuals. Study design and interim analysis of transition rate and psychological risk factors. British Journal of Psychiatry. Supplement 43, s78–s84.Google Scholar
Morrison, AP, Byrne, R, Bentall, RP (2010). DSM-V and the psychosis risk syndrome: whose best interests would it serve? Psychosis 2, 96–99.CrossRefGoogle Scholar
Morrison, AP, French, P, Parker, S, Roberts, M, Stevens, H, Bentall, RP, Lewis, SW (2007). Three-year follow-up of a randomized controlled trial of cognitive therapy for the prevention of psychosis in people at ultrahigh risk. Schizophrenia Bulletin 33, 682–687.Google Scholar
Morrison, AP, French, P, Stewart, SL, Birchwood, M, Fowler, D, Gumley, AI, Jones, PB, Bentall, RP, Lewis, SW, Murray, GK, Patterson, P, Brunet, K, Conroy, J, Parker, S, Reilly, T, Byrne, R, Davies, LM, Dunn, G (2012 a). Early detection and intervention evaluation for people at risk of psychosis: multisite randomised controlled trial. British Medical Journal 344, e2233.CrossRefGoogle ScholarPubMed
Morrison, AP, French, P, Walford, L, Lewis, SW, Kilcommons, A, Green, J, Parker, S, Bentall, RP (2004). Cognitive therapy for the prevention of psychosis in people at ultra-high risk: randomised controlled trial. British Journal of Psychiatry 185, 291–297.Google Scholar
Morrison, AP, Hutton, P, Shiers, D, Turkington, D (2012 b). Antipsychotics: is it time to introduce patient choice? British Journal of Psychiatry 201, 83–84.CrossRefGoogle ScholarPubMed
Morrison, AP, Stewart, SL, French, P, Bentall, RP, Birchwood, M, Byrne, R, Davies, LM, Fowler, D, Gumley, AI, Jones, PB, Lewis, SW, Murray, GK, Patterson, P, Dunn, G (2011). Early detection and intervention evaluation for people at high-risk of psychosis-2 (EDIE-2): trial rationale, design and baseline characteristics. Early Intervention in Psychiatry 5, 24–32.Google Scholar
NICE (2009). Schizophrenia: Core Interventions in the Treatment and Management of Schizophrenia in Adults in Primary Care and Secondary Care. NICE Clinical Guideline CG82. National Institute for Health and Clinical Excellence (http://publications.nice.org.uk/schizophrenia-cg82).Google Scholar
Nieman, DH, Rike, WH, Becker, HE, Dingemans, PM, van Amelsvoort, TA, de Haan, L, van der Gaag, M, Denys, DA, Linszen, DH (2009). Prescription of antipsychotic medication to patients at ultra high risk of developing psychosis. International Journal of Clinical Psychopharmacology 24, 223–228.Google Scholar
Niemeyer, H, Musch, J, Pietrowsky, R (2012). Publication bias in meta-analyses of the efficacy of psychotherapeutic interventions for schizophrenia. Schizophrenia Research 138, 103–112.Google Scholar
O'Brien, MP, Zinberg, JL, Bearden, CE, Daley, M, Niendam, TA, Kopelowicz, A, Cannon, TD (2007). Psychoeducational multi-family group treatment with adolescents at high risk for developing psychosis. Early Intervention in Psychiatry 1, 325–332.Google Scholar
Perlis, RH, Ostacher, M, Fava, M, Nierenberg, AA, Sachs, GS, Rosenbaum, JF (2010). Assuring that double-blind is blind. American Journal of Psychiatry 167, 250–252.Google Scholar
Phillips, LJ, Nelson, B, Yuen, HP, Francey, SM, Simmons, M, Stanford, C, Ross, M, Kelly, D, Baker, K, Conus, P, Amminger, P, Trumpler, F, Yun, Y, Lim, M, McNab, C, Yung, AR, McGorry, PD (2009). Randomized controlled trial of interventions for young people at ultra-high risk of psychosis: study design and baseline characteristics. Australian and New Zealand Journal of Psychiatry 43, 818–829.Google Scholar
Preti, A, Cella, M (2010). Randomized-controlled trials in people at ultra high risk of psychosis: a review of treatment effectiveness. Schizophrenia Research 123, 30–36.Google Scholar
Radua, J, Borgwardt, S, Crescini, A, Mataix-Cols, D, Meyer-Lindenberg, A, McGuire, PK, Fusar-Poli, P (2012). Multimodal meta-analysis of structural and functional brain changes in first episode psychosis and the effects of antipsychotic medication. Neuroscience and Biobehavioral Reviews 36, 2325–2333.Google Scholar
Rietdijk, J, Dragt, S, Klaassen, R, Ising, H, Nieman, D, Wunderink, L, Delespaul, P, Cuijpers, P, Linszen, D, van der Gaag, M (2010). A single blind randomized controlled trial of cognitive behavioural therapy in a help-seeking population with an At Risk Mental State for psychosis: the Dutch Early Detection and Intervention Evaluation (EDIE-NL) trial. Trials 11, 30.Google Scholar
Schlosser, DA, Miklowitz, DJ, O'Brien, MP, De Silva, SD, Zinberg, JL, Cannon, TD (2011). A randomized trial of family focused treatment for adolescents and young adults at risk for psychosis: study rationale, design and methods. Early Intervention in Psychiatry 6, 283–291.Google Scholar
Schulz, KF, Chalmers, I, Hayes, RJ, Altman, DG (1995). Empirical evidence of bias. Dimensions of methodological quality associated with estimates of treatment effects in controlled trials. Journal of the American Medical Association 273, 408–412.Google Scholar
Schulz, KF, Grimes, DA (2002). Sample size slippages in randomised trials: exclusions and the lost and wayward. Lancet 359, 781–785.Google Scholar
Thornley, B, Adams, C (1998). Content and quality of 2000 controlled trials in schizophrenia over 50 years. British Medical Journal 317, 1181–1184.Google Scholar
Tost, H, Braus, DF, Hakimi, S, Ruf, M, Vollmert, C, Hohn, F, Meyer-Lindenberg, A (2010). Acute D2 receptor blockade induces rapid, reversible remodeling in human cortical-striatal circuits. Nature Reviews Neuroscience 13, 920–922.Google Scholar
Valentine, JC, Pigott, TD, Rothstein, HR (2010). How many studies do you need? A primer on statistical power for meta-analysis. Journal of Educational and Behavioural Statistics 35, 215–247.Google Scholar
van der Gaag, M, Nieman, D, Wunderink, L, Klaassen, R, Rietdijk, J, Dragt, S, Ising, H, Linszen, D (2012 b). The results of a specific CBT intervention in young help-seeking patients with social decline and an ultra-high risk for developing a first episode of psychosis. [Abstracts of the 3rd Biennial Schizophrenia International Research Conference]. Schizophrenia Research 136 (Suppl. 1), S17.Google Scholar
van der Gaag, M, Nieman, DH, Rietdijk, J, Dragt, S, Ising, HK, Klaassen, RM, Koeter, M, Cuijpers, P, Wunderink, L, Linszen, DH (2012 a). Cognitive behavioral therapy for subjects at ultrahigh risk for developing psychosis: a randomized controlled clinical trial. Schizophrenia Bulletin 38, 1180–1188.Google Scholar
Woods, SW, Walsh, BC, Saksa, JR, McGlashan, TH (2010). The case for including Attenuated Psychotic Symptoms Syndrome in DSM-5 as a psychosis risk syndrome. Schizophrenia Research 123, 199–207.Google Scholar
Xia, J, Adams, CE, Bhagat, N, Bhagat, V, Bhoopathi, P, El-Sayeh, H, Pinfold, V, Takriti, Y (2009). Losing participants before the end of the trial erodes credibility of findings. Psychiatric Bulletin 33, 254–257.Google Scholar
Yung, A, McGorry, PD, McFarlane, CA, Jackson, H, Patton, GC, Rakkar, A (1996 a). Monitoring and care of young people at incipient risk of psychosis. Schizophrenia Bulletin 22, 283–303.Google Scholar
Yung, A, Phillips, LB, McGorry, PD (2004). Treating Schizophrenia in the Prodromal Phase. Taylor & Francis: London.Google Scholar
Yung, AR, McGorry, PD, McFarlane, CA, Jackson, HJ, Patton, GC, Rakkar, A (1996 b). Monitoring and care of young people at incipient risk of psychosis. Schizophrenia Bulletin 22, 283–303.Google Scholar
Yung, AR, Nelson, B, Thompson, AD, Wood, SJ (2010). Should a ‘Risk Syndrome for Psychosis’ be included in the DSMV? Schizophrenia Research 120, 7–15.CrossRefGoogle ScholarPubMed
Yung, AR, Phillips, LJ, Nelson, B, Francey, SM, PanYuen, H, Simmons, MB, Ross, ML, Kelly, D, Baker, K, Amminger, GP, Berger, G, Thompson, AD, Thampi, A, McGorry, PD (2011). Randomized controlled trial of interventions for young people at ultra high risk for psychosis: 6-month analysis. Journal of Clinical Psychiatry 72, 430–440.Google Scholar
Yung, AR, Yuen, HP, McGorry, PD, Phillips, LJ, Kelly, D, Dell'Olio, M, Francey, SM, Cosgrave, EM, Killackey, E, Stanford, C, Godfrey, K, Buckby, J (2005). Mapping the onset of psychosis: the Comprehensive Assessment of At-Risk Mental States. Australian and New Zealand Journal of Psychiatry 39, 964–971.Google Scholar
Zimbrón, J, Ruiz de Azúa, S, Khandaker, GM, Gandamaneni, PK, Crane, CM, González-Pinto, A, Stochl, J, Jones, PB, Pérez, J (2012). Clinical and sociodemographic comparison of people at high-risk for psychosis and with first-episode psychosis. Acta Psychiatrica Scandinavica. Published online: 20 08 2012 . doi:10.1111/acps.12000.Google Scholar