About this Journal Submit a Manuscript Table of Contents
BioMed Research International
Volume 2013 (2013), Article ID 819587, 8 pages
http://dx.doi.org/10.1155/2013/819587
Review Article

Neurocognitive Functioning in Schizophrenia and during the Early Phases of Psychosis: Targeting Cognitive Remediation Interventions

1Department of Outpatient Psychiatry and Organization of Psychiatric Care, Moscow Research Institute of Psychiatry, Poteshnaya Street 3, Moscow 107076, Russia
2Lomonosov Moscow State University, Mokhovaya Street 11-9, Moscow 125009, Russia
3Department of Psychiatry, Clare College, University of Cambridge and South Essex Partnership University Foundation Trust, Weller Wing Bedford Hospital, Kempston Road, Bedford MK42 9DJ, UK

Received 30 April 2013; Revised 17 July 2013; Accepted 5 August 2013

Academic Editor: Margaret A. Niznikiewicz

Copyright © 2013 Yulia Zaytseva et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Linked References

  1. E. Kraepelin, Dementia Praecox and Paraphrenia, E & S Livingston, Edinburgh, UK, 1919.
  2. R. W. Heinrichs and K. K. Zakzanis, “Neurocognitive deficit in schizophrenia: a quantitative review of the evidence,” Neuropsychology, vol. 12, no. 3, pp. 426–445, 1998. View at Publisher · View at Google Scholar · View at Scopus
  3. R. M. Bilder, R. S. Goldman, D. Robinson et al., “Neuropsychology of first-episode schizophrenia: initial characterization and clinical correlates,” American Journal of Psychiatry, vol. 157, no. 4, pp. 549–559, 2000. View at Publisher · View at Google Scholar · View at Scopus
  4. A. L. Hoff, H. Riordan, D. W. O'Donnell, L. Morris, and L. E. DeLisi, “Neuropsychological functioning of first-episode schizophreniform patients,” American Journal of Psychiatry, vol. 149, no. 7, pp. 898–903, 1992. View at Scopus
  5. T. D. Cannon, C. E. Bearden, J. M. Hollister, I. M. Rosso, L. E. Sanchez, and T. Hadley, “Childhood cognitive functioning in schizophrenia patients and their unaffected siblings: a prospective cohort study,” Schizophrenia Bulletin, vol. 26, no. 2, pp. 379–393, 2000. View at Scopus
  6. S. V. Faraone, L. J. Seidman, R. Toomey, W. S. Kremen, J. R. Pepple, and M. T. Tsuang, “Neuropsychological functioning among the nonpsychotic relatives of schizophrenic patients: a 4-year follow-up study,” Journal of Abnormal Psychology, vol. 108, no. 1, pp. 176–181, 1999. View at Publisher · View at Google Scholar · View at Scopus
  7. N. C. Andreasen, P. Nopoulos, D. S. O'Leary, D. D. Miller, T. Wassink, and M. Flaum, “Defining the phenotype of schizophrenia: cognitive dysmetria and its neural mechanisms,” Biological Psychiatry, vol. 46, no. 7, pp. 908–920, 1999. View at Publisher · View at Google Scholar · View at Scopus
  8. J. J. Blanchard and J. M. Neale, “The neuropsychological signature of schizophrenia: generalized or differential deficit?” American Journal of Psychiatry, vol. 151, no. 1, pp. 40–48, 1994. View at Scopus
  9. H. M. Conklin, C. E. Curtis, J. Katsanis, and W. G. Iacono, “Verbal working memory impairment in schizophrenia patients and their first-degree relatives: evidence from the digit span task,” American Journal of Psychiatry, vol. 157, no. 2, pp. 275–277, 2000. View at Publisher · View at Google Scholar · View at Scopus
  10. J. Nuyen, M. M. Sitskoorn, W. Cahn, and R. S. Kahn, “Verbal memory in first-episode schizophrenia: heterogeneity in performance?” Journal of the International Neuropsychological Society, vol. 11, no. 2, pp. 152–162, 2005. View at Publisher · View at Google Scholar · View at Scopus
  11. Y. Braw, Y. Bloch, S. Mendelovich et al., “Cognition in young schizophrenia outpatients: comparison of first-episode with multiepisode patients,” Schizophrenia Bulletin, vol. 34, no. 3, pp. 544–554, 2008. View at Publisher · View at Google Scholar · View at Scopus
  12. S. B. Hutton, B. K. Puri, L.-J. Duncan, T. W. Robbins, T. R. E. Barnes, and E. M. Joyce, “Executive function in first-episode schizophrenia,” Psychological Medicine, vol. 28, no. 2, pp. 463–473, 1998. View at Publisher · View at Google Scholar · View at Scopus
  13. N. C. Andreasen, S. Paradiso, and D. S. O'Leary, ““Cognitive dysmetria” as an integrative theory of schizophrenia: a dysfunction in cortical-subcortical-cerebellar circuitry?” Schizophrenia Bulletin, vol. 24, no. 2, pp. 203–218, 1998. View at Scopus
  14. T. D. Cannon, L. E. Zorrilla, D. Shtasel et al., “Neuropsychological functioning in siblings discordant for schizophrenia and healthy volunteers,” Archives of General Psychiatry, vol. 51, no. 8, pp. 651–661, 1994. View at Scopus
  15. K. A. Hawkins, J. Addington, R. S. E. Keefe et al., “Neuropsychological status of subjects at high risk for a first episode of psychosis,” Schizophrenia Research, vol. 67, no. 2-3, pp. 115–122, 2004. View at Publisher · View at Google Scholar · View at Scopus
  16. R. K. Heaton, N. Temkin, S. Dikmen et al., “Detecting change: a comparison of three neuropsychological methods, using normal and clinical samples,” Archives of Clinical Neuropsychology, vol. 16, no. 1, pp. 75–91, 2001. View at Publisher · View at Google Scholar · View at Scopus
  17. B. R. Rund, N. I. Landrø, and A. L. Ørbeck, “Stability in cognitive dysfunctions in schizophrenic patients,” Psychiatry Research, vol. 69, no. 2-3, pp. 131–141, 1997. View at Publisher · View at Google Scholar · View at Scopus
  18. T. A. Greenwood, D. L. Braff, G. A. Light et al., “Initial heritability analyses of endophenotypic measures for schizophrenia: the consortium on the genetics of schizophrenia,” Archives of General Psychiatry, vol. 64, no. 11, pp. 1242–1250, 2007. View at Publisher · View at Google Scholar · View at Scopus
  19. P. D. Harvey, B. W. Palmer, R. K. Heaton, S. Mohamed, J. Kennedy, and A. Brickman, “Stability of cognitive performance in older patients with schizophrenia: an 8-week test-retest study,” American Journal of Psychiatry, vol. 162, no. 1, pp. 110–117, 2005. View at Publisher · View at Google Scholar · View at Scopus
  20. H. Hafner, A. Riecher-Rossler, M. Hambrecht et al., “IRAOS: an instrument for the assessment of onset and early course of schizophrenia,” Schizophrenia Research, vol. 6, no. 3, pp. 209–223, 1992. View at Publisher · View at Google Scholar · View at Scopus
  21. M. Agius, C. Goh, S. Ulhaq, and P. McGorry, “The staging model in schizophrenia, and its clinical implications,” Psychiatria Danubina, vol. 22, no. 2, pp. 211–220, 2010. View at Scopus
  22. P. D. McGorry, A. R. Yung, A. Bechdolf, and P. Amminger, “Back to the future: predicting and reshaping the course of psychotic disorder,” Archives of General Psychiatry, vol. 65, no. 1, pp. 25–27, 2008. View at Publisher · View at Google Scholar · View at Scopus
  23. S. J. Wood, A. R. Yung, P. D. McGorry, and C. Pantelis, “Neuroimaging and treatment evidence for clinical staging in psychotic disorders: from the at-risk mental state to chronic schizophrenia,” Biological Psychiatry, vol. 70, no. 7, pp. 619–625, 2011. View at Publisher · View at Google Scholar · View at Scopus
  24. E. M. Meisenzahl, N. Koutsouleris, R. Bottlender et al., “Structural brain alterations at different stages of schizophrenia: a voxel-based morphometric study,” Schizophrenia Research, vol. 104, no. 1–3, pp. 44–60, 2008. View at Publisher · View at Google Scholar · View at Scopus
  25. R. Smieskova, P. Fusar-Poli, P. Allen et al., “Neuroimaging predictors of transition to psychosis—a systematic review and meta-analysis,” Neuroscience and Biobehavioral Reviews, vol. 34, no. 8, pp. 1207–1222, 2010. View at Publisher · View at Google Scholar · View at Scopus
  26. T. Takahashi, S. J. Wood, A. R. Yung et al., “Progressive gray matter reduction of the superior temporal gyrus during transition to psychosis,” Archives of General Psychiatry, vol. 66, no. 4, pp. 366–376, 2009. View at Publisher · View at Google Scholar · View at Scopus
  27. M. Walterfang, P. K. McGuire, A. R. Yung et al., “White matter volume changes in people who develop psychosis,” British Journal of Psychiatry, vol. 193, no. 3, pp. 210–215, 2008. View at Publisher · View at Google Scholar · View at Scopus
  28. K. E. Lewandowski, B. M. Cohen, and D. Öngur, “Evolution of neuropsychological dysfunction during the course of schizophrenia and bipolar disorder,” Psychological Medicine, vol. 41, no. 2, pp. 225–241, 2011. View at Publisher · View at Google Scholar · View at Scopus
  29. B. Cornblatt, M. Obuchowski, S. Roberts, S. Pollack, and L. Erlenmeyer-Kimling, “Cognitive and behavioral precursors of schizophrenia,” Development and Psychopathology, vol. 11, no. 3, pp. 487–508, 1999. View at Scopus
  30. L. T. Niemi, J. M. Suvisaari, J. K. Haukka, and J. K. Lönnqvist, “Childhood predictors of future psychiatric morbidity in offspring of mothers with psychotic disorder: results from the Helsinki high-risk study,” British Journal of Psychiatry, vol. 186, pp. 108–114, 2005. View at Publisher · View at Google Scholar · View at Scopus
  31. A. Reichenberg, A. Caspi, H. Harrington et al., “Static and dynamic cognitive deficits in childhood preceding adult schizophrenia: a 30-year study,” American Journal of Psychiatry, vol. 167, no. 2, pp. 160–169, 2010. View at Publisher · View at Google Scholar · View at Scopus
  32. L. J. Seidman, A. J. Giuliano, E. C. Meyer et al., “Neuropsychology of the prodrome to psychosis in the NAPLS consortium: relationship to family history and conversion to psychosis,” Archives of General Psychiatry, vol. 67, no. 6, pp. 578–588, 2010. View at Publisher · View at Google Scholar · View at Scopus
  33. B. Nelson, K. Yuen, and A. R. Yung, “Ultra high risk (UHR) for psychosis criteria: are there different levels of risk for transition to psychosis?” Schizophrenia Research, vol. 125, no. 1, pp. 62–68, 2011. View at Publisher · View at Google Scholar · View at Scopus
  34. T. D. Cannon, K. Cadenhead, B. Cornblatt et al., “Prediction of psychosis in youth at high clinical risk: a multisite longitudinal study in North America,” Archives of General Psychiatry, vol. 65, no. 1, pp. 28–37, 2008. View at Publisher · View at Google Scholar · View at Scopus
  35. A. R. Yung, L. J. Phillips, H. P. Yuen et al., “Psychosis prediction: 12-month follow up of a high-risk (“prodromal”) group,” Schizophrenia Research, vol. 60, no. 1, pp. 21–32, 2003. View at Publisher · View at Google Scholar · View at Scopus
  36. M. Hambrecht, M. Lammertink, J. Klosterkötter, E. Matuschek, and R. Pukrop, “Subjective and objective neuropsychological abnormalities in a psychosis prodrome clinic,” British Journal of Psychiatry, vol. 181, no. 43, pp. s30–s37, 2002. View at Scopus
  37. T. A. Niendam, C. E. Bearden, J. K. Johnson et al., “Neurocognitive performance and functional disability in the psychosis prodrome,” Schizophrenia Research, vol. 84, no. 1, pp. 100–111, 2006. View at Publisher · View at Google Scholar · View at Scopus
  38. J. Welham, M. Isohanni, P. Jones, and J. McGrath, “The antecedents of schizophrenia: a review of birth cohort studies,” Schizophrenia Bulletin, vol. 35, no. 3, pp. 603–623, 2009. View at Publisher · View at Google Scholar · View at Scopus
  39. S. J. Wood, C. Pantelis, T. Proffitt et al., “Spatial working memory ability is a marker of risk-for-psychosis,” Psychological Medicine, vol. 33, no. 7, pp. 1239–1247, 2003. View at Publisher · View at Google Scholar · View at Scopus
  40. A. D. Eastvold, R. K. Heaton, and K. S. Cadenhead, “Neurocognitive deficits in the (putative) prodrome and first episode of psychosis,” Schizophrenia Research, vol. 93, no. 1–3, pp. 266–277, 2007. View at Publisher · View at Google Scholar · View at Scopus
  41. C. Jahshan, R. K. Heaton, S. Golshan, and K. S. Cadenhead, “Course of neurocognitive deficits in the prodrome and first episode of schizophrenia,” Neuropsychology, vol. 24, no. 1, pp. 109–120, 2010. View at Publisher · View at Google Scholar · View at Scopus
  42. W. J. Brewer, S. M. Francey, S. J. Wood et al., “Memory impairments identified in people at ultra-high risk for psychosis who later develop first-episode psychosis,” American Journal of Psychiatry, vol. 162, no. 1, pp. 71–78, 2005. View at Publisher · View at Google Scholar · View at Scopus
  43. R. Cosway, M. Byrne, R. Clafferty et al., “Neuropsychological change in young people at high risk for schizophrenia: results from the first two neuropsychological assessments of the Edinburgh high risk study,” Psychological Medicine, vol. 30, no. 5, pp. 1111–1121, 2000. View at Publisher · View at Google Scholar · View at Scopus
  44. S. M. Francey, H. J. Jackson, L. J. Phillips, S. J. Wood, A. R. Yung, and P. D. McGorry, “Sustained attention in young people at high risk of psychosis does not predict transition to psychosis,” Schizophrenia Research, vol. 79, no. 1, pp. 127–136, 2005. View at Publisher · View at Google Scholar · View at Scopus
  45. R. S. E. Keefe, D. O. Perkins, H. Gu, R. B. Zipursky, B. K. Christensen, and J. A. Lieberman, “A longitudinal study of neurocognitive function in individuals at-risk for psychosis,” Schizophrenia Research, vol. 88, no. 1–3, pp. 26–35, 2006. View at Publisher · View at Google Scholar · View at Scopus
  46. T. Lencz, C. W. Smith, D. McLaughlin et al., “Generalized and specific neurocognitive deficits in prodromal schizophrenia,” Biological Psychiatry, vol. 59, no. 9, pp. 863–871, 2006. View at Publisher · View at Google Scholar · View at Scopus
  47. R. Pukrop, S. Ruhrmann, F. Schultze-Lutter, A. Bechdolf, A. Brockhaus-Dumke, and J. Klosterkötter, “Neurocognitive indicators for a conversion to psychosis: comparison of patients in a potentially initial prodromal state who did or did not convert to a psychosis,” Schizophrenia Research, vol. 92, no. 1–3, pp. 116–125, 2007. View at Publisher · View at Google Scholar · View at Scopus
  48. M. Whyte, C. Brett, L. K. Harrison et al., “Neuropsychological performance over time in people at high risk of developing schizophrenia and controls,” Biological Psychiatry, vol. 59, no. 8, pp. 730–739, 2006. View at Publisher · View at Google Scholar · View at Scopus
  49. T. A. Niendam, C. E. Bearden, J. Zinberg, J. K. Johnson, M. O'Brien, and T. D. Cannon, “The course of neurocognition and social functioning in individuals at ultra high risk for psychosis,” Schizophrenia Bulletin, vol. 33, no. 3, pp. 772–781, 2007. View at Publisher · View at Google Scholar · View at Scopus
  50. K. A. Hawkins, R. S. E. Keefe, B. K. Christensen et al., “Neuropsychological course in the prodrome and first episode of psychosis: findings from the PRIME North America Double Blind Treatment Study,” Schizophrenia Research, vol. 105, no. 1–3, pp. 1–9, 2008. View at Publisher · View at Google Scholar · View at Scopus
  51. R. Pukrop, F. Schultze-Lutter, S. Ruhrmann et al., “Neurocognitive functioning in subjects at risk for a first episode of psychosis compared with first- and multiple-episode schizophrenia,” Journal of Clinical and Experimental Neuropsychology, vol. 28, no. 8, pp. 1388–1407, 2006. View at Publisher · View at Google Scholar · View at Scopus
  52. H. E. Becker, D. H. Nieman, S. Wiltink et al., “Neurocognitive functioning before and after the first psychotic episode: does psychosis result in cognitive deterioration?” Psychological Medicine, vol. 40, no. 10, pp. 1599–1606, 2010. View at Publisher · View at Google Scholar · View at Scopus
  53. F. Schultze-Lutter, S. Ruhrmann, H. Picker et al., “Relationship between subjective and objective cognitive function in the early and late prodrome,” British Journal of Psychiatry Supplement, vol. 191, no. 51, pp. s43–s51, 2007. View at Publisher · View at Google Scholar · View at Scopus
  54. I. Frommann, R. Pukrop, J. Brinkmeyer et al., “Neuropsychological profiles in different at-risk states of psychosis: executive control impairment in the early—and additional memory dysfunction in the late—prodromal state,” Schizophrenia Bulletin, vol. 37, no. 4, pp. 861–873, 2011. View at Publisher · View at Google Scholar · View at Scopus
  55. P. A. Gochman, D. Greenstein, A. Sporn et al., “IQ stabilization in childhood-onset schizophrenia,” Schizophrenia Research, vol. 77, no. 2-3, pp. 271–277, 2005. View at Publisher · View at Google Scholar · View at Scopus
  56. P. Fusar-Poli, J. Perez, M. Broome et al., “Neurofunctional correlates of vulnerability to psychosis: a systematic review and meta-analysis,” Neuroscience and Biobehavioral Reviews, vol. 31, no. 4, pp. 465–484, 2007. View at Publisher · View at Google Scholar · View at Scopus
  57. P. Fusar-Poli, “Voxel-wise meta-analysis of fMRI studies in patients at clinical high risk for psychosis,” Journal of Psychiatry and Neuroscience, vol. 37, no. 2, pp. 106–112, 2012. View at Publisher · View at Google Scholar · View at Scopus
  58. M. F. Green, “What are the functional consequences of neurocognitive deficits in schizophrenia?” American Journal of Psychiatry, vol. 153, no. 3, pp. 321–330, 1996. View at Scopus
  59. M. F. Green, R. S. Kern, and R. K. Heaton, “Longitudinal studies of cognition and functional outcome in schizophrenia: implications for MATRICS,” Schizophrenia Research, vol. 72, no. 1, pp. 41–51, 2004. View at Publisher · View at Google Scholar · View at Scopus
  60. S. M. Silverstein, H. Hitzel, and L. Schenkel, “Identifying and addressing cognitive barriers to rehabilitation readiness,” Psychiatric Services, vol. 49, no. 1, pp. 34–36, 1998. View at Scopus
  61. A. Uçok, S. Çakir, Z. Ç. Duman, A. Dişcigil, P. Kandemir, and H. Atli, “Cognitive predictors of skill acquisition on social problem solving in patients with schizophrenia,” European Archives of Psychiatry and Clinical Neuroscience, vol. 256, no. 6, pp. 388–394, 2006. View at Publisher · View at Google Scholar · View at Scopus
  62. S. J. Schmidt, D. R. Mueller, and V. Roder, “Social cognition as a mediator variable between neurocognition and functional outcome in schizophrenia: empirical review and new results by structural equation modeling,” Schizophrenia Bulletin, vol. 37, supplement 2, pp. S41–S54, 2011. View at Publisher · View at Google Scholar · View at Scopus
  63. R. E. Carrión, T. E. Goldberg, D. McLaughlin, A. M. Auther, C. U. Correll, and B. A. Cornblatt, “Impact of neurocognition on social and role functioning in individuals at clinical high risk for psychosis,” American Journal of Psychiatry, vol. 168, no. 8, pp. 806–813, 2011. View at Publisher · View at Google Scholar · View at Scopus
  64. A. Medalia, “Saperstein AM Does cognitive remediation for schizophrenia improve functional outcomes,” Current Opinion in Psychiatry, vol. 26, pp. 151–157, 2013.
  65. O. Bracy, “CogReHab Software,” Psychological Software Service, Indianapolis, Ind, USA, 1995.
  66. A. Medalia, N. Revheim, and T. Herlands, Cognitive Remediation for Psychological Disorders: Therapist Guide, Oxford University Press, New York, NY, USA, 2009.
  67. M. Bell, G. Bryson, T. Greig, C. Corcoran, and B. E. Wexler, “Neurocognitive enhancement therapy with work therapy: effects on neuropsychological test performance,” Archives of General Psychiatry, vol. 58, no. 8, pp. 763–768, 2001. View at Scopus
  68. G. E. Hogarty, S. Flesher, R. Ulrich et al., “Cognitive enhancement therapy for schizophrenia: effects of a 2-year randomized trial on cognition and behavior,” Archives of General Psychiatry, vol. 61, no. 9, pp. 866–876, 2004. View at Publisher · View at Google Scholar · View at Scopus
  69. S. R. McGurk, K. T. Mueser, T. J. Derosa, and R. Wolfe, “Work, recovery, and comorbidity in schizophrenia: a randomized controlled trial of cognitive remediation,” Schizophrenia Bulletin, vol. 35, no. 2, pp. 319–335, 2009. View at Publisher · View at Google Scholar · View at Scopus
  70. J. P. Hansen, B. Ostergaard, M. Nordentoft, and L. Hounsgaard, “Cognitive adaptation training combined with illness,” Neuropsychopharmacology, vol. 37, pp. 43–76, 2012.
  71. S. Vinogradov, M. Fisher, and E. de Villers-Sidani, “Cognitive training for impaired neural systems in neuropsychiatric assertive community treatment: a randomised longitudinal trial,” Schizophrenia Research, vol. 135, no. 1–3, pp. 105–111, 2012.
  72. S. Pilling, P. Bebbington, E. Kuipers et al., “Psychological treatments in schizophrenia: II. Meta-analyses of randomized controlled trials of social skills training and cognitive remediation,” Psychological Medicine, vol. 32, no. 5, pp. 783–791, 2002. View at Publisher · View at Google Scholar · View at Scopus
  73. S. R. McGurk, E. W. Twamley, D. I. Sitzer, G. J. McHugo, and K. T. Mueser, “A meta-analysis of cognitive remediation in schizophrenia,” American Journal of Psychiatry, vol. 164, no. 12, pp. 1791–1802, 2007. View at Publisher · View at Google Scholar · View at Scopus
  74. L. Krabbendam and A. Aleman, “Meta-analyses of randomized controlled trials of social skills training and cognitive remediation,” Psychological medicine, vol. 33, no. 4, pp. 756–758, 2003. View at Scopus
  75. C. R. Bowie, S. R. McGurk, B. Mausbach, T. L. Patterson, and P. D. Harvey, “Combined cognitive remediation and functional skills training for schizophrenia: effects in cognition, functional competence, and real-world behavior,” American Journal of Psychiatry, vol. 169, no. 7, pp. 710–718, 2012.
  76. T. Wykes, V. Huddy, C. Cellard, S. R. McGurk, and P. Czobor, “A meta-analysis of cognitive remediation for schizophrenia: methodology and effect sizes,” American Journal of Psychiatry, vol. 168, no. 5, pp. 472–485, 2011. View at Publisher · View at Google Scholar · View at Scopus
  77. N. V. Murthy, H. Mahncke, B. E. Wexler et al., “Computerized cognitive remediation training for schizophrenia: an open label, multi-site, multinational methodology study,” Schizophrenia Research, vol. 139, pp. 87–91, 2012. View at Publisher · View at Google Scholar · View at Scopus
  78. T. D'Amato, R. Bation, A. Cochet et al., “A randomized, controlled trial of computer-assisted cognitive remediation for schizophrenia,” Schizophrenia Research, vol. 125, no. 2-3, pp. 284–290, 2011. View at Publisher · View at Google Scholar · View at Scopus
  79. C. Demily and N. Franck, “Cognitive remediation: a promising tool for the treatment of schizophrenia,” Expert Review of Neurotherapeutics, vol. 8, no. 7, pp. 1029–1036, 2008. View at Publisher · View at Google Scholar · View at Scopus
  80. R. Penades, N. Pujol, R. Catalan, et al., “Brain effects of cognitive remediation therapy in schizophrenia: a structural and functional neuroimaging study,” Biological Psychiatry, vol. 73, pp. 1015–1023, 2013.
  81. A. Bechdolf, M. Wagner, S. Ruhrmann et al., “Preventing progression to first-episode psychosis in early initial prodromal states,” British Journal of Psychiatry, vol. 200, no. 1, pp. 22–29, 2012. View at Publisher · View at Google Scholar · View at Scopus
  82. K. R. Marker, “CogPack. the cognitive training package manual,” Marker Software, Heidelberg, Ladenburg, Germany, 1987–2007, http://www.markersoftware.com.
  83. A. Bechdolf, M. Wagner, S. Ruhrmann et al., “Preventing progression to first-episode psychosis in early initial prodromal states,” British Journal of Psychiatry, vol. 200, no. 1, pp. 22–29, 2012. View at Publisher · View at Google Scholar · View at Scopus
  84. E. Kim, J. H. Jang, H.-Y. Park et al., “Pharmacotherapy and clinical characteristics of ultra-high-risk for psychosis according to conversion status: a naturalistic observational study,” Early Intervention in Psychiatry, vol. 6, no. 1, pp. 30–37, 2012. View at Publisher · View at Google Scholar · View at Scopus
  85. A. E. Simon, K. Cattapan-Ludewig, S. Zmilacher et al., “Cognitive functioning in the schizophrenia prodrome,” Schizophrenia Bulletin, vol. 33, no. 3, pp. 761–771, 2007. View at Publisher · View at Google Scholar · View at Scopus
  86. G. Sartory, C. Zorn, G. Groetzinger, and K. Windgassen, “Computerized cognitive remediation improves verbal learning and processing speed in schizophrenia,” Schizophrenia Research, vol. 75, no. 2-3, pp. 219–223, 2005. View at Publisher · View at Google Scholar · View at Scopus
  87. A. P. Morrison, P. French, S. L. K. Stewart et al., “Early detection and intervention evaluation for people at risk of psychosis: multisite randomised controlled trial,” British Medical Journal, vol. 344, no. 7852, Article ID e2233, 2012. View at Publisher · View at Google Scholar · View at Scopus