A pilot 1-year follow-up randomised controlled trial comparing metacognitive training to psychoeducation in schizophrenia: effects on insight.
Journal
Schizophrenia (Heidelberg, Germany)
ISSN: 2754-6993
Titre abrégé: Schizophrenia (Heidelb)
Pays: Germany
ID NLM: 9918367987006676
Informations de publication
Date de publication:
30 Jan 2023
30 Jan 2023
Historique:
received:
12
06
2022
accepted:
14
11
2022
entrez:
30
1
2023
pubmed:
31
1
2023
medline:
31
1
2023
Statut:
epublish
Résumé
Poor insight in schizophrenia spectrum disorders (SSD) is linked with negative outcomes. This single-centre, assessor-blind, parallel-group 1-year follow-up randomised controlled trial (RCT) tested whether metacognitive training (MCT) (compared to psychoeducation) may improve insight and outcomes in outpatients with SSD assessed: at baseline (T0); after treatment (T1) and at 1-year follow-up (T2). Insight (primary outcome) was measured with (i) the Schedule for Assessment of Insight-Expanded version- (SAI-E), including illness recognition (IR), symptom relabelling (SR), treatment compliance (TC) and total insight scores (TIS); and (ii) the Beck Cognitive Insight Scale (BCIS). Between-group comparisons were nonsignificant, while within the MCT group (but not within controls) there was a significant medium effect size for improved TIS at T2 (d = 0.67, P = 0.02). Secondary outcomes included cognitive measures: Jumping to Conclusions (JTC), Theory of Mind (ToM), plus symptom severity and functioning. Compared to psychoeducation, MCT improved the PANSS excitement (d = 1.21, P = 0.01) and depressed (d = 0.76, P = 0.05) factors at T2; and a JTC task both at T1 (P = 0.016) and at T2 (P = 0.031). Participants in this RCT receiving MCT showed improved insight at 1-year follow-up, which was associated with better mood and reduced JTC cognitive bias. In this pilot study, no significant benefits on insight of MCT over psychoeducation were detected, which may have been due to insufficient power.
Identifiants
pubmed: 36717598
doi: 10.1038/s41537-022-00316-x
pii: 10.1038/s41537-022-00316-x
pmc: PMC9886217
doi:
Types de publication
Journal Article
Langues
eng
Pagination
7Informations de copyright
© 2023. The Author(s).
Références
Escobedo-Aedo, P. J. et al. Investigating the role of insight, decision-making and mentalizing in functional outcome in schizophrenia: a cross-sectional study. Behav. Sci. 12, 28 (2022).
doi: 10.3390/bs12020028
Lincoln, T. M., Lüllmann, E. & Rief, W. Correlates and long-term consequences of poor insight in patients with schizophrenia. A systematic review. Schizophr. Bull. 33, 1324–1342 (2007).
doi: 10.1093/schbul/sbm002
Carpenter, W. T., Strauss, J. S. & Bartko, J. J. Flexible system for the diagnosis of schizophrenia: report from the WHO International Pilot Study of Schizophrenia. Science 182, 1275–1278 (1973).
doi: 10.1126/science.182.4118.1275
Amador, X. F. et al. Awareness of illness in schizophrenia and schizoaffective and mood disorders. Arch Gen. Psychiatry 51, 826–836 (1994).
doi: 10.1001/archpsyc.1994.03950100074007
Ayesa-Arriola, R. et al. Lack of insight 3 years after first-episode psychosis: an unchangeable illness trait determined from first presentation? Schizophr. Res. 157, 271–277 (2014).
doi: 10.1016/j.schres.2014.05.011
David, A. S. Insight and psychosis. Br. J. Psychiatry 156, 798–808 (1990).
doi: 10.1192/bjp.156.6.798
David, A. S. Insight and psychosis: the next 30 years. Br. J. Psychiatry 217, 521–523 (2019).
Morgan, K. D. et al. Insight, grey matter and cognitive function in first-onset psychosis. Br. J. Psychiatry 197, 141–148 (2010).
doi: 10.1192/bjp.bp.109.070888
Wiffen, B. D. R. et al. Are there specific neuropsychological deficits underlying poor insight in first episode psychosis? Schizophr. Res. 135, 46–50 (2012).
doi: 10.1016/j.schres.2011.11.017
Henry, C. & Ghaemi, S. N. Insight in psychosis: a systematic review of treatment interventions. Psychopathology 37, 194–199 (2004).
doi: 10.1159/000080131
Pijnenborg, G. H. M., van Donkersgoed, R. J. M., David, A. S. & Aleman, A. Changes in insight during treatment for psychotic disorders: a meta-analysis. Schizophr. Res. 144, 109–117 (2013).
doi: 10.1016/j.schres.2012.11.018
Lopez-Morinigo, J.-D. et al. Can metacognitive interventions improve insight in schizophrenia spectrum disorders? A systematic review and meta-analysis. Psychol. Med. 50, 2289–2301 (2020).
doi: 10.1017/S0033291720003384
Flavell, J. H. Metacognition and cognitive monitoring: a new area of cognitive-developmental inquiry. Am. Psychologist 34, 906–911 (1979).
doi: 10.1037/0003-066X.34.10.906
Wells, Adrian Metacognition and cognitive-behaviour therapy: a special issue. Clin. Psychol. Psychother. 6, 71–72 (1999).
doi: 10.1002/(SICI)1099-0879(199905)6:2<71::AID-CPP186>3.0.CO;2-G
Beck, A. T., Baruch, E., Balter, J. M., Steer, R. A. & Warman, D. M. A new instrument for measuring insight: the Beck Cognitive Insight Scale. Schizophr. Res. 68, 319–329 (2004).
doi: 10.1016/S0920-9964(03)00189-0
Lysaker, P. H., Pattison, M. L., Leonhardt, B. L., Phelps, S. & Vohs, J. L. Insight in schizophrenia spectrum disorders: relationship with behavior, mood and perceived quality of life, underlying causes and emerging treatments: world psychiatry. World Psychiatry 17, 12–23 (2018).
doi: 10.1002/wps.20508
Van Camp, L. S. C., Sabbe, B. G. C. & Oldenburg, J. F. E. Cognitive insight: a systematic review. Clin. Psychol. Rev. 55, 12–24 (2017).
doi: 10.1016/j.cpr.2017.04.011
van Oosterhout, B. et al. Metacognitive training for schizophrenia spectrum patients: a meta-analysis on outcome studies. Psychol. Med. 46, 47–57 (2016).
doi: 10.1017/S0033291715001105
van Oosterhout, B. et al. Metacognitive group training for schizophrenia spectrum patients with delusions: a randomized controlled trial. Psychol. Med. 44, 3025–3035 (2014).
doi: 10.1017/S0033291714000555
Eichner, C. & Berna, F. Acceptance and efficacy of metacognitive training (MCT) on positive symptoms and delusions in patients with schizophrenia: a meta-analysis taking into account important moderators. Schizophr. Bull. 42, 952–962 (2016).
doi: 10.1093/schbul/sbv225
Jiang, J., Zhang, L., Zhu, Z., Li, W. & Li, C. Metacognitive training for schizophrenia: a systematic review. Shanghai Arch Psychiatry 27, 149–157 (2015).
Liu, Y.-C., Tang, C.-C., Hung, T.-T., Tsai, P.-C. & Lin, M.-F. The efficacy of metacognitive training for delusions in patients with schizophrenia: a meta-analysis of randomized controlled trials informs evidence-based practice. Worldviews on Evidence-Based Nursing 15, 130–139 (2018).
doi: 10.1111/wvn.12282
Moritz, S. et al. Sowing the seeds of doubt: a narrative review on metacognitive training in schizophrenia. Clin. Psychol. Rev. 34, 358–366 (2014).
doi: 10.1016/j.cpr.2014.04.004
Philipp, R. et al. Effectiveness of metacognitive interventions for mental disorders in adults—a systematic review and meta-analysis (METACOG). Clin. Psychol. Psychother. 26, 227–240 (2019).
doi: 10.1002/cpp.2345
van Oosterhout, B. et al. Letter to the editor: should we focus on quality or quantity in meta-analyses? Psychol. Med. 46, 2003–2005 (2016).
doi: 10.1017/S003329171600009X
Penney, D. et al. Immediate and sustained outcomes and moderators associated with metacognitive training for psychosis: a systematic review and meta-analysis. JAMA Psychiatry 79, 417–429 (2022).
doi: 10.1001/jamapsychiatry.2022.0277
Birulés, I. et al. Cognitive insight in first-episode psychosis: changes during metacognitive training. J. Pers. Med. 10. https://doi.org/10.3390/jpm10040253 (2020).
Bora, E. & Pantelis, C. Theory of mind impairments in first-episode psychosis, individuals at ultra-high risk for psychosis and in first-degree relatives of schizophrenia: systematic review and meta-analysis. Schizophr. Res. 144, 31–36 (2013).
doi: 10.1016/j.schres.2012.12.013
Moritz, S. et al. A two-stage cognitive theory of the positive symptoms of psychosis. Highlighting the role of lowered decision thresholds. J. Behav. Ther. Exp. Psychiatry 56, 12–20 (2017).
doi: 10.1016/j.jbtep.2016.07.004
Brar, P. S., Sass, L., Beck, D. & Kalarchian, M. A. Metacognitive training for schizophrenia: a scoping review and phenomenological evaluation. Psychosis 14, 1–21 (2022).
doi: 10.1080/17522439.2021.1918753
Lopez-Morinigo, J.-D. et al. Investigating the contribution of decision-making, cognitive insight, and theory of mind in insight in schizophrenia: a cross-sectional study. Psychopathology 55, 104–115 (2022).
doi: 10.1159/000521915
Falcone, M. A. et al. Jumping to conclusions, neuropsychological functioning, and delusional beliefs in first episode psychosis. Schizophr Bull 41, 411–418 (2015).
doi: 10.1093/schbul/sbu104
Garety, P. Reasoning and delusions. Br. J. Psychiatry Suppl. 159, 14–18 (1991).
Garety, P. A. et al. Reasoning, emotions, and delusional conviction in psychosis. J. Abnorm. Psychol. 114, 373–384 (2005).
doi: 10.1037/0021-843X.114.3.373
Falcone, M. A. et al. Jumping to conclusions and the persistence of delusional beliefs in first episode psychosis. Schizophr. Res. 165, 243–246 (2015).
doi: 10.1016/j.schres.2015.04.019
Baron-Cohen, S., Leslie, A. M. & Frith, U. Does the autistic child have a ‘theory of mind’? Cognition 21, 37–46 (1985).
doi: 10.1016/0010-0277(85)90022-8
Weng, Y., Lin, J., Ahorsu, D. K. & Tsang, H. W. H. Neuropathways of theory of mind in schizophrenia: a systematic review and meta-analysis. Neurosci. Biobehav. Rev. 137, 104625 (2022).
doi: 10.1016/j.neubiorev.2022.104625
Balzan, R. P., Mattiske, J. K., Delfabbro, P., Liu, D. & Galletly, C. Individualized metacognitive training (MCT+) reduces delusional symptoms in psychosis: a randomized clinical trial. Schizophr. Bull. 45, 27–36 (2019).
doi: 10.1093/schbul/sby152
Briki, M. et al. Metacognitive training for schizophrenia: a multicentre randomised controlled trial. Schizophr. Res. 157, 99–106 (2014).
doi: 10.1016/j.schres.2014.06.005
Favrod, J. et al. Sustained antipsychotic effect of metacognitive training in psychosis: a randomized-controlled study. Eur. Psychiatry 29, 275–281 (2014).
doi: 10.1016/j.eurpsy.2013.08.003
Gawęda, Ł., Krężołek, M., Olbryś, J., Turska, A. & Kokoszka, A. Decreasing self-reported cognitive biases and increasing clinical insight through meta-cognitive training in patients with chronic schizophrenia. J. Behav. Ther. Exp. Psychiatry 48, 98–104 (2015).
doi: 10.1016/j.jbtep.2015.02.002
Kuokkanen, R., Lappalainen, R., Repo-Tiihonen, E. & Tiihonen, J. Metacognitive group training for forensic and dangerous non-forensic patients with schizophrenia: a randomised controlled feasibility trial. Crim. Behav. Mental Health 24, 345–357 (2014).
doi: 10.1002/cbm.1905
Ahuir, M. et al. Improvement in cognitive biases after group psychoeducation and metacognitive training in recent-onset psychosis: a randomized crossover clinical trial. Psychiatry Res. 270, 720–723 (2018).
doi: 10.1016/j.psychres.2018.10.066
Favrod, J. et al. Sustained antipsychotic effect of metacognitive training in psychosis: a randomized-controlled study. Eur. Psychiatry 29, 275–281 (2014).
doi: 10.1016/j.eurpsy.2013.08.003
Mehl, S., Werner, D. & Lincoln, T. M. Does Cognitive Behavior Therapy for psychosis (CBTp) show a sustainable effect on delusions? A meta-analysis. Front. Psychol. 6, 1450 (2015).
doi: 10.3389/fpsyg.2015.01450
Ochoa, S. et al. Randomized control trial to assess the efficacy of metacognitive training compared with a psycho-educational group in people with a recent-onset psychosis. Psychol. Med. 47, 1573–1584 (2017).
doi: 10.1017/S0033291716003421
Salas-Sender, M. et al. Gender differences in response to metacognitive training in people with first-episode psychosis. J. Consult. Clin. Psychol. 88, 516–525 (2020).
doi: 10.1037/ccp0000468
Lüdtke, T., Pult, L. K., Schröder, J., Moritz, S. & Bücker, L. A randomized controlled trial on a smartphone self-help application (Be Good to Yourself) to reduce depressive symptoms. Psychiatry Res. 269, 753–762 (2018).
doi: 10.1016/j.psychres.2018.08.113
Andreou, C. et al. Individualized metacognitive therapy for delusions: a randomized controlled rater-blind study. J. Behav. Ther. Exp. Psychiatry 56, 144–151 (2017).
doi: 10.1016/j.jbtep.2016.11.013
Aghotor, J., Pfueller, U., Moritz, S., Weisbrod, M. & Roesch-Ely, D. Metacognitive training for patients with schizophrenia (MCT): feasibility and preliminary evidence for its efficacy. J. Behav. Ther. Exp. Psychiatry 41, 207–211 (2010).
doi: 10.1016/j.jbtep.2010.01.004
Baron-Cohen, S., Wheelwright, S. & Jolliffe, T. Is there a ‘language of the eyes’? Evidence from normal adults, and adults with autism or Asperger syndrome. Visual Cognition 4, 311–331 (1997).
doi: 10.1080/713756761
Huerta-Ramos, E. et al. Translation and validation of Baron Cohen’s face test in a general population from Spain. Actas Esp Psiquiatr 49, 106–113 (2021).
Corcoran, R., Mercer, G. & Frith, C. D. Schizophrenia, symptomatology and social inference: Investigating “theory of mind” in people with schizophrenia. Schizophr. Res. 17, 5–13 (1995).
doi: 10.1016/0920-9964(95)00024-G
Langdon, R., Still, M., Connors, M. H., Ward, P. B. & Catts, S. V. Theory of mind in early psychosis. Early Interv. Psychiatry 8, 286–290 (2014).
doi: 10.1111/eip.12072
Sprong, M., Schothorst, P., Vos, E., Hox, J. & van Engeland, H. Theory of mind in schizophrenia: meta-analysis. Br. J. Psychiatry 191, 5–13 (2007).
doi: 10.1192/bjp.bp.107.035899
Wallwork, R. S., Fortgang, R., Hashimoto, R., Weinberger, D. R. & Dickinson, D. Searching for a consensus five-factor model of the positive and negative syndrome Scale for schizophrenia. Schizophr. Res. 137, 246–250 (2012).
doi: 10.1016/j.schres.2012.01.031
Sarraf, L., Lepage, M. & Sauvé, G. The clinical and psychosocial correlates of self-stigma among people with schizophrenia spectrum disorders across cultures: a systematic review and meta-analysis. Schizophr. Res. 248, 64–78 (2022).
doi: 10.1016/j.schres.2022.08.001
Moritz, S. & Woodward, T. S. Metacognitive training for schizophrenia patients (MCT): a pilot study on feasibility, treatment adherence, and subjective efficacy. German J. Psychiatry 10, 69–78 (2007).
Addington, D., Addington, J., Maticka-Tyndale, E. & Joyce, J. Reliability and validity of a depression rating scale for schizophrenics. Schizophr. Res. 6, 201–208 (1992).
doi: 10.1016/0920-9964(92)90003-N
Belvederi Murri, M. et al. Is good insight associated with depression among patients with schizophrenia? Systematic review and meta-analysis. Schizophr. Res. 162, 234–247 (2015).
doi: 10.1016/j.schres.2015.01.003
Mintz, A. R., Dobson, K. S. & Romney, D. M. Insight in schizophrenia: a meta-analysis. Schizophr. Res. 61, 75–88 (2003).
doi: 10.1016/S0920-9964(02)00316-X
Drake, R. E. & Cotton, P. G. Depression, hopelessness and suicide in chronic schizophrenia. Br. J. Psychiatry 148, 554–559 (1986).
doi: 10.1192/bjp.148.5.554
Ghaemi, S. N. Feeling and time: the phenomenology of mood disorders, depressive realism, and existential psychotherapy. Schizophr. Bull. 33, 122–130 (2007).
doi: 10.1093/schbul/sbl061
Lysaker, P. H., Roe, D. & Yanos, P. T. Toward understanding the insight paradox: internalized stigma moderates the association between insight and social functioning, hope, and self-esteem among people with schizophrenia spectrum disorders. Schizophr. Bull. 33, 192–199 (2007).
doi: 10.1093/schbul/sbl016
Lysaker, P. H., Pattison, M. L., Leonhardt, B. L., Phelps, S. & Vohs, J. L. Insight in schizophrenia spectrum disorders: relationship with behavior, mood and perceived quality of life, underlying causes and emerging treatments. World Psychiatry 17, 12–23 (2018).
doi: 10.1002/wps.20508
Palmer, E. C., Gilleen, J. & David, A. S. The relationship between cognitive insight and depression in psychosis and schizophrenia: a review and meta-analysis. Schizophr. Res. 166, 261–268 (2015).
doi: 10.1016/j.schres.2015.05.032
García-Mieres, H., De, Jesús-Romero, R., IDENTITY group, Ochoa, S. & Feixas, G. Beyond the cognitive insight paradox: Self-reflectivity moderates the relationship between depressive symptoms and general psychological distress in psychosis. Schizophr. Res. 222, 297–303 (2020).
doi: 10.1016/j.schres.2020.05.027
Ayesa-Arriola, R. et al. The dynamic relationship between insight and suicidal behavior in first episode psychosis patients over 3-year follow-up. Eur. Neuropsychopharmacol. 28, 1161–1172 (2018).
doi: 10.1016/j.euroneuro.2018.05.005
Lopez-Morinigo, J.-D. et al. Insight and risk of suicidal behaviour in two first-episode psychosis cohorts: Effects of previous suicide attempts and depression. Schizophr. Res. 204, 80–89 (2019).
doi: 10.1016/j.schres.2018.09.016
Upthegrove, R., Marwaha, S. & Birchwood, M. Depression and schizophrenia: cause, consequence, or trans-diagnostic issue? Schizophr. Bull. 43, 240–244 (2017).
Pijnenborg, G. H. M. et al. Differential effects of antipsychotic drugs on insight in first episode schizophrenia: data from the European First-Episode Schizophrenia Trial (EUFEST). Eur. Neuropsychopharmacol. 25, 808–816 (2015).
doi: 10.1016/j.euroneuro.2015.02.012
Lam, K. C. K. et al. Metacognitive training (MCT) for schizophrenia improves cognitive insight: a randomized controlled trial in a Chinese sample with schizophrenia spectrum disorders. Behav. Res. Ther. 64, 38–42 (2015).
doi: 10.1016/j.brat.2014.11.008
Sheehan, D. V. et al. The Mini-International Neuropsychiatric Interview (M.I.N.I.): the development and validation of a structured diagnostic psychiatric interview for DSM-IV and ICD-10. J. Clin. Psychiatry 59(Suppl 20), 22–33 (1998).
World Health Organization. The ICD-10 Classification of Mental and Behavioural Disorders: Diagnostic Criteria for Research (World Health Organization, 1993).
Wechsler, D. The psychometric tradition: developing the wechsler adult intelligence scale. Contemporary Educ. Psychol. 6, 82–85 (1981).
doi: 10.1016/0361-476X(81)90035-7
Lopez-Morinigo, J.-D. et al. Study protocol of a randomised clinical trial testing whether metacognitive training can improve insight and clinical outcomes in schizophrenia. BMC Psychiatry 20, 30 (2020).
doi: 10.1186/s12888-020-2431-x
Soriano-Barceló, J. Insight assessment in psychosis and psychopathological correlates: validation of the Spanish version of the Schedule for Assessment of Insight - Expanded Version. Eur. J. Psychiatry 30, 55–65 (2016).
Kemp, R. & David, A. S. Insight and compliance. Chronic mental illness. in Treatment Compliance and the Therapeutic Alliance (ed. Blackwell, B.) Vol. 5, 61–84 (Gordon and Breach, 1997).
Sanz, M., Constable, G., Lopez-Ibor, I., Kemp, R. & David, A. S. A comparative study of insight scales and their relationship to psychopathological and clinical variables. Psychol. Med. 28, 437–446 (1998).
doi: 10.1017/S0033291797006296
Gutiérrez-Zotes, J. A. et al. Spanish adaptation of the Beck Cognitive Insight Scale (BCIS) for schizophrenia. Actas Esp. Psiquiatr. 40, 2–9 (2012).
Brett-Jones, J., Garety, P. & Hemsley, D. Measuring delusional experiences: a method and its application. Br. J. Clin. Psychol. 26, 257–265 (1987).
doi: 10.1111/j.2044-8260.1987.tb01359.x
O’Connor, J. A. et al. Can cognitive insight predict symptom remission in a first episode psychosis cohort? BMC Psychiatry 17, 54 (2017).
doi: 10.1186/s12888-017-1210-9
Balzan, R. P., Delfabbro, P. H., Galletly, C. A. & Woodward, T. S. Over-adjustment or miscomprehension? A re-examination of the jumping to conclusions bias. Aust N Z J Psychiatry 46, 532–540 (2012).
doi: 10.1177/0004867411435291
Gil, D., Fernández-Modamio, M., Bengochea, R. & Arrieta, M. Adaptation of the Hinting Task theory of the mind test to Spanish. Revista de Psiquiatría y. Salud Mental 5, 79–88 (2012).
Peralta, V. & Cuesta, M. Validation of positive and negative symptom scale (PANSS) in a sample of Spanish schizophrenic patients. Psychiatry Res. 53, 31–40 (1994).
Kay, S. R., Fiszbein, A. & Opler, L. A. The positive and negative syndrome scale (PANSS) for Schizophrenia. Schizophr. Bull. 13, 261–276 (1987).
doi: 10.1093/schbul/13.2.261
Sarró, S. et al. Cross-cultural adaptation and validation of the Spanish version of the Calgary Depression Scale for Schizophrenia. Schizophr. Res. 68, 349–356 (2004).
doi: 10.1016/S0920-9964(02)00490-5
Jablensky, A. Living in a Kraepelinian world: Kraepelin’s impact on modern psychiatry. Hist Psychiatry 18, 381–388 (2007).
doi: 10.1177/0957154X07079690
Craddock, N. & Owen, M. J. The Kraepelinian dichotomy—going, going… but still not gone. Br. J. Psychiatry 196, 92–95 (2010).
doi: 10.1192/bjp.bp.109.073429
Peralta, V. & Cuesta, M. J. How many and which are the psychopathological dimensions in schizophrenia? Issues influencing their ascertainment. Schizophr. Res. 49, 269–285 (2001).
doi: 10.1016/S0920-9964(00)00071-2
van Os, J. & Kapur, S. Schizophrenia. Lancet 374, 635–645 (2009).
doi: 10.1016/S0140-6736(09)60995-8
Endicott, J., Spitzer, R. L., Fleiss, J. L. & Cohen, J. The global assessment scale. A procedure for measuring overall severity of psychiatric disturbance. Arch Gen. Psychiatry 33, 766–771 (1976).
doi: 10.1001/archpsyc.1976.01770060086012
Üstün, T. B. (ed.). Measuring Health and Disability: Manual for WHO Disability Assessment Schedule WHODAS 2.0 (World Health Organization, 2010).
Carlson, J. et al. Adaptation and validation of the quality-of-life scale: satisfaction with life domains scale by Baker and Intagliata. Compr. Psychiatry 50, 76–80 (2009).
doi: 10.1016/j.comppsych.2008.05.008
Baker, F. & Intagliata, J. Quality of life in the evaluation of community support systems. Eval Program Plann. 5, 69–79 (1982).
doi: 10.1016/0149-7189(82)90059-3
Cannon-Spoor, H. E., Potkin, S. G. & Wyatt, R. J. Measurement of premorbid adjustment in chronic schizophrenia. Schizophr. Bull. 8, 470–484 (1982).
doi: 10.1093/schbul/8.3.470
Reitan, R. M. Validity of the trail making test as an indicator of organic brain damage. Percept. Mot. Skills 8, 271–276 (1958).
doi: 10.2466/pms.1958.8.3.271
Cohen, J. Statistical Power Analysis for the Behavioral Sciences. 2nd edn. (L. Erlbaum Associates, 1988).
Mishra, P., Singh, U., Pandey, C. M., Mishra, P. & Pandey, G. Application of student’s t-test, analysis of variance, and covariance. Ann. Card. Anaesth. 22, 407–411 (2019).
doi: 10.4103/aca.ACA_94_19