Psychiatry Investig Search


Psychiatry Investig > Volume 14(1); 2017 > Article
Kim, Lee, Kim, Yu, Lee, Won, Lee, Kim, Kang, and Chung: Design and Methodology of the Korean Early Psychosis Cohort Study


The present study details the rationale and methodology of the Korean Early Psychosis Cohort Study (KEPS), which is a clinical cohort investigation of first episode psychosis patients from a Korean population. The KEPS is a prospective naturalistic observational cohort study that follows the participants for at least 2 years. This study includes patients between 18 and 45 years of age who fulfill the criteria for one of schizophrenia spectrum and other psychotic disorders according to the diagnostic criteria of DSM-5. Early psychosis is defined as first episode patients who received antipsychotic treatment for fewer than 4 consecutive weeks after the onset of illness or stabilized patients in the early stages of the disorder whose duration of illness was less than 2 years from the initiation of antipsychotic treatment. The primary outcome measures are treatment response, remission, recovery, and relapse. Additionally, several laboratory tests are conducted and a variety of objective and subjective psychiatric measures assessing early life trauma, lifestyle pattern, and social and cognitive functioning are administered. This long-term prospective cohort study may contribute to the development of early intervention strategies and the improvement of long-term outcomes in patients with schizophrenia.


Psychotic disorders such as schizophrenia are often chronic and disabling in a number of clinical aspects, including social and occupational functioning, which are characteristic factors and key diagnostic criteria associated with this disorder. In fact, there are often major changes in the psychosocial functioning of patients with schizophrenia spectrum disorders within the first 3 years of onset even though the decline infunction tends to plateau thereafter.1 Therefore, the first 3 years of this disorder have been described as a critical period during which the future course and prognosis of the patient is determined. McGorry suggested that the critical period for psychotic disorders can be regarded as covering the period following recovery from a first episode of psychosis and extending for up to five years subsequently.2
Over the last 3 decades, a number of clinical cohort studies have investigated the early stages of psychotic disorders.3456 These types of prospective cohort studies that focus on patients with first episode psychosis provide an opportunity to identify prognostic factors in the early stages of the disorder while minimizing the confounding effects of treatment interventions or secondary disabilities.7 Despite the obvious advantages of these early stage cohort studies, the majority has included only Western populations that have relatively superior mental health resources, and thus, the findings may not be generalizable to the rest of the world.8 For example, ethnic and sociocultural factors have been shown to influence the treatment pattern and clinical course of patients with psychotic disorders.9 To our knowledge, only a few large prospective longitudinal cohort studies investigating first episode psychosis have been published using subjects from Asian countries.810
In Korea, mental health services are typically characterized by low accessibility to psychiatric treatment, high caseloads, and a relatively large incidence of inpatient care.11 The duration of untreated psychosis (DUP), which is related to a poor prognosis for patients with schizophrenia,1213 is comparatively long in Korea relative to that of Western countries14 and may be attributed to the high level of stigma associated with psychosis and psychiatric treatment.15 Therefore, research investigating Korean patients with first episode psychosis and objective assessments of clinical and community treatment services are required to determine specific models of treatment that are appropriate for Korean populations.
Recently, early intervention services for young individuals with psychotic disorders have begun to be provided by some university hospitals and community mental health centers. Additionally, a nationwide long-term cohort study investigating the naturalistic clinical courses of patients with first episode psychotic disorders was initiated; the Korean Early Psychosis Cohort Study (KEPS) is the first long-term observational prospective cohort study of clinical outcomes in patients with psychotic disorders in the early stage of illness. The primary goals of the present study are to provide an overview of the KEPS and to detail its design and methodology.



The primary aims of this cohort study are to investigate the clinical trajectories of patients with first episode psychosis and to identify the risk and protective factors associated with relapse and recovery. It is the goal of the present authors that this long-term prospective cohort study will be used to develop an optimal mental health services system and effective policies for the treatment of Korean patients with first episode psychosis.

Study population

The KEPS includes patients between 18 and 45 years of age who fulfill the criteria of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) for schizophrenia, schizophreniform disorder, schizoaffective disorder, delusional disorder, brief psychotic disorder, or other specified schizophrenia spectrum and other psychotic disorders including attenuated psychosis syndrome (APS).16 Early psychosis is defined as follows: 1) first episode patients who received antipsychotic treatment for fewer than 4 consecutive weeks after the onset of illness; and 2) stabilized patients in the early stages of the disorder whose duration of illness was less than 2 years after the initiation of antipsychotic treatment and whose current antipsychotic treatment dosage had not changed for at least 2 months. The exclusion criteria consists of patients with a substance- or medication-induced psychotic disorder, psychotic disorder due to another medical condition, mental intellectual disability disorder, and/or severe neurological disorders such as epilepsy, stroke, dementia, or Parkinson's disease.

Sociodemographic and clinical data

The baseline data includes age, gender, diagnosis, education, type of medical insurance, economic status, area of residence (rural or urban), family history of psychiatric illness, familial support (5-point Likert scale), presence of a cohabitant, prescribed medications, comorbid mental and physical illnesses, illness duration, and DUP, which was defined as the amount of time from the appearance of the first psychotic symptoms for more than several days to the time when antipsychotic treatment or a psychiatric hospitalization occurred. Follow-up visit evaluations include adherence to medication, type and length of employment, type of job, use of medical and mental health resources, and socioeconomic costs, including medical costs and time spent on hospital visits and care.

Psychiatric measures

The KEPS utilizes several objective scales, including the Positive and Negative Syndrome Scale (PANSS),1718 Calgary Depression Scale for Schizophrenia (CDSS),192021 Clinical Global Impression (CGI),22 Social and Occupational Functioning Assessment Scale (SOFAS),23 and Columbia-Suicide Severity Rating Scale (C-SSRS).24 Additionally, a dimensional diagnosis using the DSM-5 criteria is conducted to rate eight key psychopathological dimensions of psychotic disorders. A research or treating psychiatrist rates all of the objective measures.
The KEPS also includes several subjective self-rating measures that are administered by a research nurse: the Prospective and Retrospective Memory Questionnaire (PRMQ)25 for measuring prospective and retrospective memory slips in everyday life; the Early Trauma Inventory Self Report-Short Form (ETISR-SF)26 for measuring childhood trauma, including physical, emotional, and sexual abuse as well as general trauma; the Brief Core Schema Scales (BCSS)27 for the assessment of schemata concerning self and others; the Brooding Scale (BS) (Chung, in preparation); the Basic Empathy Scale (BES)28 for measuring affective and cognitive empathy; the Brief Resilience Scale (BRS)29 for the assessment of the ability to bounce back or recover from stress; the Big Five Inventory-10 item (BFI-10)3031 to identify personality patterns; the Early Signs Scale (ESS)32 for measuring changes in key phenomenological and behavioral symptoms; the Social Functioning Questionnaire (SFQ)33 for the quick assessment of perceived social function; the Drug Attitude Inventory-10 item (DAI-10)3435 for measuring subjective attitudes toward antipsychotic medication; the Subjective Well-being Under Neuroleptics-Short Form (SWN-K)3637 for measuring subjective health-related quality of life; the Sexual Health Scale38 as a visual analogue scale (VAS) to assess sexual desire, function, orgasm, and satisfaction; the Frequent Food Questionnaire (FFQ)39 for measuring eating patterns and nutritional intake; the Physical Activity Rating (PAR)40 for categorizing a person's level of physical activity; the Family Adaptability and Cohesion Evaluation Scales-III (FACES-III)41 for measuring family adaptability and cohesion; the Alcohol Use Disorders Identification Test (AUDIT)42 as a screening instrument for hazardous and harmful alcohol consumption; and the Fagerstrom Test for Nicotine Dependence (FTND)43 for measuring the degree of nicotine dependence. The need for treatment services is determined using the VAS in terms of the explanation of illness, explanation of medication, time for personal interviews with clinicians, special group treatment programs, education on lifestyle (exercise, eating, sleep), communication among family members, and employment.

Laboratory measures and cognitive and emotional tasks

All patients included in the present study undergo assessments of height, weight, waist circumference, and systolic and diastolic blood pressure levels. Fasting venous blood samples are collected to determine the levels of cholesterol, glucose, hepatic function, and complete blood counts. For the exploratory genetic tests and measures of essential polyunsaturated fatty acids (EPUFA), the buffy coat and red blood cells are frozen at −80℃ and stored at 5 of the 10 study sites. They will be used as biologic markers of pathogenesis and long-term outcomes.44
Exploratory neurocognitive function assessments are conducted at 5 of the 10 study sites using the following computerized tests:45 attention span and vigilance are measured with the Digit Span Test (DST); verbal and visual memory abilities are assessed with the modified Rey Auditory Verbal Learning Test (VLT)4647 and the Visual Recognition Test,48 respectively; executive function and cognitive flexibility are measured with the Wisconsin Card Sorting Test;49 and sustained attention is assessed using the number of correct responses and reaction time on the Continuous Performance Test (CPT).50 Additionally, the Digit-Symbol Substitution Test (DSST),5152 which measures general cognitive efficiency, working memory, and information processing, and the Controlled Oral Word Association Test (COWAT),53 which measures letter and category fluency for verbal fluency, working memory, and cognitive speed, are manually performed in the study. For emotional task, we use facial expression recognition test (FERT) in which 8 facial expressions (anger, contempt, disgust, fear, happiness, neutral, sadness, and surprise) are presented on computer screen and participants are instructed to press response buttons that correspond to the emotion that is being displayed. Facial expressions were standardized with Korean actors.54 Each expression is presented for 750 ms with inter-trial interval of 4,500 ms. There are 16 trials of emotion labeling, two trials for each of the eight emotions. Measures of reaction time and response accuracy are recorded by the computer.

Study design

The KEPS is a prospective naturalistic observational study that includes a follow-up period of at least 2 years and 4 years when possible. The primary outcome measures are treatment response,555657 remission,58 recovery,65960 and relapse;61 the definitions of these variables are summarized in Table 1. The recovery criteria will be adjusted for all participants. The other criteria will be adjusted for all participants except those with APS,62 who have relatively low baseline PANSS or CGI-S scores. For participants with APS, transition to psychotic disorder and remission from the APS criteria according to a diagnostic interview are the outcome measures.63
Early psychotic symptoms can be diagnosed as various disorders and can change with the clinical course of the illness. Diagnosis at the first psychotic episode can be also changed according to the presence of comorbid mood episode or residual symptoms. Therefore, the diagnostic stability is regularly investigated using dimensional diagnosis of DSM-516 and the Mini International Neuropsychiatric Interview (MINI),64 which is administered at baseline, 6 months, 1 year, and 2 years. Primary outcome measures will be also compared according to the diagnosis at baseline.
The baseline assessments are divided into two stages as follows: 1) after screening and registration to a cohort, the PANSS and CGI-S are administered to evaluate the presence of acute psychotic symptoms and 2) a full baseline assessment that includes the PANSS and CGI-S are administered when patients are stabilized from their active psychotic symptoms, which is generally within 4 weeks of the initial baseline assessment. Follow-up assessments are conducted at 2, 6, 9, and 12 months and then biannually through the 3rd year and finally at the 4th year. The visit window is ±2 weeks from a scheduled visit until the 12-month visit and then ±4 weeks after that. The assessment measures that are administered at each follow-up visit are summarized in Table 2.
Drop-out was defined as missing two consecutive outpatient clinic visits. However, patients would be included in the cohort study if they returned to the clinic. After dropping out, the researchers try to contact them for follow-up evaluations at 1 and 2 years. To reduce the drop-out rate, when patients miss a clinic visit, the research team will call them to remind them about their visit.
Because this is a naturalistic observational study, the psychiatric medications and treatments are decided by the treating psychiatrists and are not influenced by the study design. However, patients with a SOFAS score less than 70 are recommended for psychosocial services in a community mental health center. The long-term outcomes according to the use of psychosocial services in a community mental health center will be compared in future studies.
The KEPS began in September 2014 and will be conducted for 5 years. A total of 9 university hospitals and 1 national mental hospital in Korea participate in this cohort study and more than 400 subjects with first episode psychotic disorders will be enrolled. All experimental protocols were approved by the institutional review boards and ethics committees of the applying sites.

Statistical analysis

The KEPS will conduct descriptive analyses of psychosocial and clinical characteristics, including DUP, changes in diagnosis, frequency of early trauma, and prevalence rates of metabolic syndrome and suicide attempts. The group comparisons will be conducted according to short and long DUP, diagnosis, subtype, use of community mental health centers, remission, relapse, and recovery. The changes in psychiatric measure scores, cognitive function, and diagnosis will be also analyzed, and the correlations of nutritional status and EPUFA with the psychiatric outcomes will be provided. The predictors of remission, relapse, and recovery will be analyzed with a logistic regression analysis and a Cox proportional hazard regression will be conducted to identify time and factors related to remission and recovery.
Psychotic disorders, including schizophrenia, are often chronic illnesses that tend to involve recurrent relapses and typically require long-term maintenance with antipsychotic medications. In fact, the relapse rate of patients with first episode schizophrenia within 5 years was 81.9%.65 On the other hand, the remission rate of these patients is relatively low and has been reportedly 23.0-46.4%.60 The Australian study found that the long-term social recovery and symptom remission in patients with first episode psychosis was 23.5%.60 In addition to the maintenance of antipsychotic medications, various psychosocial factors and life-style patterns are also closely associated with long-term clinical outcomes. Therefore, it is important to identify factors related to long-term outcomes in order to reduce the relapse rate and to enhance patient recovery from these disorders. Specifically, the key variables and measures assessed by the KEPS are DUP, early trauma, suicidality, physical health, lifestyle pattern, and cognitive function.
In conclusion, the KEPS is the first cohort study to include comprehensive measures of clinical outcomes and biopsychosocial clinical variables in patients with first episode psychosis in Korea. The identification of factors related to long-term clinical outcomes will provide important information regarding the understanding and management of psychotic disorders. This prospective naturalistic longitudinal study may contribute to the development of early intervention strategies and the improvement of long-term outcomes in Asian patients with schizophrenia.


This study was supported by a grant of the Korean Mental Health Technology R&D Project, Ministry of Health & Welfare, Republic of Korea (HM14C2608).


1. Birchwood M, Todd P, Jackson C. Early intervention in psychosis. The critical period hypothesis. Br J Psychiatry Suppl 1998;172:53-59. PMID: 9764127.
crossref pmid
2. McGorry PD. The recognition and optimal management of early psychosis: an evidence-based reform. World Psychiatry 2002;1:76-83. PMID: 16946857.
crossref pmid pmc
3. Lieberman JA, Alvir JM, Woerner M, Degreef G, Bilder RM, Ashtari M, et al. Prospective study of psychobiology in first-episode schizophrenia at Hillside Hospital. Schizophr Bull 1992;18:351-371. PMID: 1411327.
crossref pmid
4. Johnstone EC, MacMillan JF, Frith CD, Benn DK, Crow TJ. Further investigation of the predictors of outcome following first schizophrenic episodes. Br J Psychiatry 1990;157:182-189. PMID: 2224368.
crossref pmid
5. Mason P, Harrison G, Glazebrook C, Medley I, Dalkin T, Croudace T. Characteristics of outcome in schizophrenia at 13 years. Br J Psychiatry 1995;167:596-603. PMID: 8564314.
crossref pmid
6. Robinson DG, Woerner MG, McMeniman M, Mendelowitz A, Bilder RM. Symptomatic and functional recovery from a first episode of schizophrenia or schizoaffective disorder. Am J Psychiatry 2004;161:473-479. PMID: 14992973.
crossref pmid
7. Henry LP, Harris MG, Amminger GP, Yuen HP, Harrigan SM, Lambert M, et al. Early Psychosis Prevention and Intervention Centre long-term follow-up study of first-episode psychosis: methodology and baseline characteristics. Early Interv Psychiatry 2007;1:49-60. PMID: 21352108.
crossref pmid
8. Chen EY, Tang JY, Hui CL, Chiu CP, Lam MM, Law CW, et al. Three-year outcome of phase-specific early intervention for first-episode psychosis: a cohort study in Hong Kong. Early Interv Psychiatry 2011;5:315-323. PMID: 21726421.
crossref pmid
9. Basu S, Subramaniam M, Abdin E, Poon LY, Verma S. Does ethnicity have an impact on duration of untreated psychoses: a retrospective study in Singapore. Int J Soc Psychiatry 2015;61:623-630. PMID: 25608690.
crossref pmid
10. Koike S, Takano Y, Iwashiro N, Satomura Y, Suga M, Nagai T, et al. A multimodal approach to investigate biomarkers for psychosis in a clinical setting: the integrative neuroimaging studies in schizophrenia targeting for early intervention and prevention (IN-STEP) project. Schizophr Res 2013;143:116-124. PMID: 23219075.
crossref pmid
11. Lee MS, Lim HY, Kim Y, Lee YS. How can a change in the operating system of the mental health review board promote the discharge of long-term hospitalized psychiatric patients? A case study of Seoul city. Int J Ment Health Syst 2014;8:33PMID: 25114716.
crossref pmid pmc
12. Chang WC, Hui CL, Tang JY, Wong GH, Chan SK, Lee EH, et al. Impacts of duration of untreated psychosis on cognition and negative symptoms in first-episode schizophrenia: a 3-year prospective follow-up study. Psychol Med 2013;43:1883-1893. PMID: 23217676.
crossref pmid
13. Harris MG, Henry LP, Harrigan SM, Purcell R, Schwartz OS, Farrelly SE, et al. The relationship between duration of untreated psychosis and outcome: an eight-year prospective study. Schizophr Res 2005;79:85-93. PMID: 16005612.
crossref pmid
14. Yoo JM, Ahn SR, Cho YS, Lee MS. A study of duration of untreated psychosis (DUP) for first episode psychosis. Ment Health 2011;2:12-16.

15. Kim SW, Kim SY, Yoo JA, Bae KY, Kim JM, Shin IS, et al. The stigmatization of psychosis in Korean Newspaper articles. Korean J Schizophr Res 2011;14:42-49.

16. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. 5th Edition. Arlington, VA: American Psychiatric Publishing; 2013.

17. Kay SR, Fiszbein A, Opler LA. The positive and negative syndrome scales (PANSS) for schizophrenia. Schizophr Bull 1987;13:261-276. PMID: 3616518.
crossref pmid
18. Yi JS, Ahn YM, Shin HK, An SK, Joo YH, Kim SH, et al. Reliability and validity of the Korean version of the Positive and Negative Syndrome Scale. J Korean Neuropsychiatr Assoc 2001;40:1090-1105.

19. Addington D, Addington J, Schissel B. A depression rating scale for schizophrenics. Schizophr Res 1990;3:247-251. PMID: 2278986.
crossref pmid
20. Kim YK, Won SD, Lee KM, Choi HS, Jang HS, Lee BH, et al. A study on the reliability and validity of the Korean version of the Calgary Depression Scale for Schizophrenia (K-CDSS). J Korean Neuropsychiatr Assoc 2005;44:446-455.

21. Kim SW, Kim SJ, Yoon BH, Kim JM, Shin IS, Hwang MY, et al. Diagnostic validity of assessment scales for depression in patients with schizophrenia. Psychiatry Res 2006;144:57-63. PMID: 16904189.
crossref pmid
22. Guy W. ECDEU Assessment Manual for Psychopharmacology. Rockville, MD: US Department of Heath, Education, and Welfare Public Health Service Alcohol, Drug Abuse, and Mental Health Administration; 1976.

23. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. 4 th Edition. Washington, DC: American Psychiatric Association; 1994.

24. Chappell P, Feltner DE, Makumi C, Stewart M. Initial validity and reliability data on the Columbia-Suicide Severity Rating Scale. Am J Psychiatry 2012;169:662-663.
25. Smith G, Della Sala S, Logie RH, Maylor EA. Prospective and retrospective memory in normal ageing and dementia: a questionnaire study. Memory 2000;8:311-321. PMID: 11045239.
crossref pmid
26. Bremner JD, Bolus R, Mayer EA. Psychometric properties of the Early Trauma Inventory-Self Report. J Nerv Ment Dis 2007;195:211-218. PMID: 17468680.
crossref pmid pmc
27. Fowler D, Freeman D, Smith B, Kuipers E, Bebbington P, Bashforth H, et al. The Brief Core Schema Scales (BCSS): psychometric properties and associations with paranoia and grandiosity in non-clinical and psychosis samples. Psychol Med 2006;36:749-759. PMID: 16563204.
crossref pmid
28. Jolliffe D, Farrington DP. Development and validation of the Basic Empathy Scale. J Adolesc 2006;29:589-611. PMID: 16198409.
crossref pmid
29. Smith BW, Dalen J, Wiggins K, Tooley E, Christopher P, Bernard J. The brief resilience scale: assessing the ability to bounce back. Int J Behav Med 2008;15:194-200. PMID: 18696313.
crossref pmid
30. Rammstedt B, John OP. Measuring personality in one minute or less: a 10-item short version of the big five inventory in English and German. J Res Pers 2007;41:203-212.
31. Kim SY, Kim JM, Yoo JA, Bae KY, Kim SW, Yang SJ, et al. Standardization and validation of big five inventory-Korean version (BFI-K) in elders. Korean J Biol Psychiatry 2010;17:15-25.

32. Birchwood M, Smith J, Macmillan F, Hogg B, Prasad R, Harvey C, et al. Predicting relapse in schizophrenia: the development and implementation of an early signs monitoring system using patients and families as observers, a preliminary investigation. Psychol Med 1989;19:649-656. PMID: 2798634.
crossref pmid
33. Tyrer P, Nur U, Crawford M, Karlsen S, McLean C, Rao B, et al. The social functioning questionnaire: a rapid and robust measure of perceived functioning. Int J Soc Psychiatry 2005;51:265-275. PMID: 16252794.
34. Hogan TP, Awad AG, Eastwood R. A self-report scale predictive of drug compliance in schizophrenics: reliability and discriminative validity. Psychol Med 1983;13:177-183. PMID: 6133297.
crossref pmid
35. Yoon BH, Bahk WM, Lee KU, Hong CH, Ahn JK, Kim MK. Psychometric properties of Korean version of Drug Attitude Inventory (KDAI-10). Korean J Psychopharmacol 2005;16:480-487.

36. Naber D, Mortiz S, Lambert M, Pajonk FG, Golzbach R, Mass R, et al. Improvement of schizophrenic patients' subjective well-being under atypical antipsychotic drugs. Schizophr Res 2001;50:79-88. PMID: 11378316.
crossref pmid
37. Kim SW, Shin IS, Kim JM, Yoo JA, Ahn YM, Kwon JS, et al. A validation study of the Korean version of Subjective Well-being under Neuroleptic Treatment Scale - Short Form. Korean J Psychopharmacol 2007;18:221-230.

38. Lee JY, Kim SW, Lee YH, Kang HJ, Kim SY, Bae KY, et al. Factors associated with self-rated sexual function in Korean patients with schizophrenia receiving risperidone monotherapy. Hum Psychopharmacol 2015;30:416-424. PMID: 26123060.
crossref pmid
39. Ahn Y, Kwon E, Shim JE, Park MK, Joo Y, Kimm K, et al. , Validation and reproducibility of food frequency questionnaire for Korean genome epidemiologic study. Eur J Clin Nutr 2007;61:1435-1441. PMID: 17299477.
crossref pmid
40. Jackson AS, Blair SN, Mahar MT, Wier LT, Ross RM, Stuteville JE. Prediction of functional aerobic capacity without exercise testing. Med Sci Sports Exerc 1990;22:863-870. PMID: 2287267.
crossref pmid
41. Edman SO, Cole DA, Howard GS. Convergent and discriminant validity of FACES-III: family adaptability and cohesion. Fam Process 1990;29:95-103. PMID: 2311756.
crossref pmid
42. Saunders JB, Aasland OG, Babor TF, de la Fuente JR, Grant M. Development of the Alcohol Use Disorders Identification Test (AUDIT): WHO Collaborative Project on Early Detection of Persons with Harmful Alcohol Consumption-II. Addiction 1993;88:791-804. PMID: 8329970.
crossref pmid
43. Heatherton TF, Kozlowski LT, Frecker RC, Fagerström KO. The Fagerström Test for Nicotine Dependence: a revision of the Fagerström Tolerance Questionnaire. Br J Addict 1991;86:1119-1127. PMID: 1932883.
crossref pmid
44. Kim SW, Jhon M, Kim JM, Smesny S, Rice S, Berk M, et al. Relationship between Erythrocyte Fatty Acid Composition and Psychopathology in the Vienna Omega-3 Study. PLoS One 2016;11:e0151417PMID: 26963912.
crossref pmid pmc
45. Ha KS, Kwon JS, Lyoo IK, Kong SW, Lee DW, Youn T. Development and standardization process, and factor analysis of the computerized cognitive function test system for Korea adults. J Korean Neuropsychiatr Assoc 2002;41:551-562.

46. Rey A. L'examen clinique en psychologie. Paris: Presses Universitaires de France; 1964.

47. Kwon JS, Lyoo IK, Hong KS, Yeon BK, Ha KS. Development and standardization of the computerized memory assessment for Korean adults. J Korean Neuropsychiatr Assoc 2002;41:347-462.

48. Lezak MD, Howieson DB, Loring DW. Neuropsychological Assessment. 4th Ed. Oxford University Press: 2004.

49. Heaton RK, Chelune GJ, Talley JL, Kay GG, Curtiss G. Wisconsin Card Sorting Test Manual. Odessa, FL: Psychological Assessment Resources; 1993.

50. Nuechterlein KH, Dawson ME, Green MF. Information-processing abnormalities as neuropsychological vulnerability indicators for schizophrenia. Acta Psychiatr Scand Suppl 1994;384:71-79. PMID: 7879647.
crossref pmid
51. Wechsler D. A Manual for the Wechsler Adult Intelligence Scale. New York: Psychological Corporation; 1981.

52. Yum TH, Park YS, Oh KJ, Kim JG, Lee YH. The Manual of Korean-Wechsler Adult Intelligence Scale. Seoul: Korean Guidance Press; 1992.

53. Benton AL, Hamscher K. Multilingual Aphasia Examination Manual Revised. Iowa City, IA: University of Iowa; 1978.

54. Park JY, Oh JM, Kim SY, Lee MK, Lee CR, Kim BR, et al. Korean Facial Expressions of Emotion (KOFEE). Seoul, Korea: Section of Affect & Neuroscience, Institute of Behavioral Science in Medicine, Yonsei University College of Medicine; 2011.

55. Heres S, Don L, Herceg M, Bidzan L, Blanc M, Siracusano A, et al. , Treatment of acute schizophrenia with paliperidone ER: predictors for treatment response and benzodiazepine use. Prog Neuropsychopharmacol Biol Psychiatry 2014;48:207-212. PMID: 24096139.
crossref pmid
56. Park JI, Cho DH, Hahn SW, Jeong B, Kim JH, Kim SW, et al. The advantage of using 3-week data to predict response to aripiprazole at week 6 in first-episode psychosis. Int Clin Psychopharmacol 2014;29:77-85. PMID: 23970176.
crossref pmid
57. Masand P, O'Gorman C, Mandel FS. Clinical Global Impression of Improvement (CGI-I) as a valid proxy measure for remission in schizophrenia: analyses of ziprasidone clinical study data. Schizophr Res 2011;126:174-183. PMID: 21185155.
crossref pmid
58. Andreasen NC, Carpenter WT Jr, Kane JM, Lasser RA, Marder SR, Weinberger DR. Remission in schizophrenia: proposed criteria and rationale for consensus. Am J Psychiatry 2005;162:441-449. PMID: 15741458.
crossref pmid
59. Liberman RP. Recovery from schizophrenia: form follows functioning. World Psychiatry 2012;11:161-162. PMID: 23024668.
crossref pmid pmc
60. Henry LP, Amminger GP, Harris MG, Yuen HP, Harrigan SM, Prosser AL, et al. The EPPIC follow-up study of first-episode psychosis: longer-term clinical and functional outcome 7 years after index admission. J Clin Psychiatry 2010;71:716-728. PMID: 20573330.
crossref pmid
61. Csernansky JG, Mahmoud R, Brenner R. RISPERIDONE USA-79 STUDY GROUP. A comparison of risperidone and haloperidol for the prevention of relapse in patients with schizophrenia. N Engl J Med 2002;346:16-22. PMID: 11777998.
crossref pmid
62. Brandizzi M, Valmaggia L, Byrne M, Jones C, Iwegbu N, Badger S, et al. Predictors of functional outcome in individuals at high clinical risk for psychosis at six years follow-up. J Psychiatr Res 2015;65:115-123. PMID: 25837413.
crossref pmid
63. Simon AE, Umbricht D. High remission rates from an initial ultra-high risk state for psychosis. Schizophr Res 2010;116:168-172. PMID: 19854621.
crossref pmid
64. Sheehan DV, Lecrubier Y, Sheehan KH, Amorim P, Janavs J, Weiller E, 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 1998;59(Suppl 20):22-33.

65. Robinson D, Woerner MG, Alvir JM, Bilder R, Goldman R, Geisler S, et al. Predictors of relapse following response from a first episode of schizophrenia or schizoaffective disorder. Arch Gen Psychiatry 1999;56:241-247. PMID: 10078501.
crossref pmid
Table 1

Operational criteria for treatment response, remission, partial recovery, full recovery, and relapse


CGI-S: Clinical Global Impression-Severity, CGI-I: Clinical Global Impression of Improvement, PANSS: Positive and Negative Syndrome Scale, SOFAS: Social and Occupational Functioning Assessment Scale

Table 2

Assessment schedule of psychiatric measures


SC: screening, BL: baseline, PANSS: Positive and Negative Syndrome Scale, CGI-S: Clinical Global Impression-Severity, SOFAS: Social and Occupational Functioning Assessment Scale, FERT: Facial Expression Recognition Test, ETIS-SF: Early Trauma Inventory Self Report-Short Form, BFI-10: Big Five Inventory-10 item, BCSS: Brief Core Schema Scales, BS: Brooding Scale, BES: Basic Empathy Scale, ESS: Early Signs Scale, SFQ: Social Functioning Questionnaire, DAI: Drug Attitude Inventory, SWN: Subjective Well-being Under Neuroleptics, BRS: Brief Resilience Scale, AUDIT: Alcohol Use Disorders Identification Test, FTND: Fagerstrom Test for Nicotine Dependence


Browse all articles >

Editorial Office
#522, 27, Seochojungang-ro 24-gil, Seocho-gu, Seoul 06601, Korea
Tel: +82-2-717-0892    E-mail:                

Copyright © 2024 by Korean Neuropsychiatric Association.

Developed in M2PI

Close layer
prev next