J Med Dent Sci 2010； 57： 83－94

Original Article

Reliability and Diagnostic Validity for Schizophrenia of the Japanese Version of the Bonn Scale for Assessment of Basic Symptoms (BSABS)

Kazunari Oshima1), Tsukasa Okimura2), Tomoaki Yukizane1), Katsuhiro Yasumi3), Astushi Iwawaki4), Toru Nishikawa1) and Seiichi Hanamura1)5)

1) Section of Psychiatry and Behavioral Science, Tokyo Medical and Dental University Graduate School 2) Inagidai Hospital, 3) Health Service Center,Tokyo Institute of Technology 4) Kanuma Hospital 5) Tokyo University of Social Welfare

Schizophrenia is defined by operative diagnostic showed 0.711. Our findings suggest that, although criteria in DSM-IV with some typical symptoms as these clusters symptoms differ from DSM-Ⅳ hallucinations and duration of the disease. Huber criteria, they are related to fundamental process focused on the subjective experience of patients of schizophrenia. Use of some of these three and coined the term “basic symptoms” and created clusters with other neurophysiological markers BSABS. Our study investigated the reliability and could allow clinical evaluation of schizophrenia the diagnostic validity of the 5 clusters of BSABS from a new perspective. for DSM-IV-based diagnosis of schizophrenia with a cohort of 105 patients. Good inter-rater Key words: schizophrenia, reliability, diagnostic validity, reliability was obtained except for one item D.10. BSABS, DSM-IV As evaluated by Spearman’s rank correlation coefficients, among the 5 clusters excluding (1) Introduction Cluster 2, internal consistency was good. This suggests that, although each cluster is Schizophrenia is an illness causing dysfunction heterogeneous, cluster symptoms are the marked by repeated hallucinations and delusions, expression of physiological and biological disorganized speech, and catatonic behavior. disturbances of schizophrenia. Receiver Operating Historically, Kraepelin saw the importance of course of Characteristic Curve analysis was also used to illness in the classification of mental disorders, while show the ability of each cluster to discriminate Bleuler focused on loosening of association and schizophrenia. Results showed that the area disturbance of thought, and Schneider developed “first- representing the powers in discriminate rank symptoms” considered characteristic of schizophrenia of Cluster 4 “Adynamia”, which is schizophrenia 1). Based on this pathognomy, DSM-IV was considered related to the dynamic aspect of completed in 1994 as a set of operative diagnostic thinking,was highest, at 0.739. Cluster 1 criteria in the U.S. 2) In DSM-IV, schizophrenia is defined “Information processing disturbances” which has a by operative diagnostic criteria specifically derived predictive ability for schizophrenia showed 0.714 through statistical verification 2) :Criterion A: Two (or and Cluster 3 “Impaired tolerance to normal stress” more) of the following, each present for a significant portion of time during a 1-month period: (1) Delusions, (2) Hallucinations, (3) Disorganized speech, (4) Grossly Corresponding Author：Kazunari Oshima disorganized or catatonic behavior, and/or (5) Negative Yushima 1-5-45, Bunkyo-ku, Tokyo, 113-8519, Japan symptoms. Criterion B: Social/occupational dysfunction. Tel: 03-5803-5673 Fax: 03-5803-0245 E-mail: [email protected] Criterion C: Duration (Continuous signs of the Received September 30；Accepted November 13, 2009 disturbance persist for at least 6 months, including 84 K. Oshima et al. J Med Dent Sci periods of prodromal, active, or residual symptoms.) perception, and motor function, and covers several Schizophrenia is likewise defined by exclusion of other phases in the course of schizophrenia from subclinical mental illnesses and the direct physiological effects of signs in the prodrome, through progression to acute- a substance. 2) These DSM-IV criteria can be used to phase symptoms, to residual-phase symptoms. diagnose schizophrenia in a straightforward, operational In the dimensions of causalism-descriptivism and manner. objectivism-evaluativism, and in the context of patient- Despite national differences in traditional psychiatry, oriented psychiatry, BSABS could focus on a new these criteria have high diagnostic reliability, and the perspective on schizophrenia research. majority of current schizophrenia research worldwide Leading research using the BSABS includes the proceeds on the basis of the DSM-IV diagnostic criteria. following. In a follow-up study on development of Although DSM-IV has high reliability in diagnosis, symptoms, Klosterkötter12) followed the course of Criteria A symptoms do not account for all development from basic symptoms to first-rank schizophrenia symptoms, and the validity of DSM-IV- symptoms in 121 inpatients. Klosterkötter et al. then based diagnosis of schizophrenia has correspondingly examined the diagnostic validity of the BSABS 13) in become a topic of recent concern. 3) In the treatment of 1996. They applied a simplified version of the BSABS to schizophrenia, importance is laid on improvement of a group of 79 healthy individuals and a patient group of social function and increased interpersonal capability 243 individuals with disorders classified by WHO following acute-phase drug treatment, and there is a Classification of Diseases (ICD-10) categories as F0 - like focus on negative symptoms in the residual phase. Organic mental disorders; F1 - Mental and behavior Negative symptoms are defined only in terms of disorders due to psychoactive substance use; F2 - symptom complexes including affective flattening, Schizophrenia, schizotypal, and delusional disorders; alogia (poverty of speech), and avolition, and the Scale F3 - Mood (affective) disorders; F4 - Neurotic, stress- for the Assessment of Negative Symptoms (SANS) 4)5) is related, and somatoform disorders; and F6 - Disorders based on these clusters. In the residual phase, however, of adult personality and behavior. Through cluster a more detailed symptomatic scale relating to recovery analysis, they extracted 5 BSABS clusters and is needed. demonstrated that these clusters served as indicators In the U.S., where DSM-IV was created, a task force discriminating ICD-10 categories F0-F4 and F6. for DSM-Ｖ discussed certain dimensions of categorization of psychiatric disorders,6)7) namely: 1) causalism- Our research is original in the following two respects: descriptivism, 2) essentialism-nominalism, 3) First, it is the first to investigate the reliability and the objectivism-evaluativism, 4) internalism-externalism, 5) diagnostic validity of a simplified Japanese version of entities-agents, and 6) categories-continua. In this the BSABS by trial application among Japanese context, there is a focus on incorporating Patients’ patients. subjective experiences. 8) Second, it is also the first study using DSM-IV to In Germany, the center of descriptive phenomenology, investigate the validity of the BSABS in the diagnosis of beginning in the 1960s Huber noted the fact that many schizophrenia, although Klosterkötter used ICD-10 schizophrenia patients were aware of their own deficits diagnosis in his study of the diagnostic validity of and could also state what they were during most BSABS. phases of long-term progression. 9) He regarded this as evidence of fundamental disturbances akin to organic (2) Subjects and Methods factors and coined the term “basic symptoms.” 10) In 1982, Gross et al. provided a description and Instrument extensive listing of basic symptoms, after which the The BSABS was translated in its entirety, and a Bonn Scale for the Assessment of Basic Symptoms simplified Japanese version of the BSABS was created (BSABS) 11) was completed in 1987. from 53 items divided into 5 clusters extracted on the Klosterkötter, the successor of Huber, redefined basic basis of cluster analysis of cases with diagnosis ICD-10 symptoms as “self-perceivable” neuropsychological categories F0-F4 and F6 by Klosterkötter 13): Cluster 1 – deficits representing subtle, subclinical signs of illness. thought, language, perception, and motor disturbances The BSABS is a symptom assessment scale based on (Information processing disturbances). Cluster 2 – description of a variety of self-experienced symptoms Impaired bodily sensations (coenaesthesias), Cluster 3 – related to drive, stress-tolerance, emotion, thought, Impaired tolerance to normal stress, Cluster 4 – Reliability and Diagnostic Validity for Schizophrenia of BSABS 85

Adynamia (disorders of emotion and affect, disturbance schizophrenia. Of these 19 cases, 15 cases whom we of short-term memory and disturbance of immediate have followed did not develop schizophrenia. Among 4 recall, disturbance of thought process), and Cluster 5 – cases with schizophreniform disorder, 3 cases have still Increased emotional reactivity (Interpersonal irritation). the same diagnostic and one case stopped to come to The 5 clusters and 53 items are shown in Table Ⅰ. consultation. Among 4 cases with delusional disorder, any case did not develop schizophrenia. Among 2 Subjects cases with brief psychotic disorder, 1 case still have the same diagnostic and another case stopped to come The subjects included a total of 109 cases: A cohort to consultation. Among 9 cases with psychotic not of patients hospitalized in the Department of Psychiatry otherwise specified, 7 cases still have the same of the University Hospital of Medicine, Tokyo Medical diagnostic and 2 cases did not come to the and Dental University from 1998 to 2005 and consultation. diagnosed with schizophrenia based on DSM-IV at . admission, and another cohort of patients with To evaluate the inter-rater reliability of BSABS, two suspected schizophrenia in which confirmative raters had a interview with 35 patients among total diagnosis could not be made at admission. The latter sample of 105 patients. The distribution of diagnoses of group was selected with the following criteria: (1) 35 patients are as follows: 28 schizophrenia, 1 Psychotic symptoms such as hallucinations, delusions, schizophreniform disorder, 2 delusional disorders, 2 or catatonic symptoms present in attenuated form or psychotic disorders not otherwise specified, 2 major persisting less than 1 month; or subtle disturbance of depressive disorders.. thought. Alternatively, (2) A state demonstrating sudden deterioration in social or occupational function requiring The BSABS raters consisted of 3 psychiatrists with hospitalization. Cases in the latter cohort fulfilled some clinical experience of more than 10 years in the criteria in the diagnosis of schizophrenia according to Department of Psychiatry, University Hospital of Tokyo DSM-IV but did not satisfy all criteria of the diagnostic Medical and Dental University, who had each standard. However, they were characterized by the undergone 10 sessions of BSABS training. One rater onset or relapse of mental illness leading to conducted a semi-structured interview with the patient hospitalization and exhibited symptoms corresponding in the presence of another psychiatrist, and two raters to “incomprehensibility” and “discontinuity of meaning” performed blinded evaluation of BSABS symptoms. The as described by Jaspers. 1) two raters scored self-perceivable symptoms mentioned by the patient, with scoring on three levels as: (1) Procedure for data assessment Present (2 points), (2) Doubtful (1 point), and (3) Absent The simplified Japanese-language BSABS was tested (0 point) and determined the total score for each in 109 cases. Four cases with missing values were cluster. excluded, making the total number in the sample 105. We obtained informed consent in written form for Statistical procedures BSABS interviews and use of data for research. All First, to investigate inter-rater reliability between the cases received a confirmatory diagnosis by DSM-IV two raters, Cohen’s k coefficient was determined for during the observational evaluation phase of each BSABS item using SPSS15.0 statistical software. hospitalization. The schizophrenia cohort consisted of Inter-rater reliability was determined in 35 cases among 65 cases, including 63 with schizophrenia and 2 with 105 cases of a cohort of this study. simple deteriorative disorder (simple schizophrenia), Next, to examine the internal consistency of the while the non-schizophrenia cohort included 40 cases. BSABS, product-moment correlation was determined for All cases were also evaluated for social function at each cluster by Spearman’s rank correlation admission and discharge using the GAF (Global coefficient. Cronbach’s α coefficient was also Assessment of Functioning) Scale. Table Ⅱ presents determined. the composition of confirmatory diagnoses of 105 Finally, to determine concurrent validity with the DSM- patients by DSM-IV at discharge. IV in the diagnosis of schizophrenia by BSABS, Among 105 patients, we have followed carefully 19 Receiver Operating Characteristic Curves (ROC curves) patients with the other psychotic disorders among the were determined with horizontal plotting of false- non-cohort schizophrenia to reconfirm if they develop positive rates (1 – specificity) and vertical plotting of 86 K. Oshima et al. J Med Dent Sci

Table Ⅰ. Symptoms of the Bonn Scale for the Assessment of Basic Symptoms (BSABS) and their clusteranalytical grouping by Klosterkötter 13)17) Note: The original names of 5 Clusters revised by Klosterkötter are noted in parentheses at the end of each Cluster. The number of each symptom in the original BSABS 11) by Huber is noted at left columns of this table.

No.of D.1s1 Somatopsychic bodily depersonalization Basic Symptoms items D.2 Bodily sensations of motor weakness, ‘paralysis’ Cluster 1：Thought, language, perception and motor disturbances D.3 Unusual bodily sensations of pain in a distinct area ( Information processing disturbances) D.4 Migrating bodily sensations ‘wandering’ through the body Decreased capacity to discriminate between different kinds A.6.2 D.5 Electric bodily sensations, feelings of being electrified of emotions D.6 Thermal bodily sensations, unusual coldness or warmth C.1.1 Thought Interference Bodily sensations of movement, pulling or pressure inside D.7 C.1.2 Thought perseveration the body or on its surface C.1.3 Thought pressure Sensations of the body or parts of it being abnormally heavy, D.8 C.1.4 Thought blockage light, empty, falling or sinking Sensations of the body or parts of it extending, diminishing, C.1.6 Disturbances of receptive language, either heard or read D.9 shrinking, enlarging, growing, constricting C.1.7 Disturbances of expressive language D.10 Vestibular sensations, pseudomovements of the body Disturbances of retrieval of presently required knowledge C.1.10 from long-term memory Kinesthetic sensations like vertigo, unsure gait, walking on D.11 moving ground Decreased ability to discriminate between ideas and percep- C.1.15 tion, fantasy and true memories Dysesthetic crises(unusual bodily sensation plus central- D.14 vegetative disturbance or fear of dying any minute) C.1.16 Disturbance of abstract thinking ( ‘concretism’ ) C.2.1s1 Blurred vision Cluster ３：Impaired tolerance to normal stress (Vulnerability) C.2.1s3 Partial seeing incl. tubular vision B.1.1 Impaired tolerance to everyday stress or routine work C.2.2s1 Hypersensitivity to light or certain optic stimuli A.8.1 ＋ Impaired tolerance to unusual, unexpected or specific novel C.2.2s2 Photopsia B.1.2 demands C.2.3s1 Near and tele-vision A.8.2 ＋ Impaired tolerance to certain social situations of everyday B.1.3 life that are primarily emotionally neutral C.2.3s2 Micropsia, macropsia A.8.3 ＋ Impaired tolerance to working under pressure or time or C.2.3s3 Metamorphopsia B.1.4 rapidly changing different demands C.2.3s4 Changes in color vision A.8.4 Inability to divide attention C.2.3s5 Changed perception of the face/body of others Cluster ４： Disorders of emotion and affect (Adynamia) C.2.3s6 Changed perception of the patient’s own face C.2.3s7 Pseudomovements of optic stimuli A.6.1 Change in mood and emotional responsiveness C.2.3s8 Diplopsia, oblique vision A.6.4 Decrease in the need for contact with others C.2.3s9 Disturbances of the estimation of distances or sizes C.1.5 Difficulties concentrating C.2.3s10 Disturbances of perception of straight lines or contours Difficulties to hold things in mind for seconds ( immediate C.1.8 recall) C.2.3s12 Maintenance of optic stimuli, ‘visual echoes’ Difficulties to hold things in mind for less than half an hour C.2.4s1 Hypersensitivity to sounds or noise C.1.9 (short-term memory) C.2.4s2 Acoasms C.1.12 Slowed-down thinking Changes in the perceived intensity or quality of acoustic C.2.5s1 C.1.13 Lack of ‘thought energy’ or goal-directed thoughts stimuli C.2.5s2 Maintenance of acoustic stimuli , ‘acoustic echoes’ Cluster5：Increased emotional reactivity ( Interpersonal irritation) C.2.6 Disturbances of olfactoric, gustatoric or sensible perception A.7.1 Decrease in the ability to maintain or initiate social contacts C.2.8 Feeling overwhelmed by stimuli, hyperdistractibility Disturbances of emotional responsiveness as characterized C.2.9 Captivation of attention by details of the visual field A.7.2 by a decrease in facial expression, intonation and communi- cation gestures C.2.11 Derealization Increased emotional reactivity in response to everyday C.3.1 Motor interference exceeding simple lack of coordination B.2.1 events C.3.2 Motor blockages Increased emotional reactivity in response to routine social B.2.2 C.3.3 Loss of automatic skills interactions Increased emotional reactivity in response to misfortune to Cluster ２：Impaired bodily sensations ( Coenaesthesias ) B.2.3 strangers D.1 Unusual bodily sensations of numbness or stiffness C.1.17 Unstable ideas of reference Reliability and Diagnostic Validity for Schizophrenia of BSABS 87

Table Ⅱ. The composition of diagnoses of schizophrenia cohort and of non-schizophrenia cohort by DSM-Ⅳ A Schizophrenia Cohort 65 cases 295 Schizophrenia 63 cases 295.30 Paranoid type 29 cases 295.10 Disorganized type 4 cases 290.20 Catatonic type 1 case 295.90 Undifferentiated type 27 cases 295.60 Residual Type 2 cases Simple deteriorative disorder 2 cases

B Non-schizophrenia Cohort 40 cases Diagnoses on Axis Ⅰ Other psychotic disorders 295.40 Schizophreniform disorder 4 cases 297.1 Delusional disorder 4 cases 298.8 Brief Psychotic disorder 2 cases 298.9 Psychotic disorder Not otherwise Specified 9 cases Mood disorders 7 cases Anxiety Disorders 3 cases Somatoform Disorders 1 case Eating disorders 2 case Adjustment disorders 5 case Conduct disorder 1 case Psychiatric disorder 1 case Not otherwise Specified

No diagnosis on AxisⅠ, 1 case Diagnosis on AxisⅡ：schizotypal personality disorder

sensitivity corresponding to cut-off points for each Although the two groups exhibited similar age at cluster in the diagnosis of schizophrenia for the examination, age at onset, and number of hospitalization, schizophrenia cohort (65 cases) and non-schizophrenia the schizophrenia cohort had longer duration of disease cohort (40 cases). and duration of hospitalization, and also had more The diagnostic validity of BSABS for schizophrenia, number of hospitalization. On GAF at admission, the which is not influenced by the choice of cut-off points, schizophrenia group was approximately 8 points lower, can be assessed by a geometric approach using but at discharge no substantial difference was the area under the corresponding ROC curve. A observed between the groups. nonparametric method of this approach for related samples was used to compare the diagnostic validity 1) First, inter-rater reliability for the BSABS was for schizophrenia of 5 clusters of BSABS. determined based on Cohen’s κ coefficient. Missing values of the item C.2.11(Derealization) prevented (3) Results assessment of 1/53 items in the simplified Japanese BSABS, but good consistency was obtained among 52 All 105 cases receiving a confirmatory diagnosis by items and overall except for the item D.10 of Cluster2. DSM-IV were divided into two groups by diagnosis on Table Ⅳ shows the values of Cohen’s κ coefficient for Axis I: a schizophrenia cohort (65 cases) and a non- each item of BSABS. schizophrenia cohort (40 cases). Descriptive statistical characteristics of the two groups are shown in Table Ⅲ 2) Next, to examine the internal consistency of the 88 K. Oshima et al. J Med Dent Sci

Table Ⅲ. General Data of Sample(N＝105)

Schizophrenia (n ＝ 65) Non-schizophrenia (n ＝ 40) Mean±SD(Median) Mean±SD(Median)

Age at Examination, y 31.3 ± 10.3 29.0 ± 8.87

Age at onset, y 22.5 ± 7.64 24.3 ± 7.50

Duration of Disease, y 8.42 ± 8.39 4.75 ± 4.50

Number of hospitalization 2.57 ± 2.92 1.80 ± 1.86

Duration of hospitalization, day 144.0 ± 90.1 74.0 ± 46.3

GAF in admission 33.9 ± 11.0 41.8 ± 12.3

GAF at discharge 56.4± 11.3 57.8 ± 15.4

BSABS, the product-moment correlation was (4) Discussion determined for each cluster based on Spearman’s rank correlation coefficient, as shown in Table Ⅴ. To test the diagnostic validity of BSABS for Results of statistical analysis of product-moment schizophrenia, we first evaluated inter-rater reliability correlations among the 5 clusters evaluated by and investigated the internal consistency of BSABS and Spearman’s rank correlation coefficient were as the powers in discriminating schizophrenia of the 5 follows. Cluster 1 correlated highly with Clusters 2, 3, clusters of the BSABS. and 5, and also correlated moderately with Cluster 4. We first translated the BSABS in entirety and then Cluster 2 demonstrated high correlation with Cluster 1, created a simplified Japanese version of the BSABS and moderate correlation with Cluster 3, but exhibited from a total of 53 items divided into 5 clusters low correlations with Clusters 4 and 5. Cluster 3 was extracted on the basis of cluster analysis with ICD-10 highly correlated with Clusters 1, 4, and 5, and was diagnosis by Klosterkötter et al. 13) moderately correlated with Cluster 2. Cluster 4 demonstrated high correlation with Cluster 3, and 1) Inter-rater reliability moderate correlation with Clusters 1 and 5. Cluster 5 Gross et al. first 14) studied the reliability of BSABS in also demonstrated high correlations with Clusters 1 and 1989, and found that inter-rater consistency was good, 3, and moderate correlation with Cluster 4. with a correlation coefficient of 0.808. Furthermore, Cronbach’s α coefficient was also 0.788 In our study, inter-rater reliability was reflected in 34 for standardized items, indicating good internal items with a κ coefficient of 0.8 or higher and 48 items consistency. with a κ coefficient of 0.7 or higher, accounting for most items. Only 4 items had a value less than 0.7, a 3) Finally, Figure 1 presents Receiver Operating good result overall except for D10 (Kinesthetic Characteristic Curves (ROC curves) with horizontal sensation) in Cluster 2. . plotting of false-positive rates (1 – specificity) and In 2007, Vollmer-Larsen et al. 15) determined Cohen’s vertical plotting of sensitivity corresponding to cut-off κ coefficient for 79 BSABS items by the same method points for each cluster in schizophrenia diagnosis for we used, and while κ exceeded 0.6 for 68 items (86%), the schizophrenia cohort (65 cases) and non- we achieved higher inter-rater reliability. The BSABS is schizophrenia cohort (40 cases). The areas under the a semi-structured interview including many questions corresponding ROC curve for the 5 clusters are as and requiring a long interview time. However, through follows; training of experienced psychiatrists, our results The largest area under the ROC curve was 0.739 for exhibited good inter-rater reliability. Cluster 4, followed by 0.714 for Cluster 1, and 0.711 for Cluster 3. That of Cluster 5 was low, at 0.638, and 2) Internal consistency of BSABS that of Cluster 2 was very low, at 0.561. Our study used Spearman’s rank correlation Reliability and Diagnostic Validity for Schizophrenia of BSABS 89

Table Ⅳ. Cohen’s κ coefficient of each item of BSABS Cluster 1 Cluster 3

A.6.2 0.93 B.1.1 0.77 C.1.1 0.74 A8.1B1.2 0.90 C.1.2 0.85 B3 0.85 C.1.3 0.95 B4 0.95 C.1.4 0.95 B5 0.83 C.1.6 0.91 C.1.7 0.85 Cluster 4 C.1.10 0.86 C.1.15 1.00 A.6.1 0.79 C.1.16 0.83 A.6.4 0.74 C.2.1 0.88 C.1.5 0.85 C.2.2 0.83 C.1.8 0.85 C.2.3 0.75 C.1.9 0.90 C.2.4 0.90 C.1.12 0.85 C.2.5 0.86 C.1.13 0.90 C.2.6 0.83 C.2.8 0.80 Cluster 5 C.2.9 1.00 C.3.1 0.75 A.7.1 0.76 C.3.2 0.90 A.7.2 0.65 C.3.3 0.88 B.2.1 0.76 B.2.2 0.91 Cluster 2 B.2.3 0.90 C.1.17 0.75 D.1 0.82 D.1S1 0.69 Cohen’s κ coefficient D.2 0.84 D.3 0.76 κ Number of items D.4 0.90 D.5 0.64 0.9 ≤ κ 9 items D.6 0.94 D.7 0.76 0.8 ≤ κ＜ 0.9 25 items D.8 0.77 D.9 0.75 0.7 ≤ κ＜ 0.8 14 items D.10 0.38 D.11 0.83 κ ＜ 0.7 4 items D.14 0.71

coefficient, because the order among status in each Coefficient 0.1-0.3), moderate(0.3-0.5)and high(0.5-0.7) symptom is important and the observations are referred as Cohen 16) proposed. to as ordinal data. Results of statistical analysis of Cluster 1 correlated highly with Clusters 2, 3, and 5, product-moment correlations among the 5 clusters and also correlated moderately with Cluster 4. Cluster evaluated by Spearman’s rank correlation coefficient 2 demonstrated moderate correlation with Cluster 3, were as follows. and low correlations with Clusters 4 and 5. Cluster 3 To discuss about the internal consistency, we use for was highly correlated with Clusters 1, 4, and 5. Cluster simplicity, the descriptions, small (Correlation 4 demonstrated high correlation with Cluster 3, and 90 K. Oshima et al. J Med Dent Sci

Table Ⅴ. Internal consistency of Bonn Scale for the Assessment for Basic Symptoms

1. Spearman’s rank correlation coefficient of 5 Clusters of BSABS Cluster 1 Cluster 2 Cluster 3 Cluster 4 Cluster 5 Spearman’s rank Cluster 1 Correlation correlation coefficient coefficient .548(**) .613(**) .462(**) .569(**) Level of significance – .000 .000 .000 .000 (bilateral) N 105 105 105 105 Cluster 2 Correlation . .346(**) .189 .199(*) coefficient Level of significance – .000 .054 .042 (bilateral) N 105 105 105 Cluster 3 Correlation . .543(**) .501(**) coefficient Level of significance – .000 .000 (bilateral) N 105 105 Cluster 4 Correlation .468(**) coefficient Level of significance – .000 (bilateral) N 105 Cluster 5 Correlation coefficient Level of significance – (bilateral) N ** Correlation is significant in the 1% level (bilateral). * Correlation is significant in the 5% level (bilateral). 2. Cronbach’s α of 5 Clusters of BSABS Cronbach’s α of 5 clusters of BSABS is 0.788.

moderate correlation with Clusters 1 and 5. and thought blockage shifted to first “rank” symptoms Furthermore, Cronbach’s α coefficient was also 0.788 of experience of “passivity”, and that another type of for standardized items, indicating good internal symptom in Cluster 1; thought pressure and decreased consistency. ability to discriminate ideas and perceptions, could In long-term follow-up research by Klosterkötter et develop hallucinations. These results suggest that al. 17) about predictive ability of BSABS for schizophrenia, Cluster 1 symptoms could shift to complexes of prospective study of cases free of positive symptoms schizophrenic symptoms, and are compatible with the of the early prodrome revealed that Cluster 1 result that Cluster 1 is highly correlated with other (Information processing disturbances) had high clusters. prognostic accuracy for schizophrenia onset. In Each of the 5 clusters of the BSABS is homogeneous. addition, in another follow-up study 12), Klosterkötter After Huber created the original BSABS, 11) there was observed during hospitalization that some symptoms of criticism by Janzarik18) that the BSBAS includes Cluster 1; thought interference, thought preservation heterogeneous symptoms and that many symptoms of Reliability and Diagnostic Validity for Schizophrenia of BSABS 91

Figure 1 : Receiver Operating Caracteristics (ROC) Curves of 5 clusters of BSABS (N = 105) The horizontal plotting indicates false-positive rates (1 – specificity) and the vertical plotting indicates sensitivity, corresponding to cut-off points for each cluster in schizophrenia diagnosis for the schizophrenia cohort (65 cases) and non-schizophrenia cohort (40 cases). Areas under the ROC curve of each Cluster is as follows: Cluster1; 0.714, Cluster 2; 0.561, Cluster 3; 0.711, Cluster 4; 0.739, Cluster 5; 0.638, Sum; 0.732

the category “dynamic deficiencies” have two aspects: also 0.788, indicating good internal consistency. These basic deficiency symptom and its effect: To respond to findings suggest that, although symptom expression this point, Huber thinks the dynamic deficiency is the differs in each cluster, with the exception of Cluster 2, central psychopathology of schizophrenia and created each cluster is the expression of common process of a category of “dynamic deficiencies with direct or schizophrenia as Klosterkötter 12) demonstrated that indirect minus symptoms” to clarify the effects of complexes of complaints of cognitive thought dynamic deficiencies. In the end, Klosterkötter revised disturbances developed first “rank” symptoms like these categories using cluster analysis, which yielded 5 hallucinations or experience of passivity. That is why clusters. Huber named this fundamental disturbance “basic”. Cluster 1 represents information processing disturbances, Cluster 2 impaired bodily sensations, 3) Diagnostic validity for schizophrenia of 5 Cluster 3 impaired tolerance to normal stress, Cluster 4 clusters of BSABS disorders of emotion and affect which also include Our study investigated the discriminating power of disturbance of memory, and Cluster 5 increased each of the 5 clusters of the simplified version of emotional reactivity. Although the 5 clusters are BSBAS in the DSM-IV diagnosis of schizophrenia. psychopathologically heterogeneous and the items in Multivariate analysis by Klosterkötter 13) in the first each cluster are homogeneous, clusters other than study concerning the diagnostic validity of BSABS Cluster 2 exhibited high or moderate correlation with showed the ability of each cluster to discriminate each other as determined by Spearman’s correlation illness, as follows. In all 5 clusters, there was coefficient. Furthermore, Cronbach’s α coefficient was discrimination of F6 (disorders of adult personality and 92 K. Oshima et al. J Med Dent Sci behavior), F4 (neurotic, stress-related and somatoform category “impairment of affect and social contact” disorders), and F1 (mental and behavioural disorders among the 6 categories of the original BSABS. More due to psychoactive substance use) from what are recently, Klosterkötter et al. completed a cluster termed the traditional psychosis groups of F2 analysis of BSABS items with regard to ICD-10 diseases (schizophrenia, schizotypal, and delusional disorders), and concluded, based on the results of determination of F0 (organic, including symptomatic, mental disorders), squared correlations among items, that these 7 items fit and F3 (mood 《affective》 disorders). Results also into one cluster, “adynamia” 13), which they revised. showed that Cluster 1 – Information processing Cluster ４ Adynamia, also named “disorders of emotion disturbances discriminated schizophrenic disorders and and affect” which includes disturbance of memory, and organic mental disorders from other groups, and that some of them are related to negative symptoms. Cluster Cluster 5 – Interpersonal irritation discriminated 4 Adynamia has been considered related to the schizophrenic disorders from all other groups.This dynamic aspects of thinking and comprises 1) change study demonstrated the ability of each cluster to in mood and emotional responsiveness, 2) decrease in discriminate F2 from other psychiatric disorders the need for contact with others, 3) difficulties including F0, F1, F3, F4, and F6, which are etiologically concentrating, 4) difficulties to hold things in mind for different. seconds(immediate recall), 5) difficulties to hold things Our research focused on the power of BSABS in the in mind for less than half an hour (short-term memory), DSM-IV diagnosis of schizophrenia of discriminating it 6) slowed-down thinking, and 7) lack of ‘thought energy’ from other psychotic disorders and related mental or goal-directed thoughts. In the past, thought disorders. disturbance was regarded as a single symptom We evaluated the ability of the BSBAS to distinguish a including phenomena such as loosening of association schizophrenia cohort from a non-schizophrenia cohort and alogia 4), but theories in the U.S. and U.K. 12) hold exhibiting attenuated hallucinations, delusions, that the fundamental deficit in schizophrenia is an catatonic symptoms, or subtle thought disturbances, or inability to produce planned thought activity and acute social or occupational dysfunction requiring speech activity, and adynamia is evaluated with respect inpatient treatment. to several functions relating to production of such Diagnostically, 19 of 40 cases in the non-schizophrenia volitional thought activity. The finding that adynamia cohort represented other psychotic disorders viewed in this light had a powerful ability to distinguish (schizophreniform disorder, schizoaffective disorder, schizophrenia from other psychotic disorders and delusional disorder, brief psychotic disorder, and psychiatric disorders which had a sudden social psychotic disorders not otherwise specified), while the dysfunction after onset, is of great interest. It suggests remaining cases varied in diagnosis but shared the that disturbance of dynamic aspects of thinking is a feature of acute dysfunction. The non-schizophrenia fundamental disturbance in schizophrenia. cohort was characterized by the onset or relapses of Considering in another aspect, some symptoms of mental illness, corresponding in German psychiatry to Cluster 4 is similar to negative symptoms: affective the “incomprehensibility” and “discontinuity of meaning” flattening, alogia and avolition. It is possible that Cluster described by Jaspers. 4 symptoms have an influence of neuroleptic-induced Schizophrenia differs from non-schizophrenic diseases secondly negative symptoms. We don’t discuss about in that the durations of prodromal, acute, and residual this point further in this study and we need another phases are defined. investigation. In the study by Klosterkötter 17) which investigates 4) ROC curves of 5 clusters of BSABS predictive ability for schizophrenia, only Cluster 1 The diagnostic validity of BSABS for schizophrenia is Information processing disturbance has high predictive assessed by the area under ROC curves. power for schizophrenia. Subjects are patients who The areas under ROC curves were 0.739 for Cluster 4, don’t have positive symptoms and are at risk state or the largest, followed by 0.714 for Cluster 1, and 0.711 early prodromal phase. On the other hand, in our study, for Cluster 3. That of Cluster 5 was low, at 0.638, and subjects are patients in true prodromal phase, after that of Cluster 2 was very low, at 0.561. onset or at relapse. For the latter cohort of subjects, Cluster ４ Adynamia is characterized by 5 items that Cluster 4 could have the most discriminating power for Huber had initially included in the category “thought schizophrenia. disturbances”, and 2 items initially included in the Reliability and Diagnostic Validity for Schizophrenia of BSABS 93

In Cluster 1 – Information processing disturbances, we BSABS. 19) The responsive search score(RSS) in the also rated a wide range of information processing items exploratory eye movement indicators can be a relating to thought, language, perception, and motor vulnerability marker of schizophrenia. The RSS has disturbances. As we discussed about the internal significant correlations with Cluster 4 and Cluster 3. consistency, Cluster 1 has a strong predictive value for This study support the result that Clusters 4, 1, and 3 schizophrenia and some symptoms of Cluster 1 could are able to discriminate schizophrenia. develop first “rank” symptoms. In our study, Cluster 1 is also important to discriminate schizophrenia after onset 5) Future directions of application of BSABS or at relapse. With regard to diagnostic validity, Robins and Guze 20) In Cluster 3 – Impaired tolerance to normal stress, we as long ago as 1970 proposed levels of diagnostic rated dysfunction occurring primarily during work and validity including: 1) clinical description, 2) laboratory other such mental and physical activity, Huber thinks data research, 3) delimitation from other disorders, 4) symptoms of Cluster 3 are direct or indirect effect of follow-up study, and 5) family investigation. In 1990, dynamic deficiencies, and in DSM-Ⅳ terminology this Kendler 21) built on this concept to segment, advance cluster is related to negative symptoms and social validity, present validity (psychological/biological data), dysfunction. and predictive validity (e.g., diagnostic consistency, It is plausible that Clusters 3 could distinguish longitudinal variation in function, and responsiveness to schizophrenia with regard to the level of social treatment).3） dysfunction and its cause “dynamic deficiencies ”. The BSABS derives from descriptive phenomenology, i.e., detailed description by the patient of These results seem to be different from that of the neuropsychological deficit symptoms, and its clinical study by Klosterkötter with Cluster analysis which descriptions differ from those of the DSM-IV. indicates that Cluster5(interpersonal irritation) Our research, which focused on distinction from other distinguish F2 from other psychiatric disorder. diseases, investigated the concurrent validity in Although ICD-10 diagnosis F2 includes F20 diagnosis of schizophrenia of DSM-Ⅳ and the BSABS, schizophrenia, F21 schizotypal disorder, F22 Persistent which feature differing clinical descriptions of delusional disorders, F23 acute and transient psychotic schizophrenia. Although DSM-Ⅳ defines schizophrenia disorders, F24 Indeced delusional disorder, F25 with typical symptoms (hallucinations, delusions, schizoaffective disorders and other nonorganic disorganized speech and catatonic behavior and psychotic disorders, the study by Klosterkötter did not negative symptoms), social dysfunction and duration of focus on discriminating power of each Cluster for F20, disease, BSABS could describe and define schizophrenia. It is plausible to think that, F2 includes schizophrenia just with subjective experience schizophrenia and other psychotic disorders marked by symptoms of Cluster4 (adynamia), Cluster 1(Information a typical symptom; “idea or delusion of reference”, and processing disturbances) and Cluster3 (Impaired that’s why Cluater 5 could distinguish F2 from other tolerance to normal stress). psychiatric disorder. The simplified Japanese version of the BSABS is a Cluster 2-Impaired bodily sensation lacked power in psychopathological documentation tool which allows discriminating schizophrenia from other mental evaluation in every stage of schizophrenia, in particular, disorders. Impaired bodily sensations are thought to be evaluation of symptoms that differ from those of DSM-Ⅳ “active” symptoms and related to positive symptoms. schizophrenia in prodrome to the onset, and in recovery Accordingly, they could represent a “state” rather than phase a “trait” of schizophrenia. In addition, early detection and early intervention in schizophrenia is another topic of current importance in Clusters 4, 1, and 3 are able to discriminate psychiatry, making prodromal symptoms a focus of schizophrenia from other psychotic disorders or related interest. 22) In DSM-IV, however, prodromal symptoms mental disorders close to schizophrenia in are not fully defined, and concepts such as ARMS (At symptomatology. This means that symptoms Risk Mental State) and UHR (Ultra High Risk) are corresponding to these clusters are related to treated primarily as no more than psychotic symptoms fundamental and basic disturbances in schizophrenia such as transient, weak auditory hallucinations. differing from those of other psychotic disorders. Prodromal schizophrenia requires highly sensitive There is a exploratory eye movement study with indices with greater early utility. 94 K. Oshima et al. J Med Dent Sci

Recently, some neurophysiologial studies focus on at Ⅴ: DSM-Ⅴ should include a conceptual issues work risk or prodromal stage of schizophrenia. There are group. Am J Psychiatry. 2008 February;165:2:174-175. findings that auditory evoked potential P50 8. Flanagan EH, Davidson L, Strauss JS. Issues for DSM-Ⅴ: Incorporating patients’ subjective experiences. Am J suppression 23) was significantly impaired in patients in Psychiatry. 2007 Mach;164:3:391-392. at-risk state, prodromal phase, first episode and chronic 9. Huber G, Gross G, Schüttler R, Linz M: Longitudinal schizophrenia. On the other hand. auditory evoked studies of schizophrenic patients. Schizophrenia Bull. potential N100 suppression was significantly reduced 1980;6:592-605. in almost stages, but not at-risk subjects. This auditory 10. Gross G. The “basic” symptoms of schizophrenia. Br J gating theory is related to some symptoms of Cluster 1. Psychiatry Suppl. 1989;7:21-25. The exploratory eye movement research 19) also focus 11. Gross G, Huber G, Klosterkötter J & Linz M: BSABS: Bonner Skala für die Beurteilung von Basissymptomen on BSABS. The responsive search score(RSS) in the (Bonn Scale for the Assessment of Basic Symptoms). exploratory eye movement indicators can be a Springer. Berlin. 1987 vulnerability marker of schizophrenia. The RSS has 12. Klosterkötter J. Wie entsteht das schizophrene significant correlations with Cluster 4 and Cluster 3. Kernsyndrom ? : Ergebnisse der Bonner RSS is thought to be a trait marker of schizophrenia Ubergangsreihenstudie und angloamerikanische and Cluster 4 and Cluster 3 could represent traits of Modellvorstellung-Ein Vergleich. Der Nervenarzt. schizophrenia. 1992;63:675-682. 13. Klosterkötter J. Ebel H, Schultze-Lutter F, et al. Use of some clusters of BSABS with other Diagnostic validity of basic symptoms. Eur Arch neurophysiological markers like the auditory evoked Psychiatry Clin Neurosci. 1996;246:147-154. potential or the exploratory eye movement indicators 14. Gross G, Stassen HH, Huber G, et al. Reliability of the could make detection of schizophrenia possible in the psychopathological documentation scheme BSABS; in very early prodromal phase and allow clinical Stefanis CN. Rabavilas AD, Soldators CR (eds). A World evaluation of schizophrenia from a new perspective. Perspective. Amsterdam. Elsevier. 1990;199-203. 15. Vollmer-Larsen A, Handest P, Parnas J. et al. Reliability (5) Acknowledgements of Measuring Anomalous Experience: The Bonn Scale for the Assessment of Basic Symptoms. Psychopathology. 2007;40:345-348. We thank Professor Koichi Yoshioka of Kokusikan 16. Cohen J. Statistical power analysis for the behavioral University for his helpful advice on statistical analysis. sciences(2nd ed.). Lawrence Erlbaum.New Jersey. 1988 This study was partly supported by a research grant 17. Klosterkötter J, Helmich M, Steinmeyer EM, et al. from the Research Group for Schizophrenia of Astellas Diagnosing Schizophrenia in the Initial Prodromal Phase. Pharm Inc. Arch Gen Psychiatry. 2001;58:158-164. 18. Janzarik W. Basisstörungen : Eine Revision mit strukurdynamischen Mitteln. NervenArzt.1983; 54:122- 130 References 19. Matsushima E, Oshima K, Iwawaki A et al. Exploratory 1. Kendler KS. An historical framework for psychiatric Eye Movements as a Vulnerability Marker of nosology. Psychological Medicine. Cambridge University Schizophrenia. The World Journal of Biological Press, 2009;1-7. Psychiatry. 2005,6 (Suppl 1);61 2. American Psychiatric Association: Diagnostic and 20. Robbins E, Guze SB. Establishment of diagnostic validity Statistical Manual of Mental Disorders, Fourth Edition. in psychiatric illness : its application to schizophrenia. Am American Psychiatric Association Washington. DC. 1994. J Psychiatry. 1970;126:983-987. 3. Kupfer DJ, First MB, Regier DA ed. A RESEARCH 21. Kendler KS. Toward a scientific Psychiatric nosology : AGENDA FOR DSM –Ⅴ. American Psychiatric Publishing. strengths and limitations. Arch Gen Psychiatry. Washington D.C. 2002 1990;47:969-973. 4. Andreasen NC: Negative symptoms in schizophrenia: 22. Schultze-Lutter F. Addington J. Ruhrmann S, et al. definition and reliability. Arch Gen Psychiatry. Schizophrenia Proneness Instrument Adult version 1982;39:784-788. (SPI-A). Rome: Giovanni Fioriti Editore, 2007 Italy. 5. Andreasen NC, Olsen S: Negative v positive 23. Brockhaus-Dumke A, Schultze-Lutter F, Mueller R, et al. schizophrenia. Arch Gen Psychiatry. 1982;39:789-794. Sensory gating in schizophrenia : P50 and N100 gating 6. Zachar P, Kendler KS. Psychiatric disorders: A in antipsychotic-free subjects at risk, first-episode, and conceptual taxonomy. Am J Psychiatry. 2007 April; chronic patients. Biol Psychiatry. 2008 Sep1;64(5):376- 164:4:557-565. 384. 7. Kendler KS, Appelbaum PS, Bell CC et al. Issues for DSM-