PCN Psychiatric and Clinical Neurosciences 1323-13162003 Blackwell Science Pty Ltd 574August 2003 1130 Schizophrenia and tree-drawing morphology H. Inadomi et al. 10.1046/j.1323-1316.2003.01130.x Original Article347351BEES SGML Psychiatry and Clinical Neurosciences (2003), 57, 347 351 Regular Article Characteristics of trees drawn by patients with paranoid schizophrenia HIROYUKI INADOMI, OTR, MS, GORO TANAKA, OTR, MS AND YASUYUKI OHTA, MD, PhD Department of Occupational Therapy, School of Health Sciences, Nagasaki University, Nagasaki, Japan Abstract The objective of the present study was to investigate the relationship between schizophrenia subtype and morphological characteristics of trees drawn in the Baum test. Subjects comprised the following three groups: 20 patients diagnosed with paranoid schizophrenia according to International Classification of Diseases (10th revision; ICD-10) criteria; 26 patients with non-paranoid schizophrenia according to ICD-10 criteria; and 53 healthy individuals. Differences in psychiatric symptoms as assessed using the Brief Psychiatric Rating Scale (BPRS) score were compared between patients with paranoid and non-paranoid schizophrenia. In addition, differences in two morphological characteristics of trees, namely trunk-to-crown ratio and trunk end opening, were compared between the three groups. No differences in psychiatric symptoms were identified between patients with paranoid and non-paranoid schizophrenia. Conversely, mean ± SD trunkto-crown ratio was 13.1 ± 8.0 for patients with non-paranoid schizophrenia, 8.8 ± 4.6 for patients with paranoid schizophrenia, and 5.4 ± 3.4 for healthy individuals. Significant differences were identified between all three groups. Furthermore, mean trunk end opening was 0.80 ± 0.7 for patients with paranoid schizophrenia, 0.38 ± 0.6 for patients with non-paranoid schizophrenia, and 0.06 ± 0.3 for healthy individuals. Again, significant differences were apparent between all three groups. These findings suggest that morphological differences in trees drawn in the Baum test can be observed between the two schizophrenia subtypes in terms of not only psychopathological interpretation, but also gestalt formation, as assessed on the basis of trees with collapsed gestalt or with some degree of gestalt. This suggests the possibility of multiple disorders at a physiological level. The present study confirmed that the Baum test can quantitatively assess facets of schizophrenia that existing scales such as BPRS are unable to analyze, and is useful for investigating brain function in patients with schizophrenia. Key words Baum test, brain function, morphological analysis, schizophrenia, symptomatology. INTRODUCTION When analyzing the results of a Baum test, the most important point is the comprehensive assessment of the tree drawing based on the tester s first impression of naturalness and stability. 1 In fact, the possibility of deviating from analyses based on impressions increases when each area of the tree is evaluated quantitatively Correspondence address: Hiroyuki Inadomi, Department of Occupational Therapy, School of Health Sciences, Nagasaki University, 1-7-1 Sakamoto, Nagasaki 852-8520, Japan. Email: inadomi@net.nagasaki-u.ac.jp Received 5 September 2001; revised 6 February 2003; accepted 9 February 2003. Regular Article in greater detail. However, what Baum test-based research requires is the establishment of integrated universal quantitative standards and qualitative psychopathological analyses. Several studies have been conducted to objectively analyze trees drawn by patients with eating disorders, by quantitatively assessing the position and morphology of trees. 2 In addition, the advantages associated with the Baum test are that it is easy to administer and is not stressful to patients, and the usefulness of this test in aiding the differential diagnosis of schizophrenia, quantitative assessment of therapeutic outcomes 3,4 and facilitating the assessment of psychological recovery in schizophrenia, 5,6 has been documented.
348 H. Inadomi et al. However, few studies have investigated the relationship between the Baum test and schizophrenia subtypes. In order to deepen our understanding of the relationship between schizophrenia subtypes and the Baum test, morphological differences in trees drawn by schizophrenia patients with different subtypes were compared and analyzed. METHODS Subjects A total of 99 individuals served as subjects: 46 patients with schizophrenia and 53 age-matched healthy individuals. Schizophrenia patients were residents of private psychiatric institutions. Based on International Classification of Diseases, 10th revision (ICD-10) criteria, 7 20 patients were diagnosed with paranoid schizophrenia while the remaining 26 patients were diagnosed with non-paranoid schizophrenia (seven patients with hebephrenic schizophrenia, nine with residual schizophrenia, and 10 with undifferentiated schizophrenia). For the patients with paranoid schizophrenia (paranoid schizophrenia group), the mean age was 49.0 ± 9.2 years, mean duration of education was 10.2 ± 2.3 years, mean disease duration was 24.8 ± 10.1 years, and mean length of hospitalization was 10.0 ± 9.4 years. For patients with non-paranoid schizophrenia (nonparanoid schizophrenia group), mean age was 49.6 ± 7.6 years, mean duration of education was 10.5 ± 2.0 years, mean disease duration was 24.2 ± 9.1 years, and mean length of hospitalization was 7.7 ± 5.7 years. Schizophrenia patients in the present study had therefore had schizophrenia for an average of approximately 24 years, and had been institutionalized for more than 7 years. The 53 healthy individuals were selected from among employees of private psychiatric institutions (control group). Mean age and mean duration of education were 47.9 ± 7.5 years and 13.0 ± 2.4 years, respectively. Informed consent was obtained from every subject prior to the start of the present study. (emotional withdrawal, motor retardation, uncooperativeness, emotional stupor), manic symptoms (grandiosity, emotional excitement, psychomotor excitement), dysphoria (anxiety, guilt feeling, tension, depressive mood), and hypochondriacal symptoms (somatic concerns complaints, hostility), and the BPRS score for each category was calculated. Morphological assessment of trees In order to perform the Baum test according to Koch s original method, 10 each subject was instructed to carefully draw a single fruit-bearing tree. When a subject asked such questions as What kind of tree should I draw?, an actual tree, such as an apple or persimmon tree, was suggested. As shown in Figs 1 and 2, morphological characteristics of trees were assessed based on the following criteria: trunk-to-crown ratio (trunk length (mm)/ crown length (mm)) 10; 10,11 and trunk end opening (0 points if the top end of the trunk was closed; 1 point if the top end of the trunk was open; and 2 points if the top end of the trunk was wider than the trunk). 5,12,13 Statistical analysis Analysis of variance (ANOVA) was used to compare demographic profiles and morphological parameters between the three groups. In addition, unpaired t-tests Assessment of psychiatric functions Severity of psychiatric functions in schizophrenia patients was assessed by a single psychiatrist using the Brief Psychiatric Rating Scale (BPRS). 8 The 18 items in the BPRS were divided into five categories according to the method of Kitamura et al. 9 as follows: positive symptoms (conceptual disorganization, mannerisms/postures, suspiciousness, hallucinatory behaviors, unusual thought contents), negative symptoms Trunk-to crown ratio = (trunk length (mm)/crown length (mm))310 Figure 1. Calculation of trunk-to-crown ratios and morphological assessment criteria.
Schizophrenia and tree-drawing morphology 349 Figure 2. Morphological assessment criteria for trunk end opening. The trunk end of each tree is indicated by a circle. were used to compare BPRS scores between paranoid and non-paranoid schizophrenia groups. Because demographic profiles could not be matched except for age, the analyses outlined here were conducted to ascertain the effects of demographic profiles on the morphology of trees from Baum testing. In order to analyze morphological differences between the three groups, analysis of covariance (ANCOVA) was performed by considering trunk-tocrown ratio and trunk end opening as dependent variables, mental health status (paranoid schizophrenia, non-paranoid schizophrenia and healthy) as an independent variable; and age, education, disease duration and length of hospitalization as covariates. In ANCOVA, differences in dependent variables in relation to the independent variables and the effects of covariates were assessed simultaneously. In addition, when significant differences were detected using ANOVA, Tukey s multiple comparison test was conducted. In the present study all statistical analyses were conducted using SPSS 10.0.5J for Windows, and the level of statistical significance was set at P < 0.05. RESULTS Regarding the various demographic profiles, the paranoid and non-paranoid schizophrenia groups displayed mean durations of education that were significantly lower than that in the control group. Table 1 shows total BPRS score and BPRS score for the five categories (positive symptoms, negative symptoms, manic symptoms, dysphoria, and hypochondriacal symptoms). No significant differences between paranoid and non-paranoid schizophrenia groups were apparent in any BPRS scores. Table 2 summarizes the results of morphological analyses of Baum test trees. The trunk-to-crown ratio was highest for the non-paranoid schizophrenia group, followed by the paranoid schizophrenia and control groups, in this order. Significant differences were observed between all three groups. Furthermore, trunk end opening was highest for the paranoid schizophrenia group, followed by the non-paranoid schizophrenia and the control groups, in this order. Again, significant differences existed between all three groups. Because results were similar after taking covariates such as age, education, disease duration and length of hospitalization into account, demographic profile was considered to have no effect on tree morphology. This means that significant morphological differences existed between trees drawn by schizophrenia patients and those drawn by healthy individuals. Furthermore, although significant morphological differences were observed between trees drawn by patients
350 H. Inadomi et al. Table 1. Comparison of psychiatric functions between paranoid and non-paranoid schizophrenia groups Variables Paranoid schizophrenia Non-paranoid schizophrenia P Positive symptoms 15.7 (7.4) 12.5 (6.4) NS Negative symptoms 15.2 (2.9) 14.7 (3.4) NS Manic symptoms 3.8 (1.4) 3.4 (1.0) NS Dysphoria 6.9 (1.9) 6.3 (1.4) NS Hypochondriacal symtoms 4.2 (1.6) 3.5 (1.3) NS Total BPRS score 45.7 (10.4) 40.4 (8.4) NS BPRS, Brief Psychiatric Rating Scale; NS, not significant. No significant differences were observed in mean BPRS scores between paranoid and non-paranoid schizophrenia groups. Table 2. Comparison of morphological parameters between the three groups Variables Paranoid schizophrenia Non-paranoid schizophrenia Control Trunk-to-crown ratio 8.8 (4.6) 13.1 (8.0)* 5.4 (3.4)* Trunk end opening 0.80 (0.7) 0.38 (0.6)* 0.06 (0.3)* *P < 0.05 compared to paranoid schizophrenia group; P < 0.05 compared to non-paranoid schizophrenia group; P < 0.05 compared to control group. with paranoid schizophrenia and those drawn by patients with non-paranoid schizophrenia, no significant differences in psychiatric functions (BPRS scores) were apparent. DISCUSSION The present study clarified two important points. First, significant morphological differences exist between trees drawn by schizophrenia patients and those drawn by healthy individuals. Koch clarified that, with the Baum test, trunk-tocrown ratio decreases as linguistic abilities and abstract thinking develop. 10 Subsequent studies have also revealed that the trunk-to-crown ratio decreases with age, 11,14 suggesting that the ability to draw a tree with a crown longer than the trunk correlates to the development of linguistic ability and abstract thinking. Patients with schizophrenia who draw the tree with the crown longer than the trunk have also been shown to display better social adjustment. 5,6 Koch reported that an open-ended trunk in the Baum test indicates a lack of clear distinction between self and non-self. 10 One study found that an openended trunk in the Baum test is one of the signs associated with schizophrenia. 12 Furthermore, another study found that an open-ended trunk in the Baum test in schizophrenia patients is associated with hallucinations, delusions and chronic schizophrenia, suggesting that open-ended trunks may represent an altered ego structure. 13 The results of the present study show that the trunkto-crown ratio and trunk end opening for schizophrenia patients were significantly greater than those for healthy individuals. This suggests that linguistic ability and abstract thinking in schizophrenia patients are under-developed compared to healthy individuals, and that schizophrenia patients cannot function properly in the real world due to disharmony between self and the outside world. Second, although significant morphological differences exist between trees drawn by patients with paranoid and non-paranoid schizophrenia, no significant differences exist in psychiatric functions (BPRS scores). Regarding morphological characteristics associated with the paranoid schizophrenia group, although trunk-to-crown ratios for this group more closely resembled those of the control group than the nonparanoid schizophrenia group, trunk end opening for the paranoid schizophrenia group more closely resembled that in the non-paranoid schizophrenia group than in the control group. Basically, although trees drawn by patients with paranoid schizophrenia displayed reasonably good balance between the crown and trunk (as in Fig. 2b), the trunk was open-ended and
Schizophrenia and tree-drawing morphology 351 morphology of trees was markedly distorted. Compared to trees drawn by healthy individuals (Fig. 2a), trees drawn by schizophrenia patients exhibited marked morphological distortion (Fig. 2c). These findings support the conclusions of Utena et al., who classified Baum test trees into positive drawings (trees with collapsed gestalt) and negative drawings (trees with some degree of gestalt). 15 In recent years the Baum test has been utilized to qualitatively and quantitatively interpret the psychophysiological states of schizophrenia patients, by considering heart rate variability or simple reaction time as representative of central nervous system function. 16 18 In other words, the morphological differences between trees drawn by patients with paranoid schizophrenia and those drawn by patients with nonparanoid schizophrenia in the present study could reflect physiological differences in brain function, differing from the psychiatric functions assessed by the BPRS. 8 This suggests that schizophrenia may consist of multiple disorders. The Baum test, as described in the present study, therefore allows quantitative assessment of facets of schizophrenia that existing scales such as the BPRS, 8 the Scale for Assessment of Negative Symptoms 19 and the Positive and Negative Syndrome Scale 20 do not. The Baum test is therefore useful for investigating brain function in patients with schizophrenia. REFERENCES 1. Takahashi M, Takahashi Y. The Tree Drawing Test. Bunkyo Shoin, Tokyo, 1986. 2. Mizuta I, Inoue Y, Fukunaga T et al. Psychological characteristics of eating disorders as evidenced by the combined administration of questionnaires and two projective methods: The Tree Drawing Test (Baum Test) and the Sentence Completion Test. Psychiatry Clin. Neurosci. 2002; 56: 41 53. 3. Igimi K, Morita K, Kawamura N et al. Diagnostic evaluation of the Baum test in mental disorders. Kyushu Neuropsychiatry 2001; 47: 129 136 (in Japanese). 4. Morita K, Nakamura H, Haramura K et al. Evaluation and classification of psychiatric disorder: Analysis of time-dependent changing in the Baum test. Seishinka Chiryogaku 2001; 47: 129 136 (in Japanese). 5. Inadomi H, Morita K, Inoue H et al. Comparison of oncedaily and twice-daily long-term occupational therapy in schizophrenic patients: Additional analysis with the Baum test. Sagyo Ryoho 1998; 17: 133 142 (in Japanese). 6. Inadomi H, Morita K, Haramura K et al. Evaluation of occupational therapy: Analysis of time-dependent changes in the Baum test. Sagyo Ryoho 1996; 15: 351 357 (in Japanese). 7. World Health Organization. The Classification of Mental and Behavioral Disorders: Clinical Descriptions and Diagnostic Guidelines. WHO, Geneva, 1992. 8. Kolakowska T. Brief Psychiatric Rating Scale. Glossaries and Rating Instructions. Oxford University, Oxford, 1976. 9. Kitamura T, Yuzuriha T, Morita M et al. Oxford version of the BPRS: Development and validation of subscales. Arch. Psychiatr. Diagn. Clin. Eval. 1990; 1: 101 107 (in Japanese). 10. Koch C. The Tree Test: The Tree Drawing Test as an Aid in Psychodiagnosis. Verlag Hans Huber, Bern, 1952. (Hayashi K, Kuniyoshi M, Ichitani T. Baum Test: Jumokuga ni yoru Jinkaku- Shindanho. Nihon Bunka- Kagakusha, Tokyo, 1970 [Japanese edition]). 11. Yamashita M. A study of development in Baum test. J. Psychometry 1981; 17: 2 6 (in Japanese). 12. Saito M, Owada T. A study on the tree test (Der Baumtest) in schizophrenics. Matsushita Bull. Hum. Sci. 1969; 8: 83 92 (in Japanese). 13. Yamanaka Y. A study of Baum test in schizophrenia. J. Psychometry 1976; 12: 18 23 (in Japanese). 14. Ichitani T, Hayashi K, Kuniyoshi M et al. A study of lifespan developmental tendency by Koch s baumtest (treedrawing test) [I]. Bull. Kyoto Univ. Educ. Soc. Sci. Literature Arts Series A 1986; 69: 53 68 (in Japanese). 15. Utena H, Saitoh O, Miyake Y. Simple functional tests in clinical practice (3): The Baum test in patients with schizophrenia. Seishin Igaku 2001; 43: 737 744 (in Japanese). 16. Utena H. Occupational therapy and brain science. Method. Occup. Ther. 1999; 1: 27 31 (in Japanese). 17. Utena H. Brain and mind meet in forms and words. Rinsho Seishinbyori 2000; 21: 205 214 (in Japanese). 18. Utena H. Life-oriented approach to treatment and simple functional tests for clinical practice. In: Kashima H, Falloon IRH, Mizuno M, Asai M. (eds). Comprehensive Treatment of Schizophrenia: Linking Neurobehavioral Findings to Psychosocial Approaches.: Springer, Tokyo, 2002; 3 12. 19. Andreasen NC. The Scale for the Assessment of Negative Symptoms. University of Iowa, Iowa City, 1984. 20. Kay SR, Fiszbein A, Opler LA. The Positive and Negative Syndrome Scale (PANSS) for schizophrenia. Schizophr. Bull. 1987; 13: 261 276.