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Overlap between emotional blunting, depression, and extrapyramidal symptoms in schizophrenia
Schizophrenia Research 57 (2002) 307 – 309 www.elsevier.com/locate/schres
Letter to the Editors
Overlap between emotional blunting, depression, and extrapyramidal symptoms in schizophrenia Since the very beginning of modern psychopathology, emotional blunting has been considered as a core symptom of schizophrenia. After introduction of the Rating Scale for Emotional Blunting (SEB) (Abrams and Taylor, 1978), sufficient reliability and validity of the concept of emotional blunting has been repeatedly shown (Boeringa and Castellani, 1982, de Leon et al., 1993; Peralta et al., 1995). Affective flattening, a term often used synonymously to emotional blunting, was incorporated in recent diagnostic systems (ICD-10; DSM-IV) as one of three negative symptoms. Despite the ascertained reliability and validity of the concept, issues concerning the psychopathological specificity and the possibly underlying pathophysiology of emotional blunting remain to be investigated. The association between emotional blunting and depressive symptoms in schizophrenia and the mutual relationship with extrapyramidal symptoms (EPS) have not been addressed so far, although an overlap of negative, depressive, and akinetic symptoms has long been recognized (Siris, 1995). By using assessment instruments with the highest alleged specificity for each symptom cluster (i.e. the CDSS for depressive symptoms, the SEB for emotional blunting, and AIMS and SAS for the assessment of tardive dyskinesia and akinesia, respectively), the present study aimed to elucidate this clinically relevant issue. Forty patients with chronic DSM-IV psychotic disorder (37 with schizophrenia, 3 with schizoaffective disorder) were interviewed by a trained clinician during clinical routine. The Clinical Global Impressions Scale (CGI) (Guy, 1976), the Rating Scale for Emotional Blunting (SEB) (Abrams and Taylor, 1978), the Positive and Negative Syndrome Scale (PANSS) (Kay et al., 1987), the Abnormal and Involuntary Movements Scale (AIMS) (Guy, 1976), the Barnes Akathisa
Rating Scale (BARS) (Barnes, 1989), the Simpson – Angus Scale (SAS) (Simpson and Angus, 1970), and the Calgary Depression Rating Scale for Schizophrenia (CDSS) (Addington et al., 1990; Mu¨ller et al., 1999) were used. The SEB consists of 16 items rated on a three-point scale (0 — not present; 1 — doubtful/ slight; 2 — clearly present). The SEB sum score was used. In a preceding reliability study, an intraclass correlation coefficient of 0.94 was obtained (Mu¨ller et al., unpublished). The analysis of anonymous clinical data is in full accordance with the German regulatory laws and is approved by the local ethics committee. Pearson’s coefficient is reported for correlation analyses. To estimate the independent relationship between emotional blunting, EPS, and depression, partial correlations were computed. The level of statistical significance was set at a = 0.05. The mean ( F S.D.) age of patients was 46.7 F 6.9 years, 37% were female. The patients had a chronic course of illness (14.5 F 9.7 years), the duration of hospitalization was 38 F 15 days. All patients had received conventional neuroleptics > 6 months (lifetime) and had an antipsychotic z 4 weeks at the time of assessment (21 patients, atypical antipsychotics, 26 conventional neuroleptics, and 7, a combination of typical and atypical neuroleptics). Six patients received antidepressants, nine benzodiazepines, eight biperiden, and four mood stabilizers. The average global illness severity (CGI) was 4.6 F 1.0, PANSS negative symptoms (17.8 F 7.7) were more prominent than PANSS positive symptoms (14.6 F 5.6). The remaining rating scores were: SEB 10.8 F 6.9, CDSS 8.0 F 7.6, AIMS 2.0 F 2.3, BARS 0.4 F 0.8, and SAS 3.6 F 4.2 points. Table 1 reports correlations between psychopathological data. No significant associations emerged between psychopathology and gender, age, illness duration, and type of medication. As akathisia occurred very rarely in the present sample, BARS scores were excluded
0920-9964/02/$ - see front matter D 2002 Elsevier Science B.V. All rights reserved. PII: S 0 9 2 0 - 9 9 6 4 ( 0 1 ) 0 0 2 8 9 - 4
308
Letter to the Editors
Table 1 Correlations between psychopathological parameters (N = 40) CGI SEB CGI PANSS-POS PANSS-NEG CDSS AIMS BARS
0.52** –
PANSS-POS 0.12 0.25 –
PANSS-NEG 0.91*** 0.54*** 0.15 –
CDSS
AIMS
0.48** 0.65*** 0.35* 0.54*** –
0.70***,a 0.35* 0.24 0.67*** 0.42**,a –
BARS 0.19 0.13 0.22 0.19 0.12 0.13 –
SAS 0.64***,b 0.54*** 0.27 0.59 0.42**,b 0.30 0.28
Values are Pearson’s r correlation coefficients. CGI, Clinical Global Impressions — severity item; PANSS, Positive and Negative Syndrome Scale; POS, positive subscale; NEG, negative subscale; SEB, Scale for the Assessment of Emotional Blunting; CDSS, Calgary Depression Rating Scale for Schizophrenia; AIMS, Abnormal and Involuntary Movement Scale; BARS, Barnes Akathisia Rating Scale; SAS, Simpson – Angus Rating Scale. a Significant difference between corresponding correlation coefficients (for comparison, Fisher’s Z-transformation was used; P = 0.014). b Significant difference between corresponding correlation coefficients (for comparison, Fisher’s Z-transformation was used; P = 0.048). * P < 0.05. ** P < 0.01. *** P < 0.001.
from further analyses. When controlling for CDSS scores, the correlation between SEB and AIMS (r = 0.63, P < 0.0005) or SAS scores (r = 0.55, P < 0.0005) remained nearly unchanged. The partial correlations between CDSS and AIMS (r = 0.14) or SAS scores (r = 0.16) were non-significant when controlling for SEB scores. Furthermore, the correlation between SEB and CDSS dropped to r = 0.27 or r = 0.26 ( P z 0.10), respectively, when controlling for EPS. The results of the present study demonstrate a strong positive association of emotional blunting and EPS in schizophrenic patients which remained nearly unchanged after controlling statistically for depression. The results also show that depressive symptoms, which are heterogeneous and frequently occurring in schizophrenic disorders (Mu¨ller and Wetzel, 1998), can be separated from emotional blunting when specific instruments are used. Although the mutual relationship between negative symptoms, particularly affective flattening, depression, and akinesia is wellknown (Van Putten and May, 1978; Harrow et al., 1994; Siris, 1995; Mu¨ller et al., 2001), empirical data are still required. Design and restricted sample size of the present study cannot permit firm conclusions regarding diagnostic subtypes of schizophrenia. Nevertheless, the results imply that depression, emotional blunting, and EPS should be assessed thoroughly with standardized instruments in schizophrenic patients to provide a rationale for the difficult treatment of these
patients. Among other scales, the CDSS and the SEB can be recommended to disentangle the overlap of depressive, negative, and motor symptoms of schizophrenia.
Acknowledgements The author wishes to thank B. Kienzle for her help.
References Abrams, R., Taylor, M.A., 1978. A rating scale for emotional blunting. Am. J. Psychiatry 135, 226 – 229. Addington, D., Addington, J., Schissel, B., 1990. A depression rating scale for schizophrenics. Schizophr. Res. 3, 247 – 251. Barnes, T.R., 1989. A rating scale for drug-induced akathisia. Br. J. Psychiatry 154, 672 – 676. Boeringa, J.A., Castellani, S., 1982. Reliability and validity of emotional blunting as a criterion for diagnosis of schizophrenia. Am. J. Psychiatry 139, 1131 – 1135. de Leon, J., Peralta, V., Cuesta, M.J., 1993. Negative symptoms and emotional blunting in schizophrenic patients. J. Clin. Psychiatry 54, 103 – 108. Guy, D., 1976. ECDEU Assessment Manual for Psychopharmacology, revised. DHEU Publication. Rockville: NIMH. Harrow, M., Yonan, C.A., Sands, J.R., Marengo, J., 1994. Depression in schizophrenia: are neuroleptics, akinesia, or anhedonia involved? Schizophr. Bull. 20, 327 – 338. Kay, S.R., Fiszbein, A., Opler, L.A., 1987. The Positive and Neg-
Letter to the Editors ative Syndrome Scale (PANSS) for schizophrenia. Schizophr. Bull. 13, 261 – 276. Mu¨ller, M.J., Wetzel, H., 1998. Dimensionality of depression in acute schizophrenia: a methodological study using the BechRafaelsen Melancholia Scale (BRMES). J. Psychiatr. Res. 32, 369 – 378. Mu¨ller, M.J., Marx-Dannigkeit, P., Schlo¨sser, R., Wetzel, H., Addington, D., Benkert, O., 1999. The Calgary Depression Rating Scale for Schizophrenia: development and interrater reliability of a German version (CDSS-G). J. Psychiatr. Res. 33, 433 – 443. Mu¨ller, M.J., Szegedi, A., Wetzel, H., Benkert, O., 2001. Depressive factors and their relationships with other symptom domains in schizophrenia, schizoaffective disorder, and psychotic depression. Schizophr. Bull. 27, 19 – 28. Peralta, V., Cuesta, M.J., de Leon, J., 1995. Positive and negative symptoms/syndromes in schizophrenia: reliability and validity of different diagnostic systems. Psychol. Med. 25, 43 – 50. Simpson, G.M., Angus, J.U.S., 1970. A rating scale for extrapyramidal side effects. Acta Psychiatr. Scand. 212, 11 – 19.
309
Siris, S.G., 1995. Depression and schizophrenia. In: Hirsch, S.R., Weinberger, D.R. (Eds.), Schizophrenia. Blackwell, Oxford, pp. 128 – 145. Van Putten, T., May, R.P., 1978. ‘‘Akinetic depression’’ in schizophrenia. Arch. Gen. Psychiatry 35, 1101 – 1107.
Matthias J. Mu¨ller Department of Psychiatry, University of Mainz Untere Zahlbacher Straße 8 D-55131, Mainz, Germany E-mail address: [email protected]. klinik.uni-mainz.de Tel.: +49-6131-17-2920; fax: +49-6131-17-6690 15 April 2001
Letter to the Editors
Overlap between emotional blunting, depression, and extrapyramidal symptoms in schizophrenia Since the very beginning of modern psychopathology, emotional blunting has been considered as a core symptom of schizophrenia. After introduction of the Rating Scale for Emotional Blunting (SEB) (Abrams and Taylor, 1978), sufficient reliability and validity of the concept of emotional blunting has been repeatedly shown (Boeringa and Castellani, 1982, de Leon et al., 1993; Peralta et al., 1995). Affective flattening, a term often used synonymously to emotional blunting, was incorporated in recent diagnostic systems (ICD-10; DSM-IV) as one of three negative symptoms. Despite the ascertained reliability and validity of the concept, issues concerning the psychopathological specificity and the possibly underlying pathophysiology of emotional blunting remain to be investigated. The association between emotional blunting and depressive symptoms in schizophrenia and the mutual relationship with extrapyramidal symptoms (EPS) have not been addressed so far, although an overlap of negative, depressive, and akinetic symptoms has long been recognized (Siris, 1995). By using assessment instruments with the highest alleged specificity for each symptom cluster (i.e. the CDSS for depressive symptoms, the SEB for emotional blunting, and AIMS and SAS for the assessment of tardive dyskinesia and akinesia, respectively), the present study aimed to elucidate this clinically relevant issue. Forty patients with chronic DSM-IV psychotic disorder (37 with schizophrenia, 3 with schizoaffective disorder) were interviewed by a trained clinician during clinical routine. The Clinical Global Impressions Scale (CGI) (Guy, 1976), the Rating Scale for Emotional Blunting (SEB) (Abrams and Taylor, 1978), the Positive and Negative Syndrome Scale (PANSS) (Kay et al., 1987), the Abnormal and Involuntary Movements Scale (AIMS) (Guy, 1976), the Barnes Akathisa
Rating Scale (BARS) (Barnes, 1989), the Simpson – Angus Scale (SAS) (Simpson and Angus, 1970), and the Calgary Depression Rating Scale for Schizophrenia (CDSS) (Addington et al., 1990; Mu¨ller et al., 1999) were used. The SEB consists of 16 items rated on a three-point scale (0 — not present; 1 — doubtful/ slight; 2 — clearly present). The SEB sum score was used. In a preceding reliability study, an intraclass correlation coefficient of 0.94 was obtained (Mu¨ller et al., unpublished). The analysis of anonymous clinical data is in full accordance with the German regulatory laws and is approved by the local ethics committee. Pearson’s coefficient is reported for correlation analyses. To estimate the independent relationship between emotional blunting, EPS, and depression, partial correlations were computed. The level of statistical significance was set at a = 0.05. The mean ( F S.D.) age of patients was 46.7 F 6.9 years, 37% were female. The patients had a chronic course of illness (14.5 F 9.7 years), the duration of hospitalization was 38 F 15 days. All patients had received conventional neuroleptics > 6 months (lifetime) and had an antipsychotic z 4 weeks at the time of assessment (21 patients, atypical antipsychotics, 26 conventional neuroleptics, and 7, a combination of typical and atypical neuroleptics). Six patients received antidepressants, nine benzodiazepines, eight biperiden, and four mood stabilizers. The average global illness severity (CGI) was 4.6 F 1.0, PANSS negative symptoms (17.8 F 7.7) were more prominent than PANSS positive symptoms (14.6 F 5.6). The remaining rating scores were: SEB 10.8 F 6.9, CDSS 8.0 F 7.6, AIMS 2.0 F 2.3, BARS 0.4 F 0.8, and SAS 3.6 F 4.2 points. Table 1 reports correlations between psychopathological data. No significant associations emerged between psychopathology and gender, age, illness duration, and type of medication. As akathisia occurred very rarely in the present sample, BARS scores were excluded
0920-9964/02/$ - see front matter D 2002 Elsevier Science B.V. All rights reserved. PII: S 0 9 2 0 - 9 9 6 4 ( 0 1 ) 0 0 2 8 9 - 4
308
Letter to the Editors
Table 1 Correlations between psychopathological parameters (N = 40) CGI SEB CGI PANSS-POS PANSS-NEG CDSS AIMS BARS
0.52** –
PANSS-POS 0.12 0.25 –
PANSS-NEG 0.91*** 0.54*** 0.15 –
CDSS
AIMS
0.48** 0.65*** 0.35* 0.54*** –
0.70***,a 0.35* 0.24 0.67*** 0.42**,a –
BARS 0.19 0.13 0.22 0.19 0.12 0.13 –
SAS 0.64***,b 0.54*** 0.27 0.59 0.42**,b 0.30 0.28
Values are Pearson’s r correlation coefficients. CGI, Clinical Global Impressions — severity item; PANSS, Positive and Negative Syndrome Scale; POS, positive subscale; NEG, negative subscale; SEB, Scale for the Assessment of Emotional Blunting; CDSS, Calgary Depression Rating Scale for Schizophrenia; AIMS, Abnormal and Involuntary Movement Scale; BARS, Barnes Akathisia Rating Scale; SAS, Simpson – Angus Rating Scale. a Significant difference between corresponding correlation coefficients (for comparison, Fisher’s Z-transformation was used; P = 0.014). b Significant difference between corresponding correlation coefficients (for comparison, Fisher’s Z-transformation was used; P = 0.048). * P < 0.05. ** P < 0.01. *** P < 0.001.
from further analyses. When controlling for CDSS scores, the correlation between SEB and AIMS (r = 0.63, P < 0.0005) or SAS scores (r = 0.55, P < 0.0005) remained nearly unchanged. The partial correlations between CDSS and AIMS (r = 0.14) or SAS scores (r = 0.16) were non-significant when controlling for SEB scores. Furthermore, the correlation between SEB and CDSS dropped to r = 0.27 or r = 0.26 ( P z 0.10), respectively, when controlling for EPS. The results of the present study demonstrate a strong positive association of emotional blunting and EPS in schizophrenic patients which remained nearly unchanged after controlling statistically for depression. The results also show that depressive symptoms, which are heterogeneous and frequently occurring in schizophrenic disorders (Mu¨ller and Wetzel, 1998), can be separated from emotional blunting when specific instruments are used. Although the mutual relationship between negative symptoms, particularly affective flattening, depression, and akinesia is wellknown (Van Putten and May, 1978; Harrow et al., 1994; Siris, 1995; Mu¨ller et al., 2001), empirical data are still required. Design and restricted sample size of the present study cannot permit firm conclusions regarding diagnostic subtypes of schizophrenia. Nevertheless, the results imply that depression, emotional blunting, and EPS should be assessed thoroughly with standardized instruments in schizophrenic patients to provide a rationale for the difficult treatment of these
patients. Among other scales, the CDSS and the SEB can be recommended to disentangle the overlap of depressive, negative, and motor symptoms of schizophrenia.
Acknowledgements The author wishes to thank B. Kienzle for her help.
References Abrams, R., Taylor, M.A., 1978. A rating scale for emotional blunting. Am. J. Psychiatry 135, 226 – 229. Addington, D., Addington, J., Schissel, B., 1990. A depression rating scale for schizophrenics. Schizophr. Res. 3, 247 – 251. Barnes, T.R., 1989. A rating scale for drug-induced akathisia. Br. J. Psychiatry 154, 672 – 676. Boeringa, J.A., Castellani, S., 1982. Reliability and validity of emotional blunting as a criterion for diagnosis of schizophrenia. Am. J. Psychiatry 139, 1131 – 1135. de Leon, J., Peralta, V., Cuesta, M.J., 1993. Negative symptoms and emotional blunting in schizophrenic patients. J. Clin. Psychiatry 54, 103 – 108. Guy, D., 1976. ECDEU Assessment Manual for Psychopharmacology, revised. DHEU Publication. Rockville: NIMH. Harrow, M., Yonan, C.A., Sands, J.R., Marengo, J., 1994. Depression in schizophrenia: are neuroleptics, akinesia, or anhedonia involved? Schizophr. Bull. 20, 327 – 338. Kay, S.R., Fiszbein, A., Opler, L.A., 1987. The Positive and Neg-
Letter to the Editors ative Syndrome Scale (PANSS) for schizophrenia. Schizophr. Bull. 13, 261 – 276. Mu¨ller, M.J., Wetzel, H., 1998. Dimensionality of depression in acute schizophrenia: a methodological study using the BechRafaelsen Melancholia Scale (BRMES). J. Psychiatr. Res. 32, 369 – 378. Mu¨ller, M.J., Marx-Dannigkeit, P., Schlo¨sser, R., Wetzel, H., Addington, D., Benkert, O., 1999. The Calgary Depression Rating Scale for Schizophrenia: development and interrater reliability of a German version (CDSS-G). J. Psychiatr. Res. 33, 433 – 443. Mu¨ller, M.J., Szegedi, A., Wetzel, H., Benkert, O., 2001. Depressive factors and their relationships with other symptom domains in schizophrenia, schizoaffective disorder, and psychotic depression. Schizophr. Bull. 27, 19 – 28. Peralta, V., Cuesta, M.J., de Leon, J., 1995. Positive and negative symptoms/syndromes in schizophrenia: reliability and validity of different diagnostic systems. Psychol. Med. 25, 43 – 50. Simpson, G.M., Angus, J.U.S., 1970. A rating scale for extrapyramidal side effects. Acta Psychiatr. Scand. 212, 11 – 19.
309
Siris, S.G., 1995. Depression and schizophrenia. In: Hirsch, S.R., Weinberger, D.R. (Eds.), Schizophrenia. Blackwell, Oxford, pp. 128 – 145. Van Putten, T., May, R.P., 1978. ‘‘Akinetic depression’’ in schizophrenia. Arch. Gen. Psychiatry 35, 1101 – 1107.
Matthias J. Mu¨ller Department of Psychiatry, University of Mainz Untere Zahlbacher Straße 8 D-55131, Mainz, Germany E-mail address: [email protected]. klinik.uni-mainz.de Tel.: +49-6131-17-2920; fax: +49-6131-17-6690 15 April 2001