Motor features in psychotic disorders. II: Development of diagnostic criteria for catatonia
Introduction
Psychiatry, unlike most other areas of medicine, has no diagnostic laboratory tests for defining disorders. As a result, mental disorders generally are defined by a constellation of symptoms and other clinical descriptors. In the realm of ‘functional’ psychotic disorders, recognition of catatonia is clinically important since it may be life-threatening and its identification and treatment may be live-saving (Fink and Taylor, 1991). Treatment of catatonia by means of lorazepam or electro-convulsive therapy (ECT) clearly differs from that recommended for those disorders usually co-occurring with it — namely mood disorders and schizophrenia. Moreover, there is some evidence that the effectiveness of the resolution of motor signs by means of ECT is independent of primary diagnosis (Rohland et al., 1993). On the other hand, the neuroleptic drugs that are routinely prescribed in psychotic disorders may worsen the syndrome or even precipitate it. Therefore, accurate recognition of the catatonic syndrome is a critical step to appropriate treatment.
In 1874, Karl Ludwig Kahlbaum published a monograph entitled Die Katatonie oder das Spannungsirresein (Kahlbaum, 1973) in which he described the clinical features of 25 patients with a “brain disease” he named catatonia. Kahlbaum defined catatonia as a disease that progresses through a series of stages eventually leading to the development of a defect state. Most of the patients described by Kahlbaum displayed, at some time during its evolution, the full range of symptoms of the major psychiatric disorders. However, for Kahlbaum, the mood symptoms were primary in nature, and the motor features the most characteristic and those that give unity to the disorder (Peralta et al., 1997).
Despite this emphasis on the affective features of the disorder, after Kahlbaum, the concept of catatonia has been identified by the motor features alone. Bleuler, 1950, Kraepelin, 1919 considered catatonia (i.e. the motor features) to be a subtype of schizophrenia, which is how it continued to be officially classified until very recently. In contrast to this prevalent view, a number of studies published at the turn of the century showed an association of motor symptoms with manic-depressive illness (Bonner and Kent, 1936, Kirby, 1913, Lange, 1922, Wilmanns, 1907). In Germany, the Wernicke–Kleist–Leonhard school of psychiatry also set some motor disorders (i.e. periodic catatonia and motility psychosis) outside the limits of chronic schizophrenia (Leonhard, 1979). However, none of these studies gained wide acceptance against the influential view of Kraepelin and Bleuler.
In the 1970s, renewed interest in the clinical study of catatonia led to the publication of numerous studies, best represented by the Chicago school (Abrams and Taylor, 1976, Taylor and Abrams, 1977); these confirmed the old, previous studies linking catatonia with mood disorders, and revealed that catatonia patients had a more favorable outcome than one generally expects with the diagnosis of schizophrenia. The official diagnostic criteria of mental disorders have reflected the nosological view of Kraepelin and Bleuler, and until the publication of the DSM-IV (American Psychiatric Association, 1994), which acknowledge catatonia as a specifier of mood disorders, it was recognized only as a subtype of schizophrenia.
Over the years catatonia has been viewed as a symptom, a syndrome or a nosological entity. Nowadays, however, most authors would agree that catatonia is a nonspecific but strongly differentiated syndrome (Cernovsky et al., 1998), which may appear in different psychiatric or somatic conditions (Gelenberg, 1976). The differentiated phenomenology and therapy of catatonia relative to other psychiatric disorders has led to some authors to propose that catatonia should be considered as a separate diagnostic category (Fink and Taylor, 1991, Pataki et al., 1992).
As noted by Bush et al. (1996), more than 40 signs have been ascribed to catatonia, and no consensus exists about which ones are necessary or sufficient for defining the syndrome (Ungvari et al., 1995). In recent years, six explicit operative diagnostic criteria for catatonia have been proposed (American Psychiatric Association, 1994, Bush et al., 1996, Fink and Taylor, 1991, Lohr and Wisniewsky, 1987, Rosebush et al., 1990, World Health Organization, 1992). All these systems share the common feature of being based on classical definitions of the disorder, but beyond this resemblance they differ in a variety of factors, such as type and number of symptoms included, and diagnostic weight given to particular symptoms. For example, while for Lohr and Wisniewsky (1987) catalepsy, positivism and negativism are the cardinal features, for Rosebush et al. (1990) they are immobility, mutism and negativism. In line with this disagreement, from one to four signs have been proposed as sufficient to diagnose catatonia. Many other criteria have been reported (Barnes et al., 1986, Gelenberg, 1976, Johnson, 1993, Peralta et al., 1999, Starkstein et al., 1996, Taylor, 1990); they, however, were either ad hoc criteria for particular studies or were not specified in an operational way.
The current confusion about how catatonia should be diagnosed may be explained by two related factors. First, existing criteria are based largely on either subjective or theoretical grounds; and second, diagnostic criteria based on empirical data are lacking. The present study aimed to develop empirically based operational criteria for diagnosing catatonia.
Section snippets
Methods
In the process of developing the diagnostic criteria for the catatonic syndrome, we have mainly followed the method recommended by Pfohl and Andreasen (1978) for the development of classification systems in psychiatry. This method comprises four consecutive steps: (1) selection of patients and variables; (2) division of patients into groups; (3) development of diagnostic criteria; and (4) evaluation of the validity of the diagnostic system.
Cluster analysis
Cluster analysis dichotomized the study sample into a group of 32 catatonic patients and a group of 155 noncatatonic patients. Examination of the cluster centers revealed that all catatonic symptoms but mannerisms/stereotypy, staring and agitation had substantially higher values in the catatonic group respective the noncatatonic one.
Multiple discriminant and ROC analyses
As expected, multiple discriminant analysis resulted in a highly significant discriminant function: Wilk's lambda=0.133, χ2=357.9, df=14, P<0.0001. Table 2 shows
Discussion
The present study represents the first attempt to empirically develop operational diagnostic criteria for catatonia. Existing diagnostic systems have been based on nonempirical (either historical or clinical intuition) grounds. This has produced definitions that differ greatly in terms of inclusiveness and type of patients diagnosed as having the syndrome, which renders the concept under study in a state of confusion. This assertion is supported by the finding that, with the exception of the
References (33)
The catatonic syndrome
Lancet
(1976)- et al.
Serum iron in catatonic and noncatatonic psychotic patients
Biol. Psychiatry
(1999) - et al.
The Kahlbaum syndrome: a study of its clinical validity, nosological status and relationship with schizophrenia and mood disorder
Comp. Psychiatry
(1997) - et al.
Development of classification systems in psychiatry
Comp. Psychiatry
(1978) - et al.
ECT in the treatment of the catatonic syndrome
J. Affect. Dis.
(1993) - et al.
Catatonia. A prospective clinical study
Arch. Gen. Psychiatry
(1976) Diagnostic and Statistical Manual for Mental Disorders (DSM-IV)
(1994)- et al.
The syndrome of Karl Ludwig Kahlbaum
J. Neurol. Neurosurg. Psychiatry
(1986) Dementia Praecox or the Group of Schizophrenias
(1950)- et al.
Overlapping symptoms in catatonic excitement and manic excitement
Am. J. Psychiatry
(1936)