Introduction
Autism spectrum disorders (ASDs) are early onset neurodevelopmental disorders categorized by persistent deficits in social communication and restricted and repetitive patterns of behavior [1]. It is increasingly accepted that ASD are additionally associated with difficulties in sensory processing [Reference Kern, Trivedi, Garver, Grannemann, Andrews and Savla2] and motor function [Reference Gowen and Hamilton3].
Catatonia, originally described in 1874, is a complex syndrome of abnormal motor, vocal, and behavioral symptoms, with impaired volition and vegetative function [Reference Kahlbaum4]. Catatonia has historically been associated with psychosis [5] and was categorized under schizophrenia; however, this condition is now recognized within a range of different disorders, which most commonly occurs in individuals with mood disorders [Reference Taylor and Fink6]. DSM-5 allows catatonia to be coded as being associated with various mental disorders through the use of a specifier (e.g., neurodevelopmental disorder, brief psychotic disorder, schizophreniform disorder, schizophrenia, schizoaffective disorder, bipolar disorder, major depressive disorder, or other mental disorder) [1]. DSM-5 defines catatonia as being characterized by the presence of at least three of the following symptoms: catalepsy, waxy flexibility, stupor, mutism, negativism, agitation, posturing, stereotypes, mannerisms, grimacing, echolalia, and echopraxia [1] (Supplementary Table S1). Nonetheless, despite the current definition, catatonia remains a poorly recognized condition [Reference Taylor and Fink6].
There has been increasing interest in the overlap of catatonia and ASD. Symptoms of social indifference, mannerisms, and echolalia are common to both catatonia and ASD [1]. Diagnosis of catatonia in ASD might result in difficulties in its identification due to the overlap in symptoms between these two conditions.
Several explanations for the cooccurrence of catatonia and ASD have been proposed. A prior study has indicated abnormal GABAergic functioning in both conditions when compared to healthy controls [Reference Northoff, Steinke, Czcervenka, Krause, Ulrich and Danos7,Reference Chagnon8]. Common structural abnormalities in neural circuitry have also been hypothesized [Reference Dhossche, Carroll and Carroll9]. Neuroimaging studies have revealed small cerebellar structures in catatonia and ASD [Reference Courchesne, Yeung-Courchesne, Hesselink and Jernigan10]. Furthermore, some authors have suggested a possible genetic connection, with potential susceptibility regions on chromosome 15 implicated in both catatonia and ASD [Reference Chagnon8,Reference Lauritsen, Mors, Mortensen and Ewald11]. Cases studies of adverse experiences preceding the onset of catatonia also suggest a role for emotional factors [Reference Dhossche, Ross and Stoppelbein12]. In addition, catatonia has been associated with mood disorders [Reference Fink and Taylor13], and has been proposed to be an expression of severe anxiety [Reference Moskowitz14]. Susceptibility to anxiety and mood disorders in individuals with ASD might therefore contribute to the high rates of catatonia in this population [Reference Dhossche15,Reference DeLong16].
The presence of catatonic features in ASD has been studied previously [Reference Dhossche, Reti and Wachtel17–Reference Burns, Grissett, Macaluso, Raza and Gracious22]; nevertheless, to our knowledge, this is the first meta-analysis, that comprehensively assesses the relationship between catatonia and ASD, and quantifies the presence of catatonic features in ASD.
Methods
This study was done according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses reporting guideline (PRISMA Checklist) [Reference Page, JE, Bossuyt, Boutron, Hoffmann and Mulrow23], as well as the Meta-analysis of Observational Studies in Epidemiology (MOOSE) reporting guideline [Reference Stroup, Berlin, Morton, Olkin, Williamson and Rennie24] (Supplementary Table S2). The study protocol was registered in PROSPERO (CRD42021248615).
Search strategy and selection criteria
A multistep search of the literature was undertaken by two independent researchers (J.V.S and G.S.P.) through the Web of Science database (Clarivate Analytics), incorporating the Web of Science Core Collection, BIOSIS Citation Index, KCI-Korean Journal Database, MEDLINE, Russian Science Citation Index, SciELO Citation Index, Cochrane Central Register of Reviews, and Ovid/PsychINFO databases from inception until July 10, 2021, using the following keywords: “Catatonia” OR “Catatonic” OR “Catatoni*” AND “Autism” OR “Autism Spectrum Disorders” OR “Autistic Disorder” OR “ASD.”
Preprint servers “medRxiv” and “PsyArXiv” were also searched from inception until July 10, 2021, using the keywords “Catatonia” AND “Autism.” To supplement the search, the references of systematic reviews or meta-analyses that were retrieved were also manually searched. Following the screening out of the abstracts of articles identified deemed not relevant, the remaining full-text articles were then assessed against the eligibility (inclusion and exclusion) criteria.
Eligibility criteria
Inclusion criteria
The included studies were: (a) individual studies, including abstracts, conference proceedings, or gray literature (i.e., “medRxiv” and “PsyArXiv”); (b) in (i) individuals with ASD in whom the presence of catatonia is reported; (ii) individuals with catatonia in whom the presence of ASD is reported, and (iii) in which the overlapping and/or distinctive features between catatonia and ASD are described, providing important data on the relationship between them; and (c) published in English.
Additional inclusion criteria were used for the meta-analysis: (a) reporting meta-analyzable data, and (b) nonoverlapping samples. As described above overlap between the included studies was actively searched by evaluating the country, setting, university, and program from which the study sample was obtained. The recruitment period was also examined. If there was a case, when more than one study from the same sample was identified, the study with the largest sample was included.
Exclusion criteria
The following exclusion criteria used were: (a) reviews, clinical cases, and study protocols; (b) studies that did not formally assess and select participants with catatonia or ASD, and (c) studies written in languages other than English.
Outcome measures and data extraction
Independent data extraction was performed by two researchers (J.V.S. and G.S.P.), and discrepancies were resolved through discussions with the senior author (P.S.). The following variables were extracted: Study (first author and year of publication); Program; City; Country; Setting; Recruitment Period; Study Type (original or abstract); Design of the Study (longitudinal or cross-sectional); Main Outcome; Topic Investigated; Diagnoses; % ASD; % Catatonia; Comparison Group (if available); Sample Size; Age (mean, SD); Sex (% Males); Age of Onset; Diagnostic Instrument; Comorbidity (if applicable); Treatment Received (if applicable); Key Findings, and Quality Assessment.
Quality assessment
Study quality was evaluated in all the included studies. Although quality assessments can be conducted in meta-analyses, their use in observational studies is controversial, with no clear agreement on rating methods or their use in the analysis [Reference Jüni, Witschi, Bloch and Egger25].
The quality assessment was performed using a modified version of the Newcastle-Ottawa Scale for the evaluation of longitudinal and cross-sectional studies, (www.ohri.ca/programs/clinical_epidemiology/oxford.asp) [Reference Wells, Shea, O’Connell, Peterson, Welch and Losos26], in line with prior meta-analyses [Reference Vaquerizo-Serrano, Salazar de Pablo, Singh and Santosh27]. Scores ranged from 0 to 8 (Supplementary Table S3).
Data synthesis and meta-analysis
In this study, the existing evidence on the relationship between catatonia and ASD was systematically reviewed. We focused on overlapping features, including clinical, therapeutic, and cognitive aspects. When reporting the data, the results were extracted according to the type of study, that is, the data described at the baseline were obtained from cross-sectional studies and the characteristics developed over time were obtained from longitudinal studies. The presence of catatonia in individuals with ASD (%, Standard Error) was the primary outcome.
Due to the notion that the studies in this meta-analysis were expected to be heterogeneous, the random-effects model was used [Reference DerSimonian and Laird28]. Heterogeneity between studies was measured with the Q statistic and its magnitude was evaluated with the I-squared index [Reference Lipsey and Wilson29]. We performed a sensitivity analysis, stratified by group that evaluated the design of the study to determine whether there were differences between cross-sectional and longitudinal studies. Publication bias was assessed by visually inspecting funnel plots [Reference Sterne, Egger and Smith30] and applying the regression intercept of Egger [Reference Egger, Smith, Schneider and Minder31]. Due to the scarcity in the number of evaluable studies, a test of moderating factors using meta-regression analysis to estimate sources of heterogeneity could not be performed. All p-values reported in the meta-analysis were two-sided and the level of significance was set at a p-value of less than 0.05. Comprehensive Meta-analysis Software, version 3 (Biostat, Inc., Englewood, NJ) [Reference Borenstein, Hedges, Higgins and Rothstein32] was used.
Results
Database
The literature search returned 268 citations that were screened for eligibility. Of those, 215 were excluded during the title and abstract screening, and overall 53 full-text articles were assessed for eligibility. This step resulted in a total of 12 studies being included in the current systematic review, which included a total of 1,534 individuals. After excluding overlapping samples, and those studies that did not provide meta-analyzable data, seven studies comprising 969 individuals, were included in the meta-analysis on the prevalence of catatonia in ASD (Figure 1).
PRISMA flowchart.
Study characteristics
The characteristics of the included studies are detailed in Table 1. Four studies (33.3%) were from the US [Reference Ghaziuddin, Dhossche and Marcotte33–Reference Wachtel36], seven (58.3%) from Europe [Reference Billstedt, Gillberg and Gillberg37–Reference Périsse, Amiet, Consoli, Thorel, Gourfinkel-An and Bodeau43] and one (8.3%) from Asia [Reference Ohta, Kano and Nagai44]. All 12 studies reported data on general characteristics of catatonia and ASD.
Main characteristics of the included studies regarding catatonia and ASD.
Abbreviations: ABC, the Autistic Behavior Checklist; ABQ, the Attenuated Behavior Questionnaire; ADI-R, the Autism Diagnostic Interview-Revised; ADOS, Autism Diagnostic Observation Schedule; ASD, Autism Spectrum Disorder; BFCRS, Bush–Francis Catatonia Rating Scale; CARS, the Childhood Autism Rating Scale; DISCO, the DIagnosis of Social and COmmunication Disorder Schedule; DSM-III, Diagnostic and Statistical Manual of Mental Disorders, third edition; DSM-IV, Diagnostic and Statistical Manual of Mental Disorders, fourth edition; DSM-5, Diagnostic and Statistical Manual of Mental Disorders, fifth edition; ECT, electroconvulsive therapy; HBSS, the MRC Handicaps, Behavior & Skills (HBS) schedule; HC, healthy control; ICD-10, International Classification of Diseases 10th Revision; NOS, Newcastle-Ottawa Scale for the evaluation of longitudinal and cross-sectional studies; SAPPA, the Schedule for Assessment of Psychiatric Problems Associated with Autism.
The mean age across the 12 included studies was 21.25 (7.5) years, ranging from 12.7 to 27.6 years. Two studies (16.6%) included only children and adolescents [Reference Ghaziuddin, Dhossche and Marcotte33,Reference Périsse, Amiet, Consoli, Thorel, Gourfinkel-An and Bodeau43]. Most of the studies had a higher percentage of males, (range between 70 and 100% of the total sample) (key findings in Supplementary Table S4).
Clinical characteristics of individuals with ASD and catatonic features
The systematic review showed that 20.2% of ASD individuals had features of catatonia [Reference Breen and Hare38,Reference Hare, Breen, Bell, Amoaka, Oliver and Moss45]. Of those ASD individuals with catatonic features, 85% had motor disturbances [Reference Breen and Hare38]; 5.7–81.6% had an intellectual disability (ID) [Reference Billstedt, Gillberg and Gillberg37,Reference Breen and Hare38,Reference Hutton, Goode, Murphy, Le Couteur and Rutter40], and 14.1–46.6% of those had severe impairment [Reference Billstedt, Gillberg and Gillberg37,Reference Hutton, Goode, Murphy, Le Couteur and Rutter40]. A total of 34.2% had language problems, with poorer functioning being associated with a lack of phrase speech during early childhood [Reference Billstedt, Gillberg and Gillberg37].
In terms of catatonic symptomatology: (a) impaired speech was present in 29.0–100% [Reference Ghaziuddin, Dhossche and Marcotte33,Reference Wing and Shah41]; (b) lack of cooperation and negativism was present in 69.5–85.0% [Reference Wing and Shah42]; (c) agitation uninfluenced by external stimuli in 62.0–75.2% [Reference Ghaziuddin, Dhossche and Marcotte33,Reference Wing and Shah42]; (d) aggression was reported in 62.0–70.3% [Reference Ghaziuddin, Dhossche and Marcotte33,Reference Wing and Shah42]; (e) posturing was informed in 63.3% of individuals [Reference Wing and Shah41]; (f) echolalia was present in 47.5–61.3% [Reference Wing and Shah42]; (g) grimacing in 54.0–55.6% [Reference Wing and Shah42]; (h) stereotypies and other repetitive movements were present in 19.4–61.1% [Reference Wing and Shah41,Reference Wing and Shah42]; (i) 30% had odd social communication and difficulty in identifying emotions or experiences [Reference Wing and Shah41], and (j) 50% of the ASD individuals with catatonic features were passive in social interactions [Reference Wing and Shah41,Reference Wing and Shah42].
Comorbid psychopathology in individuals with ASD and catatonic features
Comorbid psychopathology in ASD individuals with catatonic features included anxiety in 22.2–69.45% [Reference Wing and Shah42], of whom 39–83% had marked anxiety [Reference Wing and Shah42]; obsessive–compulsive traits were present in 26.6% [Reference Wing and Shah41], and 44.0–55.6% had hyperactivity [Reference Wing and Shah42]. Further, 11.1–13.0% had epilepsy [Reference Ghaziuddin, Dhossche and Marcotte33,Reference Wing and Shah41]. Importantly, ASD subjects with more core catatonic features had significantly more depressive symptoms [Reference Breen and Hare38,Reference Hare, Breen, Bell, Amoaka, Oliver and Moss45].
Clinical characteristics of ASD individuals who developed catatonic features during follow-up
During the follow-up of ASD individuals, 2.2–12.0% developed catatonic features [Reference Billstedt, Gillberg and Gillberg37,Reference Hutton, Goode, Murphy, Le Couteur and Rutter40]. The catatonic symptoms described were: (a) agitation in 18.2–95.5% [Reference Ghaziuddin, Dhossche and Marcotte33,Reference Wachtel36,Reference Wing and Shah41,Reference Wing and Shah42]; (b) stereotypies in 90.1% [Reference Wachtel36]; (c) posturing in 81.8% [Reference Wachtel36]; (d) negativism in 77.3% [Reference Wachtel36]; (e) mutism in 63.6% [Reference Wachtel36]; (f) grimacing in 31.8% [Reference Wachtel36]; (g) echolalia in 9.1% individuals [Reference Wachtel36]; (h) aggression in 18.2–19.0% [Reference Ohta, Kano and Nagai44], and (i) self-harming behaviors in 27.7–90.9% [Reference Wachtel36,Reference Billstedt, Gillberg and Gillberg37,Reference Ohta, Kano and Nagai44]. In addition, 71% had severe intellectual disability [Reference Billstedt, Gillberg and Gillberg37] and 3.7–12.0% present severe motor initiation problems at follow-up [Reference Billstedt, Gillberg and Gillberg37].
Clinical comorbidity of ASD individuals who developed catatonic features during follow-up
In ASD individuals who developed catatonic features, 60.0–72.7% [Reference Hutton, Goode, Murphy, Le Couteur and Rutter40,Reference Ohta, Kano and Nagai44] reported obsessive–compulsive symptoms. A total of 9.1% had depression, adjustment disorder and sleep disturbances [Reference Hutton, Goode, Murphy, Le Couteur and Rutter40]. A total of 9.1–33.0% reported hyperactivity [Reference Billstedt, Gillberg and Gillberg37,Reference Ohta, Kano and Nagai44], and 27% had Tourette syndrome [Reference Ohta, Kano and Nagai44]. In addition, 27% had epilepsy [Reference Ohta, Kano and Nagai44].
Interventions for catatonic features in ASD
Several treatments have been used in ASD with catatonic features. Our review found that antipsychotics were used in 27–100% of individuals [Reference Ghaziuddin, Dhossche and Marcotte33] and benzodiazepines were used in 55.6–95.5% [Reference Wachtel35]. Electroconvulsive therapy (ECT) was used in 22 individuals out of 1,534 [Reference Wachtel34,Reference Wachtel35]. The systematic review showed that ECT improved catatonic symptoms, but benzodiazepines did not show a clear benefit in the resolution of catatonia, with benzodiazepines being discontinued in 33.3% due to lack of improvement; 38.1% due to only partial response; 9.5% due to sedation; and 9.5% because of behavioral worsening [Reference Wachtel35].
Results of the meta-analysis
Seven studies had data that allowed meta-analysis, comprising 969 individuals [Reference Ghaziuddin, Dhossche and Marcotte33,Reference Billstedt, Gillberg and Gillberg37,Reference Breen and Hare38,Reference Hutton, Goode, Murphy, Le Couteur and Rutter40,Reference Wing and Shah41,Reference Périsse, Amiet, Consoli, Thorel, Gourfinkel-An and Bodeau43,Reference Ohta, Kano and Nagai44]. Overall, the meta-analytical results show that 10.4%, (5.8–18.0 95%CI) of individuals with ASD have catatonia (Figure 2). Heterogeneity was significant (Q = 36.597, I 2 = 83.605%). Egger’s test result did not reveal significant publication bias (t = 0.018, p = 0.986) (Supplementary Figure S1 and Supplementary Table S5).
Meta-analysis. Catatonia in autism spectrum disorder.
Sensitivity analyses stratified by group, (cross-sectional vs. longitudinal studies), revealed that 12.1%, (5.5–24.6 95%CI) of individuals with ASD have catatonia cross-sectionally, and 8.0% (2.4–23.4 95%CI) of subjects diagnosed with ASD develop catatonic symptoms during the follow-up. There were no statistical differences in prevalence between cross-sectional and longitudinal studies (p = 0.801).
Quality assessment
The quality assessment of the included studies, evaluated using a modified version of the Newcastle-Ottawa Scale, was 5.41 ± 1.24 and ranged from 4 [Reference Wachtel34,Reference Wachtel35,Reference Ohta, Kano and Nagai44] to 7 [Reference Ghaziuddin, Dhossche and Marcotte33,Reference Wachtel36–Reference Breen and Hare38,Reference Hutton, Goode, Murphy, Le Couteur and Rutter40–Reference Périsse, Amiet, Consoli, Thorel, Gourfinkel-An and Bodeau43,Reference Hare, Breen, Bell, Amoaka, Oliver and Moss45].
The full results are detailed in Supplementary Tables S6 and S7.
Discussion
This is the first meta-analysis that comprehensively addresses the presence of catatonia in ASD. We systematically reviewed 12 studies which had information about both ASD and catatonic features, allowing us to explore the relationship between these two conditions. In addition, we meta-analytically addressed the presence of catatonia in ASD.
Individuals with catatonia and ASD present as a heterogeneous group. The present study demonstrates that these individuals are young, (mean age range 12.7–27.6 years), with catatonia having an onset in late adolescence in ASD, with a peak between 15 and 19 years [Reference Wing and Shah41,Reference Wing and Shah42,Reference Ohta, Kano and Nagai44]. Furthermore, according to our findings, catatonia appears more frequently in males, (70–100%), which is also concordant with previous studies [Reference Consoli, Raffin, Laurent, Bodeau, Campion and Amoura46,Reference Beratis, Gabriel and Hoidas47].
Our meta-analysis revealed that 10.4%, (5.8–18.0 95%CI) of individuals with ASD have catatonia, which is in keeping with the results from the review, and not too dissimilar from the 9.0% prevalence of catatonia in a variety of psychiatric or medical conditions [Reference Solmi, Pigato, Roiter, Guaglianone, Martini and Fornaro48]. However, this was reported to be lower (7.8%) in a subgroup with low heterogeneity [Reference Solmi, Pigato, Roiter, Guaglianone, Martini and Fornaro48]. Sensitivity analyses stratified by group revealed no differences depending on the type of study, meaning that we could consider the overall sample included in both cross-sectional and longitudinal studies to calculate the presence of catatonia in ASD.
The symptom overlap between catatonia and ASD have been clearly described (Supplementary Table S8). The differentiating feature is that the symptoms in catatonia are typically new-onset (usually during late adolescence) or due to a considerable worsening of existing symptoms, unlike ASD, which starts in early preschool years. Catatonia and ASD are well-known to exhibit symptom overlap, including mutism, negativism, abnormal speech, echolalia, posturing, grimacing, stereotypies, mannerisms, and purposeless agitation [Reference Dhossche, Wing, Ohta and Neumarker21,Reference Wachtel and Dhossche49]. Motor abnormalities, mannerisms, and stereotypies are present in ASD independent of the cooccurrence of catatonia [Reference Chebli, Martin and Lanovaz50,Reference Melo, Ruano, Jorge, Pinto Ribeiro, Oliveira and Azevedo51], and a recent meta-analysis revealed that the prevalence of stereotypies in ASD was around 51.8%, with a range between 21.9 and 97.5% [Reference Melo, Ruano, Jorge, Pinto Ribeiro, Oliveira and Azevedo51].
When intelligence is considered, 70–75% of ASD were traditionally estimated to have intellectual disability (ID) [Reference Newschaffer, Croen, Daniels, Giarelli, Grether and Levy52]; however, recent estimates suggest that only 50–55% of ASD individuals have ID [Reference Charman, Pickles, Simonoff, Chandler, Loucas and Baird53]. In our systematic review, the rate of ID in ASD with catatonia ranged between 5.7 and 81.6% [Reference Billstedt, Gillberg and Gillberg37,Reference Breen and Hare38,Reference Hutton, Goode, Murphy, Le Couteur and Rutter40], reaching 100% when considering clinic-based studies [Reference Wachtel35,Reference Wing and Shah41,Reference Wing and Shah42,Reference Ohta, Kano and Nagai44]. Nonetheless, those studies have clinical populations and use older definitions of ASD, with very high comorbidity of ID, which does not represent the current frequency of ID in ASD.
When clinical symptomatology at presentation is reviewed from the perspective of both clinic and population-based studies, our systematic review showed that the proportion of ASD with catatonia have a history of speech reduction is somewhat higher (29.0–100% vs. 42.9%) compared to that reported in previous studies [Reference Cuevas-Esteban, Iglesias-González, Rubio-Valera, Serra-Mestres, Serrano-Blanco and Baladon54]. Literature highlights the presence of mutism (up to 97.0%) [Reference Cuevas-Esteban, Iglesias-González, Rubio-Valera, Serra-Mestres, Serrano-Blanco and Baladon54–Reference Rasmussen, Mazurek and Rosebush57] and negativism (ranging between 59.5 and 85.0%) [Reference Wing and Shah42,Reference Cuevas-Esteban, Iglesias-González, Rubio-Valera, Serra-Mestres, Serrano-Blanco and Baladon54] in individuals with catatonia. Agitation uninfluenced by external stimuli was reported between 62.0 and 75.2%, which is similar to previous studies, where agitation was reported in 64.3% of catatonic individuals [Reference Cuevas-Esteban, Iglesias-González, Rubio-Valera, Serra-Mestres, Serrano-Blanco and Baladon54]. Considering the literature, where stupor and negativism are more frequently reported in earlier studies [Reference Peralta and Cuesta58,Reference Rosebush, Hildebrand, Furlong and Mazurek59], there might be a lack of recognition of the agitated subtype of catatonia. Stereotypies and posturing were reported in 90.1 and 81.8%, respectively [Reference Wachtel36], but other studies have reported lower figures of 35.7% for stereotypies and 19.0% for posturing [Reference Cuevas-Esteban, Iglesias-González, Rubio-Valera, Serra-Mestres, Serrano-Blanco and Baladon54]. Stupor and immobility have been reported as common symptoms in catatonia [Reference Taylor and Fink6,Reference Rasmussen, Mazurek and Rosebush57]. In the longitudinal data that we examined, agitation was the commonest catatonic symptom in those with ASD who developed catatonia, reported in 18.2–95.5%. Further, self-harming behaviors were observed up to 90.9%. It is well documented that self-injury and aggression are often seen in catatonia [Reference Billstedt, Gillberg and Gillberg37,Reference Wachtel and Dhossche49,Reference Wing60] and ASD [Reference Oliphant, Smith and Grahame61].
The presence of obsessive–compulsive symptoms and catatonia appears to be particularly characteristic in ASD individuals [Reference Hutton, Goode, Murphy, Le Couteur and Rutter40]; however, the relationship between both is still generally misunderstood [Reference Fontenelle, Lauterbach, Telles, Versiani, Porto and Mendlowicz62]. Obsessive–compulsive symptoms were found in 26.6–72.7% preceding catatonic symptoms [Reference Wing and Shah41,Reference Ohta, Kano and Nagai44]. At the symptomatic level, it has been described that patients with obsessive–compulsive disorder might present catatonic features as a direct result of their obsessive–compulsive symptoms. Especially obsessive slowness and counting rituals can present as catatonic symptoms. Catatonia has also been reported to occur more frequently in people with mood disorders [Reference Fink and Taylor13]. Prior studies have found that mood disorders appeared between 36.0 and 63.2% in catatonic individuals [Reference Cuevas-Esteban, Iglesias-González, Rubio-Valera, Serra-Mestres, Serrano-Blanco and Baladon54,Reference Parker, McClure and Paterson63,Reference Unal, Bulbul, Alpak, Virit, Copoglu and Savas64]. Our review showed that 9.1% of ASD individuals with catatonia had depression, a much lower rate compared to previously reported. This discrepancy might be due to the heterogeneity of the diagnostic criteria, and the lower rates of recognition of depression in ASD. Further, tics and Tourette’s syndrome have been described to be comorbid with ASD in several studies [Reference Baron-Cohen, Scahill, Izaguirre, Hornsey and Robertson65,Reference Canitano and Vivanti66], and are also seen in catatonia [Reference Wachtel and Dhossche49]. In our review, 27% ASD subjects with catatonia also had Tourette syndrome; however, in a prior study, 87% of patients with Tourette’s syndrome described the presence of catatonic symptoms [Reference Cavanna, Robertson and Critchley67]. Surprisingly, tics have not regularly been described in catatonia, which may appear unusual as repetitive movement abnormalities are considered classic symptoms of catatonia [Reference Dhossche, Reti, Shettar and Wachtel68].
Varied treatments have been tried to treat catatonia. Our systematic review revealed that in catatonia with ASD, antipsychotics were very frequently used (27–100%) [Reference Ghaziuddin, Dhossche and Marcotte33,Reference Wachtel34], and that the catatonia did not clearly respond to benzodiazepines, and often had to be stopped because of treatment-induced side effects [Reference Wachtel35]. This pharmacological profile significantly differs from the treatment response reported in catatonia generally, where it is accepted that there is no evidence for the use of antipsychotics in catatonic patients without an underlying psychotic disorder [Reference Pelzer, van der Heijden and den Boer69]. There is support for the efficacy of benzodiazepines, especially lorazepam, in mild catatonia in typically developing individuals associated with affective symptoms when treatment is initiated quickly after symptom onset [Reference Rosebush, Hildebrand, Furlong and Mazurek59,Reference Greenfeld, Conrad, Kincare and Bowers70]. Further, benzodiazepines are the most extensively studied treatment, with reports of good response and good tolerability [Reference Pelzer, van der Heijden and den Boer69]; Our review suggests that catatonic patients with ASD may respond less robustly to benzodiazepines, based on a retrospective chart review of inpatient and outpatient clinical records in 22 ASD patients being treated for catatonia [Reference Wachtel35]. Although the underpinnings of treatment response are unclear in catatonia with and without ASD, catatonia in ASD might have distinctive underlying deficits that might make it less responsive to certain treatments such as benzodiazepines. Some literature suggests that GABA dysfunction appears to be a common biological substrate in both [Reference Fink and Taylor13,Reference Wachtel and Dhossche49]. With regard to antipsychotic treatment, its use should be carefully considered [Reference Taylor, Barnes and Young71]. Some authors recommend avoiding antipsychotics altogether in catatonic patients, due to the risk of worsening the condition or even inducing malignant catatonia [Reference Rasmussen, Mazurek and Rosebush57,Reference Taylor, Barnes and Young72,Reference Sienaert, van Harten and Rhebergen73]; however, this unfavorable effect is especially associated with the use of first-generation antipsychotics [Reference Paparrigopoulos, Tzavellas, Ferentinos, Mourikis and Liappas74]. Nevertheless, low doses of atypical antipsychotics are known to have weak γ-aminobutyric acid agonist activity and serotonin antagonism, that could stimulate dopamine release in the prefrontal cortex and thus alleviate catatonic symptoms [Reference Sienaert, Dhossche, Vancampfort, De Hert and Gazdag75]. There are case reports of successful treatment with atypical antipsychotics [Reference Taylor, Barnes and Young71,Reference Stahl76,Reference Van Den Eede, Van Hecke, Van Dalfsen, Van den Bossche, Cosyns and Sabbe77]. While this information is useful, further work is needed in larger samples to further gauge the usefulness of different treatments.
Limitations
The small number of studies appraised and the differences in diagnostic criteria used within these studies limits the generalizability of our findings. This is further confounded because at present there is no gold-standard measure used for the identification of catatonia features in autism. Furthermore, the quality appraisal showed that the quality of most of the included studies was low. In addition, when addressing catatonia, most studies in the previous literature were case reports and clinic-based studies, which makes it difficult to extrapolate and infer clinically meaningful findings.
Despite the total number of participants included in the current meta-analysis is large (n = 969 from 7 studies), and the results are significant with precise 95% CIs to evaluate the presence of catatonia in ASD, due to the lack of data in publications, our meta-analysis did not allow us to do meta-regression analyses to examine the relationship of characteristics such as clinical, psychopathological, therapeutic, cognitive, and neurobiological aspects within these two conditions. Likewise, we were unable to analyze the presence of other comorbid conditions in individuals with autism and catatonia.
Moving forward, longer-term studies would be required to evaluate the overlap between catatonia and ASD regarding social, volitional, verbal, and motor impairments. Additionally, longitudinal studies are required to investigate the relationship between catatonia and ASD, especially treatment response. Furthermore, studies that measure anxiety, low mood, motor impairment, anhedonia, mutism, stressful life events, and treatment response in catatonia with and without ASD will help to further our understanding on the different features in both of these conditions. Timely assessment and intervention in individuals with catatonia and ASD offer more scope to improve upon current treatment pathways.
Conclusions
Different features of catatonia can exist in individuals with ASD. Core symptoms of catatonia are reported in ASD. Motor abnormalities, mannerisms and stereotypies are present in both conditions. From a clinical perspective, the neurobiological overlap between catatonia and ASD might make early intervention and treatment more difficult. Longitudinal studies are required to investigate the relationship between catatonia and ASD, and to explore treatment response to antipsychotics and benzodiazepines in catatonia with and without ASD.
Supplementary Materials
To view supplementary material for this article, please visit http://doi.org/10.1192/j.eurpsy.2021.2259.
Data Availability Statement
The data that support the findings of this study are available from the corresponding author upon reasonable request.
Author Contributions
All authors meet all four ICMJE criteria for authorship and have approved the final version of this manuscript. J.V.S. had full access to all the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis. Study concept and design: P.S.; Acquisition, analysis, or interpretation of data: J.V.S., G.S.P.; Statistical analysis: J.V.S., G.S.P.; Drafting of the manuscript: J.V.S., P.S.; Study supervision: J.S., P.S.; Critical revision of the manuscript for important intellectual content: J.V.S., G.S.P., J.S., P.S.
Financial Support
J.V.S. and G.S.P. are supported by the Alicia Koplowitz Foundation.
Conflict of Interest
P.S. is currently the Principal Investigator (PI) for the Anavex Life Sciences Corp. (Protocol No: ANAVEX2-73-RS-002) clinical trial in individuals with Rett syndrome. P.S. was the PI on the Sarizotan (Protocol No. Sarizotan/001/II/2015; ClinicalTrials.gov Identifier: NCT02790034) and GW Pharma (Protocol Number: GWND18064) clinical trials.
P.S. is the co-inventor, Chief Executive Officer and a shareholder of HealthTrackerTM.
J.S. is presently the Research Manager for the Anavex Life Sciences Corp. clinical trial for individuals with Rett syndrome (Protocol No: ANAVEX2-73-RS-002). J.S. has also been a Trial Research Methodologist on the Sarizotan Clinical Trial (Protocol No Sarizotan/001/II/2015; ClinicalTrials.gov Identifier: NCT02790034). J.S. also advises for Reverse Rett.
J.V.S. and G.S.P. have no conflict of interests to declare.
Acknowledgment
We are grateful to Leighton McFadden (King’s College London) for assisting with the checking of the manuscript and the submission process.
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