Characteristics of autism spectrum disorders are associated with longer duration of anorexia nervosa: A systematic review and meta‐analysis

Abstract

ObjectiveAnorexia nervosa (AN) is associated with neuropsychological characteristics such as impairments in central coherence, cognitive flexibility, and emotion recognition. The same features also manifest in autism spectrum disorders (ASD) and have been suggested to be associated with illness prolongation in AN. The purpose of this meta‐analysis was to examine whether pronounced neuropsychological characteristics related to ASD are associated with illness duration in AN.MethodFour databases (Medline, PsycINFO, Scopus, PubMed) were searched for eligible studies. Search terms were (a) “anorexia nervosa” and (b) “cognitive flexibility” or “set‐shifting” or “central coherence” or “emotion recognition” or “theory of mind”. The final sample consisted of 53 studies. Duration of AN was divided into three categories in order to investigate differences between the groups with varying illness duration. The meta‐analysis was performed with Review Manager using a random‐effects model.ResultsDeficits in central coherence, cognitive flexibility, and emotion recognition were pronounced among individuals with prolonged AN compared to those with shorter illness duration.DiscussionA prolonged course of AN appears to be associated with underlying neuropsychological characteristics that are also distinctive to ASD. Neuropsychological impairments may lead to prolonged AN, and prolonged illness may contribute to the subsequent “neurological scar effect,” further strengthening these impairments.

The autism diagnostic observation schedule: Patterns in individuals with anorexia nervosa

“…Compared with other samples, however, our sample had a large proportion of individuals recently diagnosed with AN, potentially diminishing such an effect in our study. Interestingly, autistic traits were positively associated with duration of AN illness in a meta‐analysis (Saure et al, 2020). The autistic traits included in the meta‐analysis were cognitive flexibility, emotion recognition and Theory of Mind, all of which were assessed with neuropsychological testing rather than observation of social interaction such as the ADOS‐2.…”

“…For example, adolescents, as well as adults, with AN display inefficiencies in nonverbal, expressive aspects of social functioning, such as facial expression (Cardi et al, 2015; Dapelo et al, 2015; Leppanen et al, 2017; Rhind, Mandy, Treasure, & Tchanturia, 2014). These inefficiencies may have important clinical implications, as they are associated with less optimal response to treatment for AN (Stewart, McEwen, Konstantellou, Eisler, & Simic, 2017; Tchanturia, Larsson, & Adamson, 2016), and a recent meta‐analysis documented a positive association between autistic traits and duration of AN (Saure et al, 2020).…”

Pragmatic Sensory Screening in Anorexia Nervosa and Associations with Autistic Traits

“…However, the AQ-10 and the original 50-item AQ may lack efficacy in distinguishing autism cases in clinical populations [38][39][40][41]. In the current study, that the AQ-10 may lack accuracy is suggested by the fact that participants in the HAT group had a lower, albeit non-significant, duration of illness compared the LAT group, whereas characteristics associated with autism assessed with experimental measures are associated with longer illness durations in AN [17]. Future research in this area should consider exploring sensory sensitivity in individuals with AN only compared to people with AN and a diagnosis of autism, or using gold-standard autism measures such as the Autism Diagnostic Observation Schedule (ADOS) known to be effective in this population [42].…”

“…Research suggests that autistic traits in AN may be associated with longer illness durations and poorer treatment outcomes, suggesting that treatment adaptations may be required. Recent qualitative research suggests that people with AN and high autistic traits may particularly benefit from adaptations addressing sensory difficulties associated with autism [16][17][18][19]. This research indicates that that sensory difficulties in autism may impact AN and its treatment in two key ways: firstly, food-related sensitivities such as an aversion to certain textures may motivate food avoidance [20][21][22].…”

Central coherence and set‐shifting between nonunderweight eating disorders and anorexia nervosa: A systematic review and meta‐analysis

“…Several authors have previously summarized the literature on central coherence and set‐shifting in eating disorders. However, these reviews either: (a) only looked at central coherence across eating disorder diagnoses (Lang et al, 2014a; Lopez, Tchanturia, Stahl, & Treasure, 2008a); (b) only looked at set‐shifting across eating disorder diagnoses (Roberts, Tchanturia, Stahl, Southgate, & Treasure, 2007; Wu et al, 2014); (c) only examined AN (Saure et al, 2020); (d) did not use a meta‐analysis approach (Idini, Marquez‐Medina, Pifarre, Buj‐Alvarez, & Castan‐Campanera, 2012; Kanakam & Treasure, 2013; Smith, Mason, Johnson, Lavender, & Wonderlich, 2018; van Elburg & Treasure, 2013); (e) were not in English (Solano‐Pinto, de la Pena, Solbes‐Canales, & Bernabeu‐Brotons, 2018); or (f) a combination of the above (Christensen, Bentz, Clemmensen, Strandberg‐Larsen, & Olsen, 2019; Cury et al, 2020; Fuglset, 2019; Jáuregui‐Lobera, 2014; Lang et al, 2014b; Lang et al, 2016; Miles, Gnatt, Phillipou, & Nedeljkovic, 2020; Reville, O'Connor, & Frampton, 2016; Stedal, Frampton, Landrø, & Lask, 2012; Van Autreve & Vervaet, 2015; Van den Eynde et al, 2011; Voon, 2015; Westwood, Stahl, Mandy, & Tchanturia, 2016). Thus, to date, no single paper has looked at both central coherence and set‐shifting across eating disorder diagnoses.…”