Obsessive-compulsive symptoms and executive functioning in eating disorders, body dysmorphic disorder and autism spectrum disorders

In a recent review (Wildes & Marcus, 2013) several limitations of current
categorical approaches to psychiatric classification like the Diagnostic and
Statistical Manual of Mental Disorders (DSM-5)(American Psychiatric
Association, 2013) and the International Classification of Diseases 10th
edition (ICD-10)(World Health Organization, 1992) have been mentioned. One of
the shortcomings that has been mentioned amongst other things, is the high rate
of co-occurrence between putatively distinct diagnoses. In the past two decades
the notion of a spectrum of obsessive-compulsive related disorders has gained
popularity (Bartz & Hollander, 2006). The OC-spectrum was proposed in response
to observations that a number of disparate disorders, for example obsessive
compulsive disorder (OCD), body dysmorphic disorder (BDD), eating disorders
(ED) and autism spectrum disorders (ASD), share obsessive*compulsive features
(Allen, King, & Hollander, 2003). Obsessions are characterized by recurrent,
time-consuming, and intrusive thoughts that cause anxiety and distress. To
reduce these negative feelings or prevent an unwanted event individuals engage
in repetitive, time-consuming behaviors and carrying them out is not
pleasurable (Phillips, McElroy, Hudson, & Pope, 1995). Although the content of
the obsessions can differ, they are often remarkably similar (McElroy,
Phillips, & Keck, 1994). Symmetry obsessions for example were found to be the
most common obsessions in patients with anorexia nervosa (AN) occurring in
about 70% of the patients (Phillips & Kaye, 2007; Kaye, Bulik, Thornton,
Barbarich, & Masters, 2004). Symmetry obsessions and repeating, ordering and
counting compulsions also appear to be particularly common in autism spectrum
disorders (ASD) (Jacob, Landeros-Weisenberger, & Leckman, 2009). Symmetry
obsessions are a well-known and common symptoms in OCD with prevalence rates
ranging form 36% to 50% in adult OCD samples (Pinto et al., 2008; Pinto,
Mancebo, Eisen, Pagano, & Rasmussen, 2006). Furthermore, Hart and Phillips
(2013) found that appearance-related symmetry concerns were reported in more
than 25% of individuals with BDD. This excessive concern about symmetry was a
relatively common feature of BDD and is not specific to OCD.
People with BDD engage in repetitive, compulsion-like behaviors such as looking
in the mirror over and over again, asking other people about the imagined
defect and skin-picking. Repetitive and restrictive behaviors are also core
symptoms of ASD (Allen et al., 2003; Oldershaw, Treasure, Hambrook, Tchanturia,
& Schmidt, 2011) in particular repeating, ordering and counting compulsions are
most often seen (Jacob et al., 2009). Also individuals with eating disorders
have strict rules about eating and perform all kinds of ritualized behaviors.
Furthermore they repeatedly check their bodies by weighing or mirror gazing
(Treasure, Claudino, & Zucker, 2010).
Co-occurrence of the different disorders might be seen as indicative for a
common etiological base (Altman & Shankman, 2009). Both BDD and ED are body
image disorders that are since long hypothesized to be related to OCD. The
similarity in the kind of obsessions and compulsions is considerable in ED and
OCD (Altman & Shankman, 2009). A close relation between OCD and BDD has been
considered for more than a century (Phillips & Kaye, 2007). There is also
potential overlap between ASD and OCD (Anagnostou et al., 2011). In eating
disorders, BDD appears to be prevalent in 15-60% of the individuals (Grant,
Kim, & Eckert, 2002; Dingemans, van Rood, de Groot, & van Furth, 2012; Kollei,
Schieber, de, Svitak, & Martin, 2013; Hartmann, Greenberg, & Wilhelm, 2013). In
a sample of individuals with BDD, 32.5% met criteria for a lifetime comorbid
eating disorder (Ruffolo, Phillips, Menard, Fay, & Weisberg, 2006; Phillips,
Menard, & Fay, 2006). Less is known about the comorbidity between BDD and ASD.
We found one description of body image obsessions and compulsions in a young
man with autism (Warren, Sanders, & Veenstra-VanderWeele, 2010). Co-morbid
diagnosis of ASD in populations of eating disorders has been found in several
studies (Courty et al., 2013; Wentz et al., 2005; Baron-Cohen et al., 2013).
Also elevated levels of eating disturbances have been found in adolescent girls
with asperger symdrome (Kalyva, 2009). Furthermore AN and ASD appear to
co-exist in families (Zucker et al., 2007; Oldershaw et al., 2011). Parents of
autistic children with high levels of repetitive behavior showed more OCD
traits or OCD than those of children with low levels (Hollander, King, Delaney,
Smith, & Silverman, 2003). A relatively high incidence of autism was found in
siblings of patients with ED (Gillberg, 1985).
Besides the similarities in obsessive and compulsive features, there seems to
be an overlap in their cognitive and neuropsychological functioning.
Accumulating evidence suggests that specific impairments in executive
functioning are central to the development and maintenance of obsessions and
compulsions (Steinglass, Walsh, & Stern, 2006; Steinglass & Walsh, 2006; Hill,
2004; Chamberlain et al., 2008; Harkin & Kessler, 2011). Executive functioning
is intrinsic to the ability to adapt behavior to novel situations and is also
the basis of many cognitive, emotional, and social skills (Lezak, Howieson, &
Loring, 2011). Typical of compulsive (ritualized) behaviors is that it is
difficult to learn and develop healthy alternative behaviors, once they are
consolidated (Steinglass & Walsh, 2006). An example of executive functioning is
set-shifting which concerns the ability to move back and forth between multiple
tasks, operations or mental sets; it represents cognitive flexibility. Recent
studies (Tchanturia et al., 2004; Holliday, Tchanturia, Landau, Collier, &
Treasure, 2005; Hambrook, Tchanturia, Schmidt, Russell, & Treasure, 2008;
Roberts, Tchanturia, & Treasure, 2010; Roberts, Tchanturia, Stahl, Southgate, &
Treasure, 2007; Oldershaw et al., 2011) found that patients with ED and ASD
both have problems with set-shifting. Both groups are typified by a rigid
cognitive style and have difficulties switching their problem solving approach
(Baron-Cohen et al., 2001; Roberts et al., 2007, Tchanturia et al., 2011),
probably resulting in repetitive, rigid behavior (Lopez, 2005, Treasure, 2007).
These cognitive impairments are also seen in first-degree relatives of patients
with ED, OCD and ASD (Wong, Maybery, Bishop, Maley, & Hallmayer, 2006; Roberts
et al., 2010; Chamberlain et al., 2007; Hughes, Leboyer, & Bouvard, 1997;
Friederich & Herzog, 2011).
Another cognitive impairment that has been found in patients with ED and ASD is
weak coherence. This refers to the cognitive style where there is a bias
towards detail accompanied by difficulties in the integrative processing of
information (Happé & Booth, 2008) and is most often linked to ASD (Frith,
1989). It has been hypothesized that weak coherence may also be linked to ED;
however the results of different studies are inconclusive (see review (Lopez,
Tchanturia, Stahl, & Treasure, 2008). A recent review (Madsen, Bohon, &
Feusner, 2013) comparing AN and BDD, stated that the literature on AN and BDD
suggested a pattern of over-attention to detail, reduced processing of global
features, and a tendency to focus on symptom-specific details in their own
images (body parts in AN, facial features in BDD), with cognitive strategy at
least partially mediating the abnormalities.
As mentioned above a considerable number of separate studies investigated
similarities and differences between these disorders which all share core
obsessive and compulsive features to some degree. However, studies comparing
these disorders directly and investigating common pathways are lacking.
Investigating this similarity in psychopathology is needed in order to examine
underlying mechanisms that may be responsible for the development or
maintenance of the disorders. If empirical studies confirm joint etiological
factors, new treatment approaches could be tested and inclusion of treatment
components that are successful in one disorder could be transferred to the
respective others (Hartmann et al., 2013). For example, Dingemans et al. (2014)
recently conducted a randomized controlled trial investigating the
effectiveness of cognitive remediation therapy (CRT), which was developed to
improve cognitive flexibility, thereby increasing the likelihood of improved
outcome. The findings suggested that CRT enhances the effectiveness of
simultaneous and subsequent treatment with respect to ED psychopathology and
quality of life, particularly for patients with poor set-shifting abilities.

The aim of the current study is to investigate obsessive-compulsive symptoms
and executive functioning in ED, BDD, OCD and ASD. Symptoms of ED, BDD, OCD and
ASD will be assessed in all four disorders, as well as executive functioning.
We hypothesize that these disorders share obsessive*compulsive symptoms and
that these symptoms are associated with deficits in set-shifting and central
coherence. Current psychiatric categories provide no insight into potential
mechanisms that may drive these disorders, which limits their ability to inform
models of etiology and maintenance and hinders the development of interventions
(eg Cognitive Remediation Therapy (CRT) e.g. Dingemans et al. 2014) directed at
shared underlying mechanisms (Wildes & Marcus, 2013).
1) Is there within each diagnostic category a positive correlation between the
other three other disorders? Before associations between OC spectrum severity
and executive functioning can be investigated, we first need to confirm that
the individuals with ED, BDD, ASD and OCD in our sample have overlapping
symptoms and characteristics. It is hypothesized that within a diagnostic
disorder category there is a positive association between the symptoms of the
other three disorders, because of the high rates of co-occurrence between these
OCS-disorders found in previous studies (Wildes & Marcus, 2013). Therefore,
within each diagnostic category, correlations will be computed with the other
three disorder specific symptoms. For example it is hypothesized that there is
a significant correlation between dysmorphic appearance concerns, autistic
symptoms and obsessive compulsive symptoms in the group of individuals with a
primary diagnosis of an eating disorder. In the same way correlations will be
computed for the BDD, ASD and OCD sample.
2) Is there a positive correlation between a composite score of ED-BDD-OCD-ASD
symptoms on the one side and obsessive- compulsive spectrum severity and
executive functioning on the other side? Individuals who have high scores on
all four disorder-specific questionnaires investigating the symptoms of ED,
BDD, OCD and ASD are hypothesized to report more severe OC- Spectrum-symptoms
and more deficits in executive functioning. In order to test this a composite
score will be calculated by means of a factor-analysis. Correlations will be
computed between the composite score and OC spectrum severity and executive
functioning.
3) Is there a positive correlation between OC-Spectrum severity and executive
functioning in the total sample? It is hypothesized that individuals with more
obsessive and compulsive spectrum, symptoms will have more deficits in
executive functioning. Therefore we expect a positive correlation.

Participants are asked to fill out seven questionnaires (duration approxomately
50 to 60 minutes)

not applicable