Neuropsychological Profile of Childhood-Onset Obsessive-Compulsive Disorder
Neuropsychology of OCD 1
Running Head: Neuropsychology of OCD
Neuropsychological Profile of Childhood-Onset Obsessive-Compulsive Disorder
Metehan Irak & Martine M. Flament
University of Ottawa Institute Mental Health Research
September 16th , 2006
Neuropsychology of OCD 2
Summary
In this review paper, studies focusing on the neuropsychological characteristics of childhood-onset obsessive-
compulsive disorder (OCD) were evaluated. Systematic electronic searches were undertaken using MEDLINE
and Psycinfo databases (until June 2006). The presented results are of those that focus on the processes of
attention, memory, and executive functions related to the aspects of the measured instruments used. The aim of
this review was to provide a general neuropsychological profile of childhood-onset OCD based on the reviewed
studies. In general, results showed that there is no clear evidence that the neuropsychological aspects of
childhood-onset OCD differ from those of adult-onset OCD. In parallel with this, the processes of attention and
memory in childhood-onset OCD are observed to be selective and biased, and this bias is directed towards
threat-relevant stimuli related to obsessions and compulsions. In addition, dysfunction in memory and
visuospatial processes in OCD patients do not result from memory impairment per se, but rather from an
impaired ability to apply efficiently elaborated memory strategies. In childhood-onset OCD, the various lines of
evidence consistently include impairment of response suppression and motor inhibition abilities; there is less
consistent evidence for reduced set shifting, fluency, conceptual thinking, and planning ability. Whereas clinical
observation suggests that a central problem in OCD is at the meta-memory level and that people with OCD have
less meta-cognitive ability, processing of meta-cognition in childhood-onset OCD has not yet been investigated
adequately. Finally, the results of the reviewed studies were evaluated in terms of the effects of basic co-
morbidity, such as depression, Tourette’s disorder, tic disorder, and other confounding variables.
Key words: childhood-onset obsessive-compulsive disorder, attention, memory, executive functions
Neuropsychology of OCD 3
Clinical Characteristics of Childhood-Onset OCD
Obsessive-compulsive disorder (OCD) is a psychiatric disorder characterized by repetitive obsessions
and compulsions. It is chronic, but can be cyclic, significantly affecting an individual’s social and daily
functioning. Although OCD has been recognized as a disorder commonly observed in adulthood, studies have
shown that the prevalence rate of OCD is 1%-4 % among adolescents (Douglass et al., 1995; Flament et al.,
1988), with more than 80% of OCD patients reporting relevant symptoms starting before the age of 18 years
(Pauls et al., 1995). OCD is often comorbid with other psychiatric disorders, namely depression, tic disorder,
and other anxiety disorders. The onset of OCD has been observed earlier in boys than in girls, with behaviors
reaching their peak approximately around pre-adolescence, and then again in early adulthood (Pauls et al., 1995;
Rasmussen and Eisen, 1992; Zohar, 1999). Adult- and childhood-onset OCD differ from each other in terms of
certain clinical characteristics. Childhood-onset OCD, as opposed to adult-onset OCD, starts as early as
adolescence and progresses rapidly. These differences lead to neurobiological and other related consequences
(Sobin et al., 2000).
There have been numerous theoretical approaches about the etiological factors and treatment of OCD,
including psychological and neurobiological explanations. , Recently, cognitive-behavioral therapy (CBT) and
pharmacological treatment approaches have been commonly used for the treatment of OCD. Although both of
these treatment approaches are used for childhood-onset OCD, it is a common opinion that there is a need for
more research on the effectiveness and reliability of these treatment modalities (Flament and Cohen, 2002). On
the other hand, research focusing on OCD suggests that neuropsychological approach/evaluation is becoming
more common. Based on this, in the following paragraphs theoretical approaches and research findings focusing
on the neuropsychological characteristics of OCD are discussed.
Neuropsychology of OCD 4
Neuropsychological Test Results in Childhood-Onset OCD
Today, the existence of many neuropsychological tests with advanced psychometric characteristics,
which are sensitive to detailed brain functioning, makes it possible for neuropsychological tests to be taken by
patient groups, to be performed on one dimension, and to be score-based. With these particular characteristics,
neuropsychological testing and evaluation, like in other psychiatric disorder groups, are part of the research
approach focusing on cognitive processes in OCD. We reviewed studies on the neuropsychological performance
of childhood-onset OCD patients and present an evaluation of the results. With this purpose in mind, a literature
search was performed using both MedLine and PsycInfo databases encompassing studies dated until June 2006.
This study included research investigating the neuropsychological performance of 0 to 19 year-old OCD
patients, and did not directly investigate the effects of any treatment methods (pharmacotherapy and/or
psychotherapy) on their effects on cognitive performance. The keywords used in the literature search were as
follows: OCD, neuropsychology, cognition, attention, memory, executive functions, information processing,
meta-cognition, and meta-memory. As a result of the literature search, 6 studies focusing on the relevant issues
were found and are presented in Table 1. Among these studies, only the study by Gladstone et al. (1993) was
published as a summary in a conference, and details of this study were taken from the review article by Cox
(1997). Findings are presented under attention, memory, and executive function subheadings, respectively.
Insert Table 1 here
Attention
In one of the first studies in this area, Foa and McNally (1986) found that in a dichotic listening task,
adult OCD patients understood or noticed threat-related words better than they did neutral words. The
difficulties experienced during cognitive performance are suggested to be closely related to anxiety, leading to
disruptive effects and interfering thoughts prohibiting fluency during cognitive processing, and occupying
consciousness (Eysenck, 1997; Gotlib et al., 1996). When cognitive functioning in OCD is in question, OCD
patients are said to not display any problems with attention performance. Cnsequently, the more commonly
accepted approach suggests that these patients have selective attention tendencies; defined as paying attention to
Neuropsychology of OCD 5
selective characteristics of stimuli in the environment and not paying attention to or ignoring the remainder of
the stimuli (Diniz et al., 2004; Kuelz et al., 2004; Moritz et al., 2004).
Many of the studies which have studied various aspects of attention performance in childhood-onset
OCD, have reported that it is less of a factor in adult OCD patients. In a study by Cox et al. (1989), the
neuropsychological performance of 8 to 18 year-old OCD patients was compared to that of a healthy control
group matched in terms of age, sex, and hand preference (Table 1). In terms of attention performance, the only
difference found between the two groups was in their dichotic listening task total linear scores; the total linear
percentage of the OCD group was lower than the healthy control group. Similarly, in a study by Gladstone et al.
(1993) 8 to 13 year-old children with Tourette’s disorder (TD) were matched for age, sex, and intelligence
quotient (IQ) with children diagnosed with OCD, and their neuropsychological performances were compared.
Results showed that the sustained attention performance in both groups was lower than normative values (Cox,
1997). The authors interpreted the results as attention being disrupted in OCD and TD (Gladstone et al., 1993).
In a study by Behar et al. (1984) the neuropsychological test performance of OCD patients (mean age:
13.7 years) who were receiving a 10-week clomipramine treatment were compared to a healthy control group
matched for age, gender, and IQ. Additionally, the sizes of their cerebral ventricles were measured with CT
(computer tomography). According to the CT results, cerebral ventricles of the OCD patients were significantly
larger than those of the healthy control group. Although in some memory tests the OCD group scored
significantly lower (Table 1) than controls, there was no significant difference between the scores of attention
and perception tests between the two groups. More specifically, although the scores of the Dihaptic (Tactual)
Testing, Reaction Time, and Two-Flash Threshold Test were in favor of the healthy control group, the
differences between the two groups were not found to be statistically significant. As the reaction time and
reaction threshold scores were not significantly different, the authors suggested that the lower scores of the
OCD patients on some neuropsychological tests could not be explained by an attention problem or by obsessive
style. In summary, the findings on attention indicate that in childhood-onset OCD, as in the adult group, there is
Neuropsychology of OCD 6
a bias in attention processing. However, as there are only a few studies on attention and the variation of the
basic characteristics measured by the applied tests, it was not possible to create a general profile on this topic.
Memory
Aspects of the behaviour seen in people with OCD (e.g., checking) are certainly suggestive of memory
problems (e.g., failure to appropriately encode memories for self-actions). For example, a problem such as
checking might indicate that the individual is either unable to code his or her behavior in memory in a suitable
way or that he or she cannot remember it. Although there are…
