Download Spatial behavior reflects the mental disorder in OCD patients with

ORIGINAL RESEARCH
CNS Spectrums, page 1 of 14. & Cambridge University Press 2013
doi:10.1017/S1092852913000424
Spatial behavior reflects the mental disorder
in OCD patients with and without comorbid
schizophrenia
Anat Gershoni,1 Haggai Hermesh,2 Naomi A. Fineberg,3 and David Eilam1*1
Department of Zoology, Tel-Aviv University, Ramat-Aviv, Israel
CBT Unit, Geha Mental Health Center, Petah Tikva, Sackler Faculty of Medicine, Tel Aviv University, Ramat-Aviv, Israel
3
National OCD Treatment Service, Queen Elizabeth II Hospital, Welwyn Garden City, UK
2
Objective. Resolving the entangled nosological dilemma of whether obsessive-compulsive disorder (OCD)
with and without schizophrenia (schizo-OCD and OCD, respectively) are two independent entities or
whether schizo-OCD is a combined product of its parent disorders.
Methods. Studying motor activity in OCD and in schizo-OCD patients. Performance of the patients was
compared with the performance of the same motor task by a matching control individual.
Results. Behavior in both schizo-OCD and OCD patients differed from controls in the excessive repetition
and addition of acts, thus validating an identical OC facet. However, there was a significant difference in
spatial behavior. Schizo-OCD patients traveled over a greater area with less focused activity as typical to
schizophrenia patients and in contrast to OCD patients, who were more focused and traveled less in a
confined area. While schizo-OCD and OCD patients share most of the OC ritualistic attributes, they differ
in the greater spread of activity in schizo-OCD, which is related to schizophrenia disorder.
Discussion. It is suggested that the finding on difference in spatial behavior is a reflection of the mental
differences between OCD and schizophrenia. In other words, this could be an overt and observable
manifestation of the mental state, and therefore may facilitate the nosology of OC spectrum disorders and OCD.
Conclusion. It seems as if both the OCD patients’ focus on specific thoughts, and the contrasting wandering
thoughts of schizophrenia patients, are reflected in the focused activity of the former and wandering from
one place to the next of the latter.
Received 26 March 2013; Accepted 16 May 2013
Keywords: OC behavior, OCD, Rituals, Schizophrenia, Spatial behavior.
Clinical Implications
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There is an overt behavioral difference between
comorbid schizophrenia and OCD (schizo-OCD)
compared with OCD.
OCD patients are mostly stationary, whereas
schizo-OCD patients wander over a large space.
However, as in OCD, schizo-OCD patients have
excessive repetition and addition of acts.
These features may serve as bedside sign and facilitate
the nosology of OC spectrum disorders and OCD.
These overt differences may also reflect the
differences between OCD and schizophrenia in
cognition, attention, and brain malfunctioning.
y We are grateful to the anonymous patients and control individuals
who willingly participated in this study.
*Address for correspondence: David Eilam, Ph.D., Department of
Zoology, Tel-Aviv University, Ramat-Aviv 69978, Israel.
(Email: [email protected])
Introduction
Obsessive-compulsive disorder (OCD) and schizophrenia are distinct diagnostic entities.1,2 The main
features of OCD are as follows: (i) obsessions, which are
recurring, persistent thoughts, impulses, or images
that are experienced as intrusive and unwanted and
causing marked distress or anxiety, and (ii) compulsions, which are repetitive motor behaviors such as
checking or mental behaviors such as counting that
occur in response to an obsession and are performed
according to strictly applied rules.3 However, observations have revealed that disparate mental disorders
may also possess obsessive-compulsive (OC) features,
leading to the concept of the OC spectrum disorder
(OCSD).4–9 Schizophrenia, on the other hand, consists
of both positive symptoms, such as delusions (fixed
false beliefs), hallucinations, disorganized speech,
and abnormal psychomotor behavior, and negative
symptoms, such as diminished emotional expression.3
2
A. Gershoni et al.
Two nosological notions have been suggested to explain
the association and relationship between OCD and
other Axis-I mental diagnoses, including schizophrenia
disorder: comorbidity and spectrum. According to the
comorbidity notion, there is an endophenotype that is a
combination of OCD and schizophrenia (‘‘schizo-OCD’’),
whereas according to the spectrum notion, schizo-OCD
is a subtype of schizophrenia.10–12 While comorbidity
implies that each disorder maintains its own features,
the spectrum notion suggests that schizo-OCD patients
have a unique pattern of neuropsychological deficits.10,13
Furthermore, schizo-OCD patients are considered more
impaired14 and have greater neurocognitive deficits
compared with either patients with OCD or schizophrenia alone.10 A synthesis of both comorbidity and
spectrum notions has also been suggested, presenting a
continuum of comorbidity between OCD and schizophrenia.1 This spectrum comprises four subgroups:
(i) schizophrenia in OCD patients, (ii) schizotypal
personality disorder (SPD) in OCD patients, (iii) OCD
with poor insight, and (iv) schizophrenia with OC
features. The prevalence of schizophrenia in OCD
patients has been reported to be as high as 4%;
nonetheless, OCD patients have no greater chance of
developing schizophrenia later in life.1,15 Schizophrenia
patients with OC symptoms are a well-described
group, comprising 7.8–55% of schizophrenics.1,16–18
Traditionally, it was suggested that, for the most part,
schizo-OCD patients are primarily schizophrenic
patients that additionally suffer from comorbid OC
symptoms.1 A comparison of schizophrenic symptoms
and signs between patients with schizophrenia with or
without OCD revealed no difference,16,19–21 though
increased levels of cognitive inflexibility have been
detected in neurocognitive tests in schizo-OCD.22 Thus,
the target of this study was to answer the outstanding
question regarding schizo-OCD: Is it a comorbidity that
integrates symptoms of its parent disorders, or is it a
subtype of one of the parent disorders?
OCD, schizo-OCD, and schizophrenia may represent different states along the continuum of thought
disorder. One end of this continuum is that of the
obsessive thought process that characterizes OCD,
consisting of repetitive thoughts that the patients
perceive as senseless and unwanted.14,23 The other
end of the continuum is that of the delusive process of
fixed false beliefs that characterizes schizophrenia.3,14
In between these ends, there are the overvalued ideas
and OCD with poor insight that appears in schizoOCD. In this state, patients no longer address their
obsessions as senseless and unwanted, but view them
as realistic.14–16 Despite the above differences between
the three states, several studies have suggested that
schizo-OCD patients do not differ significantly from
patients with schizophrenia (without OCD) in terms of
the global assessments of functioning.19 Schizophrenic,
schizo-OCD, and OCD patients may also differ in the
motor manifestation of the respective disorders.
Schizophrenic patients mainly suffer from several
motor dysfunctions, including hypokinesia, catatonia,
catalepsy, and Parkinsonism without overt motor
tasks.24 In contrast, schizo-OCD patients display
compulsive motor tasks that are reminiscent of those
displayed by nonpsychotic OCD patients.25 Accordingly, in the present study, we set out to compare the
motor behavior of OCD and schizo-OCD patients in
order to uncover the differences and similarities
between these two psychiatric categories.
Spatial motor behavior in schizophrenic patients
spreads over a wide area, involving a greater
locomoted distance,26 whereas OCD motor behavior
(compulsions) is repetitive, comprising numerous
nonfunctional acts that seem irrelevant for the current
task, and are performed with high concentration.27–29
In light of these differences, we assumed that the
dissimilar cognitive impairments in both illnesses
would manifest differently in the spatial organization
of their motor behaviors. Specifically, OCD patients
were expected to pay more attention and have more
confined and focused motor behavior, whereas schizoOCD patients were expected to be more disoriented,
paying less attention to details, and featuring dispersed motor behavior. A comparison of OCD and
schizo-OCD behavior may facilitate the nosology of
OC spectrum disorders and OCD, and may facilitate
the separation of these disorders with overt motor
signs, adding a different and new perspective to the
effort to resolve the nosological dilemma of whether
schizo-OCD is an independent entity or merely a
combination of its basic parent disorders.
Methods
Participants
Ten motor tasks of OCD patients, 10 tasks of patients
suffering from schizo-OCD, and 20 tasks of normal
controls were extracted from video files. Patients met
Diagnostic and Statistical Manual of Mental Disorders,
4th ed. (DSM-IV) and SCID (structural clinical interview
for DSM-IV) criteria for OCD, both without or with
schizophrenia disorder. All patients have demonstrated
compulsions with obvious motor rituals. In the frequent
case of comorbidity, OCD was the primary disorder
among all anxiety and/or mood disorders. None of the
participants had either Tourette disorder or multiple
tic disorders. The 10 OCD tasks were contributed
by 7 patients, with 3 of them performing 2 tasks each
and 4 performing 1 task each. The 10 schizo-OCD tasks
were contributed by 6 patients, 3 of them performing 2
Behavior in OCD with and without schizophrenia
tasks each, and the other 3 patients performing 1 task
each. The themes of the tasks were determined by the
patients, with each performing a behavior that was
prevalent in her/his recent behavior. Each of the above
OCD and schizo-OCD patients was matched with a
healthy control individual of the same gender and age,
who was requested to perform the same motor task that
the patient performed. The patients’ background and
task characteristics are depicted in Table 1. Tics not
meeting criteria for Tourette disorder were observed in
patient #15. Patients from both groups did not differ in
age (F1,11 5 1.42; P 5 0.26), number of mental diagnoses
(F1,11 5 0.38; P 5 0.55), and Y-BOCS score (F1,11 5 1.5;
P 5 0.24). Patients were recruited from an Israeli regional
psychiatric outpatient clinic and an anxiety disorder and
cognitive behavioral therapy (CBT) unit at the Geha
Mental Health Center, Israel. The study was approved
by the Helsinki Committee of Geha Mental Health
Center. Participants signed an informed consent.
Procedure
Patients and their respective controls were each
videotaped by the psychiatrist and experimenter
at their homes, where they routinely perform their
motor behavior. Assessment of each patient was made
by a senior clinical psychiatrist using the Y-BOCS
(Yale–Brown Obsessive Compulsive Scale) questionnaire. Afterward, a short conversation about the
patient’s current mental state and the compulsive
behaviors commonly performed in the recent period
led to a decision about the specific tasks, which would
be video-recorded for analysis. The patients were then
asked to perform the task on camera in the same
manner as they do in their everyday life. Each control
individual was requested to perform the same task as
her/his respective patient.
Data acquisition and analysis
A task was defined as the set of acts executed by the
patients or control individuals. Each of them set the
beginning and end of their task. For example, the start
was set when a patient said he was showing how he
‘‘washes hands,’’ and ended when he said that he was
done. Similarly, the matched control was requested to
show how he washed his hands, until he said that he
was done. All the acts performed between the
beginning and end of each task were listed and scored.
Acts were scored according to the location or object on
which they were performed. For example, in the task
of ‘‘washing hands,’’ the act ‘‘turn on’’ was performed
on the object ‘‘tap’’ and the act ‘‘take’’ was performed
on the object ‘‘soap’’; in the task ‘‘going out from
home,’’ the act ‘‘turning lights on and off’’ was
performed at two locations: ‘‘the bedroom’’ and ‘‘the
3
living room.’’ According to this procedure, the patients,
by setting the beginning and end of the task, also set the
task domain to include all the objects/locations on which
they performed acts during the task. The acts and the
locations/objects at which they were performed were
scored using the Observer XT 10.1 (Noldus Information
Technology, the Netherlands), a software program for
ethological description. The Observer output contained a
sequential list of the acts and objects/locations. Acts
underwent further classification in accordance with the
proximity to the performer, as follows:
1. Self—acts that were performed on the patient’s
body while the patient was stationary. An example
of an act with self proximity is ‘‘rubbing hands’’ or
checking a trouser’s pocket.
2. Stationary—acts performed on objects other than the
patient’s body, while she/he did not move from
their place. An example of an act with stationary
proximity is ‘‘touching the doorknob.’’
3. Travel—acts performed on an object/location
requiring the patient to walk to that location/
object. This category was further divided into two
subcategories:
i. Nearby travel—a travel trajectory of up to 2 steps
(up to 75cm).
ii. Far travel—a travel trajectory of more than 2
steps (further than 75 cm). This definition was
based on a step-length of ca. 32 cm (http://
www.footlab.co.il/03_walk/19_measures.asp).
Statistics
A two-way analysis of variance (ANOVA) with repeated
measure (ANOVA-RM) was used to analyze the
differences among OCD, schizo-OCD, and normal
control groups (between-group factor) and the spatial
categories of acts (proximity—self, stationary, and travel;
within-group factor). Post-hoc Tukey HSD (honestly
significant difference) tests were used as needed to
further analyze the ANOVAs results. A comparison of
the number of locations/objects in a task and the
number of visits in each location/object was carried
out by means of a one-way ANOVA. A comparison of
the number of steps each individual executed in the
ritual was carried out by means of a one-way ANOVA.
Significance was determined at p , 0.05. Continuous
data are presented as mean and standard error (±SEM).
Findings
OCD and schizo-OCD patients differed in their
spatial behavior but not in the OC rituals
Figure 1 depicts the distribution of the proximity of
acts in OCD, schizo-OCD, and control individuals.
4
A. Gershoni et al.
Table 1. Characteristics and motor tasks in obsessive-compulsive disorder (OCD) patients with and without schizophrenia.
Patient
no.
Type of OCD
Motor task
Age
Age of OCD onset
1
2
3
OCD
OCD
OCD
Clean phone
Lock door
Go out
50
31
68
25
12
25
4
OCD
Go out
26
13
5
OCD
54
12
6
OCD
62
27
OCD; Generalized anxiety disorder; MDD;
simple phobic disorder (panic & agoraphobia)
OCD; Panic; IBS; Agoraphobia; MDD
7
OCD
21
18
11
Schizo-OCD
Wash hands
Lock door
Clean cloth
Clean closet
Lock door
Wash hands
Make tea
28
Not known
12
Schizo-OCD
42
6
13
14
Schizo-OCD
Schizo-OCD
47
32
18
10
15
Schizo-OCD
36
12
16
Schizo-OCD
23
14
Go out
Arrange closet
Wash hands
Go out
Clean sink
Go out
Clean table
Lock door
Medication
mg/day
Diagnoses
OCD; MDD
OCD
OCD; Compulsive shopping; Dysthymia;
Agoraphobia; Borderline personality; MDD;
Hypochondriasis
OCD; MDD; Nail Biting
Y-BOCS
Clomipramine 300; quetiapine 400
Clomipramine 300 ; mazoril 150
Amantadine 100; lamotrigine 350;
flouxetine 60
25
19
22
Clomipramine 300; olanzepine 15;
citalopram 20
Fluvoxamine 100; diazepam 5; sulpiride 200
30
14
Eltroxin 50; flouxetine 40–50; olanzepine
26
OCD; GSP; IBS; DSPS; Stuttering
Sertraline 200
21
OCD; Schizophrenia; BDD
Clotiapine 160; paroxetine 80;
carbamezapine 400 ; clonazepam 1.5
Lithium 1500; trihexyphenidyl 5;
levomepromazine 500
Sulpiride 100; clozapine 500; citalopram 20
Clomipramine 300; risperidone 4
36
21
22
Amisulpride 100; trazodone 50
21
Olanzepine 15; flouxetine 20
25
OCD; Schizophrenia;
Borderline personality disorder
OCD; Schizophrenia
OCD; Schizophrenia;
SP; s/p MDD; s/p BDD
OCD; Schizophrenia;
SP; Trichotillomania; Tics
OCD; Schizophrenia
34
Other disorders noted in the table are as follows: MDD–major depressive disorder; IBS–irritable bowel syndrome; GSP–generalized social phobia; DSPS–delayed sleep phase syndrome;
BDD–body dysmorphic disorder; SP–social phobia; Y-BOCS–Yale–Brown obsessive compulsive scale.41
Behavior in OCD with and without schizophrenia
5
Figure 1. Proportion of acts according to their proximity in
OCD, schizo-OCD, and control individuals. All the acts that
comprised each motor task were divided into self, stationary,
and travel acts. The proportion of act proximity is depicted
as the average (± SEM) percentage of all acts in each motor
task. The asterisk indicates a significant difference in travel
acts between the schizo-OCD and OCD groups.
revealed that the percentage of ‘‘travel’’ acts in schizoOCD patients was significantly greater than in OCD
patients and control individuals.
‘‘Travel’’ acts underwent further classification into
‘‘nearby’’ and ‘‘far’’ acts (see Methods section). The
relative number of these subtypes was compared by
means of ANOVA-RM, which revealed a significant
difference between OCD, schizo-OCD, and control
individuals (between-group effect; F2,37 5 17.25,
p , 0.0001), a significant difference between nearby
and far acts (within-group effect; F1,37 5 26.32,
p , 0.0001), but no significant interaction (F2,37 5 0.28,
p 5 0.69). Notably, there were no ‘‘far’’ acts in any
of the 10 OCD motor tasks (Figure 2). Thus, while
OCD patients were more stationary than control
individuals, schizo-OCD patients traveled further
compared to control individuals when performing
the same activity.
The number of steps taken by the participating
individuals during the task differed significantly
between OCD, schizo-OCD, and control groups (oneway ANOVA, F2,37 5 20.3, p , 0.0001). The Tukey HSD
test revealed a significant difference between OCD and
schizo-OCD patients and between the schizo-OCD and
the control groups, but no significant difference
between OCD patients and control individuals. These
results highlighted the contribution of schizophrenia to
the spreading out of the motor activity in schizo-OCD
patients, as manifested in the increased number of
steps. Indeed, OCD patients and control individuals
performed fewer steps compared with schizo-OCD
patients, with the latter taking significantly more steps
and covering a greater area (Figure 3).
In the present analysis, spatial behavior is considered
as a set of locations or objects that the tested individuals
visited during the activity, and the set of acts performed
Figure 2. ‘‘Nearby’’ and ‘‘far’’ traveling in each motor task.
These are depicted as the percent average (± SEM) of each
travel category (nearby/far) out of the total travel acts. The
asterisk indicates a difference between nearby acts in schizoOCD compared with all other act types and groups in this
figure; # indicates a significant difference between far acts in
schizo-OCD and OCD patients.
Figure 3. The number of steps taken by OCD, schizo-OCD,
and control individuals. The asterisk indicates significant
difference between schizo-OCD compared with OCD and
control individuals.
ANOVA-RM revealed that there was a significant
difference between the three diagnostic groups
(F2,37 5 4.78, p 5 0.014), a significant difference
between proximities (F2,74 5 52.58, p , 0.0001), and a
significant interaction (disorder 3 proximity; F4,74 5 2.94,
p 5 0.025). The interaction implies a difference in
proximity among the three groups (schizo-OCD,
OCD, and control individuals). A Tukey HSD test
revealed that the share of stationary acts in OCD
behavior was significantly higher than that of both
self and travel acts (71%, 20%, and 8%, respectively;
Figure 1). In schizo-OCD behavior, the share of
stationary acts was smaller, along with an increase in
‘‘travel’’ (55%, 15%, and 30%, respectively; Figure 1).
Control behavior matched that of OCD rituals (70%,
17%, and 13%, respectively; Figure 1). Tukey HSD tests
6
A. Gershoni et al.
at each such object/location. A one-way ANOVA
revealed a significant difference in both the number of
objects/locations and in the total number of visits
to these objects/locations (F2,37 5 5.55, p 5 0.007 and
F2,37 5 4.59, p 5 0.016 for locations and for visits,
respectively; Figure 4). A Tukey HSD revealed
that the control and schizo-OCD groups differed
significantly, whereas the OCD group featured an
intermediate rank. These results illustrate a trend of
increased spatial activity that reached significance in
only the schizo-OCD group. It should be noted that
the index for the wider task domain in schizo-OCD
Figure 4. The number of objects/locations and the number
of visits to each object/location. Asterisks indicate a
significant difference between the number of visits and
objects/locations in control individuals compared with
schizo-OCD patients.
behavior is the proximity among objects or locations
(Figures 1–3), whereas the number of objects/locations
and the visits to these objects/locations (Figure 4) is an
index of activity rather than for the spatial distribution
of this activity.
The above results demonstrate that OCD activity was
focused and confined in space, with the patients being
mostly stationary; in contrast, activity in schizo-OCD
was dispersed over a greater area. This is illustrated in
Figure 5 (and the supplementary file), which displays
an animation of one OCD and one schizo-OCD patient
showing the same motor activity that they had both
described as ‘‘going out from the apartment.’’ As shown,
the OCD patient was mostly stationary, standing in one
place and checking the contents of his pockets and then
taking the keys and mobile phone and going to the
door. In contrast, the schizo-OCD patient traveled
around in the apartment, first going to switching on
and off lights in the toilets, taking the keys and phone
and going to the door, but then returning to scan the
bedroom, then taking again the keys and phone and
going to the door, but returning again to empty the
ashtray, taking again the keys and phone and going to
the door, and so on. Altogether, the differences between
the stationary nature of OCD behavior compared with
the dispersed activity in schizo-OCD are apparent in
this exemplary animation.
Figure 5. The trajectories and acts in exemplary OCD and schizo-OCD patients, each performing the motor tasks of ‘‘going
out from the home.’’ The location of each circle represents an object/location, while circle size represents the number of acts
that took place at that location/object. The green line represents the trajectories of each individual between the locations.
Behavior in OCD with and without schizophrenia
OCD did not differ from schizo-OCD patients in the
structural components of their rituals
In contrast with the discernible above differences
between OCD and schizo-OCD patients in terms of
their spatial behavior, these patients did not differ
significantly in any of the 24 parameters that characterize obsessive-compulsive motor behavior29–31;
however, each group of patients significantly differed
in these parameters from their respective control
groups. This is illustrated in Table 2, which lists the
9 most important obsessive-compulsive behavioral
parameters (according to Eilam et al.31). The finding
implies that both schizo-OCD and OCD patients share
similar obsessive-compulsive characteristics that differ
from normal behavior; but also differ from one another
in the spatial distribution of this obsessive-compulsive
behavior.
OCD patients are known to have numerous repetitions and additions of unnecessary acts in their motor
activity, which makes their behavior nonfunctional.30
Here we found that compared with their respective
controls, OCD and schizo-OCD patients seemed equally
nonfunctional when performing similar motor tasks.
Tables 3 and 4 depict a ‘‘clean object’’ motor task, and
Tables 5 and 6 depict a ‘‘going out’’ task. Each of these
motor tasks is described for both the OCD and schizoOCD patients, compared with their respective control
individuals. Each column in these tables stands for the
object/location at which each of the specified acts took
place. The order of act performance is given left-to-right
and top-to-bottom. Altogether, these tables illustrate the
similarity between OCD and schizo-OCD behavior.
The activity displayed in Tables 3–6 is summarized
in Table 7, which demonstrates the cumulative
differences between OCD and schizo-OCD motor
behavior. Clearly, compared with the control individuals, both OCD and schizo-OCD patients displayed
more elaborate activity that included more repetitions
and the addition of unnecessary acts, as well as more
7
objects/locations. However, these OC properties did
not greatly differ between OCD and schizo-OCD,
suggesting that the difference between these disorders
is in the spatial organization of behavior.
Discussion
In our study, schizo-OCD patients traveled more across
the room compared with the OCD or normal controls
who performed similar motor tasks. Schizo-OCD
patients also displayed a ritualistic behavior reminiscent
of that of OCD patients without schizophrenia. We
suggest that these features indicate that traits of both
OCD and schizophrenia occur in schizo-OCD patients,
supporting the notion of comorbidity. More specifically,
we found that the overall level of OC activity did not
differ between schizo-OCD and OCD patients, but that
the spatial distribution of their activity greatly differed.
Indeed, OCD patients were mostly stationary when
performing motor tasks, whereas schizo-OCD patients
were much more mobile, wandering over a large area.
Control individuals had a mixture of both stationary
and nonstationary behavior. In the following discussion, we suggest that the difference in spatial behavior
between OCD and schizo-OCD patients offers a reliable
reflection of the mental differences between OCD and
schizophrenia, and that such a difference may facilitate
the nosology of OC spectrum disorders and OCD.5,8,9,32
Obsessions, disturbed thought processes, and their
manifestation in OCD and schizophrenia
OCD and schizophrenia seem to represent two extremes
on a continuum of disrupted thought processes.14
In OCD, the patients suffer from obsessions that refer
to recurring, persistent thoughts, impulses, or images
that inappropriately intrude into awareness and cause
marked distress or anxiety. In response to obsessions,
OCD patients may display compulsions, which are
over-repetition of physical behaviors such as checking,
Table 2. Structural components of motor activity in OCD compared with Schizo-OCD patients (values are mean ± SEM). Results of
Man-Whitney test are depicted for each parameter (U and P values).
Parameter
Task duration (sec.)
Number of visits in a task (repetitions included)
Visit duration (sec.)
Number of different locations/objects (repetitions excluded)
Visit repetition
Number of acts in a task (repetitions included)
Act duration
Number of different acts (repetitions excluded)
Act repetition
OCD
Schizo-OCD
U
P
56.1 ± 24.3
12.8 ± 5.1
13.8 ± 4.8
9.4 ± 3.6
2.1 ± 0.2
8.0 ± 3.8
23.3 ± 8.4
6.2 ± 2.4
15.0 ± 8.8
89.5 ± 37.1
22.4 ± 9.1
24.8 ± 10.0
14.4 ± 5.5
3.0 ± 0.6
19.5 ± 9.1
38.4 ± 14.5
8.4 ± 3.2
24.8 ± 9.1
29
31
29
32
35
25
44
27
33
0.11
0.15
0.11
0.19
0.26
0.06
0.65
0.08
0.20
8
A. Gershoni et al.
Table 3. Exemplary set of acts of an OCD patient and the respective control, both performing a cleaning task. Objects/locations are listed
in the top row and the sequence of acts performed at each object/location is given by reading left to right and top to bottom.
Objects/locations
Body
Rag
Headset
Phone
Notepad
Numbers
Line
Paper
Control individual
Bend over
Lift
Hold 3 2
Turn
Move forward
Bend over
Touch
Wipe with rag 3 2
Lift
Wipe with rag
Bend over
Put down
Straighten
Move back
OCD patient
Lift
Lift
Lift
Put down
Wipe with rag 3 8
Hands hold 3 2
Move
Wipe with rag
Wipe with rag 3 2
Move
Turn over
Wipe with rag 3 4
Wipe with rag
Move
Put down 3 2
Lift
Wipe with rag 3 2
Lift
Move 3 2
Wipe with rag
Put down
Hand hold
Move
Move
Put down
or mental behaviors such as counting things.3 Schizophrenia includes delusions and disorganized behavior,
trouble with thinking and concentration, and difficulty
in paying attention and making decisions.33 Here we
suggest that the distinctive cognitive properties of
each disorder are also manifested in the overt motor
behavior, as revealed in the present and previous
studies. Specifically, a high or exaggerated attentional
focus and over-concentration is a salient feature of OCD
patients when they display their motor tasks.27–30,34
In other words, we suggest that OCD patients demonstrated restricted spatial motor behavior as a reflection
of their high concentration in performing their
highly organized motor routines.27 The present results
contribute to this by revealing that the high concentration and focusing on performance by OCD patients
are accompanied by their being stationary and
relatively immobile. In contrast, schizophrenia patients
Behavior in OCD with and without schizophrenia
9
Table 4. Exemplary Schizo-OCD (bottom) and control (top) individuals performing a cleaning task. Objects/locations are listed in the
top row. The structure of the table is similar to that in Table 3.
Objects/locations
Body
Dispenser
Top part table
Short end table
Ashtray
Button right side
Button left side
Control individual
Move forward
Take out soap
Bend over
Put down
Rise up
Bend over
Wipe with rag
Lift
Rise up
Move forward
Schizo-OCD patient
Bend over
Wipe with rag
Wipe with rug
Move
Wipe with rag
Move back
Bend over
Wipe with rag
Move forward
Wipe with rag
Rise up
Wipe with rag
Wipe with rag
Rise up
Move back
Move forward
Wipe with rag
Bend over
Rise up
Move forward
Band over
Wipe with rag
Wipe with rag
Wipe with rag
Rise up
Wipe with rug
Move forward
demonstrated extensive exploratory behavior, traveling back and forth across the room.26 Furthermore,
compared with normal controls, these latter patients
are more active in the center of the room and spend
more time walking during their exploration.26 Accordingly, schizo-OCD patients seem to combine motor
features from both OCD and schizophrenia. Our study
thus suggests that schizo-OCD patients combine on
the one hand the addition and repetition of acts that
are reminiscent of OCD, and on the other hand, they
travel back and forth during their ritual in a manner
that is reminiscent of schizophrenia, thus supporting
the notion of comorbidity.
Attention deficits in OCD and schizo-OCD
OCD and schizophrenia patients experience opposite
impairments in their attention abilities. While OCD
patients are obsessed with recurring thoughts or
rituals, schizo-OCD patients are disorganized in their
thoughts and behavior.28,35 In other words, OCD is
a disorder of incessant repetition of thoughts and
10
A. Gershoni et al.
Table 5. Exemplary OCD (bottom) and control (top) of individuals going out from home. Objects/locations are listed in the top row. The
structure of the table is similar to that in Table 3.
Objects/locations
Door
Touching the
door/handle
Body
Touching or
turning the key
Upper lock
Walls
Pushing the carpet
with one of the legs
Control individual
Open
Right hand
Move forward
Turning
Close
Right hand
Right hand
Turning
Locking
Schizo-OCD patient
Move forward
Opening
Left hand
Pushing
Move forward
Turning
Left hand
Move back
Left hand
Move forward
Left hand
Open
Right hand
Turning
Touching
Left hand
Pushing
Right hand
Close
Touching
Left hand
Turning
Taking
Touching
Right leg
Move back
Right leg 3 2
Move back
Move forward
Right leg
Move back
Right leg 3 4
Turning
Move forward
activities, whereas schizophrenia is a disorder of
continuous shifting from one thought/activity to the
next. Indeed, early studies in schizophrenia patients
showed a remarkable characteristic of attention
deficit35 that correlates with the severity of the disorder
and remains constant in time.36 In contrast, a salient
feature of OCD patients is their high attention when
displaying their motor tasks.27–30,34,37 In other words,
OCD patients have difficulty in shifting their attention
from one part of the motor task to another, resulting in
Behavior in OCD with and without schizophrenia
11
Table 6. Exemplary schizo-OCD (bottom) and control (top) individuals going out from home. Objects/locations are listed in the top row.
The structure of the table is similar to that in Tables 3–5.
Objects/locations
Door
Touching the
door/handle
Body
Touching or Holding and touching
turning the key
then keychain
Turning lock
Right hand
Control individual
Left hand
Open
Move
forward
Hold
Turning
Left hand
Close
Touching
Turning
Touching
Move back
Holding
OCD patient
Left hand
Open
Move
forward
Turning
Close
Left hand
Touching
Turning
Touching
Holding
Holding
Left hand
Touching
Turning
Left hand
Turning
Right hand
Open and close
Right hand
Back and
forward
Turning
Holding
Move
forward
a delay in task performance.22 Furthermore, OCD
patients perform significantly better than schizophrenia patients in a simple attention task.38 Compared
with schizophrenic patients, schizo-OCD patients
had a lower score in tests for attention abilities.22
Nonetheless, both schizo-OCD and schizophrenia
patients demonstrate the same category of impaired
attention in contrast with OCD patients, indicating a
similar origin of cognitive deficits. Considering that
behavior is a direct manifestation of brain activity, we
suggest that the focused and confined activity in OCD
compared with the divergent activity over a large area
12
A. Gershoni et al.
Table 7. Comparison between the OCD, schizo-OCD, and control individuals who displayed the activities show in Tables 3–6
Going out from home
Cleaning task
Control
Schizo-OCD
Control
OCD
Control
Schizo-OCD
Control
OCD
9
1.3
5
1
38
2.7
7
8
12
1
5
8
23
1.6
7
6
10
1.4
3
3
27
3
7
9
16
1.3
4
8
39
1.6
6
24
Number
Average
Number
Number
of acts (repetitions included)
rate of act repetition
of objects/locations
of unique acts
Data for each individual are depicted along the columns. The data column of each patient is followed by the data of his or her
respective control.
in schizo-OCD is a reflection of the focused attention in
the former and the continuously shifting attention in
the latter. In other words, the attentional deficit in the
schizo-OCD patients is an overt schizophrenia feature.
Cognitive deficits in the executive function in OCD
and schizo-OCD
Attention is the foundation of other high cognitive
abilities, such as executive functions and memory
performance.35 Executive functioning is an umbrella
term for cognitive processes, such as attention, working memory, and planning.39 Therefore, cognitive
dysfunction can be manifested in the impairment of
executive functions.35 Such an impairment could be
differentially manifested in OCD and schizophrenia.16,40 Schizophrenia patients experience deficits in
the integration of cognitive activity and the inability to
pay attention to details. In contrast, OCD patients
demonstrate a different type of deficit in executive
functions, as manifested in dysfunction of impulse
control and regulation of behavior.40 In light of this
difference, it was suggested that schizo-OCD patients
would represent a more severe executive function
impairment that combines both types of deficits, due
to the comorbid nature of their disorder.40 For
example, in a task of ‘‘going out from home,’’ the
schizo-OCD patient took his key, walked to the door,
then went back inside to check the lights in the
bedroom, went back to the door, returned back to
check the bathroom light, then went back to the door,
and so on. The OCD patient did not go back and forth,
but stood at the light switch and checked it repeatedly.
In all, schizo-OCD patient cognitive impairments in
both the fields of attention and of regulation additionally support the notion of comorbidity.
Conclusion
The present findings demonstrate that the spatial
distribution of motor activity varies between OCD
and schizo-OCD patients, with the former being
mostly stationary and the latter wandering over a
large space. We suggest that these overt differences
reflect the differences between OCD and schizophrenia
in cognition, attention, and brain malfunctioning.
These behavioral differences may serve as bedside
signs and facilitate the nosology of OC spectrum
disorders and OCD.
Disclosures
Naomi Fineberg has the following disclosures: Servier
advisor, support fees, research, research support;
Lundbeck advisor, consulting fees; Transept consultant, consulting fees. The other authors have nothing
to disclose.
Supplementary materials
To view supplementary material for this article, please
visit http://dx.doi.org/ 10.1017/S1092852913000424
References
1.
2.
3.
4.
5.
6.
Poyurovsky M, Koran L. Obsessive-compulsive disorder
(OCD) with schizotypy vs. schizophrenia with OCD:
diagnostic dilemmas and therapeutic implications.
J Psychiatr Res. 2005; 39: 399–408.
Poyurovsky M, Zohar J, Glick I, et al. Obsessivecompulsive symptoms in schizophrenia: implications for
future psychiatric classifications. Compr Psychiatry. 2012;
53: 480–483.
American Psychological Association. Diagnostic and
Statistical Manual of Mental Disorders, 4th ed. Washington,
DC: American Psychological Association; 2000.
Jenike MA, Baer L, Minichiello WE. Obsessive-Compulsive
Disorders: Theory and Management, 2nd ed. Chicago: Year
Book Medical Publishers, Inc.; 1990.
Hollander E. Obsessive-Compulsive Related Disorders.
Washington, DC: American Psychiatric Press; 1993.
du Toit PL, van Kradenburg J, Niehaus D, Stein DJ.
Comparison of obsessive-compulsive disorder
patients with and without comorbid putative
obsessive-compulsive spectrum disorders using a
Behavior in OCD with and without schizophrenia
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
structured clinical interview. Compr Psychiatry. 2001;
42: 291–300.
Fineberg NA, Saxena S, Zohar J, Craig KJ. Obsessivecompulsive disorder: boundary issues. CNS Spectr. 2007;
12: 359–375.
Hollander E, Friedberg JP, Wasserman S, Yeh CC,
Iyengar R. The case for the OCD spectrum. In:
Abramowitz JS, Houts AC, eds. Handbook of Controversial
Issues in Obsessive-Compulsive Disorder. Kluwer
Academic Press, New York; 2005.
McElroy SL, Phillips KA, Keck PE. Obsessive
compulsive spectrum disorder. J Clin Psychiatry. 1994;
55: 33–51.
Bottas A, Cooke RG, Richter MA. Comorbidity and
pathophysiology of obsessive–compulsive disorder in
schizophrenia: is there evidence for a schizo-obsessive
subtype of schizophrenia? J Psychiatry Neurosci. 2005; 30:
187–193.
Pallanti S, Castellini G, Chamberlain SR, et al. Cognitive
event-related potentials differentiate schizophrenia with
obsessive-compulsive disorder (schizo-OCD) from OCD
and schizophrenia without OC symptoms. Psychiatry
Res. 2009; 170: 52–60.
Pallanti S, Grassi G, Sarrecchia ED, Cantisani A,
Pellegrini M. Obsessive–compulsive disorder
comorbidity: clinical assessment and therapeutic
implications. Front Psychiatry. 2011; 2: 70–87.
Poyurovsky M, Weizman A, Weizman R. Obsessivecompulsive disorder in schizophrenia: clinical
characteristics and treatment. CNS Drugs. 2004; 18:
989–1010.
Kitis A, Akdede BBK, Alptekin K, et al. Cognitive
dysfunctions in patients with obsessive-compulsive
disorder compared to the patients with schizophrenia
patients: relation to overvalued ideas. Prog
Neuropsychopharmacol Biol Psychiatry. 2007; 31:
254–261.
Tynes LL, White K, Steketee GS. Toward a new nosology
of obsessive compulsive disorder. Compr Psychiatry.
1990; 31: 465–480.
Tumkaya S, Karadag F, Oguzhanoglu NK, et al.
Schizophrenia with obsessive-compulsive disorder and
obsessive-compulsive disorder with poor insight: a
neuropsychological comparison. Psychiatry Res. 2009;
165: 38–46.
Mukhopadhaya K, Krishnaiah R, Taye T, et al.
Obsessive-compulsive disorder in UK clozapine-treated
schizophrenia and schizoaffective disorder: a cause for
clinical concern. J Psychopharmacol. 2009; 23: 6–13.
Tibbo P, Kroetsch M, Chue P, Warneke L. Obsessivecompulsive disorder in schizophrenia. J Psychiatr Res.
2000; 34: 139–146.
Nechmad A, Ratzoni G, Poyurovsky M, et al. Obsessivecompulsive disorder in adolescent schizophrenia
patients. Am J Psychiatry. 2003; 160: 1002–1004.
Ohta M, Kokai M, Morita Y. Features of
obsessive–compulsive disorder in patients primarily
diagnosed with schizophrenia. Psychiatry Clin Neurosci.
2003; 57: 67–74.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
35.
36.
13
Poyurovsky M, Kriss V, Weisman G, et al. Comparison
of clinical characteristics and comorbidity in
schizophrenia patients with and without obsessivecompulsive disorder: schizophrenic and OC symptoms
in schizophrenia. J Clin Psychiatry. 2003; 64: 1300–1307.
Patel D, Laws K, Padhi A, et al. The neuropsychology of
the schizo-obsessive subtype of schizophrenia: a new
analysis. Psychol Med. 2010; 40: 921–933.
Phillips KA, Pinto A, Hart AS, et al. A comparison of
insight in body dysmorphic disorder and
obsessive–compulsive disorder. J Psychiatr Res. 2012; 46:
1293–1299.
Peralta V, Campos MS, De Jalón EG, Cuesta MJ. Motor
behavior abnormalities in drug-naı̈ve patients with
schizophrenia spectrum disorders. Mov Disord. 2010; 25:
1068–1076.
Pulford BD, Johnson AB, Awaida M. A cross-cultural
study of predictors of self-handicapping in university
students. Personality and Individual Differences. 2005; 39:
727–737.
Perry W, Minassian A, Henry B, et al. Quantifying overactivity in bipolar and schizophrenia patients in a
human open field paradigm. Psychiatry Res. 2010; 178:
84–91.
Boyer P, Lienard P. Why ritualized behavior? Precaution
systems and action parsing in developmental,
pathological and cultural rituals. Behav Brain Sci. 2006;
29: 595–650.
Eilam D. Ritualized behavior in animals and humans:
time, space and attention. Behav Brain Sci. 2006; 29:
616–617.
Zor R, Hermesh H, Szechtman H, Eilam D. Turning
order into chaos through repetition and addition of
elementary acts in obsessive compulsive disorder
(OCD). World J Biol Psychiatry. 2009; 10(4 Pt 2): 480–487.
Zor R, Keren H, Hermesh H, et al. Obsessive-compulsive
disorder (OCD): a disorder of pessimal (non-functional)
motor behavior. Acta Psychiatr Scand. 2009; 120: 288–298.
Eilam D, Zor R, Fineberg N, Hermesh H. Animal
behavior as a conceptual framework for the study of
obsessive-compulsive disorder (OCD). Behav Brain Res.
2012; 231: 289–296.
Jenike MA. Illnesses related to obsessive-compulsive
disorder. In: Jenike MA, Baer LB, Minichiello WE, eds.
Obsessive Compulsive Disorders: Theory and Management.
Chicago: Year Book Medical; 1990: 39–60.
Graybiel AM, Rauch SL. Toward a neurobiology review
of obsessive-compulsive disorder. Neuron. 2000; 28:
343–347.
Keren H, Boyer P, Mort J, Eilam D. Pragmatic and
idiosyncratic acts in human everyday routines: the
counterpart of compulsive rituals. Behav Brain Res. 2010;
212: 90–95.
Bowie CR, Harvey PD. Cognition in schizophrenia:
impairments, determinants, and functional importance.
Psychiatr Clin North Am. 2005; 28: 613–633.
Menzies L, Chamberlain SR, Laird AR, et al. Integrating
evidence from neuroimaging and neuropsychological
studies of obsessive-compulsive disorder: the
14
37.
38.
A. Gershoni et al.
orbitofronto-striatal model revisited. Neurosci Biobehav
Rev. 2008; 32: 525–549.
Kuelz AK, Hohagen F, Voderholzer U. Neuropsychological
performance in obsessive-compulsive disorder: a critical
review. Biol Psychol. 2004; 65: 185–236.
Martin V, Huber M, Rief W, Exner C. Comparative
cognitive profiles of obsessive-compulsive disorder
and schizophrenia. Arch Clin Neuropsychol. 2008; 23:
487–500.
39.
40.
41.
Hutton S, Puri B, Duncan LJ, et al. Executive function
in first-episode schizophrenia. Psychol Med. 1998; 28:
463–473.
Spitznagel MB, Suhr JA. Executive function deficits
associated with symptoms of schizotypy and obsessive–
compulsive disorder. Psychiatry Res. 2002; 110: 151–163.
Goodman WK, Price L, Rasmussen SA, et al. The YaleBrown obsessive-compulsive scale 1. Development, use,
and reliability. Arch Gen Psychiatry. 1989; 46: 1006–1011.