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Comorbidity in Obsessive-Compulsive Disorder (OCD): A Report from theInternational College of Obsessive-Compulsive Spectrum Disorders (ICOCS)

Christine Lochner, Naomi A. Fineberg, Joseph Zohar, Michael van Amerin-gen, Alzbeta Juven-Wetzler, Alfredo Carlo Altamura, Natalie L. Cuzen,Eric Hollander, Damiaan Denys, Humberto Nicolini, Bernardo Dell‘Osso,Stefano Pallanti, Dan J. Stein, Jose Menchon Magrina, Lucheza Hranov, OguzKaramustafalioglu, Donatella Marazziti

PII: S0010-440X(14)00145-XDOI: doi: 10.1016/j.comppsych.2014.05.020Reference: YCOMP 51325

To appear in: Comprehensive Psychiatry

Received date: 27 May 2013Revised date: 8 May 2014Accepted date: 28 May 2014

Please cite this article as: Lochner Christine, Fineberg Naomi A., Zohar Joseph, vanAmeringen Michael, Juven-Wetzler Alzbeta, Altamura Alfredo Carlo, Cuzen Natalie L.,Hollander Eric, Denys Damiaan, Nicolini Humberto, Dell‘Osso Bernardo, Pallanti Ste-fano, Stein Dan J., Magrina Jose Menchon, Hranov Lucheza, Karamustafalioglu Oguz,Marazziti Donatella, Comorbidity in Obsessive-Compulsive Disorder (OCD): A Reportfrom the International College of Obsessive-Compulsive Spectrum Disorders (ICOCS),Comprehensive Psychiatry (2014), doi: 10.1016/j.comppsych.2014.05.020

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Comorbidity in Obsessive-Compulsive Disorder (OCD):

A Report from the International College of Obsessive-Compulsive Spectrum Disorders (ICOCS)

Christine Lochner1*

; Naomi A. Fineberg2,3,4

; Joseph Zohar5; Michael van Ameringen

6; Alzbeta Juven-

Wetzler5; Alfredo Carlo Altamura

7; Natalie L. Cuzen

8, Eric Hollander

9; Damiaan Denys

10,11; Humberto

Nicolini12

; Bernardo Dell‘Osso7; Stefano Pallanti

13; Dan J. Stein

1,8

1. MRC Unit on Anxiety and Stress Disorders, Department of Psychiatry, University of

Stellenbosch, South Africa

2. Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge

3. Department of Psychiatry (NAF), Queen Elizabeth II Hospital, Welwyn Garden City,

Hertfordshire

4. Postgraduate Medical School (NAF), University of Hertfordshire, Hatfield, United Kingdom

5. Chaim Sheba Medical Center, Department of Psychiatry, Israel

6. Department of Psychiatry and Behavioural Neurosciences, McMaster University, Ontario, Canada

7. Department of Psychiatry, University of Milan, Fondazione IRCCS Policlinico, Milano

8. Department of Psychiatry and Mental Health, University of Cape Town, South Africa

9. Department of Psychiatry, Montefiore Medical Center University Hospital, Albert Einstein College of

Medicine, New York, New York

10. Department of Psychiatry, Academic Medical Center, University of Amsterdam, the Netherlands

11. The Netherlands Institute for Neuroscience, an Institute of the Royal Netherlands Academy of Arts

and Sciences, Amsterdam, the Netherlands

12. Carracci Medical Centre, Mexico City, Mexico

13. Department of Psychiatry, University of Florence, Florence, Italy

ICOCS Project Group:

Jose Menchon Magrina1, Lucheza Hranov

2, Oguz Karamustafalioglu

3, Donatella Marazziti

4

1. Neuroscience Group-Institut d'Investigació Biomèdica de Bellvitge, Psychiatry Department, Bellvitge

University Hospital-Catalan Health Institute, University of Barcelona, Centro de Investigación Biomédica

en Red de Salud Mental

2. Department of Psychiatry, University Hospital of Neurology and Psychiatry, St. Naum, Sofia, Bulgaria

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3. Sisli Etfal Research and Teaching Hospital, Department of Psychiatry, Istanbul, Turkey.

4. Dipartimento d Medicina Clinica e Sperimentale, University of Pisa, Pisa, Italy

* To whom correspondence should be addressed:

PO Box 19063, Tygerberg, 7505

South Africa

Email: cl2@sun.ac.za

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ABSTRACT

Background: Obsessive-compulsive disorder (OCD) is often associated with significant psychiatric

comorbidity. Comorbid disorders include mood and anxiety disorders as well as obsessive-

compulsive spectrum disorders (OCSDs). This paper aims to investigate comorbidity of DSM Axis I-

disorders, including OCSDs, in patients with OCD from 10 centers affiliated with the International

College of Obsessive-Compulsive Spectrum Disorders (ICOCS).

Methods: This is a cross-sectional study of comorbidity of Axis I disorders including OCSDs in 457

outpatients with primary OCD (37% male; 63% female), with ages ranging from 12 to 88 years (mean:

39.8 ± 13). Treating clinicians assessed Axis I disorders using the Mini International Neuropsychiatric

Interview and assessed OCSDs using the Structured Clinical Interview for OCD related/spectrum

disorders (SCID-OCSD).

Results: In terms of the OCSDs, highest comorbidity rates were found for tic disorder (12.5%), BDD

(8.71%) and self-injurious behaviour (7.43%). In terms of the other Axis I-disorders, major depressive

disorder (MDD; 15%), social anxiety disorder (SAD; 14%), generalized anxiety disorder (GAD; 13%)

and dysthymic disorder (13%) were most prevalent.

Discussion: High comorbidity of some OCSDs in OCD supports the formal recognition of these

conditions in a separate chapter of the nosology. Rates of other Axis I disorders are high in both the

general population and in OCSDs, indicating that these may often also need to be the focus of

intervention in OCD.

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BACKGROUND

Obsessive-compulsive disorder (OCD) is often associated with significant psychiatric comorbidity, in

both epidemiological [[1,2]] and clinical studies [[3]]. DSM-IV Axis I comorbidity in OCD consists not

only of anxiety and mood disorders but also of obsessive-compulsive spectrum (including impulse-

control), substance use and psychotic disorders. In the National Comorbidity Survey Replication

(NCS-R), a nationally representative survey of U.S. adults [[2]], the most common comorbid conditions

in OCD were anxiety disorders (75.8%), followed by mood disorders (63.3%), impulse-control

disorders (55.9%), and substance use disorders (38.6%). Clinical samples (e.g. [[4-7]]) have

demonstrated similar patterns.

The relationship between OCD and the putative OCD spectrum disorders (OCSDs) has been the

focus of considerable discussion. The OCSDs are thought to be related to OCD insofar as they have

similar phenomenological and psychobiological features, are assessed and evaluated in analogous

ways, and may respond to a somewhat similar set of interventions. In DSM-5, several of the putative

OCD spectrum disorders were included in the new chapter of obsessive-compulsive and related

disorders [[8]], reflecting the literature on the diagnostic validity and clinical utility of this construct.

While many studies have discussed the relationship between OCD and specific OCD spectrum

disorders, surprisingly few studies have systematically investigated the comorbidity of OCDSDs in

OCD patients. An early study by Du Toit and colleagues [[4]] showed that 57.6% of their sample

currently met criteria for at least one putative OCSD, and that 67.1% had a lifetime history of at least

one comorbid OCSD. In that study, the OCSDs with the highest prevalence were compulsive self-

injury (22.4%), compulsive buying (10.6%), and intermittent explosive disorder (10.6%). More

recently, a cluster analysis of OCSDs in a sample of 210 OCD patients identified 3 separate clusters

that were named: i.) “Reward deficiency” (including hair-pulling disorder [trichotillomania, or HPD],

pathological gambling, hypersexual disorder and Tourette’s disorder [TD]), ii.) “Impulsivity” (including

compulsive shopping, kleptomania, eating disorders, self-injury and intermittent explosive disorder,

and iii.) “Somatic” (including body dysmorphic disorder [BDD] and hypochondriasis) [[9]]. However,

there is a need to assess whether such comorbidity findings also hold in different contexts. There is

also a need to determine the relationship between such comorbidity and OCD severity.

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Further investigation of comorbidity in OCD is important for a number of reasons. First, comorbidity

may influence treatment decisions (e.g. [[10]]); for example, patients with severe depression require

robust antidepressant treatment [[11]], or modified psychotherapy since they may find exposure and

response prevention (ERP) - a specialized form of cognitive behavioral therapy (CBT) – difficult [[10]],

Also, patients with comorbid tic disorders may require pharmacotherapy augmentation with a D2

antagonist (e.g. [[12]]). Second, comorbidity patterns may shed light on the pathogenesis of OCD and

OCSDs; for example, findings that TD is common in OCD patients and family members while OCD is

common in TD patients and family members have led to strong interest in genetic overlap between the

conditions [[13,14]] . Third, comorbidity patterns may impact on discussions about the nosology of

OCD and OCSDs; high comorbidity of a particular putative OCSD in OCD may suggest a more

specific relationship between such a condition and OCD (e.g. [[9,15,16]]).

The International College of Obsessive-Compulsive Spectrum Disorders (ICOCS) includes clinical

research sites from across the globe - i.e. North America (Canada, the United States and Mexico),

Africa (South Africa), Europe (Spain, Italy, Turkey, Bulgaria), and the Middle East (Israel) – providing a

unique database of 504 OCD patients with demographic, diagnostic, treatment and symptom severity

data. This cross-sectional study of OCD aimed at obtaining a “snap shot” view of the rates of

comorbidity of DSM Axis I-disorders, including the OCSDs.

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METHODS

Consecutive patients at different stages of treatment were recruited at nine of the ICOCS sites. Out of

the total of 504, there were some comorbidity data for 462 consecutive outpatients with a primary

diagnosis OCD. Data from patients with a current diagnosis of schizophrenia or other psychotic

disorders were excluded from the analyses (N=5).

Written informed consent was obtained from all patients. The Institutional Review Boards of the

participating sites approved the relevant protocol and consent procedures at each site. Socio-

demographic and clinical data were collected after the project was approved by the IRB’s of the

respective sites and the data were subsequently included in a common web-database.

Measures:

OCD participants were interviewed by clinical psychologists, psychiatrists or other mental health

professionals with expertise in the field (but including trainees who work under the supervision of

experienced clinicians). A basic demographics questionnaire to assess age, gender, nationality,

educational status, current professional status and level of income was included. The Mini-

International Neuropsychiatric Interview (MINI) [[17,18]], a short structured diagnostic interview. was

administered to diagnose OCD and any current psychiatric (non-OCSD) comorbidity (DSM-IV criteria

[[19,20]]). This instrument is used widely in psychiatric settings and has been shown to have sound

psychometric properties [[18,21,22]]. If a comorbid disorder was present, OCD had to be the primary

diagnosis, i.e. causing the most impairment and distress. The SCID-OCSD [[4]] was used (at some

sites) to assess for the presence of comorbid OCSDs. This instrument follows the structure of the

established SCID-I/P [23]), but the psychometric properties of this scale have not been evaluated yet.

The Yale-Brown Obsessive Compulsive Scale (YBOCS) [[24]] is a rater-administered 10-item scale

that was included as the OCD severity measure. It focuses on 5 domains for obsessions and

compulsions, including time, distress, interference, resistance, and control. The YBOCS has

established reliability and validity, is widely accepted as the major outcome measure for OCD [[24]].

The different sites used either validated assessment scales, or the English versions of scales.

Data analysis:

For the present investigation, comorbidity of mood, anxiety, and substance use disorders as well as a

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broad range of selected putative OCSDs (anorexia nervosa, bulimia nervosa, binge-eating disorder,

BDD, compulsive shopping, kleptomania, pathological gambling, intermittent explosive disorder,

hypersexual disorder, tic disorder, TD, and HPD) (using DSM-IV criteria [[19,20]]) were assessed. In

addition, patients at the participating sites were compared in terms of available demographic and

clinical variables (i.e. age, gender, educational level, income, professional status and

pharmacotherapy type) which may affect comorbidity,

Data analysis was performed using Statistica software (Statsoft 12, version 2, 2013). Chi-square

analyses and analysis of variance (ANOVA) were used to examine the associations between

variables. Bootstrap analysis were used where the assumption of normal data distribution could not

be made.

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RESULTS

Demographics:

The sample included 457 consecutive outpatients consisting of 171 males (37%) and 286 females

(63%), with ages ranging from 12 to 88 years (mean: 39.8 ± 13 years). The mean number of years in

education for the whole sample was 13.16 (SD: 3.66). Participants from the different sites differed

significantly in terms of age, gender and level of education (all p<0.001).

In terms of their professional status (with options: working / unemployed / student / retired),

approximately 70% of the sample reported that they were currently employed (54%) or were studying

(16.6%). Twenty two percent were unemployed and 7.3 % reported retirement. Income varied widely

in the sample, with 53.5% reporting above average, 19.4% average, and 26.8% below average

income. Study sites differed significantly on both these variables (both p<0.001).

Comorbidity findings:

The numbers of patients for whom comorbidity data were available varied from disorder to disorder

(the exact numbers of patients for whom data were available are included in the tables).

Comorbidity: Axis I-disorders (non-OCSDs)

Table 1 depicts the mean current comorbidity rates of Axis I-disorders (i.e., non-OCSDs) in the ICOCS

dataset. Highest comorbidity rates were noted for major depressive disorder (MDD; 15.42%), social

anxiety disorder (SAD; 14.37%), generalized anxiety disorder (GAD; 13.35%) and dysthymic disorder

(13.13%).

[Insert Table 1 here]

Data for all of the above non-OCSD Axis-I disorders were available for 149 individuals. The total

number of these comorbid conditions per patient ranged between 0 and 6. There were 63 (42.3% of

the total) patients with 1 or more of these comorbid conditions. The correlation between the number of

comorbid non-OCSD Axis I-disorders per patient and age was not significant. There was a significant

positive correlation between the number of comorbid non-OCSD Axis I-disorders and OCD severity

(r=0.26; p<0.01).

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Comorbidity: OCSDs

Lifetime comorbidity rates of OCSDs in the ICOCS dataset are depicted in Table 2. Highest

comorbidity rates were found for tic disorder (12.5%), BDD (8.71%) and self-injurious behaviours

(7.43%). Five percent (5.3%) had intermittent explosive disorder and HPD, respectively.

[Insert Table 2 here]

Data for all the comorbid conditions (i.e. OCSD and non-OCSD) were available for 118 individuals.

The total number of comorbid conditions per patient ranged between 0 and 7, with 64 (54.2%) having

one or more. The number of comorbid OCSDs per patient, and age and OCD severity, respectively,

were not significantly correlated.

Cross-national comorbidity rates:

Comorbidity rates of some Axis I-disorders differed significantly across sites (Table 3). These were

MDD (p=0<001), dysthymic disorder (p<0.001), SAD (p<0.001), GAD (p=0.02) and panic disorder

(p=0.006). The number of Axis I disorders also differed significantly across sites (p=0.03); post hoc

analyses indicated that the South African sample had significantly larger number of comorbid Axis I

compared to Spain (p=0.007).

Comorbidity rates of OCSDs also differed significantly across sites (Table 3), for tic disorder

(p<0.001), BDD (p<0.001), self-injurious behaviours (p<0.001), anorexia nervosa (p=0.002), bulimia

nervosa (p<0.001), binge-eating disorder (p=0.003), HPD (p<0.001) and compulsive shopping

(p=0.001). However, the different sites did not differ significantly in terms of the total number of

comorbid OCSDs.

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DISCUSSION

This study provides rates of comorbidity of DSM Axis I-disorders, including the OCSDs, in a large

sample of OCD patients from 9 ICOCS centers from around the globe. The highest comorbidity rates

of anxiety and mood disorders were for MDD, SAD, GAD and dysthymic disorder. The highest

comorbidity rates of OCSDs were for tic disorder, BDD and self-injurious behaviours. The number of

comorbid disorders correlated positively with OCD severity.

There is much evidence to suggest high prevalence of anxiety and mood disorders in OCD. Previous

clinical studies reports high rates of lifetime comorbidity between OCD and other anxiety disorders;

ranging from 18% for SAD and 12% for panic disorder (e.g. [25,26]), and 20% and higher for GAD

(e.g. [[25,27]]). Similarly, many clinical OCD studies have found high rates of current depression (e.g.

between 13-73% of children with OCD have comorbid depression [[28,29]] and approximately 50-80%

of adults with OCD have comorbid depression [[30]]). In our study, rates of anxiety and mood

disorders were generally slightly lower (e.g. 14.37% with SAD, 11.69% with panic disorder, 13.35%

with GAD and 15.42% with depression) than in a number of these previous publications, perhaps

reflecting that many of the patients included in our study were already on effective treatment. Notably,

of the 361 participants with available data on psychopharmacotherapy, 317 (87.81%) were on

psychotropic medication at the time of the assessments [[31]], and clinical improvement rates for the

SSRIs indeed indicated relatively good treatment response. Alternatively, however, we may have

missed some of the lifetime diagnoses owing to the ‘snapshot’ single interview method, which is

subject to recall bias. Prospective longitudinal studies, such as the Brown Longitudinal Obsessive-

Compulsive study [[6]] and the Zurich cohort study [[1]] that found rates of depression around 67% and

60%, respectively, may be less subject to such bias.

Rates of comorbid substance use disorders (SUDs) in our sample were less than 1%. This finding

also stands in contrast to earlier clinical studies that found much higher rates (e.g. 27% of 323 OCD

patients in another study [[32]]). However, our results are consistent with those of Denys et al [[33]]

and a prospective longitudinal cohort study of OCD [[1]], in which the rate of either alcohol or drug

abuse disorder was not elevated. In addition, a recent large-scale case-control family-based study

was unable to show a direct association between OCD and substance abuse [[34]]. Indeed, it has

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been suggested that while there is a high rate of SUDs in community studies of OCD, in patients with

more severe illness, seen in specialized clinics, there is less such comorbidity [[35]].

Rates of comorbid OCSDs were also high, particularly given the relatively low base rate of many such

disorders in the general population. This is consistent with earlier work [[4]], which has emphasized

the high prevalence of tic disorders as well as OCDS in OCD. However, comorbidity in the current

sample was lower than in some previous work [[36,37]]. Indeed, there were differences in comorbidity

rates across sites in our sample, consistent with different thresholding of the clinical significance

criteria or other methodological differences across sites.

Nevertheless, the relative high comorbidity of some of the OCSDs in OCD found here arguably

supports the formal recognition of some of these conditions in a separate chapter of the nosology; i.e.

that on obsessive-compulsive and related disorders. Our data on the high rates of tics in OCD, for

example, support the DSM-5 proposal to have a subtype of tic-related OCD; individuals with OCD and

tics often have earlier onset of OCD, are more likely to be male, and may be less likely to respond to

standard first line treatments [[38]].

It is notable that the severity of OCD symptoms correlated strongly with the number of comorbid

anxiety and mood disorders. Comorbid anxiety and affective disorders have previously been

associated with increased OCD severity and duration of illness, respectively [[1]]. However there are

surprisingly few randomized controlled trials on the treatment of OCD with comorbid anxiety and mood

disorders. For example, it is important to know, say, whether OCD with comorbid anxiety is

associated with a greater response to adjunctive antipsychotic agents, or whether comorbid substance

abuse is associated with a greater response to adjunctive treatment with mood-stabilizing agents.

Our findings are tempered by a few limitations, including the relatively small sample size and the

relative paucity of data on comorbid Axis I-disorders (non-OCSDs) on the ICOCS database. Thus

there is insufficient statistical power to make strong claims about differences in comorbidity across

site, and there is a need for additional work on the relationship between OCD and a range of other

conditions such as bipolar disorder [[39]]. In addition, information on the specific stages of medication

treatment (i.e. whether patients were at the beginning of, or at the end of a course of

pharmacotherapy) which may have influenced comorbidity rates, was not available for analysis.

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Information on response to CBT or whether the CBT trials were optimal (e.g. adequate number of

sessions, with expert clinicians etc.) was also not available. Nevertheless, the pharmacotherapy

response data that were available generally suggested good treatment response in the majority of the

sample, perhaps explaining the lower rates of comorbidity found here compared to previous literature.

The lack of validated translations of assessment scales in some countries is another important study

limitation. Nevertheless, the fact that this was an international sample is one of the strengths of the

project and the findings here are consistent with those which have emerged from prior single site

studies. Moreover, the international nature of our sample puts us in a position to address the question

whether comorbidity in OCD differs across regions. However, as noted above, such differences may

reflect differences in varous factors across sites, including differences in terms of socio-demographic

variables, which cannot be fully investigated here. For example, the very high prevalence rates of

mood disorders (MDD and dysthymia) and some of the anxiety disorders (GAD and PD) at the Turkish

site, and the very high prevalence of BDD in participants from Canada, deserves further consideration.

In conclusion, high comorbidity of (some) OCSDs in OCD arguably supports the formal recognition of

these conditions in a separate chapter of the nosology and pathogenesis. On the other hand, rates of

other non-OCSD (Axis I-) disorders are also high, indicating that these may often also need to be the

focus of intervention in OCD. Future longitudinal studies should examine risk factors for comorbidity in

OCD, as well as its impact on treatment outcomes.

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[23] M. B. First, R. L. Spitzer, M. Gobbon, and J. B. W. Williams, Structured clinical interview for DSM-IV Axis I disorders - Patient edition (SCID-I/P, Version 2.0, 8/98 revision), New York State Psychiatric Institute, Biometrics Research Department, New York 1998.

[24] W. K. Goodman, L. Price, Rasmussen SA, C. Mazure, R. Fleischmann, C. Hill, and et al, The Yale-Brown Obsessive Compulsive Scale. I. Development, use, and reliability., Arch Gen Psychiatry, 46 (1989), pp. 1006-1011.

[25] V. Brakoulias, V. Starcevic, P. Sammut, D. Berle, D. Milicevic, K. Moses, and A. Hannan, Obsessive-compulsive spectrum disorders: a comorbidity and family history perspective, Australas. Psychiatry, 19 (2011), pp. 151-155.

[26] T. A. Pigott, F. L'Heureux, B. Dubbert, S. Bernstein, and D. L. Murphy, Obsessive compulsive disorder: comorbid conditions, J Clin Psychiatry, 55 Suppl (1994), pp. 15-27.

[27] J. L. Eisen, W. K. Goodman, M. B. Keller, M. G. Warshaw, L. M. DeMarco, D. D. Luce, and S. A. Rasmussen, Patterns of remission and relapse in obsessive-compulsive disorder: a 2-year prospective study, J Clin Psychiatry, 60 (1999), pp. 346-351.

[28] D. A. Geller, J. Biederman, S. Griffin, J. Jones, and T. R. Lefkowitz, Comorbidity of juvenile obsessive-compulsive disorder with disruptive behavior disorders, J Am Acad. Child Adolesc. Psychiatry, 35 (1996), pp. 1637-1646.

[29] D. A. Geller, B. Coffey, S. Faraone, L. Hagermoser, N. K. Zaman, C. L. Farrell, B. Mullin, and J. Biederman, Does comorbid attention-deficit/hyperactivity disorder impact the clinical expression of pediatric obsessive-compulsive disorder?, CNS. Spectr., 8 (2003), pp. 259-264.

[30] L. Besiroglu, F. Uguz, M. Saglam, M. Y. Agargun, and A. S. Cilli, Factors associated with major depressive disorder occurring after the onset of obsessive-compulsive disorder, J Affect. Disord., 102 (2007), pp. 73-79.

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[31] Van Ameringen M., W. Simpson, B. Patterson, B. Dell'Osso, N. Fineberg, E. Hollander, L. Hranov, G. Hranov, C. Lochner, O. Karamustafalioglu, D. Marazziti, J. M. Menchon, H. Nicolini, S. Pallanti, D. J. Stein, and J. Zohar, Pharmacological treatment strategies in obsessive compulsive disorder: A cross-sectional view in nine international OCD centers, J Psychopharmacol, (2014).

[32] M. C. Mancebo, J. E. Grant, A. Pinto, J. L. Eisen, and S. A. Rasmussen, Substance use disorders in an obsessive compulsive disorder clinical sample, J Anxiety. Disord., 23 (2009), pp. 429-435.

[33] D. Denys, N. Tenney, H. J. van Megen, G. F. de, and H. G. Westenberg, Axis I and II comorbidity in a large sample of patients with obsessive-compulsive disorder, J Affect. Disord., 80 (2004), pp. 155-162.

[34] R. MacDonald, R. M. Crum, C. L. Storr, A. Schuster, and O. J. Bienvenu, Sub-clinical anxiety and the onset of alcohol use disorders: longitudinal associations from the Baltimore ECA follow-up, 1981-2004, J Addict. Dis., 30 (2011), pp. 45-53.

[35] N. L. Cuzen, D. J. Stein, C. Lochner, and N. A. Fineberg, Comorbidity of obsessive-compulsive disorder and substance use disorder: a new heuristic, Hum. Psychopharmacol, 29 (2014), pp. 89-93.

[36] H. L. Leonard, M. C. Lenane, S. E. Swedo, D. C. Rettew, E. S. Gershon, and J. L. Rapoport, Tics and Tourette's disorder: a 2- to 7-year follow-up of 54 obsessive-compulsive children, Am J Psychiatry, 149 (1992), pp. 1244-1251.

[37] R. K. Pitman, R. C. Green, M. A. Jenike, and M. M. Mesulam, Clinical comparison of Tourette's disorder and obsessive-compulsive disorder, Am J Psychiatry, 144 (1987), pp. 1166-1171.

[38] C. Lochner and D. J. Stein, Heterogeneity of obsessive-compulsive disorder: a literature review, Harv. Rev. Psychiatry, 11 (2003), pp. 113-132.

[39] N. A. Fineberg, D. S. Baldwin, J. M. Menchon, D. Denys, E. Grunblatt, S. Pallanti, D. J. Stein, and J. Zohar, Manifesto for a European research network into obsessive-compulsive and related disorders, Eur Neuropsychopharmacol, 23 (2013), pp. 561-568.

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Table 1. The lifetime comorbidity rates of non-OCSD Axis I-disorders in the ICOCS dataset*

Number of

patients for

whom data were

available

n (% of total

sample n=457)

With

n (%)

Without

n (%)

Major depressive

disorder

402 (87.96%) 62 (15.42%) 340 (85.58%)

Social anxiety

disorder

355 (77.68%) 51 (14.37%) 304 (85.63%)

Generalized

anxiety disorder

352 (77.02%) 47 (13.35%) 305 (86.65%)

Dysthymic

disorder

358 (78.34%) 47 (13.13%) 311 (86.87%)

Panic disorder

with/out

agoraphobia

402 (87.96%) 47 (11.69%) 355 (88.31%)

Alcohol abuse 300 (65.65%) 12 (4%) 288 (96%)

Alcohol

dependence

276 (60.39%) 7 (2.54%) 269 (97.46%)

Posttraumatic

Stress Disorder

251 (54.92%) 5 (1.99%) 246 (98.01%)

Substance

dependence

325 (71.12%) 2 (0.62%) 323 (99.38%)

Substance abuse 326 71.33%) 1 (0.31%) 325 (99.69%)

* presented from highest to lowest prevalence

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Table 2. Lifetime comorbidity rates of OCSDs in the ICOCS dataset*

Number of

patients for

whom data were

available

n (% of total

sample n=457)

With

n (%)

Without

N (%)

Tic disorder 376 (82.28%) 47 (12.5%) 329 (87.5%)

Body dysmorphic

disorder

241 (52.73%) 21 (8.71%) 220 (91.29%)

Self-injurious

behaviours

269 (80.74%) 20 (7.43%) 249 (92.57%)

Compulsive

shopping

244 (53.39%) 17 (6.97%) 227 (93.03%)

Intermittent

explosive disorder

244 (53.39%) 13 (5.33%) 231 (94.67%)

Hair-pulling

disorder

(trichotillomania)

245 (53.61%) 13 (5.31%) 232 (94.69%)

Tourette’s

disorder

261 (57.11%) 11 (4.21%) 250 (95.79%)

Binge-eating

disorder

387 (84.68%) 14 (3.62%) 373 (96.38%)

Anorexia Nervosa 249 (54.49%) 8 (3.21%) 241 (96.79%)

Kleptomania 247 (54.05%) 5 (2.02%) 242 (97.98%)

Bulimia Nervosa 243 (53.17%) 4 (1.64%) 239 (98.35%)

Pathological

gambling

242 (52.95%) 3 (1.24%) 239 (98.76%)

Hypersexual

disorder

241 (52.74%) 1 (0.4%) 240 (99.59%)

* presented from highest to lowest prevalence

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Table 3. Lifetime comorbidity rates of non-OCSD Axis I-disorders and OCSDs across sites

Comorbi

d

conditio

ns

ICOCS sites (N (%)) Chi

-

squ

are

d

f

p

Mexi

co

Ne

w

Yo

rk*

Can

ada

Isra

el

Italy

(Mila

n)

Italy

(Flor

ence)

Bulg

aria

Spai

n

Turk

ey

Sout

h

Afric

a

Major

depressi

ve

disorder

2/13

(15.3

8%)

0/0 8/67

(11.9

4%)

5/55

(9.09

%)

1/51

(1.96

%)

9/46

(19.5

7%)

0/11 3/39

(7.69

%)

11/2

0

(55

%)

23/1

00

(23

%)

40.

16

9 <0.

001

Dysthymi

c

disorder

0/6 0/0 2/58

(3.45

%)

9/49

(18.3

7%)

0/47 6/41

(14.6

3%)

1/8

(12.5

%)

2/38

(5.26

%)

4/11

(36.3

6%)

23/1

00

(23

%)

36.

15

9 <0.

001

Social

anxiety

disorder

1/6

(16.6

7%)

0/0 21/6

2

(33.8

7%)

7/46

(15.2

2%)

2/44

(4.55

%)

0/45 1/8

(12.5

%)

3/37

(8.11

%)

1/7

(14.2

9%)

15/1

00

(15

%)

34.

77

9 <0.

001

Generali

zed

anxiety

disorder

1/8

(12.5

%)

0/0 4/59

(6.78

%)

5/41

(12.2

%)

9/50

(18

%)

5/39

(12.8

2%)

2/10

(20

%)

2/37

(5.41

%)

6/9

(66.6

7%)

13/9

9

(13.1

3%)

19.

97

9 0.0

2

Panic

disorder

with/out

agoraph

obia

2/13

(15.3

8%)

0/0 13/6

7

(19.4

%)

1/55

(1.82

%)

6/52

(11.5

4%)

9/52

(17.3

1%)

1/11

(9.09

%)

1/38

(2.63

%)

5/14

(35.7

1%)

9/10

0

(9%)

23.

12

9 0.0

06

Posttrau

matic

Stress

Disorder

0/5 0/0 0/4 3/46

(6.52

%)

0/6 0/35 0/9 0/36 0/10 2/10

0

(2%)

7.2

7

9 0.6

1

Alcohol

abuse

2/9

(22.2

0/0 2/23

(8.7

2/45

(4.44

4/44

(9.09

0/28 0/8 0/35 0 2/98

(2.04

14.

94

9 0.0

9

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%) %) %) %) %)

Alcohol

depende

nce

1/5

(20

%)

0/0 1/19

(5.26

%)

2/39

(5.13

%)

0/46 0/22 0/2 0/37 1/7

(14.2

9%)

2/99

(2.02

%)

11.

34

9 0.2

5

Substanc

e abuse

0/12 0/0 0/27 0/43 1/43

(2.33

%)

0/33 0/9 0/38 0/23 0/98 4.0

7

9 0.9

1

Substanc

e

depende

nce

0/12 0/0 0/32 0/36 0/50 1/39

(2.56

%)

0/6 1/38

(2.63

%)

0/13 0/99 5.8 9 0.7

6

Tic

disorder

8/13

(61.5

4%)

0/0 5/62

(8.06

%)

13/2

7

(48.1

5%)

0/49 5/54

(9.26

%)

1/9

(11.1

1%)

4/36

(11.1

1%)

4/26

(15.3

8%)

7/10

0

(7%)

56.

09

9 <0.

001

Tourette’

s

disorder

1/10

(10

%)

0/0 1/5

(20

%)

5/54

(9.26

%)

0/5 1/37

(2.7%

)

0/4 1/39

(2.56

%)

1/8

(12.5

%)

1/99

(1.01

%)

10.

67

9 0.3

Hair-

pulling

disorder

(trichotill

omania)

4/4

(75

%)

0/0 2/3

(66.6

7%)

3/53

(5.66

%)

1/1

(100

%)

0/38 0/2 0/39 0/6 4/99

(4.04

%)

36.

76

9 <0.

001

Body

dysmorp

hic

disorder

1/3

(33.3

3%)

0/0 7/9

(77.7

8%)

1/55

(1.82

%)

0/0 0/30 0/2 3/39

(7.69

%)

0/7 9/96

(9.38

%)

38.

37

9 <0.

001

Binge-

eating

disorder

1/13

(7.69

%)

0/0 9/65

(13.8

5%)

2/55

(3.64

%)

1/50

(2%)

0/36 0/6 1/38

(2.63

%)

0/26 0/98 24.

86

9 0.0

03

Anorexia

Nervosa

0/1 0/0 4/11

(36.3

6%)

0/56 0/2 1/32

(3.13

%)

0/3 3/39

(7.69

%)

0/6 0/97 26.

28

9 0.0

02

Bulimia

Nervosa

0/1 0/0 3/10 0/53 1/1 0/31 0/3 0/38 0/9 0/97 28. 9 <0.

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(30

%)

57 001

Self-

injurious

behaviou

rs

1/2

(50

%)

0/0 14/2

7

(51.8

5%)

1/55

(1.82

%)

1/1

(100

%)

0/38 0/3 1/39

(2.56

%)

0/6 2/98

(2.04

%)

63.

44

9 <0.

001

Compulsi

ve

shopping

1/2

(50

%)

0/0 5/7

(71.4

3%)

1/53

(1.89

%)

0/1 1/34

(2.94

%)

0/3 2/37

(5.41

%)

0/7 7/10

0

(7%)

26.

98

9 0.0

01

Kleptom

ania

0/2 0/0 2/4

(50

%)

0/54 0/1 0/38 0/2 2/39

(5.13

%)

0/8 1/99

(1.01

%)

16.

4

9 0.0

6

Pathologi

cal

gambling

0/1 0/0 0/2 0/53 0/0 2/39

(5.13

%)

0/3 1/39

(2.56

%)

0/6 0/99 7.2

3

9 0.6

1

Intermitte

nt

explosive

disorder

0/3 0/0 3/9

(33.3

3%)

1/52

(1.92

%)

0/1 1/33

(3.03

%)

0/1 2/39

(5.13

%)

2/7

(28.5

7%)

4/99

(4.04

%)

13.

57

9 0.1

4

Hyperse

xual

disorder

0/0 0/0 1/4

(25

%)

0/53 0/1 0/36 0/3 0/39 0/6 0/99 8.4

7

9 0.4

9

* The New York site contributed 1 case with a primary diagnosis of OCD, of whom comorbidity data

were not available.