SANTANA, LÍVIA Psic; FONTENELLE, JÚLIA M. Psic; YÜCEL, MURAT PhD; FONTENELLE, LEONARDO F. MD, PhD
Obsessive-compulsive disorder (OCD) is characterized by intrusive and distressing images, thoughts, or impulses (obsessions) and/or repetitive mental or motor acts aimed at reducing anxiety or performed according to certain rules (compulsions). Epidemiological studies employing the Composite International Diagnostic Interview (CIDI) suggest that OCD is a common condition, with 1-month prevalence rates ranging from 0.3% to 3.1%.1 As early as 1990, annual costs due to lost productivity associated with OCD were estimated to be $6.2 billion.2 More recently, OCD was ranked tenth on the Global Burden of Mental, Neurological and Substance-Use Disorders based on disability-adjusted life years (DALYs) (i.e., the number of future years of disability-free life that are lost as a result of premature deaths or disability occurring in a particular year).3
It has been estimated that up to 90% of patients with OCD may experience some degree of recovery if they remain in conventional treatment on a longterm basis.4,5 Conventional treatment includes one or multiple sequential trials of high dose serotonin reuptake inhibitors for at least 12 weeks (augmented by antipsychotics, if needed) and/or at least 20 sessions of cognitive-behavioral therapy (CBT).6 Therefore, it is reasonable to speculate that poor treatment adherence in OCD prolongs suffering and increases economic costs, although no clear information on the clinical, functional, and economic impact of treatment nonadherence in OCD is currently available.7 Identifying the correlates of and/or risk factors for treatment nonadherence in patients with OCD would help guide clinicians to develop more effective strategies to maintain patients on an established therapeutic plan.
Treatment nonadherence comprises the concepts of “refusal” (not entering a treatment despite receiving a recommendation from a health professional) and “dropout” (leaving treatment before its end).8 While both “dropouts”9,10 and “refusals”8,11 have been studied in OCD, the results have been relatively inconclusive and the rates and correlates of treatment nonadherence remain elusive.7 This lack of conclusive results may have been due to the marked methodological heterogeneity of studies in this area. For instance, studies on treatment adherence in OCD have differed in terms of the therapeutic modalities employed (CBT, pharmacotherapy, or a combination of treatments); the settings in which these treatments were administered (research or naturalistic settings); the time frames assessed (shortor longterm treatment); and the use of validated instruments (e.g., the Treatment Adherence Survey-Patient Version [TAS-P]8 or the Patient Exposure/Response Prevention (EX/RP) Adherence Scale,12 which assesses patients’ adherence to exposure and response prevention instructions between sessions ).
A number of different factors may contribute to decreased treatment adherence in OCD. These include reasons that patients report spontaneously (e.g., during ordinary interviews), reasons that they report on demand (i.e., when assessed with structured instruments such as the TAS-P8 or the Patient EX/RP Adherence Scale12), or reasons they are not completely aware of or are unwilling to tell but that may be observable by the clinician in a careful examination. With regard to the last possibility, patients with OCD may not adhere to treatment because of symptoms that undermine their capacity to start or remain in treatment (e.g., hoarding and related indecision, avoidance, and procrastination,13,14 or depression8), because they do not understand the procedures involved in treatment due to cognitive impairment,15 or because they do not recognize OCD as an illness (i.e., have poor insight).16
Clearly, more systematic and comprehensive studies of treatment adherence in OCD are needed. The goal of the study described here was to identify rates and correlates of lifetime treatment refusal and/or dropout in a treatment-seeking sample of patients with OCD using validated instruments. We also investigated relationships between treatment adherence and different OCD dimensions, comorbid conditions, intelligence, and insight into OCD. We hypothesized that we would find high rates of refusal and/or dropout in our treatment-seeking sample of patients with OCD and that refusal and dropout would be associated with severity of hoarding symptoms, depression, lower IQ, and/or poor insight into OCD symptoms.
In this cross-sectional study, 60 patients with OCD who were being treated in the Anxiety and Depression Research Program, a specialized university OCD clinic, were consecutively selected according to the following criteria: (1) A diagnosis of OCD according to the criteria in the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision17 (DSM-IV-TR); if other psychiatric disorders were present, OCD had to be the most severe disorder and the one associated with the earliest age at onset; (2) Age between 18 and 65 years; (3) Ability to read and successfully complete relevant forms; and (4) No current neurological, endocrine, or systemic medical illness that could interfere with the patient’s patterns of response. The Anxiety and Depression Research Program, based at the Institute of Psychiatry of the Federal University of Rio de Janeiro, is the only public clinic dedicated to the assessment and treatment of obsessive-compulsive spectrum disorders in the greater Rio de Janeiro metropolitan area. Most patients with OCD treated in the Program are managed pharmacologically and, if deemed appropriate, are also referred to the CBT clinic of the Institute of Psychology at the same university. Decisions regarding predominance of behavioral and/or cognitive approaches and frequency of sessions are made on a case-by-case basis, after discussion with an experienced supervisor. The emphasis is on exposure and response prevention, although cognitive therapy is also often employed, particularly for patients who are resistant to the idea of being exposed to situations that create anxiety. As a consequence, almost all patients receive pharmacotherapy and recommendations to undergo CBT.
Study Procedure and Assessment Tools
The research protocol complied with the Declaration of Helsinki and was approved by the local Institutional Review Board. Informed consent was obtained from subjects after the nature of the procedures was explained. The following procedures were involved in the patients’ assessment. First, the patient was diagnosed with OCD by attending physicians on clinical grounds. Then, two psychologists (LS and JF) confirmed the diagnosis of DSM-IV-TR OCD and assessed associated psychiatric disorders using the Mini-International Neuropsychiatric Interview 6.0.18 Obsessive-compulsive symptoms, depression, and disability were assessed using self-report instruments, including the Dimensional Yale-Brown Obsessive-Compulsive Scale-Short Version,19 the Beck Depression Inventory,20 and the Sheehan Disability Scale,21 respectively. Finally, the two psychologists (LS and JF) assessed therapeutic adherence with the TAS-P,8 insight into OCD with the Brown Assessment of Beliefs Scale,22 and intelligence with the Wechsler Abbreviated Scale of Intelligence.23
The TAS-P is a rater-administered questionnaire based on an instrument for assessing barriers to treatment seeking in depression developed by Blumenthal and Endicott.24 The TAS-P collects data on CBT and pharmacotherapy received by patients with OCD.8 It has been shown to have excellent psychometric properties, including test-retest reliability and concurrent validity.8 The TAS-P elicits information on i) whether CBT and pharmacotherapy were recommended, started, abandoned (“dropouts”), or refused (“refusals”); ii) the total number of CBT sessions and/or weeks of medication use; and iii) possible reasons for nonadherence to CBT or pharmacotherapy, which are divided into six subdomains: too anxious/fearful, perceived environmental barriers, perceived utility of treatment, beliefs regarding severity of illness, relationship with clinician, and issues regarding stigma/confidentiality.8 The TAS-P contains an additional domain that asks about medication-related adverse events (e.g., sexual side effects, sedation, constipation). In our study, we investigated lifetime treatment adherence, including adherence to treatment recommendations made while in our clinic.
Categorical variables were summarized in terms of frequencies and percentages and continuous variables were summarized in terms of means (± standard deviations [SDs]). Since the majority of the analyzed variables displayed a non-parametric distribution (according to the Shapiro-Wilk test), nonparametric tests were used. Patients who reported refusing treatment (CBT or pharmacotherapy) at least once during their lifetime were compared with patients without such a history using chi-square or Fisher’s exact test for categorical variables and Mann-Whitney test for continuous variables. Since the reasons for dropout were likely to overlap with reasons for refusal, we decided that, by comparing patients with and without a history of treatment refusal rather than patients with and without a history of treatment dropout, we would avoid multiple comparisons and be more likely to identify nonspurious correlates of nonadherence to treatment.
The sample comprised a total of 60 treatment-seeking subjects with a lifetime (current or past) history of DSM-IV-TR OCD, 55 of whom had a current diagnosis of OCD, while 5 were asymptomatic. We looked at lifetime histories because our OCD clinic includes mostly chronic patients. We included 5 patients who were asymptomatic but were being followed by our clinic for maintenance treatment, since these patients were also subject to nonadherence. In terms of comorbidity, 28 patients had a current major depressive disorder (47%), 20 had generalized anxiety disorder (33%), 15 had panic disorder with or without agoraphobia (25%), and 15 had social phobia (25%). Fifteen patients (25%) did not display any comorbid psychiatric disorder, 22 patients (37% of the sample) had one comorbid disorder, 9 (15%) had two comorbid disorders, 7 (12%) had three comorbid disorders, 4 (7%) had four comorbid disorders, and 3 (5%) had six comorbid disorders.
The patients’ mean age was 41.8 years (SD 13.5 years), with 28 patients (47%) reporting onset of OCD when they were between 10 and 18 years of age.The majority of the patients were female (n=35;58%), single (n=38; 63%), with at least a secondary level of formal education (n=48; 80%). Of the 60 patients, 29 were currently working (48%), 13 were unemployed (22%), 7 were retired (12%), 4 were students or homemakers (7% each), and 3 were on medical leave (5%).
Using the criteria from the Brazilian Association of Market Research Institutes, 30 patients belonged to class C (50%), 19 to class B (32%), 7 to class D (12%), and 2 to classes A and E (3% each), with E being the lowest and A being the highest socioeconomic class. (The Brazilian socioeconomic classification system is based on a complex formula that takes into account scores based on numbers of each of the following personal belongings: cars, color televisions, bathrooms, housemaids, radios, washing machines, VCRs, vacuum cleaners, and refrigerators or freezers.) Twenty-five patients were Catholics (42%), 14 were Protestants (23%), 11 had no religion (18%), and 10 were Spiritists (17%) (Spiritism, also know as Kardecism, is a Christian religion developed by Alan Kardec, based, among other things, on reincarnation beliefs that is quite popular in Brazil, but less prevalent than Catholicism and Protestantism). In terms of ethnicity, 39 patients were white (65%), 14 were of mixed origin (23%), 4 were of Asian descent (7%), two were black (3%), and 1 (2%) did not declare ethnicity.
Adherence to Cognitive Behavioral Therapy
Forty-eight patients (81.4% of the 59 patients for whom this information was available) reported that a doctor or other professional had recommended that they receive CBT for their OCD during their lifetime (including while at our clinic), while 32 of the 60 patients (53%) reported actually having received CBT for their OCD in the same timeframe. Of the patients who had already received CBT, 2 patients (6%) received 1–4 sessions, 6 (19%) received 5–10 sessions, 7 (22%) received 11–15 sessions, 4 (12%) received 16–20 sessions and 14 (44%) received more than 20 sessions of CBT. Among patients who started CBT, 51% reported stopping CBT before completing therapy. In addition, the 20 patients with OCD who decided not to participate in CBT at least once during their lifetime despite professional recommendations to do so (46%) displayed greater rates of obsessions with aggressive/ violent content (Table 1). Of note, this latter group did not differ from the 24 patients who always decided to participate in CBT in terms of the total number of CBT sessions (Z=–0.57; P=0.59).
Reasons for not undergoing CBT or discontinuing attendance at CBT included: i) a number of perceived environmental barriers (56%), such as being too busy or believing that treatment was inconvenient, a lack of money to pay for CBT, not having a health insurance plan to cover the costs of CBT, or not having CBT available to them; ii) a negative perception of the utility of treatment (19%), such as believing that CBT is ineffective for OCD; iii) problems related to the relationship with the clinician (16%), reflected in the perception that the CBT provider is not competent, or believing that OCD symptoms are too personal to discuss; iv) feeling too anxious/fearful to participate in CBT (9%); v) having unresolved issues regarding stigma/confidentiality (9%), such as being worried about stigma or about being labeled mentally ill, or wanting to avoid having a “record” of treatment; and vi) displaying distorted beliefs regarding severity of illness (6%), so that the person believes that his or her OCD is not severe enough to justify a need for CBT.
When asked on the TAS-P about the main reason for not getting or for stopping CBT, 44% of patients did not list a reason. Not having enough money to pay for therapy was reported by 19% of patients; thinking that CBT for OCD would not work was reported by 13% of patients; being too busy/believing that treatment was inconvenient, or feeling that OCD symptoms were too personal to discuss with others were each reported by 6% of patients; and not having CBT available, believing that their OCD was not severe enough or not a big enough problem to justify the need for CBT, feeling embarrassed for people to find out they were in treatment, and feeling too anxious or fearful to participate in CBT for OCD were each reported by 3% of patients.
Adherence to Drug Treatment
Fifty-nine patients (98%) reported that a medical professional had recommended pharmacotherapy to treat their OCD during their lifetime (including while at our clinic). Of the 58 patients (97%) who actually received pharmacotherapy during the same timeframe, 61% reported having taken their medications less frequently or at smaller doses than prescribed, or discontinuing the use of medication altogether. The 31 patients (52%) who refused pharmacotherapy at least once during their lifetime displayed a greater severity of OCD (particularly hoarding), less insight into symptoms, and greater disability in family and domestic life (Table 2). It should be noted that these patients did not differ from those who complied with recommended pharmacotherapy regimes for their OCD in terms of the total length of time medication was administered (Z=–0.17; P=0.86).
The reasons for refusing medication or taking medications less frequently or at lower doses than prescribed included: i) disliking the side effects of medication (41%); ii) perceived environmental barriers (31%), such as feeling too busy or believing that treatment was inconvenient, not having enough money to pay for medication, or not having a health insurance plan to help cover the costs of medication; iii) feeling too anxious/fearful of taking medication (26%); iv) having a negative opinion about the potential efficacy of treatment (23%); v) having issues regarding stigma/confidentiality (21%), reflected in worry about being labeled “mentally ill,” feeling embarrassed, and having a “record” of psychiatric treatment; vi) having specific beliefs regarding severity of illness (13%) (e.g., believing that his or her OCD is not severe enough to justify need for medication); and, finally vii) having problems of rapport with the clinician (10%), such as not feeling comfortable with the psychiatrist or believing that the OCD symptoms were too personal to discuss with him or her.
When asked on the TAS-P about the main reason for not taking or stopping medication, 39% of patients did not list a reason. Not liking the side effects of the medications was reported by 18% of patients; not having enough money to pay for medications was reported by 13%; feeling too anxious or fearful of taking medications was reported by 10%; not believing in taking medication for OCD was reported by 8%; believing that their OCD was not severe enough or not a big enough problem to justify the need for medications was reported by 5%; and worry about stigma or being labeled as mentally ill, not feeling comfortable with the treatment providers who prescribed medications, and believing that OCD symptoms were too personal to discuss with others were each reported by 3% of patients.
The single side effect that patients found most salient in influencing their decision not to take medication, or to take medication less frequently or at lower doses than prescribed, was insomnia/difficulty sleeping, which was reported by 25% of patients. Other side effects that influenced patients’ decision not to take medication, or to take medication less frequently or at lower doses, included dry mouth (50%); constipation (40%); diarrhea (15%); sedation/tiredness (45%); weight gain (35%); decreased libido (50%); agitation (30%); nervousness (40%); headaches (30%); upset stomach/nausea (30%); emotional numbing (30%); or other reasons (25%). The side effects reported as being most distressing included: reduced libido (25%); sedation/tiredness (20%); emotional numbing (15%); weight gain (10%); and dry mouth, constipation, or headaches (5% each).
A key finding of this study was the high prevalence of nonadherence to CBT and pharmacotherapy, including elevated rates of treatment refusals and dropouts, among patients with OCD. A history of refusal of CBT was greatest among patients with OCD who had obsessions with aggressive/violent content, while patients who had a history of refusal of pharmacotherapy displayed greater severity of OCD (particularly hoarding), less insight into symptoms, and greater disability in family and domestic life. However, we did not find any difference between refusers and non-refusers in IQ levels and BDI scores, suggesting that, at least in our sample, intelligence and depression were not key determinants of adherence to treatment.
Although the majority of our sample endorsed having been recommended to undergo CBT, only half reported having actually received CBT. This finding suggests that, despite appropriate referrals for CBT, a relatively large proportion of patients with OCD are not following therapeutic recommendations. In addition, among our patients who started CBT, more than half described discontinuing CBT before completing treatment. These findings are somewhat different from those reported in the North American Brown Longitudinal Obsessive Compulsive Study (BLOCS), a 2-year follow-up of 202 participants with DSM-IV OCD that also employed the TAS-P.11 In that study, while a smaller proportion of patients (relative to the current study) reported having CBT recommended by their clinician (59% vs. 81%), a greater fraction endorsed having actually undergone CBT (74% vs. 55%), and fewer patients (31% vs. 51%) reported dropping out before completing treatment.11
We can only speculate as to the reasons for these differences. For instance, while the BLOCS protocol recruited individuals from different mental health specialty sites, our study enrolled patients from a single specialized OCD clinic in the Rio de Janeiro metropolitan area. This strategy might have led to greater enrollment of individuals with severe and treatment-resistant OCD, which might explain a history of more referrals for CBT. Conversely, poorer treatment adherence to CBT in our sample might reflect differences in the specific reasons given by the patients with OCD for not participating in CBT (e.g., not having CBT therapists available).
An examination of individual causes for nonadherence in the two studies might help provide further insights in this regard. Thus, in our study, the most common reasons for not participating in CBT or discontinuing attendance at CBT included perceived environmental barriers (56%), justifications not listed on the TAS-P (53%), perceptions about the utility of treatment (19%), and problems related to rapport with clinicians (16%). These findings are somewhat different from the ones reported in the earlier retrospective BLOCS,8 which assessed treatment history prior to study entry among a subset of the intake sample. In that study, the main reasons for not participating in CBT also included similar rates of perceived environmental barriers (50%) and problems related to rapport with clinicians (23%), but markedly lower rates of reasons not listed on the TAS-P (12% on the prospective BLOCS) and greater problems with perceived utility of treatment (41%) and feelings of anxiety/fearfulness about participation in CBT (55%). While these disparities might reflect different profiles of OCD symptoms across the samples, it is also possible that cultural factors might have played a role, with Brazilian patients being more trustful regarding the utility and safety of CBT but endorsing more idiosyncratic reasons for not attending CBT.
We also found that patients with OCD who refused to participate in CBT despite professional recommendations (46%) displayed greater rates of obsessions with aggressive/violent content. Although our refusal rates were higher than the ones reported in the BLOCS (26%),11 the BLOCS did not provide the frequency of different symptom dimensions among its research participants. Therefore, an increased prevalence of OCD symptoms with aggressive/violent content (harm obsessions) in our study might help explain the different dropout rates in the two studies. While other factors may interact with aggressive/violent obsessions to increase rates of refusal to adhere to CBT, harm obsessions tend to mix thought-action fusion, fear of losing control, and inflated responsibility,25 thus leading to socially unacceptable OCD symptoms,26 severe avoidant behaviors, and treatment refusals. For instance, patients with harming obsessions tend to believe that, by exposing themselves to the threatening stimuli, they increase the odds of being arrested or imprisoned or that a dreaded event might occur.27 Since therapeutic alliance and readiness to engage in specific CBT procedures are also related to adherence to CBT in patients with OCD,12 it might be important to modify the way treatment is explained to patients to decrease CBT refusal among this subgroup of patients. It is also interesting that different studies found a significant association between harm-related obsessions and improved response to CBT28 and serotonin reuptake inhibitors.29
In our study, 61% of patients with OCD who were given pharmacotherapy reported having taken their medications less frequently or at smaller doses than prescribed or discontinuing their medications altogether. This finding is broadly consistent with that reported in the BLOCS, in which 57% of patients with OCD who were prescribed pharmacotherapy reported nonadherence.8 In addition, our study found that 52% of patients reported refusing medication at least once during their lifetime. These patients displayed greater severity of OCD (particularly hoarding), less insight into symptoms, and greater disability in their domestic lives. While medication refusal rates in our study were somewhat higher than previously reported (versus 39% in the early retrospective BLOCS8), correlates have been described in other contexts. For example, in a study of patients with OCD who were diagnosed in a dermatology clinic, delayed treatment seeking was associated with poor insight into symptoms and obsessions of hoarding.30 The presence of hoarding has also been found to be associated with dropout during the course of CBT,12,13 while poor insight, agoraphobia, high anxiety levels, and being treated with “group-based” CBT were all independently associated with the probability of treatment discontinuation.10
While the presence of lower levels of insight among patients with a history of pharmacotherapy refusal is easier to understand, an explanation for the finding of increased severity of hoarding in the same group is less intuitive. We suspect that, given their increased levels of perfectionism, indecision, and procrastination,14 as well as harm avoidance,31 individuals with prominent hoarding symptoms may overestimate the occurrence and severity of drugrelated side effects listed on package inserts, leading them to refuse to take medications. Since we did not employ specific diagnostic instruments to evaluate for hoarding disorder (such as the Structured Interview for Hoarding Disorder32), we were unable to disentangle the effects of OCD-related hoarding symptoms from the presence of a comorbid hoarding disorder (note this is a newly described disorder proposed for inclusion in DSM-5).33 Nevertheless, as it has been argued that hoarding disorder is relatively uncommon in samples of patients with OCD,34 we believe that our results can be ascribed to OCDrelated hoarding symptoms.
The most common reasons for refusing medication for OCD or taking medication less frequently or at lower doses than prescribed included disliking the side effects of medication (41%), perceived environmental barriers (31%), and feeling too anxious/ fearful about taking medication (26%). Conversely, in the early retrospective BLOCS,8 the most common reasons for not adhering to medication included disliking the side effects of medication (78%), perceived poor efficacy of treatment (41%), and feeling too anxious/fearful about taking medications (41%). Therefore, our sample was characterized by much lower rates of concern about potential side effects and about taking the medications per se. In fact, it is not only culturally determined beliefs and behavioral patterns that may influence patients’ perceptions of treatment response, adherence, and interactions with clinicians, but the metabolism and disposition of medications (pharmacokinetics) and their interactions with therapeutic targets (pharmacodynamics) may also differ between patients of different ethnicities.35
Our findings should be interpreted within the context of a number of limitations. First, our study employed a cross-sectional approach to assess lifetime treatment adherence in patients who were currently being treated. Therefore, while it is likely that certain OCD attributes can result in lower adherence to drug treatment, we cannot exclude the inverse possibility—i.e. that poor treatment adherence results in these OCD attributes. Nevertheless, given that the number of weeks of drug treatment and the number of CBT sessions did not differ between treatment adherent and nonadherent patients, we believe the latter possibility is an unlikely explanation. Second, one could argue that the “at least once” refusal criterion might include patients with different degrees of nonadherence (occasional vs. systematic treatment refusal). This is a legitimate claim, since the current version of the TAS-P is unable to provide greater quantification of adherence. It would be helpful if future versions of this instrument could address this problem. Third, all patients with OCD in this study were recruited from a pharmacotherapy-oriented OCD clinic. Therefore, it is possible that patients who specifically sought out psychiatric treatment might display positive attitudes regarding medication. As such, there might be an implicit, yet negative, attitude towards CBT, leading to lower adherence to this strategy.11 Finally, although there are reasons to believe that patients received optimal pharmacological treatment, we were unable to directly assess the quality of CBT that was provided. Use of instruments such as the Patient EX/RP Adherence Scale12 would provide interesting information on this question.
1. Fontenelle LF, Mendlowicz MV, Versiani M. The descriptive epidemiology of obsessive-compulsive disorder. Prog Neuropsychopharmacol Biol Psychiatry. 2006;30:327–37
2. DuPont RL, Rice DP, Shiraki S, et al. Economic costs of obsessive-compulsive disorder. Med Interface. 1995;8:102–9
3. Collins PY, Patel V, Joestl SS, et al. Grand challenges in global mental health. Nature. 2011;475:27–30
4. Jenike MAJenike MA, Baer L, Minichiello WE. Drug treatment of obsessive-compulsive disorders. Obsessive-compulsive disorders: Practical management. 1998third edition St. Louis Mosby:469–532
5. Denys D. Pharmacotherapy of obsessive-compulsive disorder and obsessive-compulsive spectrum disorders. Psychiatr Clin North Am. 2006;29:553–84 xi
6. Fontenelle LF, de Menezes GB, Versiani M
7. Santana L, Fontenelle LF. A review of studies concerning treatment adherence of patients with anxiety disorders. Patient Prefer Adherence. 2011;5:427–39
8. Mancebo MC, Pinto A, Rasmussen SA, et al. Development of the Treatment Adherence Survey-Patient Version (TASP) for OCD. J Anxiety Disord. 2008;22:32–43
9. Hansen AM, Hoogduin CA, Schaap C, et al. Do drop-outs differ from successfully treated obsessive-compulsives? Behav Res Ther. 1992;30:547–50
10. Diniz JB, Malavazzi DM, Fossaluza V, et al. Risk factors for early treatment discontinuation in patients with obsessive-compulsive disorder. Clinics (Sao Paulo). 2011;66:387–93
11. Mancebo MC, Eisen JL, Sibrava NJ, et al. Patient utilization of cognitive-behavioral therapy for OCD. Behav Ther. 2011;42:399–412
12. Maher MJ, Wang Y, Zuckoff A, et al. Predictors of patient adherence to cognitive-behavioral therapy for obsessivecompulsive disorder. Psychother Psychosom. 2012;81:124–6
13. Mataix-Cols D, Marks IM, Greist JH, et al. Obsessive-compulsive symptom dimensions as predictors of compliance with and response to behaviour therapy: Results from a controlled trial. Psychother Psychosom. 2002;71:255–62
14. Timpano KR, Exner C, Glaesmer H, et al. The epidemiology of the proposed DSM-5 hoarding disorder: Exploration of the acquisition specifier, associated features, and distress. J Clin Psychiatry. 2011;72:780–6 quiz 878–9
15. Moritz S, Kloss M, Jacobsen D, et al. Neurocognitive impairment does not predict treatment outcome in obsessive-compulsive disorder. Behav Res Ther. 2005;43:811–9
16. Fontenelle JM, Santana S, Lessa R, et al. The concept of insight in patients with obsessive-compulsive disorder. Rev Bras Psiquiatr. 2010;32:77–82
17. Diagnostic and statistical manual of mental disorders. 2000fourth edition Washington, DC American Psychiatric Association text revision
18. Amorim P. Mini International Neuropsychiatric Interview (MINI): Validation of a short structured diagnostic psychiatric interview. Rev Bras Psiquiatri. 2000;22:106–15
19. Rosario-Campos MC, Miguel EC, Quatrano S, et al. The dimensional Yale-Brown obsessive-compulsive scale (DYBOCS): An instrument for assessing obsessive-compulsive symptom dimensions. Mol Psychiatry. 2006;11:495–504
20. Cunha JA Manual da versão em português das Escalas Beck. São Paulo, SP2001
21. Sheehan DV, Harnett-Sheehan K, Raj BA. The measurement of disability. Int Clin Psychopharmacol. 1996;11:89–95
22. Eisen JL, Phillips KA, Baer L, et al. The Brown Assessment of Beliefs Scale: Reliability and validity. Am J Psychiatry. 1998;155:102–8
23. Yates DB, Trentini CM, Tosi SD, et al. Apresentação da Escala de Inteligência Wechsler Abreviada (WASI). Avaliação Psicológica. 2006;5:227–33
24. Blumenthal R, Endicott J. Barriers to seeking treatment for major depression. Depress Anxiety. 1996;4:273–8
25. Rachman SAntony MM, Purdon C, Summerfeldt LJ. Treating religious, sexual, and aggressive obsessions. Psychological treatment of obsessive-compulsive disorder. 2007 Washington, DC American Psychological Association:209–99
26. Simonds LM, Thorpe SJ. Attitudes toward obsessive-com-pulsive disorders—An experimental investigation. Soc Psychiatry Psychiatr Epidemiol. 2003;38:331–6
27. Salkovskis PMPeck DF, Shapiro CM. Obsessions, compulsions and intrusive cognitions. Measuring human problems: A practical guide. 1990 Chichester Wiley:91–118
28. Storch EA, Merlo LJ, Larson MJ, et al. Symptom dimensions and cognitive-behavioural therapy outcome for pediatric obsessive-compulsive disorder. Acta Psychiatr Scand. 2008;117:67–75
29. Landeros-Weisenberger A, Bloch MH, Kelmendi B, et al. Dimensional predictors of response to SRI pharmacotherapy in obsessive-compulsive disorder. J Affect Disord. 2010;121:175–9
30. Demet MM, Deveci A, Taskin EO, et al. Risk factors for delaying treatment seeking in obsessive-compulsive disorder. Compr Psychiatry. 2010;51:480–5
31. Alonso P, Menchon JM, Jimenez S, et al. Personality dimensions in obsessive-compulsive disorder: Relation to clinical variables. Psychiatry Res. 2008;157:159–68
34. Torres AR, Fontenelle LF, Ferrao YA, et al. Clinical features of obsessive-compulsive disorder with hoarding symptoms: A multicenter study. J Psychiatr Res. 2012;46:724–32
35. Chen PY, Wang SC, Poland RE, et al. Biological variations in depression and anxiety between East and West. CNS Neurosci Ther. 2009;15:283–94
© 2013 Lippincott Williams & Wilkins, Inc.