The Netherlands Obsessive Compulsive Disorder Association (NOCDA) study: design and rationale of a longitudinal naturalistic study of the course of OCD and clinical characteristics of the sample at baseline

Loneliness in OCD and its determinants

Obsessive-compulsive disorder (OCD) is a psychiatric condition characterized by intrusive thoughts and repetitive behaviors, affecting approximately 1.3 % of the population. Loneliness has serious consequences for future health outcomes. Although it has been extensively studied in depression, its prevalence in obsessive-compulsive disorder (OCD) has hardly been investigated. The current study sought to examine the association between loneliness and OCD, through an exploratory investigation of their demographic and clinical correlates. This cross-sectional study utilized data from the Netherlands Obsessive-Compulsive Disorder Association (NOCDA) study, designed to investigate determinants, course, and consequences of OCD in a large clinical sample. In this data base, a cohort of 363 OCD adult patients underwent assessment for loneliness severity, OCD symptomatology, comorbid conditions, and demographic variables. Findings reveal a high prevalence of loneliness among OCD patients, with nearly three-quarters (73.6 %) experiencing elevated levels. Loneliness was associated with greater depression severity and specific demographic factors such as gender, age, and education level. However, the relationship between OCD severity and loneliness was explained by depression severity. Clinical and theoretical implications are discussed as well as limitations and directions for future research.

Long-term remission rates and trajectory predictors in obsessive-compulsive disorder: Findings from a six-year naturalistic longitudinal cohort study

BACKGROUND

This naturalistic study, utilizing data from the Netherlands Obsessive-Compulsive Disorder Association (NOCDA) cohort, investigated the long-term remission rates and predictors of different trajectories of obsessive-compulsive disorder (OCD) within a clinical population.

METHODS

A sample of 213 participants was classified into three illness trajectories: "Chronic," "Episodic, "and "Remitted-OCD." Long-term remission rates were calculated based on three follow-up measurements over a 6-year period. A multinomial logistic regression model, incorporating five selected predictors with high explanatory power and one covariate, was employed to analyze OCD trajectory outcomes.

RESULTS

The long-term full remission rates, calculated from all the measurements combined (14%), were significantly lower than what was observed in earlier studies and when compared to assessments at each individual follow-up (∼30%). Moreover, high baseline symptom severity and early age of onset were identified as significant risk factors for a chronic course of OCD, while male sex and younger age predicted a more favorable trajectory. Notably, the likelihood of an episodic course remained high even without identified risk factors.

LIMITATIONS

The bi-annual data collection process is unable to capture participants' clinical conditions between assessments. Additionally, no data was collected regarding the specific type and duration of psychological treatment received. Regarding the type of treatment participants received.

CONCLUSIONS

Results suggest that long-term remission rates may be lower than previously reported. Consequently, employing multiple assessment points in longitudinal studies is necessary for valid estimation of long-term full remission rates. The results emphasize the importance of personalized clinical care and ongoing monitoring and maintenance for most OCD cases.

How sustainable is resilience? A mixed-methods study on the COVID-19-pandemic as a challenge to resilience resources of older adults who previously recovered from depression

OBJECTIVES

Despite expanding knowledge about the internal and external resources that contribute to resilience among individuals who have experienced depression, the long-term accessibility and protectiveness of these resources across different stressors is unknown. We investigated whether and how the resilience resources of individuals who previously recovered from late-life depression remained protective during the COVID-19 pandemic.

METHODS

We used a sequential explanatory mixed methods design. Quantitative data were derived from two psychiatric case-control cohorts and included twelve repeated measures during the COVID-19 pandemic (n = 465, aged ≥ 60). Qualitative data included two sequential interviews held in 2020 (n = 25) and 2021 (n = 19). We used thematic analysis to determine the protective resources after depression and during the COVID-19 pandemic and linear mixed models to examine the effect of these resources on change in depressive symptoms during the COVID-19 pandemic.

RESULTS

While resources of 'Taking agency', 'Need for rest', 'Managing thought processes' and 'Learning from depression' remained accessible and protective during the pandemic, 'Social support' and 'Engaging in activities' did not. 'Negotiating with lockdown measures', 'changing social contact' and 'changing activities' were compensating strategies. Quantitative data confirmed the protectiveness of social contact, social cohesion, sense of mastery, physical activity, staying active and entertained and not following the media.

CONCLUSION

Many of the resources that previously helped to recover from depression also helped to maintain good mental health during the COVID-19 pandemic. Where accessibility and protectiveness declined, compensatory strategies or new resources were used. Hence, the sustainability of resilience is enabled through adaptation and compensation processes.

Anxiety during the long-term course of obsessive-compulsive disorder

OBJECTIVE

The study aimed to investigate anxiety and its relation with obsessive-compulsive symptoms during the long-term course of obsessive-compulsive disorder (OCD).

METHODS

We used data from the Netherlands OCD Association (NOCDA) study, which included 419 participants with OCD (aged 18-79 years). Severity of obsessive-compulsive symptoms and anxiety at baseline and after two, four, and six years were entered into three models, which were analyzed using structural equation modeling: 1) the cross-lagged model, which assumes that anxiety and obsessive-compulsive symptoms are two distinct groups of symptoms interacting directly on the long-term; 2) the stable traits model, which assumes that anxiety and obsessive-compulsive symptoms result from two distinct latent factors, which are stable over the time and interact with each other; and 3) the common factor model, which assumes that anxiety and obsessive-compulsive symptoms are presentations of the same latent factor.

RESULTS

The cross-lagged model and the stable traits model both were valid models with a good model fit. The common factor model had a poor model fit and was rejected.

LIMITATIONS

The duration of OCD varied widely between the participants (0-64 years). The majority experienced obsessive-compulsive symptoms since several years, which may have affected results on the course of anxiety and the interaction between anxiety and obsessive-compulsive symptoms.

CONCLUSIONS

Anxiety and obsessive-compulsive symptoms in OCD patients do not result from a shared underlying factor but are distinct, interacting symptom groups, probably interacting by distinct latent factors.

Predictors of the 6-year outcome of obsessive-compulsive disorder: Findings from the Netherlands Obsessive-Compulsive Disorder Association study

OBJECTIVE

Obsessive-compulsive disorder is characterized by a chronic course that can vary between patients. The knowledge on the naturalistic long-term outcome of obsessive-compulsive disorder and its predictors is surprisingly limited. The present research was designed to identify clinical and psychosocial predictors of the long-term outcome of obsessive-compulsive disorder.

METHODS

We included 377 individuals with a current diagnosis of obsessive-compulsive disorder, who participated in the Netherlands Obsessive Compulsive Disorder Association study, a multicenter naturalistic cohort study. Predictors were measured at baseline using self-report questionnaires and clinical interviews. Outcome was assessed using the Yale-Brown Obsessive Compulsive Scale at 2-, 4- and 6-year follow-up.

RESULTS

The overall course of obsessive-compulsive disorder was characterized by two prominent trends: the first reflected an improvement in symptom severity, which was mitigated by the second, worsening trend in the long term. Several determinants affected the course variations of obsessive-compulsive disorder, namely, increased baseline symptom severity, late age of onset, history of childhood trauma and autism traits.

CONCLUSION

The long-term outcome of obsessive-compulsive disorder in naturalistic settings was characterized by an overall improvement in symptom severity, which was gradually halted to the point of increased worsening. However, after 6 years, the severity of symptoms remained below the baseline level. While certain determinants predicted a more favorable course, their effect diminished over time in correspondence to the general worsening trend. The results highlight the importance of a regular and continuous monitoring for symptom exacerbations as part of the management of the obsessive-compulsive disorder, regardless of the presence of putative predictors.

Changes in insight throughout the natural four-year course of obsessive-compulsive disorder and its association with OCD severity and quality of life

Objective

Patients with obsessive-compulsive disorder (OCD) and poor insight show higher symptom severity, lower quality of life (QoL), and a reduced treatment response compared to patients with good insight. Little is known about changes in insight. This study explored the course of insight and its association with OCD severity and QoL among 253 patients with OCD participating in the prospective naturalistic Netherlands Obsessive Compulsive Disorder Association (NOCDA) Study.

Results

In 70% of the participants with available insight data, the level of insight changed during the four-year course. Insight was most variable in participants with poor insight. Improvement of insight scores was statistically significantly associated with improvement of Y-BOCS scores (r = 0.19), but not with changes in QoL scores. Change in insight in the first 2 years was not statistically significantly predictive of OCD severity or QoL at four-year follow-up.

Conclusion

These findings suggest that patients' levels of insight may change during the natural four-year course of OCD and that improvement in the level of insight have a positive association with improvement in OCD severity.

The impact of COVID-19-pandemic-related adversity on mental health: longitudinal study in Dutch populations with and without mental health disorders

BACKGROUND

Despite growing concerns about mental health during the COVID-19 pandemic, particularly in people with pre-existing mental health disorders, research has shown that symptoms of depression and anxiety were generally quite stable, with modest changes in certain subgroups. However, individual differences in cumulative exposure to COVID-19 stressors have not been yet considered.

AIMS

We aimed to quantify and investigate the impact of individual-level cumulative exposure to COVID-19-pandemic-related adversity on changes in depressive and anxiety symptoms and loneliness. In addition, we examined whether the impact differed among individuals with various levels of pre-pandemic chronicity of mental health disorders.

METHOD

Between April 2020 and July 2021, 15 successive online questionnaires were distributed among three psychiatric case-control cohorts that started in the 2000s (N = 1377). Outcomes included depressive and anxiety symptoms and loneliness. We developed a COVID-19 Adversity Index (CAI) summarising up to 15 repeated measures of COVID-19-pandemic-related exposures (e.g. exposure to COVID-19 infection, negative economic impact and quarantine). We used linear mixed linear models to estimate the effects of COVID-19-related adversity on mental health and its interaction with pre-pandemic chronicity of mental health disorders and CAI.

RESULTS

Higher CAI scores were positively associated with higher increases in depressive symptoms, anxiety symptoms and loneliness. Associations were not statistically significantly different between groups with and without (chronic) pre-pandemic mental health disorders.

CONCLUSIONS

Individual differences in cumulative exposure to COVID-19-pandemic-related adversity are important predictors of mental health, but we found no evidence for higher vulnerability among people with (chronic) pre-pandemic mental health disorders.

Heterogeneity in depressive and anxiety symptoms and loneliness during the COVID-19 pandemic: Results from three Dutch psychiatric case-control cohorts from April 2020 to February 2022

OBJECTIVE

While research found heterogeneous changes in mental health during the COVID-19 pandemic, less is known about the long-term changes in mental health in psychiatric groups. Therefore, we applied a data-driven method to detect sub-groups with distinct trajectories across two years into the pandemic in psychiatric groups, and described their differences in socio-demographic and clinical characteristics.

METHOD

We conducted sixteen rounds of questionnaires between April 2020 and February 2022 among participants (n = 1722) of three psychiatric case-control cohorts that started in the 2000's. We used Growth Mixture Modelling and (multinomial) logistic regression to identify characteristics associated with trajectory membership.

RESULTS

We found low decreasing (1228 [72%] participants), intermediate (n = 348 [22%] participants) and high stable (106 [6%] participants) trajectories of depressive symptoms; decreasing low/intermediate (1507 [90%] participants) and high stable (161 [10%] participants) trajectories of anxiety symptoms; and stable low (1109 [61%] participants), stable high (315 [17%] participants), temporary lowered (123 [9%]) and temporary heightened (175 [13%] participants) trajectories of loneliness. Chronicity and severity of pre-pandemic mental disorders predicted unfavourable sub-group membership for all outcomes. Being female, having a low education and income level were associated with unfavourable trajectories of depression, being younger with unfavourable trajectories of anxiety and being female and living alone with unfavourable trajectories of loneliness.

CONCLUSION

We found relatively stable trajectories of depression and anxiety symptoms over two years, suggesting low heterogeneity in outcomes during the pandemic. For loneliness, we found two specific sub-groups with temporary increase and decrease in loneliness during the pandemic.

Predictors of mental health deterioration from pre- to post-COVID-19 outbreak

BACKGROUND

Mental health was only modestly affected in adults during the early months of the COVID-19 pandemic on the group level, but interpersonal variation was large.

AIMS

We aim to investigate potential predictors of the differences in changes in mental health.

METHOD

Data were aggregated from three Dutch ongoing prospective cohorts with similar methodology for data collection. We included participants with pre-pandemic data gathered during 2006-2016, and who completed online questionnaires at least once during lockdown in The Netherlands between 1 April and 15 May 2020. Sociodemographic, clinical (number of mental health disorders and personality factors) and COVID-19-related variables were analysed as predictors of relative changes in four mental health outcomes (depressive symptoms, anxiety and worry symptoms, and loneliness), using multivariate linear regression analyses.

RESULTS

We included 1517 participants with (n = 1181) and without (n = 336) mental health disorders. Mean age was 56.1 years (s.d. 13.2), and 64.3% were women. Higher neuroticism predicted increases in all four mental health outcomes, especially for worry (β = 0.172, P = 0.003). Living alone and female gender predicted increases in depressive symptoms and loneliness (β = 0.05-0.08), whereas quarantine and strict adherence with COVID-19 restrictions predicted increases in anxiety and worry symptoms (β = 0.07-0.11).Teleworking predicted a decrease in anxiety symptoms (β = -0.07) and higher age predicted a decrease in anxiety (β = -0.08) and worry symptoms (β = -0.10).

CONCLUSIONS

Our study showed neuroticism as a robust predictor of adverse changes in mental health, and identified additional sociodemographic and COVID-19-related predictors that explain longitudinal variability in mental health during the COVID-19 pandemic.

Mental health and perceived impact during the first Covid-19 pandemic year: A longitudinal study in Dutch case-control cohorts of persons with and without depressive, anxiety, and obsessive-compulsive disorders

BACKGROUND

Little is known about the longer-term impact of the Covid-19 pandemic beyond the first months of 2020, particularly for people with pre-existing mental health disorders. Studies including pre-pandemic data from large psychiatric cohorts are scarce.

METHODS

Between April 2020 and February 2021, twelve successive online questionnaires were distributed among participants of the Netherlands Study of Depression and Anxiety, Netherlands Study of Depression in Older Persons, and Netherlands Obsessive Compulsive Disorder Association Study (N = 1714, response rate 62%). Outcomes were depressive symptoms, anxiety, worry, loneliness, perceived mental health impact of the pandemic, fear of Covid-19, positive coping, and happiness. Using linear mixed models we compared trajectories between subgroups with different pre-pandemic chronicity of disorders and healthy controls.

RESULTS

Depressive, anxiety and worry symptoms were stable since April-May 2020 whereas happiness slightly decreased. Furthermore, positive coping steadily decreased and loneliness increased - exceeding pre-Covid and April-May 2020 levels. Perceived mental health impact and fear of Covid-19 fluctuated in accordance with national Covid-19 mortality rate changes. Absolute levels of all outcomes were poorer with higher chronicity of disorders, yet trajectories did not differ among subgroups.

LIMITATIONS

The most vulnerable psychiatric groups may have been underrepresented and results may not be generalizable to lower income countries.

CONCLUSIONS

After a year, levels of depressive and worry symptoms remained higher than before the pandemic in healthy control groups, yet not in psychiatric groups. Nevertheless, persistent high symptoms in psychiatric groups and increasing loneliness in all groups are specific points of concern for mental health care professionals.

Prediction of illness remission in patients with Obsessive-Compulsive Disorder with supervised machine learning

INTRODUCTION

The course of OCD differs widely among OCD patients, varying from chronic symptoms to full remission. No tools for individual prediction of OCD remission are currently available. This study aimed to develop a machine learning algorithm to predict OCD remission after two years, using solely predictors easily accessible in the daily clinical routine.

METHODS

Subjects were recruited in a longitudinal multi-center study (NOCDA). Gradient boosted decision trees were used as supervised machine learning technique. The training of the algorithm was performed with 227 predictors and 213 observations collected in a single clinical center. Hyper-parameter optimization was performed with cross-validation and a Bayesian optimization strategy. The predictive performance of the algorithm was subsequently tested in an independent sample of 215 observations collected in five different centers. Between-center differences were investigated with a bootstrap resampling approach.

RESULTS

The average predictive performance of the algorithm in the test centers resulted in an AUROC of 0.7820, a sensitivity of 73.42%, and a specificity of 71.45%. Results also showed a significant between-center variation in the predictive performance. The most important predictors resulted related to OCD severity, OCD chronic course, use of psychotropic medications, and better global functioning.

LIMITATIONS

All recruiting centers followed the same assessment protocol and are in The Netherlands. Moreover, the sample of the data recruited in some of the test centers was limited in size.

DISCUSSION

The algorithm demonstrated a moderate average predictive performance, and future studies will focus on increasing the stability of the predictive performance across clinical settings.

The correlates of social phobia in OCD: Findings from a large clinical sample

OBJECTIVES

Obsessive-compulsive disorder (OCD) is a debilitating psychiatric disorder, often complicated with comorbidities. Social phobia (SP) is the most frequent co-occurring anxiety disorder in OCD, associated with increased clinical severity. However, no study had examined the relevance of interpersonal processes in this comorbidity, which are at the core of SP. This study characterized the clinical (i.e., symptom profile, age of onset, chronicity, and comorbidity), vulnerability (i.e., childhood trauma, negative life events), and interpersonal (attachment style, expressed emotion, and social support) correlates of comorbid SP in a large sample of OCD patients.

METHODS

We analysed the data of 382 OCD patients participating in the Netherlands Obsessive Compulsive Disorder Association (NOCDA) study. We examined the correlates of SP in OCD using self-report questionnaires and structured clinical interviews. In addition, data of 312 non-OCD SP patients were drawn from the Netherlands Study of Depression and Anxiety (NESDA), to compare the age of onset of SP between groups. Descriptive univariate analyses were followed by backward stepwise logistic regression analyses.

RESULTS

Social phobia was present among approximately 20% of OCD patients. Social phobia in OCD was associated with increased depression severity and decreased ratings of secure attachment style. Among OCD patients, SP had a significantly earlier age onset as compared to SP in non-OCD patients.

CONCLUSION

Social phobia in OCD might render a vulnerable clinical picture, characterized with early onset of SP symptoms, insecure attachment style, and increased depressive symptoms. Future studies should use prospective designs to better understand the nature of comorbid SP in OCD.

PRACTITIONER POINTS

Approximately one fifth of OCD patients were diagnosed with comorbid social phobia in a large representative clinical sample. OCD patients with comorbid social phobia presented with a vulnerable clinical picture, characterized with increased depression severity and decreased ratings of secure attachment style. Social phobia in OCD was associated with an earlier AOO as compared to the AOO of social phobia without OCD. The findings are limited by a cross-sectional design; thus, causality could not be assessed. Research is needed to further examine the mechanisms of comorbid social phobia in OCD.

The mental health impact of the COVID-19 pandemic on people with and without depressive, anxiety, or obsessive-compulsive disorders: a longitudinal study of three Dutch case-control cohorts

BACKGROUND

The impact of the COVID-19 pandemic on mental health in people with pre-existing mental health disorders is unclear. In three psychiatry case-control cohorts, we compared the perceived mental health impact and coping and changes in depressive symptoms, anxiety, worry, and loneliness before and during the COVID-19 pandemic between people with and without lifetime depressive, anxiety, or obsessive-compulsive disorders.

METHODS

Between April 1 and May 13, 2020, online questionnaires were distributed among the Netherlands Study of Depression and Anxiety, Netherlands Study of Depression in Older Persons, and Netherlands Obsessive Compulsive Disorder Association cohorts, including people with (n=1181) and without (n=336) depressive, anxiety, or obsessive-compulsive disorders. The questionnaire contained questions on perceived mental health impact, fear of COVID-19, coping, and four validated scales assessing depressive symptoms, anxiety, worry, and loneliness used in previous waves during 2006-16. Number and chronicity of disorders were based on diagnoses in previous waves. Linear regression and mixed models were done.

FINDINGS

The number and chronicity of disorders showed a positive graded dose-response relation, with greater perceived impact on mental health, fear, and poorer coping. Although people with depressive, anxiety, or obsessive-compulsive disorders scored higher on all four symptom scales than did individuals without these mental health disorders, both before and during the COVID-19 pandemic, they did not report a greater increase in symptoms during the pandemic. In fact, people without depressive, anxiety, or obsessive-compulsive disorders showed a greater increase in symptoms during the COVID-19 pandemic, whereas individuals with the greatest burden on their mental health tended to show a slight symptom decrease.

INTERPRETATION

People with depressive, anxiety, or obsessive-compulsive disorders are experiencing a detrimental impact on their mental health from the COVID-19 pandemic, which requires close monitoring in clinical practice. Yet, the COVID-19 pandemic does not seem to have further increased symptom severity compared with their prepandemic levels.

FUNDING

Dutch Research Council.

Predictors of Intensive Treatment in Patients With Obsessive-Compulsive Disorder

Background: Few studies have investigated which patients with obsessive-compulsive disorder (OCD) do not recover through regular cognitive behavior therapy or pharmacotherapy and subsequently end up in intensive treatment like day treatment or inpatient treatment. Knowing the predictors of intensive treatment in these patients is significant because it could prevent intensive treatment. This study has identified predictors of intensive treatment in patients with OCD. Methods: Using 6-year longitudinal data of the Netherlands Obsessive Compulsive Disorder Association (NOCDA), potential predictors of intensive treatment were assessed in patients with OCD (n = 419). Intensive treatment was assessed using the Treatment Inventory Costs in Patients with Psychiatric Disorders (TIC-P). Examined potential predictors were: sociodemographics, and clinical and psychosocial characteristics. Logistic Generalized Estimating Equations was used to estimate to what extent the various characteristics (at baseline, 2- and 4-year assessment) predicted intensive treatment in the following 2 years, averaged over the three assessment periods. Results: Being single, more severe comorbid depression, use of psychotropic medication, and a low quality of life predicted intensive treatment in the following 2 years. Conclusions: Therapists should be aware that patients with OCD who are single, who have more severe comorbid depression, who use psychotropic medication, and who have a low quality of life or a drop in quality of life are at risk for intensive treatment. Intensive treatment might be prevented by focusing regular treatment not only on OCD symptoms but also on comorbid depression and on quality of life. Intensive treatment might be improved by providing extra support in treatment or by adjusting treatment to impairments due to comorbid depressive symptoms or a low quality of life.

Classification of comorbidity in obsessive-compulsive disorder: A latent class analysis

OBJECTIVE

Patients with OCD differ markedly from one another in both number and kind of comorbid disorders. In this study, we set out to identify and characterize homogeneous subgroups of OCD patients based on their comorbidity profile.

METHODS

In a cohort of 419 adult subjects with OCD, the lifetime presence of fifteen comorbid disorders was assessed. Latent class analysis was used to identify comorbidity-based subgroups. Groups were compared with regard to core clinical characteristics: familiality, childhood trauma, age at onset, illness severity, OCD symptom dimensions, personality characteristics, and course of illness.

RESULTS

The study sample could be divided in a large group (n = 311) with a low amount of comorbidity that could be further subdivided into two subgroups: OCD simplex (n = 147) and OCD with lifetime major depressive disorder (n = 186), and a group (n = 108) with a high amount of comorbidity that could be further subdivided into a general anxiety-related subgroup (n = 49), an autism/social phobia-related subgroup (n = 27), and a psychosis/bipolar-related subgroup (n = 10). Membership of the high-comorbid subgroup was associated with higher scores on childhood trauma, illness severity, and the aggression/checking symptom dimension and lower scores on several personality characteristics.

CONCLUSION

Grouping OCD patients based on their comorbidity profile might provide more homogeneous, and therefore, more suitable categories for future studies aimed at unraveling the etiological mechanisms underlying this debilitating disorder.

The long-term association of OCD and depression and its moderators: A four-year follow up study in a large clinical sample

Background:

Depression is the most common comorbidity in obsessive-compulsive disorder (OCD). However, the mechanisms of depressive comorbidity in OCD are poorly understood. We assessed the directionality and moderators of the OCD-depression association over time in a large, prospective clinical sample of OCD patients.

Methods:

Data were drawn from 382 OCD patients participating at the Netherlands Obsessive-Compulsive Disorder Association (NOCDA) study. Cross-lagged, structural equation modeling analyses were used to assess the temporal association between OCD and depressive symptoms. Assessments were conducted at baseline, two-year and four-year follow up. Cognitive and interpersonal moderators of the prospective association between OCD and depressive symptoms were tested.

Results:

Cross-lagged analyses demonstrated that OCD predicts depressive symptoms at two-year follow up and not vice a versa. This relationship disappeared at four-year follow up. Secure attachment style moderated the prospective association between OCD and depression.

Conclusions:

Depressive comorbidity in OCD might constitute a functional consequence of the incapacitating OCD symptoms. Both OCD and depression symptoms demonstrated strong stability effects between two-year and four-year follow up, which may explain the lack of association between them in that period. Among OCD patients, secure attachment represents a buffer against future depressive symptoms.

Childhood trauma and attachment style predict the four-year course of obsessive compulsive disorder: Findings from the Netherlands obsessive compulsive disorder study

INTRODUCTION

Obsessive compulsive disorder (OCD) is a chronic psychiatric disorder where most patients do not reach full symptomatic remission. Identifying predictors of course can improve patients' care by informing clinicians on prognosis and enhancing treatment strategies. Several predictors associated with improved outcome of OCD were identified. However, research focused mainly on clinical, illness-related predictors of the course of OCD. This study examined the contribution of environmental and interpersonal predictors on the long-term outcome of OCD, in addition to the previously identified clinical indicators.

METHODS

We used the baseline, two and four-year data of 382 adult OCD patients participating in the naturalistic cohort study of the Netherlands Obsessive Compulsive Disorder Association (NOCDA). Remission was assessed using the Yale-Brown Obsessive Compulsive Scale (Y-BOCS). Predictors of outcome were assessed at baseline, via clinician-rated and self-report instruments.

RESULTS

Remission at two and at four-year follow-up ranged from 11% to 26%. Early age of onset and the presence of childhood trauma predicted a worse four-year course. Secure attachment style emerged as a protective predictor of improved outcome.

LIMITATIONS

The naturalistic design of our study did not enable a systematic estimation the effect of treatments received during the follow-up period. Furthermore, age of onset and childhood trauma were assessed retrospectively, which may contribute to recall bias.

CONCLUSION

Results coincide with previous prediction research and stress the importance of adaptive interpersonal functioning in the course of OCD. Clinical implications and future research directions are discussed.

Four-year course of quality of life and obsessive-compulsive disorder

OBJECTIVE

Patients with obsessive compulsive disorder (OCD) have high disease burden. It is important to restore quality of life (QoL) in treatment, so that patients become able to live a fulfilling life. Little is known about the longitudinal course of QoL in patients with OCD, its association with remission from OCD, and about factors that contribute to an unfavourable course of QoL in remitting patients.

METHODS

Study on the 4-year course of QoL of patients with chronic (n = 144), intermittent (n = 22), and remitting OCD (n = 73) using longitudinal data of the Netherlands Obsessive Compulsive Disorder Association (NOCDA; complete data: n = 239; imputed data n = 382). The EuroQol five-dimensional questionnaire (EQ-5D) utility score was used to assess QoL. In patients with remitting OCD, we examined patient characteristics that contributed to an unfavourable course of QoL, including sociodemographics, OCD characteristics, psychiatric comorbidity, and personality traits.

RESULTS

Course of QoL was associated with course of OCD. QoL improved in those who remitted from OCD; however, even in these patients, QoL remained significantly below the population norms. The correlation between QoL and severity of OCD was only moderate: r = - 0.40 indicating that other factors besides OCD severity contribute to QoL. In remitters, more severe anxiety and depression symptoms were related to a lower QoL. Results were similar in complete and imputed data sets.

CONCLUSIONS

Remission from OCD is associated with improvement of QoL, but comorbid anxiety and depression symptoms hamper the improvement of QoL. QoL could be improved by reducing OCD symptoms in patients with OCD and by treating comorbid anxiety and depression symptoms in remitting patients.

Cognitive control networks in OCD: A resting-state connectivity study in unmedicated patients with obsessive-compulsive disorder and their unaffected relatives

OBJECTIVES

Executive network deficits are putative neurocognitive endophenotypes for obsessive-compulsive disorder (OCD). Yet, unlike alterations in fronto-striatal and limbic connectivity, connectivity in the fronto-parietal (FPN) and cingulo-opercular (CON) networks involved in cognitive control has received little attention.

METHODS

The coherence of FPN, CON and fronto-limbic networks was investigated in 39 unmedicated OCD patients, 16 of their unaffected siblings and 36 healthy controls using resting-state functional-connectivity MRI and a seed-based analysis approach.

RESULTS

FPN and CON connectivity was similar for patients and controls. Siblings showed higher connectivity than patients within the CON, and between the CON and FPN compared to patients and controls (trend level). In OCD patients, but not in siblings, fronto-limbic hyperconnectivity was present compared to controls. In contrast to our expectations, no group differences in resting-state connectivity of the cognitive control networks were observed between OCD patients and controls.

CONCLUSIONS

The increased within- and between-network connectivity in siblings, but not in patients, could indicate a mechanism of increased cognitive control that may act as a protective mechanism. None of the observed network alterations can be considered an endophenotype for OCD since differences were present in either patients or siblings, but not in both groups.

Obsessive compulsive disorder with and without hoarding symptoms: Characterizing differences

OBJECTIVE

In recent years there has been some ambiguity about the way hoarding and OCD are related to each other. The present study examines the differences between persons with OCD/hoarding and OCD/non-hoarding and examines which characteristics are associated with the OCD/hoarding group. Information is established about prevalences, socio-demographical characteristics, OCD and related characteristics, OCD subtypes, comorbidity (depression, anxiety disorders and PTSD) and personality traits.

METHODS

Data from baseline assessment of The Netherlands Obsessive Compulsive Disorder Association (NOCDA) study are used. The NOCDA sample consists of 419 participants between 18 and 79 years of age, including participants with current or remitted full DSM-IV-TR criteria for OCD.

RESULTS

Results show that 58 persons (14.3%) are classified as persons with OCD/hoarding and 349 persons (85,7%) are classified as persons with OCD/non-hoarding. OCD/hoarding is independently associated with severity of autism symptoms (p<.001), living without a partner (p<.05) and being less conscientious (p<.05). Persons with OCD/hoarding are not associated with childhood trauma (p=.31), PTSD (p=.91) and AD(H)D, inattentive type (p=.22) and hyperactive type (p=.57).

LIMITATIONS

Causal interferences about associations between the risk indicators and hoarding symptoms were precluded since results were based on cross-sectional data.

CONCLUSION

This study confirmed differences between persons with OCD/hoarding and persons with OCD/non-hoarding. The most relevant outcome of this study was the association between persons with OCD/hoarding and the increased severity of autism symptoms. These results provide a better understanding of persons with OCD/hoarding and have the potential to improve treatment.

Body mass index in obsessive-compulsive disorder

BACKGROUND

Psychiatric disorders are associated with overweight/obesity. Obsessive-compulsive disorder (OCD) may be an exception, as anecdotal evidence suggests lower BMI in OCD. Additionally, depression is associated with elevated BMI, but effects of comorbid secondary depression are unknown. The aim of the present study was to assess BMI and risk for overweight/obesity in OCD and to assess the effect of comorbid depression on BMI.

METHODS

BMI, demographics, and clinical status were assessed in large samples of individuals with OCD, anxiety disorders, depressive disorders, comorbid anxiety/depressive disorders, and non-clinical controls (NCC).

RESULTS

Although no initial differences were found between the samples on BMI, the non-depressed OCD subsample had significantly lower BMI and risk for overweight/obesity compared to all other clinical samples. NCC were nearly twice as likely to be overweight compared to non-depressed OCD.

LIMITATIONS

Eating disorders were excluded in the OCD sample, but BMI < 17 was used as an exclusion criterion in the clinical control groups in lieu of screening for Anorexia. Group differences on demographics were controlled for. Recruitment methodology differed between samples.

CONCLUSIONS

OCD is associated with significantly lower rates of obesity and overweight, but this relationship was not found when comorbid depression was present. This suggests that the purer the phenotype of OCD, the more substantial protective factor against overweight/obesity emerges compared to other clinical samples and NCC. An OCD-specific reward/anhedonia model, previously offered to elucidate lower smoking rates in OCD, may account for lower BMI in OCD. These results warrant careful clinical attention to the negative impact of comorbid depression on OCD that spans from increasing risk for obesity and cigarette smoking, to hindering treatment response.

Relieving the Burden of Family Members of Patients with Obsessive-Compulsive Disorder

OBJECTIVE

Obsessive-compulsive disorder (OCD) burdens family members. Certain responses of family members to OCD augment their burden, namely accommodation and antagonism. Family interventions are successful in reducing severity of OCD but surprisingly, the impact of family interventions on the burden of family members has received little attention.

METHOD

16 family members of patients with OCD were treated - together with the patient - with our brief CBT family intervention focusing on accommodation, antagonism and normalizing the family relationship. Family burden, accommodation and antagonism were measured before and after the family intervention with: Involvement Evaluation Questionnaire, Impact on Relatives Scale, EuroQol five dimensional questionnaire (EQ-5D), Family Accommodation Scale - Self Report and the Perceived Criticism Measure.

RESULTS

The burden of family members of patients with OCD was considerable and comparable to the burden of family members of patients with schizophrenia. Family burden was diminished after the brief dyadic family intervention and correlated to a decrease in accommodation.

CONCLUSIONS

Our brief dyadic family intervention is promising in relieving the burden of family members of patients with OCD.

Examining the factor structure of the self-report Yale-Brown Obsessive Compulsive Scale Symptom Checklist

Obsessive-compulsive symptom dimensions are important in studies about the pathogenesis and treatment of obsessive-compulsive disorder. More than 30 factor analytic studies using the Yale-Brown Obsessive Compulsive Scale Symptom Checklist (Y-BOCS-SC) interview version have been published. However, a drawback of the Y-BOCS-SC interview is that it is time-consuming for the clinician. Baer's self-report version of the Y-BOCS-SC could be a less time-consuming alternative. The purpose of this study was to examine the factor structure of Baer's self-report Y-BOCS-SC. In a sample of 286 patients, we performed two factor analyses, one using categories and one using items of the Y-BOCS-SC. Using category-level data, we identified four factors; when using items we identified six factors. Symptom dimensions for contamination/cleaning, symmetry/repeating/counting/ordering and hoarding were found in both analyses. The impulsive aggression, pathological doubt, sexual, religious somatic and checking categories formed one factor in the analysis using category-level data and divided into three factors using item-level data. These factors correspond with studies using the interview version and support our hypothesis that the self-report version of the Y-BOCS-SC could be an alternative for the interview version.

Perceptions of free will in obsessive-compulsive disorder: a quantitative analysis

BACKGROUND

The aim of this study was to explore perceptions of free will in the repetitive behaviors of patients with obsessive-compulsive disorder (OCD) and to explore their relation with core clinical characteristics.

METHODS

Experiences of free will were assessed with the Symptomatology And Perceived Free will rating scale (SAPF) in 295 subjects with a lifetime diagnosis of OCD. Patients' scores on the SAPF were subjected to an explorative principal axis factor analysis (PAF). Factor scores were regressed on five OCD symptom dimensions and on seven clinical variables: illness duration, severity of OCD, insight, anxiety and depression, suicidal ideation and quality of life.

RESULTS

The PAF revealed three factors: the perceived ability to control and change one's course of action when faced with an obsession or compulsion (the "alternative possibilities" factor); the experience of obsessions or compulsions as intentional (the "intentionality" factor); and the experience of being the source or owner of the obsessions or compulsions (the "ownership" factor). Lower scores on the "alternative possibilities" factor were associated with lower scores on the washing dimension (β = 0.237, p = 0.004) and higher scores on the precision dimension (β = - 0.190, p = 0.025) and independently associated with longer illness duration (β = - 0.134, p = 0.039), higher illness severity (β = - 0.298, p < 0.001) and lower quality of life (β = 0.172, p = 0.046). Lower scores on the "intentionality" factor were independently associated with lower quality of life (β = 0.233, p = 0.027). Higher scores on the "ownership" factor were associated with higher scores on the precision dimension (β = 0.207, p = 0.023) and independently associated with poorer insight (β = 0.170, p = 0.045).

CONCLUSIONS

The most notable finding of this study is that a diminished experience of free will in OCD is associated with core clinical characteristics: illness duration and severity, insight and quality of life.

Chronic obsessive-compulsive disorder: prognostic factors

BACKGROUND

The course of illness in obsessive-compulsive disorder (OCD) varies significantly between patients. Little is known about factors predicting a chronic course of illness. The aim of this study is to identify factors involved in inducing and in maintaining chronicity in OCD.

METHODS

The present study is embedded within the Netherlands Obsessive Compulsive Disorder Association (NOCDA) study, an ongoing multicenter naturalistic cohort study designed to identify predictors of long-term course and outcome in OCD. For this study, 270 subjects with a current diagnosis of OCD were included. Chronicity status at 2-year follow-up was regressed on a selection of baseline predictors related to OCD, to comorbidity and to stress and support.

RESULTS

Psychotrauma [odds ratio (OR) 1.98, confidence interval (CI) 1.22-3.22, p = 0.006], recent negative life events (OR 1.42, CI 1.01-2.01, p = 0.043), and presence of a partner (OR 0.28, CI 0.09-0.85, p = 0.025) influenced the risk of becoming chronic. Longer illness duration (OR 1.46, CI 1.08-1.96, p = 0.013) and higher illness severity (OR 1.09, CI 1.03-1.16, p = 0.003) increased the risk of remaining chronic.

CONCLUSIONS

External influences increase the risk of becoming chronic, whereas the factors involved in maintaining chronicity are illness-related. As the latter are potentially difficult to modify, treatment should be devoted to prevent chronicity from occurring in the first place. Therapeutic strategies aimed at alleviating stress and at boosting social support might aid in achieving this goal.

The relationship between cognitions and symptoms in obsessive-compulsive disorder

BACKGROUND

The cognitive theory of obsessive-compulsive disorder (OCD) ascertains that catastrophic (mis)interpretations of normally occurring intrusive thoughts are related to the maintenance of OCD. Nonetheless, findings supporting the relationship between cognitive biases and OCD symptoms are largely inconsistent. In the present study we examined the relationship between OCD cognitions and symptoms among 382 OCD patients participating in the longitudinal Netherlands Obsessive Compulsive Disorder Association (NOCDA) study.

METHODS

OCD cognitions and OC, anxiety and depressive symptoms were assessed using self-report questionnaires at baseline and at two-year follow-up. Baseline multiple regression analyses assessed the specificity of OC cognitions to OCD symptoms. Cross-lagged analyses examined whether cognitions predict OCD symptoms at two-year follow up.

RESULTS

Baseline analyses demonstrated significant relationships between comorbid anxiety, depressive severity and OC cognitions, adjusted for OCD symptoms (β = .283, p < .001 and β = .246, p < .001, respectively). OCD severity adjusted for comorbid symptoms was unrelated to cognitions at baseline (β = .040, p = n.s). Unique associations were found between cognitions and two OCD symptom subtypes (Impulses: β = .215, p < .001; Rumination/doubting: β = .205, p < .001). Longitudinal analyses yielded non-significant associations between OCD cognitions and symptom severity. Prospective analyses of cognitions and OCD symptom subtypes yielded significant effects for both bidirectional and unidirectional associations (β = .11-.16, p < .05).

LIMITATIONS

Given the naturalistic design of the study, we did not assess therapeutic interventions between baseline and follow-up.

CONCLUSIONS

Results only partially concord with the predictions of the cognitive theory of OCD. Future studies should focus on mechanisms alternative to cognitions when investigating the course of OCD.

The relation between depressive and obsessive-compulsive symptoms in obsessive-compulsive disorder: Results from a large, naturalistic follow-up study

OBJECTIVE

Despite the frequent occurrence of depressive symptoms in obsessive-compulsive disorder (OCD), little is known about the reciprocal influence between depressive and obsessive-compulsive symptoms during the course of the disease. The aim of the present study is to investigate the longitudinal relationship between obsessive-compulsive and depressive symptoms in OCD patients.

METHOD

We used the baseline and 1-year follow-up data of the Netherlands Obsessive Compulsive Disorder Association (NOCDA) study. In 276 patients with a lifetime diagnosis of obsessive-compulsive disorder, depressive and obsessive-compulsive symptoms were assessed at baseline and at one-year follow-up with the Beck Depression Inventory (BDI) and the Yale-Brown Obsessive Compulsive Symptom (Y-BOCS) scale. Relations were investigated using a cross-lagged panel design.

RESULTS

The association between the severity of depressive symptoms at baseline and obsessive-compulsive symptoms at follow-up was significant (β=0.244, p<0.001), while the association between the severity of obsessive-compulsive symptoms at baseline and depressive symptoms at follow-up was not (β=0.097, p=0.060). Replication of the analyses in subgroups with and without current comorbid major depressive disorder (MDD) and subgroups with different sequence of onset (primary versus secondary MDD) revealed the same results.

LIMITATIONS

There may be other factors, which affect both depressive and obsessive-compulsive symptoms that were not assessed in the present study.

CONCLUSION

The present study demonstrates a relation between depressive symptoms and the course of obsessive-compulsive symptoms in OCD patients, irrespective of a current diagnosis of MDD and the sequence of onset of OCD and MDD.

Mild White Matter Changes in Un-medicated Obsessive-Compulsive Disorder Patients and Their Unaffected Siblings

Objective: Obsessive-compulsive disorder (OCD) is a common neuropsychiatric disorder with moderate genetic influences and white matter abnormalities in frontal-striatal and limbic regions. Inconsistencies in reported white matter results from diffusion tensor imaging (DTI) studies can be explained, at least partly, by medication use and between-group differences in disease profile and stage. We used a family design aiming to establish whether white matter abnormalities, if present in un-medicated OCD patients, also exist in their unaffected siblings.

Method: Forty-four OCD patients, un-medicated for at least the past 4 weeks, 15 of their unaffected siblings, and 37 healthy controls (HC) underwent DTI using a 3-Tesla MRI-scanner. Data analysis was done using tract-based spatial statistics (TBSS). Fractional anisotropy (FA), axial diffusivity (AD), radial diffusivity (RD), and mean diffusivity (MD) values were compared within seven skeletonised regions of interest (ROIs), i.e., corpus callosum, bilateral cingulum bundle, bilateral inferior longitudinal fasciculus/frontal-occipital fasciculus (ILF/FOF) and bilateral superior longitudinal fasciculus (SLF).

Results: Un-medicated OCD patients, compared with HC, had significantly lower FA in the left cingulum bundle. FA was trend-significantly lower in all other ROIs, except for the corpus callosum. Significant three-group differences in FA (and in RD at trend-significant level) were observed in the left cingulum bundle, with the unaffected siblings representing an intermediate group between OCD patients and HC.

Conclusions: OCD patients showed lower FA in the left cingulum bundle, partly driven by trend-significantly higher values in RD. Since the unaffected siblings were found to be an intermediate group between OCD patients and HC, this white matter alteration may be considered an endophenotype for OCD.

Emotion regulation before and after transcranial magnetic stimulation in obsessive compulsive disorder

BACKGROUND

Impaired emotion regulation may underlie exaggerated emotional reactivity in patients with obsessive compulsive disorder (OCD), yet instructed emotion regulation has never been studied in the disorder.

METHOD

This study aimed to assess the neural correlates of emotion processing and regulation in 43 medication-free OCD patients and 38 matched healthy controls, and additionally test if these can be modulated by stimulatory (patients) and inhibitory (controls) repetitive transcranial magnetic stimulation (rTMS) over the left dorsolateral prefrontal cortex (dlPFC). Participants performed an emotion regulation task during functional magnetic resonance imaging before and after a single session of randomly assigned real or sham rTMS. Effect of group and rTMS were assessed on self-reported distress ratings and brain activity in frontal-limbic regions of interest.

RESULTS

Patients had higher distress ratings than controls during emotion provocation, but similar rates of distress reduction after voluntary emotion regulation. OCD patients compared with controls showed altered amygdala responsiveness during symptom provocation and diminished left dlPFC activity and frontal-amygdala connectivity during emotion regulation. Real v. sham dlPFC stimulation differentially modulated frontal-amygdala connectivity during emotion regulation in OCD patients.

CONCLUSIONS

We propose that the increased emotional reactivity in OCD may be due to a deficit in emotion regulation caused by a failure of cognitive control exerted by the dorsal frontal cortex. Modulatory rTMS over the left dlPFC may influence automatic emotion regulation capabilities by influencing frontal-limbic connectivity.

Compensatory frontoparietal activity during working memory: an endophenotype of obsessive-compulsive disorder

BACKGROUND

Subtle deficits in executive functioning are present in patients with obsessive-compulsive disorder (OCD) and their first-degree relatives, suggesting involvement of the frontoparietal circuits. The neural correlates of working memory may be a neurocognitive endophenotype of OCD.

METHODS

Forty-three unmedicated OCD patients, 17 unaffected siblings, and 37 matched comparison subjects performed a visuospatial n-back task, with a baseline condition (N0) and three working memory load levels (N1, N2, N3) during functional magnetic resonance imaging. Task-related brain activity was compared between groups in frontoparietal regions of interest. Generalized psychophysiological interaction analyses were used to study task-related changes in functional connectivity.

RESULTS

Obsessive-compulsive disorder patients, compared with comparison subjects and siblings, showed increased error rates at N3. Compared with comparison subjects, OCD patients showed task-related hyperactivation in left dorsal frontal areas and left precuneus associated with better task performance. Siblings exhibited hyperactivation in a bilateral frontoparietal network. Increased task load was associated with increased task-related brain activity, but in OCD patients and siblings this increase was smaller from load N2 to N3 than in comparison subjects. Obsessive-compulsive disorder patients, compared with siblings and comparison subjects, showed increased task-related functional connectivity between frontal regions and bilateral amygdala.

CONCLUSIONS

These findings indicate that compensatory frontoparietal brain activity in OCD patients and their unaffected relatives preserves task performance at low task loads but is insufficient to maintain performance at high task loads. Frontoparietal dysfunction may constitute a neurocognitive endophenotype for OCD, possibly reflecting limbic interference with and neural inefficiency within the frontoparietal network.

Obsessive-compulsive disorder; chronic versus non-chronic symptoms

OBJECTIVE

Understanding chronicity in OCD is hampered by contradictory findings arising from dissimilar definitions of chronic OCD. The purpose of this study was to investigate the magnitude of chronicity in OCD and to examine if chronic OCD is critically different from non-chronic OCD, using a chronicity definition that reflects empirical findings.

METHOD

Baseline data of the Netherlands Obsessive Compulsive Disorder Association (NOCDA) study, in which 379 OCD patients participated, were analyzed. Chronic OCD was defined as "continuous presence of at least moderately severe OCD symptoms during at least two years", and was assessed retrospectively using a Life-Chart Interview.

RESULTS

Application of the chronicity criterion resulted in two groups with highly distinguishable course patterns. The majority of the sample (61.7%) reported a chronic course. Patients with a chronic course reported significantly more severe OCD symptoms, more illness burden, more comorbidity, an earlier OCD onset and more contamination and washing - and symmetry and ordering symptoms. Multivariable logistic regression analysis revealed that chronic OCD was independently associated with more OCD-subtypes (p<0.001), contamination and washing symptoms (p<0.001), earlier OCD onset (p=0.05) and higher severity of compulsions (p<.01).

LIMITATIONS

The findings are based on a cross-sectional survey. Furthermore course was assessed retrospectively, implying the possibility of overestimation of persistence and severity of symptoms.

CONCLUSION

Chronicity is the rule rather than the exception in OCD in clinical samples. Chronic OCD is critically different from non-chronic OCD. Further attempts to break down the heterogeneity of OCD in homogeneous course subtypes should be made to allow for a more precise determination of the pathogenesis of OCD and better treatment.

Age of onset in obsessive-compulsive disorder: admixture analysis with a large sample

BACKGROUND

Research into age of onset in obsessive-compulsive disorder (OCD) has indicated significant differences between patients with early and late onset of the disorder. However, multiple criteria have been used arbitrarily for differentiating between early- and late-onset OCD, rendering inconsistent results that are difficult to interpret.

METHOD

In the current study, admixture analysis was conducted in a sample of 377 OC patients to determine the number of underlying populations of age of onset and associated demographic and clinical characteristics. Various measures of anxiety, depression, co-morbidity, autism, OCD, tics and attention deficit hyperactivity disorder (ADHD) symptoms were administered.

RESULTS

A bimodal age of onset was established and the best-fitting cut-off score between early and late age of onset was 20 years (early age of onset ≤19 years). Patients with early age of onset were more likely to be single. Early age of onset patients demonstrated higher levels of OCD severity and increased symptoms on all OCD dimensions along with increased ADHD symptoms and higher rates of bipolar disorder.

CONCLUSIONS

It is suggested that 20 years is the recommended cut-off age for the determination of early versus late age of onset in OCD. Early age of onset is associated with a generally graver OCD clinical picture and increased ADHD symptoms and bipolar disorder rates, which may be related to greater functional implications of the disorder. We propose that age of onset could be an important marker for the subtyping of OCD.

Clinical relevance of comorbidity in obsessive compulsive disorder: the Netherlands OCD Association study

BACKGROUND

This study describes lifetime and current rates of comorbidity, its onset and its consequences in a large clinical sample of patients with obsessive compulsive disorder (OCD). A wide range of risk factors and clinical characteristics were also examined to determine whether pure OCD is different from OCD with current comorbidity. Finally, the temporal sequencing of the disorders was examined.

METHOD

Data were obtained from the Netherlands Obsessive Compulsive Disorder Association (NOCDA) study. A sample of 382 participants with current OCD (during the past month) was evaluated.

RESULTS

Current comorbidity occurred in 55% of patients with OCD, while 78% suffered from lifetime comorbidity. Comorbidity is associated with more severe OCD, anxiety and depressive symptoms and more negative consequences on daily life. Multiple comorbid disorders often precede OCD and influence both its course and severity. Childhood trauma and neuroticism are vulnerability factors for the development of multiple comorbid disorders in OCD.

LIMITATIONS

It should be noted that causal inferences about the association between risk factors and OCD are precluded since our results were based on cross-sectional data.

CONCLUSION

(Multiple) comorbidity in OCD is clinically relevant since it is associated with a specific pattern of vulnerability, with greater chronicity, with more severe OCD and more negative consequences on daily life. This indicates that the diagnosis and treatment of all comorbid disorders is clinically relevant, and clinicians should be especially aware of multiple disorders in cases of childhood trauma and high levels of neuroticism. Primary OCD has a different developmental and comorbidity pattern compared to secondary OCD.