Obsessive-compulsive disorder with comorbid major depression: what is the role of cognitive factors?

Individuals with obsessive-compulsive disorder (OCD) commonly experience comorbid mood disturbances such as major depressive disorder (MDD). Previous studies that have compared OCD patients with and without MDD have revealed differences in demographic characteristics, clinical severity, and symptom presentation between these two patient groups. Previous studies have not, however, examined whether there are differences with respect to cognitive processes. The present study therefore aimed to address this gap in the literature. Eighty patients with OCD and no unipolar mood disorders were compared with 34 OCD patients with comorbid major depression on measures of OCD symptoms, cognitions, and insight, as well as on measures of depression and functional impairment. Whereas depressed OCD patients evidenced higher scores than non-depressed OCD patients on semi-idiographic measures of OCD symptoms and cognitions, this was not the case for nomothetic measures. Functional impairment and the tendency to misinterpret innocuous intrusive thoughts as significant emerged as unique predictors of depression within the entire sample of OCD patients. Results are discussed in terms of (a) the importance of semi-idiographic assessment of OCD, (b) possible explanations for the relationship between OCD symptoms, depression, and cognitive processes, and (c) the psychological treatment of comorbid OCD and MDD.     

No evidence for object alternation impairment in obsessive-compulsive disorder (OCD)

Recent neuroimaging studies have consistently ascribed the orbito-frontal cortex (OFC) a pivotal role in the pathogenesis of obsessive-compulsive disorder (OCD). Cognitive tests presumed sensitive to this region, such as the Object Alternation Task (OAT), are considered important tools to verify this assumption and to investigate the impact of cortical dysfunction on behavior. The aim of the present study was to assess if patients with OCD show enhanced perseveration errors on the OAT relative to healthy controls taking into account several potential moderators, especially comorbid depression and OCD subtype. Thirty-five OCD patients and 18 healthy controls underwent the OAT as well as the Trail-Making Tests (TMT) A and B. In line with prior studies, OCD patients were slowed on both TMT tasks. In contrast, samples performed similarly on the OAT. While the latter finding does not invalidate the assumption that the OFC is affected in OCD, dysfunctions involving this region may be more subtle than often claimed and likely encompass only a small subset of functional domains hosted in the OFC.     

The semantic Simon effect in Tourette's syndrome and obsessive-compulsive disorder

Core symptoms of Tourette's syndrome (TS) and obsessive-compulsive disorder (OCD) may be attributed to an impairment in inhibitory control. Neuropsychological studies have addressed inhibition in both disorders, but findings have been inconsistent. The aim of this study was to examine cognitive inhibition, using a semantic Simon effect paradigm, in patients with TS and OCD. Furthermore, to address comorbidity a group of TS+OCD patients was also examined. Results indicated that patients with TS and OCD were affected by the inhibitory components of the task. TS groups performed similarly to controls on simple and choice RT tasks, but were particularly compromised as increasingly complex inhibitory demands were imposed. OCD patients were slower and committed more errors than controls, especially in the more cognitively demanding conditions, and were particularly disadvantaged by incongruent stimulus-response compatibilities. Findings implicate possible fronto-striatal dysfunction, are consistent with previously reported inhibitory deficits in TS and OCD, and support the theory that comorbid TS+OCD is more closely linked to pure TS than OCD.     

Assessment of executive functions in a Brazilian sample of bipolar subjects

Research has demonstrated impairments in executive functions in Bipolar Mood Disorder patients. Evidence shows that this impairment is present in both periods of active symptoms of the disorder, as well as euthymic stages, and is compounded by mood episodes, especially manic phases. The purpose of this study was to compare the executive performance of a sample of Brazilian bipolar patients in depressive episodes, (44 participants), euthymia (37 participants), and in controls (43 participants). The main instrument for evaluation was the Wisconsin Card Sorting Test. Significant differences were found in performance on the Wisconsin Card Sorting Test between Bipolar subjects (Type I) (both in depression and euthymia) and the controls. No significant correlations were found between the number of manic episodes and the performance on execute measurement variables. The findings suggest that the executive dysfunctions in Bipolar Disorder may be related to both transitory and permanent deficits.     

Subtyping obsessive-compulsive disorder: neuropsychological correlates

We administered neuropsychological measures considered sensitive to prefrontal dysfunction (both orbitofrontal and dorsolateral prefrontal neocortex) to obsessive-compulsive disorder (OCD) patients and control subjects. OCD subjects exhibited performance deficits, in comparison to community controls, on three measures sensitive to orbitofrontal neocortex dysfunction. Contrary to expectation, OCD patients also exhibited performance deficits on measures sensitive to dorsolateral prefrontal neocortex dysfunction. However, distinct neurocognitive profiles emerged when we examined the impact of comorbid schizotypal personality features on neuropsychological test performance. Primary OCD patients displayed impaired performance on measures sensitive to orbitofrontal dysfunction; however, they did not differ from control subjects on tests of dorsolateral function. OCD subjects presenting with schizotypal personality features performed poorly not only on tests sensitive to orbitofrontal dysfunction, but also on tests sensitive to dorsolateral dysfunction. Findings suggest that OCD can be subdivided into clinical subtypes, and distinct prefrontal subsystems may be differentially involved in these subtypes.     

Violent obsessions are associated with suicidality in an OCD analog sample of college students

The picture of suicide in obsessive-compulsive disorder (OCD) is unclear because previous research did not uniformly control for depressive symptoms when examining the relationship between OCD and suicidality. Specific links between OC symptom dimensions and suicidality were also not adequately studied. As such, we investigated specific associations between OC symptom dimensions and suicidality, beyond the contribution of depressive symptoms, in an OCD analog sample of college students, a group traditionally at risk for suicide. One hundred and forty-six college students (103 females; 43 males) who exceeded the clinical cut-off for OC symptoms on the Obsessive-Compulsive Inventory, Revised (OCI-R) were recruited. Participants completed an online questionnaire containing measures that assessed suicidality and OC and depressive symptom severity. Total OC symptom severity, unacceptable thoughts, and especially violent obsessions exhibited significant positive zero-order correlations with suicidality. However, analyses of part correlations indicated that only violent obsessions had a significant unique association with suicidality after controlling for depressive symptoms. Our findings support the hypothesis that violent obsessions have a specific role in suicidality beyond the influence of depressive symptoms in an OCD analog sample of college students. A strong clinical focus on suicide risk assessment and safety planning in college students reporting violent obsessions is therefore warranted. Future related research should employ longitudinal or prospective designs and control for other possible comorbid symptoms in larger and more representative samples of participants formally diagnosed with OCD in order to verify the generalizability of our findings to these groups.     

Sleep disturbances in treatment‐seeking OCD‐patients: Changes after concentrated exposure treatment

Research indicates that patients with Obsessive Compulsive Disorder (OCD) frequently suffer from comorbid sleep difficulties, and that these difficulties often are not clinically recognized and diagnosed. There has been limited research investigating if comorbid sleep difficulties impair treatment outcome for OCD and if the sleep difficulties change following OCD‐treatment. Thirty‐six patients with obsessive compulsive disorder underwent concentrated exposure treatment delivered in a group over four consecutive days and were assessed with measures of OCD, depressive symptoms and sleep disturbance at three different time points (pre, post and 6 months follow‐up). The sample was characterized by a high degree of comorbidity with other psychiatric disorders. At pre‐treatment nearly 70% of the patients reported sleep difficulties indicative of primary insomnia. The results showed that patients had large reductions of OCD‐symptoms as well as significant improvements in sleep disturbance assessed after treatment, and that these improvements were maintained at follow‐up. Sleep disturbance did not impair treatment outcome, on the contrary patients with higher degree of sleep disturbance at pre‐treatment had better outcome on OCD‐symptoms after treatment. The results indicated that the majority of the OCD sample suffered from sleep disturbances and that these sleep disturbances were significantly reduced following adequate treatment of OCD without specific sleep interventions. However, a proportion of the patients suffered from residual symptoms of insomnia after treatment.     

Cognitive deficits of executive functions and decision‐making in obsessive‐compulsive disorder

The nature of cognitive deficits in obsessive‐compulsive disorder (OCD) is characterized by contradictory findings in terms of specific neuropsychological deficits. Selective impairments have been suggested to involve visuospatial memory, set shifting, decision‐making and response inhibition. The aim of this study was to investigate cognitive deficits in decision‐making and executive functioning in OCD. It was hypothesized that the OCD patients would be less accurate in their responses compared to the healthy controls in rational decision‐making on a version of the Cambridge gambling task (CGT) and on the color‐word interference test and on a version of the Tower of Hanoi test (tower test) of executive functioning. Thirteen participants with OCD were compared to a group of healthy controls (n = 13) matched for age, gender, education and verbal IQ. Results revealed significant differences between the OCD group and the healthy control group on quality of decision‐making on the CGT and for achievement score on the tower test. On these two tasks the OCD group performed worse than the healthy control group. The symptom‐dimension analysis revealed performance differences where safety checking patients were impaired on the tower test compared to contamination patients. Results are discussed in the framework of cognition and emotion processing and findings implicate that OCD models should address, specifically, the interaction between cognition and emotion. Here the emotional disruption hypothesis is forwarded to account for the dysfunctional behaviors in OCD. Further implications regarding methodological and inhibitory factors affecting cognitive information processing are highlighted.     

Deficits in set-shifting ability in nonclinical compulsive checkers

Recent studies suggest deficits in set-shifting ability in patients with obsessive-compulsive disorder (OCD) as measured by tasks such as the Wisconsin Card Sorting Test (WCST; Berg, 1948). The present study examined the extent to which these deficits were demonstrated by nonclinical subjects selected on the basis of their checking scores on the Maudsley Obsessional-Compulsive Inventory. A multivariate analysis revealed that frequent checkers performed significantly worse on the WCST than noncheckers, making more total errors and more perseverative errors and requiring more time to complete the test. A follow-up analysis on a subset of the original sample found similar performance deficits in checkers. While the poorer performance of checkers could be statistically accounted for by anxiety during the first administration of the WCST, anxiety could not explain the relationship between checking status and WCST performance at follow-up. Therefore, there does appear to be some relationship between checking status and WCST performance beyond what can be explained by affective variables.     

The role of the orbitofrontal cortex in normally developing compulsive-like behaviors and obsessive-compulsive disorder

Mounting evidence concerning obsessive-compulsive disorders points to abnormal functioning of the orbitofrontal cortices. First, patients with obsessive-compulsive disorder (OCD) perform poorly on tasks that rely on response suppression/motor inhibition functions mediated by the orbitofrontal cortex relative to both normal and clinical controls. Second, patients with OCD exhibit functional hyperactivity in lateral orbitofrontal and related structures corresponding with symptom severity. In this article, we compare these neurocognitive correlates of OCD with the executive and neural underpinnings of "compulsive-like" behaviors that are common in normal childhood. We discuss the phenomenology and natural history of normative compulsive-like behaviors as well as the behavioral, emotional, and cognitive continuities between typical and pathological obsessive-compulsive behaviors. We then examine associations between children's executive performance deficits and their observed compulsive-like characteristics. We relate these patterns to executive deficits shown by adults with OCD. Finally, we speculate on the developmental neurobiology of children's compulsive-like behaviors, with particular attention to orbitofrontal functions including behavioral and emotional regulation, and we suggest similarities and differences with the neurobiology of OCD. In making these comparisons, we hope to open a dialogue between researchers who study underlying brain pathologies associated with OCD and those who explore the neurocognitive bases of normal development.     

The role of treatment expectancy in youth receiving exposure-based CBT for obsessive compulsive disorder

The purpose of this investigation was to examine correlates of parent, child, and therapist treatment expectations and their role in the exposure-based treatment of childhood obsessive compulsive disorder (OCD). Treatment expectations were assessed among 49 youth with primary OCD, their parents, and therapists as part of the baseline evaluation and post-treatment clinical outcomes were determined by blind evaluators. Baseline depressive symptoms, child/parent-rated functional impairment, externalizing behavior problems, number of comorbid psychiatric disorders, and a lower perception of control were associated with lower pre-treatment expectations. Parent expectation was associated with parental OCD symptoms, child depressive symptoms and child-reported impairment. Therapist expectations inversely correlated with child depressive symptoms, externalizing problems, and child-rated impairment. Pre-treatment OCD severity and prior treatment history were not linked to expectancy. Finally, higher treatment expectations were linked to better treatment response, lower attrition, better homework compliance, and reduced impairment.     

Understanding Obsessive–Compulsive Disorder: Focus on Decision Making

Current approaches to obsessive-compulsive disorder (OCD) have suggested that neurobiological abnormalities play a crucial role in the etiology and course of this psychiatric illness. In particular, a fronto-subcortical circuit, including the orbitofrontal cortex, basal ganglia and thalamus appears to be involved in the expression of OCD symptoms. Neuropsychological studies have also shown that patients with OCD show deficits in cognitive abilities that are strictly linked to the functioning of the frontal lobe and its related fronto-subcortical structures, such as executive functioning deficits and insufficient cognitive-behavioral flexibility. This article focuses on decision making, an executive ability that plays a crucial role in many real-life situations, whereby individuals choose between pursuing strategies of action that involve only immediate reward and others based on long-term reward. Although the role of decision-making deficits in the evolution of OCD requires further research, the collected findings have significant implications for understanding the clinical and behavioral heterogeneity that characterizes individuals with OCD.     

Deregulated semantic cognition contributes to object‐use deficits in Alzheimer's disease: A comparison with semantic aphasia and semantic dementia

Executive control is impaired from the early stages of Alzheimer's Disease (AD) and this produces deregulated semantic cognition (Corbett, Jefferies, Burns, & Lambon Ralph, 2012 ; Perry, Watson, & Hodges, 2000 ). While control deficits should affect semantic retrieval across all modalities, previous studies have typically focused on verbal semantic tasks. Even when non‐verbal semantic tasks have been used, these have typically employed simple picture‐matching tasks, which may be influenced by abnormalities in covert naming. Therefore, in the present study, we examined 10 patients with AD on a battery of object‐use tasks, in order to advance our understanding of the origins of non‐verbal semantic deficits in this population. The AD patients’ deficits were contrasted with previously published performance on the same tasks within two additional groups of patients, displaying either semantic degradation (semantic dementia) or deregulation of semantic retrieval (semantic aphasia; Corbett, Jefferies, Ehsan, & Lambon Ralph, 2009 ). While overall accuracy was comparable to the scores in both other groups, the AD patients’ object‐use impairment most closely resembled that observed in SA; they exhibited poorer performance on comprehension tasks that placed strong demands on executive control. A similar pattern was observed in the expressive domain: the AD and SA groups were relatively good at straightforward object use compared to executively demanding, mechanical puzzles. Error types also differed: while all patients omitted essential actions, the SA and AD groups’ demonstrations also featured unrelated intrusions. An association between AD patients’ object use and their scores on standard executive measures suggested that control deficits contributed to their non‐verbal semantic deficits. Moreover, in a task specifically designed to manipulate executive demand, patients with AD (and SA) exhibited difficulty in thinking flexibly about the non‐canonical uses of everyday objects, especially when distracted by semantically related objects. This study provides converging evidence for the notion that a failure of regulatory control contributes to multimodal semantic impairment in AD and uniquely demonstrates this pattern for the highly non‐verbal domain of object use.     

Overactive action monitoring in obsessive-compulsive disorder: evidence from functional magnetic resonance imaging

The anterior cingulate cortex (ACC) in patients with obsessive-compulsive disorder (OCD) has been found to be hyperactive at rest, during symptom provocation, and after commission of errors in cognitive tasks. This hyperactivity might reflect an abnormality in conflict detection, a hypothesized basic mechanism for the action-monitoring function of the ACC. This hypothesis was tested using functional magnetic resonance imaging, by scanning 11 OCD patients and 13 matched control subjects while they performed a version of the continuous-performance task with four trial types that induced graded levels of response conflict. Although a behavioral index of conflict (i.e., accuracy) was similar for patients and control subjects, the ACC activation was increased in patients during high-conflict trials. The error-related activity in the same brain region was also higher in patients, consistent with previous electrophysiological findings. Both conflict- and error-related activity showed trends for positive correlations with severity of OCD symptoms, but not with anxiety. These findings suggest that as part of an overactive action-monitoring system, the ACC is more directly involved in the pathophysiology of OCD than previously thought.     

The Effect of Anxiety on the Cognitive Functioning in Non-clinical Schizotypal Individuals

Schizotypal personality disorder (SPD) is characterized by eccentric behavior and perceptual distortions that closely resemble the patterns observed in those with schizophrenia. Schizophrenia and related personality disorders (i.e., SPD) are associated with deficits in sustained attention, slower than normal reaction times, and manifestations of working memory deficits and erratic cognitive tasks. The present study used the schizotypal personality scale (STA) to compare cognitive abilities of self-reported low schizotypic tendency subjects with high schizotypic tendency subjects. The group scores on the STA differed significantly. Those with high STA scores also tended to have higher state and trait anxiety scores based on the State-Trait Anxiety Inventory (STAI). The groups did not significantly differ on any of the demographic variables tested, including age, education, self-rated health status, and medication. Along with an executive function test, two computerized tasks tested subjects on reaction time and memory. Even when covariates (i.e., state, trait anxiety scores) were analyzed, there were no significant differences between the groups and tasks, although the gathered data showed trends in the expected direction.     

The Effect of Anxiety on the Cognitive Functioning in Non-clinical Schizotypal Individuals

Schizotypal personality disorder (SPD) is characterized by eccentric behavior and perceptual distortions that closely resemble the patterns observed in those with schizophrenia. Schizophrenia and related personality disorders (i.e., SPD) are associated with deficits in sustained attention, slower than normal reaction times, and manifestations of working memory deficits and erratic cognitive tasks. The present study used the schizotypal personality scale (STA) to compare cognitive abilities of self-reported low schizotypic tendency subjects with high schizotypic tendency subjects. The group scores on the STA differed significantly. Those with high STA scores also tended to have higher state and trait anxiety scores based on the State-Trait Anxiety Inventory (STAI). The groups did not significantly differ on any of the demographic variables tested, including age, education, self-rated health status, and medication. Along with an executive function test, two computerized tasks tested subjects on reaction time and memory. Even when covariates (i.e., state, trait anxiety scores) were analyzed, there were no significant differences between the groups and tasks, although the gathered data showed trends in the expected direction.     

Executive and attentional contributions to Theory of Mind deficit in attention deficit/hyperactivity disorder (ADHD)

Attention deficit/hyperactivity disorder (ADHD) in children has been associated with attentional and executive problems, but also with socioemotional difficulties possibly associated with deficits in Theory of Mind (ToM). Socioemotional problems in ADHD are associated with more negative prognoses, notably interpersonal, educational problems, and an increased risk of developing other psychiatric disorders that emphasize the need to clarify the nature of their ToM deficits. In this study, we hypothesized that ToM dysfunction in children with ADHD is largely attributable to their attentional and/or executive deficits. Thirty-one children with ADHD (8–12 years, IQ > 85) and 31 typically developing (TD) children were assessed using executive functions (inhibition, planning, and flexibility) and attentional tasks, as well as two advanced ToM tasks (Reading the Mind in the Eyes and Faux Pas) involving different levels of executive control. Children with ADHD performed more poorly than TD children in attentional, executive function, and ToM tasks. Linear regression analyses conducted in the ADHD group indicated that inhibition scores predicted performance on the “Faux Pas” task the best, while attention scores were the best for predicting performance on the Reading the Mind in the Eyes task. When controlled for inhibition and attentional variables, ToM performance in children with ADHD was actually similar to TD children. Contrarily, controlling for ToM scores did not normalize performance for inhibition and attentional tasks in children with ADHD. This unidirectional relationship suggests that deficits in the EF and attentional domains are responsible for ToM deficits in ADHD, which therefore may contribute to their socioemotional difficulties.     

Adult attention-deficit/hyperactivity disorder: neuropsychological correlates and clinical presentation

We compared the neuropsychological test performance of adult ADHD patients to the neurocognitive profiles of control subjects recruited from the general population. We administered a neuropsychological test battery consisting of measures considered sensitive to either orbitofrontal or dorsolateral-prefrontal (DLPF) dysfunction. Orbitofrontal hypoarousal is associated with behavioral disinhibition and a relative indifference to punishment. The DLPF region may function as a central executive system. Indeed, DLPF dysfunction may underlie many of the cardinal symptoms associated with ADHD. We tested the following hypotheses: (1) adult subjects meeting DSM-IV criteria for ADHD, predominantly hyperactive-impulsive type, would display neuropsychological deficits on tasks sensitive to orbitofrontal dysfunction; (2) adult subjects meeting DSM-IV criteria for ADHD, predominantly inattentive type, would perform poorly on measures sensitive to DLPF dysfunction; and (3) adult subjects meeting DSM-IV criteria for ADHD, combined type, would exhibit performance deficits on orbitofrontal measures and on DLPF tasks. Results partially confirmed our hypotheses. Subtyping ADHD patients revealed important group differences. Distinct neurocognitive and clinical profiles were observed.     

Task feedback effects on conflict monitoring and executive control: relationship to subclinical measures of depression

Emerging evidence suggests that depression is associated with executive dysfunction, particularly after committing errors or receiving negative performance feedback. To test this hypothesis, 57 participants performed two executive tasks known to elicit errors (the Simon and Stroop Tasks) during positive or negative performance feedback. Participants with elevated depressive symptoms (Beck Depression Inventory scores >or= 13) were characterized by impaired posterror and postconflict performance adjustments, especially during emotionally negative task-related feedback. Additionally, for both tasks, depressive symptoms were inversely related to postconflict reaction time adjustments following negative, but not positive, feedback. These findings suggest that subclinical depression is associated with impairments in behavioral adjustments after internal (perceived failure) and external feedback about deficient task performance.