Cognitive endophenotypes in OCD: A study of unaffected siblings of probands with familial OCD

Background

Impairments in executive functions and non-verbal memory are considered potential endophenotype markers of obsessive–compulsive disorder (OCD). For the neuropsychological deficits to be considered endophenotypes, they should be demonstrable in unaffected family members.

Aim

To compare the neuropsychological performance in unaffected siblings of probands with familial OCD with that of individually matched healthy controls.

Methods

Twenty-five unaffected siblings of OCD probands with familial OCD, and 25 individually matched healthy controls were assessed with tests of attention, executive function, memory and intelligence.

Results

Unaffected siblings showed significant deficits in tests of decision making and behavioural reversal i.e., the Iowa Gambling Task (IGT) and the Delayed Alternation Test (DAT) respectively, but performed adequately in other tests.

Conclusions

Our study suggests that the deficits in decision making and behavioural reversal could be potential endophenotypes in OCD. These deficits are consistent with the proposed neurobiological model of OCD involving the orbitofrontal cortex. Future studies could couple cognitive and imaging strategies to identify neurocognitive endophenotypes in homogenous samples of OCD.     

Autobiographical memory and its association with neuropsychological function in bipolar disorder

Objective

The aim of this study was to investigate the overgeneralization of autobiographical memory (AM) in bipolar disorder (BD) and assess its association with multiple cognitive domains.

Method

Twenty-eight clinically stable bipolar I patients and an equal number of age- and gender-matched healthy controls (HC) were included. All participants were examined using the autobiographical memory test (AMT) and the neuropsychological battery including the general intelligence, attention, verbal memory, verbal fluency, visual memory, and executive functions domain. Demographic, clinical, and test variables were compared between BD and HC groups. Correlation analyses of AMT scores with cognitive functions were performed within each group, controlling for demographic and clinical variables.

Results

Total and negative scores of AMT were significantly lower in BD patients compared to HC individuals. AMT scores were significantly correlated with WAIS similarities, WCST perseverative errors, and WCST categories completed in BD, whereas AMT scores were correlated with verbal memory and verbal fluency in HC.

Conclusion

Our findings suggest that overgeneral AM is a characteristic of BD and is related to executive function. Future studies should investigate the benefit of additional treatment focusing on overgeneral AM in BD.     

Cognitive functions and serum levels of brain-derived neurotrophic factor in patients with major depressive disorder

Objective

We assessed major cognitive domains in major depressive disorder (MDD) compared to a healthy control group using neurocognitive tests. We hypothesized that lower serum brain-derived neurotrophic factor (BDNF) levels would be associated with poorer neurocognitive performance in patients with major depression and that these associations would be shown in healthy controls as well.

Method

Executive functions, sustaining and focusing of attention, memory functions, and verbal fluency were assessed in this study using the Trail-Making Test (TMT), Stroop Color Word Interference Test-TBAG Form (SCWT), Wisconsin Card Sorting Test (WCST), Test of Variables of Attention (TOVA), Auditory Consonant Trigram test (ACTT), Digit Span subtest of the Wechsler Memory Scale (DST), Rey Auditory Verbal Learning Test (RAVLT), and Controlled Oral Word Association Test (COWAT).

Results

The MDD group showed significantly poorer performance than the control group in cognitive functions; they also had lower levels of BDNF than the control group. However, there was no correlation between cognitive performances and BDNF levels except in the TMT, Part B.

Conclusions

The current understanding of the importance of neurocognitive assessment and related biological markers in depression is improving. Further studies with larger sample sizes evaluating neurocognitive functions with molecular analyses of BDNF levels may reveal a novel marker for predicting and monitoring neurocognitive deficits in depression.     

Underlying mechanisms of verbal memory deficits in obsessive-compulsive disorder and major depression--the role of cognitive self-consciousness

Background and Objectives

Previous studies have demonstrated that some individuals suffering from obsessive-compulsive disorder (OCD) are impaired in verbal memory performance. This study was designed to investigate the role of cognitive self-consciousness (CSC) as a putative underlying mechanism of these cognitive deficits.

Methods

Verbal memory performance of 36 participants with OCD, 36 individuals with major depression disorder (MDD) and 36 healthy controls was assessed with the California Verbal Learning Test under three different experimental conditions: (1) single-task condition, (2) while simultaneously focusing on their thoughts (CSC condition), (3) while simultaneously focusing on external stimuli (dual-task condition).

Results

Memory performance in the CSC condition and in the dual-task condition was reduced compared to single-task condition but no interaction effect was found.

Limitations

It remains unclear whether CSC and other concepts with an inward self-referential focus of attention (e.g. rumination) differ in the way they influence cognitive performance.

Conclusions

These results confirm the deteriorating influence of heightened CSC on verbal memory encoding but suggest that the effect is not specific to OCD.     

Cognition and communication dysfunctions in early-onset schizophrenia: Effect of risperidone

Background

Cognitive impairment and formal thought disorder, also referred to as communication disturbances, are considered the core symptoms of schizophrenia, strongly affecting social functioning and long-term outcome. Several studies in adult patients suggest improvement of both functions after the treatment with atypical antipsychotic drugs. Such medications are also used as first line treatment in early-onset schizophrenia, however their efficacy in cognitive and communication domains in this population have not been systematically assessed.

Aim of the study

Evaluation of risperidone efficacy at psychopathological symptoms, cognitive impairment and formal thought disorder in adolescents with schizophrenia spectrum diagnosis.

Material and method

Psychopathological symptoms, cognitive functioning and formal thought disorder were evaluated in 32 hospitalized adolescent patients with schizophrenia spectrum diagnosis at the beginning of risperidone treatment and after clinical improvement and compared to the results of matched healthy control group.

Results

Risperidone treatment was associated with reduction of symptom severity and moderate improvement of formal thought disorder and some aspects of executive functions. Working memory and verbal fluency were not improved. There were few correlations between psychopathological symptoms and results of cognitive tests, mainly between negative symptoms and executive functions.

Discussion

In early-onset schizophrenia spectrum disorders atypical antipsychotic treatment is associated with alleviation of symptoms and only selective and moderate cognitive and communication improvement.     

Cognitive deficits in patients with chronic fatigue syndrome compared to those with major depressive disorder and healthy controls

Object

Chronic fatigue syndrome (CFS) patients report usually cognitive complaints. They also have frequently comorbid depression that can be considered a possible explanation for their cognitive dysfunction. We evaluated the cognitive performance of patients with CFS in comparison with a control group of healthy volunteers and a group of patients with MDD.

Patients and methods

Twenty-five patients with CFS, 25 patients with major depressive disorder (MDD), and 25 healthy control subjects were given standardized tests of attention, working memory, and verbal and visual episodic memory, and were also tested for effects related to lack of effort/simulation, suggestibility, and fatigue.

Results

Patients with CFS had slower phasic alertness, and also had impaired working, visual and verbal episodic memory compared to controls. They were, however, no more sensitive than the other groups to suggestibility or to fatigue induced during the cognitive session. Cognitive impairments in MDD patients were strongly associated with depression and subjective fatigue; in patients with CFS, there was a weaker correlation between cognition and depression (and no correlation with fatigue).

Conclusions

This study confirms the presence of an objective impairment in attention and memory in patients with CFS but with good mobilization of effort and without exaggerated suggestibility.     

Neuropsychological study of patients with obsessive-compulsive disorder and their parents in China: searching for potential endophenotypes

Objective The existence of neuropsychological deficits has been implicated in obsessive-compulsive disorder (OCD), particularly memory, attention, and executive functions. However, few studies have focused on neuropsychological deficits in the relatives of OCD patients. The aim of this study was to investigate cognitive deficits in OCD patients and their parents. Methods Forty patients with OCD, 48 parents of these patients, and 87 healthy controls completed a neuropsychological testing battery. Results Both OCD patients and their parents showed impairments in delayed verbal memory and delayed visual memory. Furthermore, they performed worse than healthy controls in problem-solving ability. Conclusion Our study demonstrated familial aggregation of delayed memory deficits and impaired problem-solving ability, which may be the potential neuropsychological endophenotypes of hereditary susceptibility to OCD.     

Reduced contribution of executive functions in impaired working memory performance in mild traumatic brain injury patients

Aim

Mild traumatic brain injury (MTBI) is associated with often selective impairment of both working memory (WM) and the executive functions (EFs). Research indicates that one of the commonest deficits present in MTBI patients falls in the domain of WM. We aimed to investigate the role of EFs in WM impairment following MTBI.

Methods

Performance on the tests of EFs and the verbal and visuo-spatial WM of 30 consecutive MTBI patients were compared with age/education/IQ matched 30 normal healthy control participants. Correlation between EFs and WM was studied separately for the MTBI and the control group.

Results

The MTBI and control group were tested on a range of EF tests and WM. The MTBI group was demonstrated impairment on verbal and visuo-spatial WM and category fluency tests only. Furthermore, the MTBI group had fewer significant correlations between the WM and EFs (5 out of 54 possible correlations) than in the control group (13 out of 54 possible correlations).

Conclusions

We suggest that MTBI may lead to WM deficits as the contribution of executive processes to support the WM is diminished following MTBI. Such an understanding of the poor WM performance in MTBI patients will be helpful when planning appropriate strategies for cognitive rehabilitation.     

Comparative Analysis of Cognitive Function in Schizophrenia with and without Obsessive Compulsive Disorder

Objective

We investigated the neurocognitive deficits in schizophrenic patients with and without obsessive-compulsive disorder (OCD).

Methods

We grouped 27 patients as either obsessive-compulsive or non-obsessive-compulsive based on the presence of OCD. The two groups completed the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS), Positive and Negative Symptom Scale (PANSS), and Hamilton Depression Scale. The intelligence quotient (IQ) was tested using the Korean Wechsler Adult Intelligence Scale. The memory quotient (MQ) was tested using the Korean-Auditory Verbal Learning and Korean-Complex Figure Test. The executive intelligence quotient (EIQ) was determined using the Kims executive intelligence test (EXIT).

Results

Ten of the 27 patients had OCD. The compulsion score of Y-BOCS was positively correlated with positive symptoms, negative symptoms, and the total scores of PANSS. The OCD-schizophrenia patients had higher IQs. No difference was found in MQ. Although the EIQ did not differ between the two groups, the OCD-schizophrenia patients performed better at the Stroop-interference and verbal fluency tests, which was highly dependent on executive function.

Conclusion

Our findings suggest that OCD may have a protective effect on some cognitive function, at least in relatively early stage of illness. Moreover, based on clinical, neurocognitive features, schizophrenia with OCD could be considered as a distinct subtype of schizophrenia.     

Evaluación de la función ejecutiva en una población escolar con síntomas de déficit de atención e hiperactividad

Objective

To identify impairment of executive functions (EF) in children with attention deficit hyperactivity disorder (ADHD).

Subjects and methods

A case-control study was performed on a sample of schoolchildren with low socioeconomic levels in Bogota, Colombia. ADHD was diagnosed using the DSM IV checklist and the Behavior Assessment System for Children scale. Children with cognitive deficits were excluded. We evaluated scores from six measurements of executive function (EF). We conducted a bivariate statistical analysis to compare the variables, a multivariate study controlled by sex and age, and a logistic regression analysis.

Results

The study sample included 119 children with ADHD and 85 controls, all aged between 6 and 12 years. Controlling by sex, age, and type of school showed that EF measurements in children with ADHD were significantly more impaired than in controls, especially for measurements of verbal and graphic fluency, Rey-Osterrieth Complex Figure, and cognitive flexibility. Comparison of ADHD subgroups showed that results in children with multiple deficits were similar to those in the global ADHD group. Graphic fluency impairment was the sole impairment in cases with only attention deficit or only hyperactivity-impulsivity manifestations.

Conclusions

EF measures in children with ADHD revealed more problems, particularly those having to do within planning, inhibition, working memory and cognitive control. Age and sex may affect the degree of EF impairment.     

Semantic strategy training increases memory performance and brain activity in patients with prefrontal cortex lesions

Objective

Memory deficit is a frequent cognitive disorder following acquired prefrontal cortex lesions. In the present study, we investigated the brain correlates of a short semantic strategy training and memory performance of patients with distinct prefrontal cortex lesions using fMRI and cognitive tests.

Methods

Twenty-one adult patients with post-acute prefrontal cortex (PFC) lesions, twelve with left dorsolateral PFC (LPFC) and nine with bilateral orbitofrontal cortex (BOFC) were assessed before and after a short cognitive semantic training using a verbal memory encoding paradigm during scanning and neuropsychological tests outside the scanner.

Results

After the semantic strategy training both groups of patients showed significant behavioral improvement in verbal memory recall and use of semantic strategies. In the LPFC group, greater activity in left inferior and medial frontal gyrus, precentral gyrus and insula was found after training. For the BOFC group, a greater activation was found in the left parietal cortex, right cingulated and precuneus after training.

Conclusion

The activation of these specific areas in the memory and executive networks following cognitive training was associated to compensatory brain mechanisms and application of the semantic strategy.     

Working memory and attention deficits in adolescent offspring of schizophrenia or bipolar patients: comparing vulnerability markers

Background

Working memory deficits abound in schizophrenia and attention deficits have been documented in schizophrenia and bipolar disorder. Adolescent offspring of patients may inherit vulnerabilities in brain circuits that subserve these cognitive domains. Here we assess impairments in offspring of schizophrenia (SCZ-Offspring) or bipolar (BP-Offspring) patients compared to controls (HC) with no family history of mood or psychotic disorders to the second degree.

Methods

Three groups (n = 100 subjects; range: 10-20 yrs) of HC, SCZ-Offspring and BP-Offspring gave informed consent. Working memory was assessed using a delayed spatial memory paradigm with two levels of delay (2 s & 12 s); sustained attention processing was assessed using the Continuous Performance Task—Identical Pairs version.

Results

SCZ-Offspring (but not BP-Offspring) showed impairments in working memory (relative to HC) at the longer memory delay indicating a unique deficit. Both groups showed reduced sensitivity during attention but only BP-Offspring significantly differed from controls.

Conclusions

These results suggest unique (working memory/dorsal frontal cortex) and potentially overlapping (attention/fronto-striatal cortex) vulnerability pathways in adolescent offspring of patients with schizophrenia and bipolar disorder. Working memory and attention assessments in these offspring may assist in the clinical characterization of the adolescents vulnerable to SCZ or BP.     

Deterioro cognitivo y tratamiento antirretroviral en pacientes con virus de la inmunodeficiencia humana en una población peruana

Background

HIV-associated cognitive impairment occurs even in the early stages of infection. Short-term memory, psychomotor speed, attention, and executive functioning are the main capacities affected. Controversy exists regarding whether highly active antiretroviral therapy (HAART) is helpful in combating this process. The objective of the present study is to determine the association between cognitive impairment and HAART in HIV-infected patients from Hospital Regional de Huacho.

Methods

Prospective study of HIV patients meeting criteria to start HAART. Twenty-one HIV-positive patients were recruited between April and July 2011. Researchers administered a standardised neuropsychological test battery before and 4 weeks after onset of HAART. Psychomotor speed, executive function, short term memory (visual and verbal), attention, and visuospatial performance were evaluated.

Results

Nineteen patients completed the study (14 males and 5 females). In the pre-HAART evaluation, most patients scored below average on the executive function and psychomotor speed subtests. Psychomotor speed and immediate visual memory improved significantly after four months of treatment with HAART.

Conclusions

Some degree of cognitive decline may present even in the early and asymptomatic stages of HIV infection. The benefits of antiretroviral treatment for cognitive performance can be detected after only a few weeks of follow-up.     

Impact of peripheral levels of chemokines,BDNF and oxidative markers on cognition in individuals with schizophrenia

Objective

To investigate possible differences in peripheral levels of chemokines, BDNF and oxidative markers between patients with Schizophrenia (SZ) and matched healthy controls, and investigate the correlation of these biomarkers with cognitive performance.

Methods

Thirty individuals with SZ and 27 healthy controls were included and the following plasmatic biomarkers' levels were determined according to manufacturers' instructions: BDNF, TBARS, protein carbonyl content (PCC) and the chemokines CXCL-10/IP-10, CXCL-8/IL-8, CCL-11, CCL-24/Eotaxin-2, CCL-2/MCP-1, CCL-3/MIP-1. Selected neuropsychological tasks were administered to assess verbal learning (Hopkins Verbal Learning Test), verbal fluency (FAS test), working memory (Visual Working Memory Task, Keep Track Task, Letter Memory Task), set shifting (Plus–minus task, Number–letter task), inhibition (Computerized Stroop Task, Semantic Generation Task) and complex executive function tasks (Tower of London and the shortened version of the WCST-64).

Results

Compared with the healthy control group, individuals with SZ presented significantly higher levels of BDNF and the chemokine CCL-11, and lower levels of TBARS and the chemokine CXCL-10/IP-10. When we examined only the SZ group, BDNF levels were positively correlated with semantic generation tasks. Working memory ability was negatively correlated with PCC. Regarding chemokines, CCL-11 was negatively correlated to performance in working memory test, and positively correlated with cognitive flexibility task. CXCL-8/IL-8 was positively correlated with verbal fluency. CCL-24/Eotaxin-2 was positively correlated with semantic generation ability and letter memory task.

Conclusions

Our results indicate that cognitive performance in SZ is associated with mediators of neuroplasticity that can be measured peripherally.     

Cognitive impairment and optic nerve axonal loss in patients with clinically isolated syndrome

Objective

To investigate cognitive impairment, to assess optical nerve axonal loss, and to determinate whether there is correlation between optical nerve axonal loss and cognition impairment in Clinically Isolated Syndrome (CIS).

Methods

Fifteen CIS patients and 15 controls were submitted to Wechsler memory scale, Rey Auditory Verbal Learning, Rey Complex Figure, Paced Auditory Serial Addition, Digit Span, verbal fluency, stroop color, D2, and Digit Symbol tests. CIS patients were evaluated by optical coherence tomography (OCT) (23 eyes).

Results

CIS patients had worse performance in Paced Auditory Serial Addition Test (PASAT) 2 seconds (P = 0.009) and fluency tests (P = 0.0038). Optical nerve axonal loss was found more frequently in eyes with previous optic neuritis (ON) (85.7%) than in those without previous ON (21.7%) (P = 0.0146). There were no significant correlations between optical nerve axonal loss and cognitive findings.

Conclusions

CIS patients had worse cognitive performance than controls. OCT can detect axonal loss resulting from optical neuritis and subclinical axonal loss in eyes without previous optical neuritis. Optical nerve axonal loss was not correlated with cognition.     

Involuntary social cue integration in patients with obsessive compulsive disorder

Objective

Patients with obsessive compulsive disorder (OCD) have inferior social functioning compared to healthy controls, but the exact nature of these social deficits, and the underpinning mechanisms, are unknown. We sought to investigate social functioning in patients with OCD by measuring their involuntary/spontaneous processing of social cues using a specifically designed test, which might reveal deficits in these patients that explicit voluntary tasks do not detect.

Methods

The sample of the study consisted of an OCD group (n = 25) and a control group (n = 26). Both groups performed an adaptation of the Social Distance Judgment Task (SDJT; Jellema et al., 2009), in which participants have to judge the geometrical distance between two human cartoon figures presented on a computer screen. Head/gaze direction and body direction were manipulated to be either compatible, i.e. both directed to the left or to the right (Compatible condition) or incompatible, i.e. body directed toward the observer (frontal view) and head/gaze directed to the left or right (Incompatible condition).

Results

In the Compatible condition, controls nor OCD patients were influenced by the social cues in their judgments of the geometrical distances. However, in the Incompatible condition, where the attentional cue was more conspicuous, both groups were influenced by the cues, but the controls to a significantly larger extent than the OCD patients.

Conclusions

This study showed that patients with OCD are less likely, compared to controls, to automatically/spontaneously integrate the other’s direction of attention into their visual percept. This may have resulted in their judgments of the geometrical distances between the agents to be more accurate than those of controls. The suggested impairment in automatically integrating social cues may have important repercussions for the social functioning of OCD patients.     

Effects of tapering of long-term benzodiazepines on cognitive function in patients with schizophrenia receiving a second-generation antipsychotic

Background

The high use of long-term benzodiazepines (BZDs) with second-generation antipsychotics (SGAs) has been identified as an important issue in the treatment of schizophrenia in Japan. The aim of this study was to evaluate the effects of gradual reduction or discontinuation of daytime BZD use on cognitive function and quality of life (QOL) in patients with chronic schizophrenia receiving an SGA.

Methods

Thirty schizophrenic patients who had received an SGA with concomitant BZDs for at least 3 months were enrolled. Before and 4 weeks after tapering of daytime BZDs, the Brief Assessment of Cognition in Schizophrenia Japanese-language version (BACS-J) and the Schizophrenia Quality of Life Scale Japanese-language version (SQLS-J) were administered. Clinical evaluation also included the Positive and Negative Syndrome Scale (PANSS). To compare for practice effects on the BACS-J, 10 patients with chronic schizophrenia were assessed without tapering BZDs.

Results

BZDs were reduced or discontinued safely in most patients, and no emergent withdrawal symptoms were observed. Significant improvements were shown in verbal memory, working memory, and composite score, as measured by the BACS-J without practice effects. In addition, the motivation/energy score on the SQLS-J, the negative symptoms and total scores on the PANSS significantly improved after tapering BZDs.

Conclusion

Reduction or discontinuation of long-term daytime use of BZDs may be warranted in patients with schizophrenia treated with SGAs, as it may improve cognitive function, subjective QOL, and psychiatric symptoms with no significant adverse effects.     

Serum brain-derived neurotrophic factor in patients with trauma psychopathology

Objective

Brain-derived neurotrophic factor (BDNF) has an important role in learning, motivation and regulation of mood. The aim of this study was to investigate levels of serum BDNF in patients with trauma psychopathology (acute and post-traumatic stress disorder) when compared to age and gender matched controls.

Method

A consecutive sample of 34 patients was evaluated regarding socio-demographic and clinical variables by means of a standard protocol, Davidson Trauma Scale, Beck Depression Inventory, Clinical Global Impression and the Global Assessment of Functioning. BDNF serum levels were measured right after the intake interview.

Results

Patients had higher BDNF levels than controls. Those levels, however, were higher right after the traumatic event, decreasing over time. When two groups of patients (recent and remote trauma) were investigated in separate, the recent trauma group (less than 1 year since the traumatic event) had higher BDNF than controls, but this effect was not detected in the remote trauma group. The recent and remote trauma groups had different BDNF levels. Those findings persisted, even controlling for symptom severity, use of psychotropic medication, and history of psychiatric disease.

Conclusions

As far as we know this is the first report of elevated serum BDNF levels in patients with recent trauma. Based in animal models that implicate BDNF in memory formation and consolidation, higher BDNF in recent PTSD could be related to memory and learning disruption central in PTSD psychopathology.     

Cognitive dysfunctions in patients with obsessive-compulsive disorder compared to the patients with schizophrenia patients: relation to overvalued ideas

OBJECTIVE: The clinical overlaps between schizophrenia and obsessive-compulsive disorder (OCD) seem to be related to thought disorders involving obsessions, overvalued ideas, and delusions. Overvalued ideas are beliefs falling in between obsessions and delusions and are stronger than obsessions but weaker than delusions. The goal of the present study was to compare patients with OCD to those with schizophrenia in terms of cognitive functions and to relate cognition and overvalued ideas in OCD. METHODS: Twenty three patients with OCD (free of depression), 24 patients with schizophrenia, and 22 healthy subjects matched to patients in age, gender, education, and hand dominance were included in the study. All subjects were administered neurocognitive tests assessing verbal learning-memory, executive functions, verbal fluency, attention and verbal working memory. RESULTS: Patients with schizophrenia showed worse performance on cognitive tests than the OCD and control groups. The severity of overvalued ideas was significantly correlated to cognitive functions in the OCD group. There were no significant differences in cognitive functions between schizophrenia group and the OCD patients who had higher scores on the Overvalued Ideas Scale (OVIS). CONCLUSION: Overvalued ideas in OCD may be related to cognitive dysfunctions in OCD and this subtype of OCD may have similar characteristics to schizophrenia in terms of cognition.     

Neuropsychological predictors of response to randomized treatment in obsessive–compulsive disorder

Objective

To identify neuropsychological predictors of treatment response to cognitive–behavioral therapy (CBT) and fluoxetine in treatment-naïve adults with obsessive–compulsive disorder (OCD).

Method

Thirty-eight adult outpatients with OCD underwent neuropsychological assessment, including tasks of intellectual function, executive functioning and visual and verbal memory, before randomization to a 12-week clinical trial of either CBT or fluoxetine. Neuropsychological measures were used to identify predictors of treatment response in OCD.

Results

Neuropsychological measures that predicted a better treatment response to either CBT or fluoxetine were higher verbal IQ (Wechsler Abbreviated Scale of Intelligence) (p = 0.008); higher verbal memory on the California Verbal Learning Test (p = 0.710); shorter time to complete part D (Dots) (p < 0.001), longer time to complete part W (Words) (p = 0.025) and less errors on part C (Colors) (p < 0.001) in the Victoria Stroop Test (VST). Fewer perseverations on the California Verbal Learning Test, a measure of mental flexibility, predicted better response to CBT, but worse response to fluoxetine (p = 0.002).

Conclusion

In general, OCD patients with better cognitive and executive abilities at baseline were more prone to respond to either CBT or fluoxetine. Our finding that neuropsychological measures of mental flexibility predicted response to treatment in opposite directions for CBT and fluoxetine suggests that OCD patients with different neuropsychological profiles may respond preferentially to one type of treatment versus the other. Further studies with larger samples of OCD patients are necessary to investigate the heuristic value of such findings in a clinical context.