Preservation of memory for people in semantic memory disorder: Further category-specific semantic dissociation

ML, a 70-year-old right-handed woman, presented with a history of semantic memory difficulties and a profound anomia affecting both proper nouns and common nouns following a left-hemisphere CVA some years earlier. She was found to show a striking contrast between her ability to make fine-grained semantic distinctions between objects and animals, on the one hand, and famous faces and names, on the other. Although she was impaired on a series of picture and word semantic comprehension tests when the stimuli consisted of exemplars of object and animal categories, her performance was intact when the materials comprised famous faces and names, suggesting a dissociation between the representation of person-specific knowledge and other categories of semantic information. A number of cases have been reported in which person-specific knowledge has been selectively impaired, but we would suggest that our case provides the clearest evidence so far of the reverse dissociation, in which person-specific knowledge is selectively preserved. We speculate on possible differences in the ways in which person-specific knowledge may be represented, relative to information about objects and animals.     

Verbal and nonverbal memory processing in patients with obsessive-compulsive disorder: its relationship to clinical variables

Memory deficits have been reported in several neuropsychological studies of obsessive-compulsive disorder (OCD). Dysfunction in nonverbal memory has been consistently reported, whereas findings on verbal memory are more heterogeneous. The authors studied 50 patients with OCD who were matched for sex, age, educational level, and hand dominance with 50 healthy controls (HC). Cognitive performance in both groups was assessed on verbal and nonverbal memory tasks, and several clinical variables were also assessed in the patient group. Patients with OCD showed a pattern of cognitive dysfunction with alterations in areas of nonverbal memory (recall and recognition), and verbal memory (learning and recall). Older age at onset of OCD was associated with poorer performance on verbal memory tasks. Low scores on some verbal memory tasks were associated with severity of OCD, and nonverbal memory was influenced by depressive symptoms. The study suggests the existence of dysfunction in the execution of verbal and nonverbal memory tasks in OCD; the influence of clinical variables depends on the specific neuropsychological function.     

Relationship between obsessive-compulsive disorder and chaos

Pharmacological treatment using serotonin reuptake inhibitors is often useful for patients with obsessive-compulsive disorder (OCD). Brain imaging studies indicated that hyperactivity of the striatum observed in OCD patients is normalized after successful pharmacological treatment. But, so far, there is no available model, which can explain both of these phenomena. This report proposes a hypothesis that serotonin reuptake inhibitors can induce chaos in the activity of striatal neurons and this chaotic behavior is essential to improve OCD symptoms and normalize the hyperactivity in the striatum. Moreover, it can be explained also by this model that there exists a subtype of patients for whom pharmacological treatment is not useful. As a method, simulation using the Hodgkin-Huxley equations and the chaotic neural network, which can reproduce the chaotic behavior in the real neuron, are used.     

Deficits of organizational strategy and visual memory in obsessive-compulsive disorder

This study was conducted to investigate the deficits of organizational strategy and visual memory in obsessive-compulsive disorder (OCD). Thirty OCD patients and 30 healthy controls aged 20-35 years participated. The Maudsley Obsessive-Compulsive Inventory, Beck Anxiety Inventory, Wechsler Adult Intelligence Scale, and Rey-Osterrieth Complex Figure (ROCF) test were administered to participants. The authors scored ROCF performances using the Boston Qualitative Scoring System. The OCD patients showed poorer planning ability and higher fragmentation than did healthy controls when copying the ROCF, and they showed even poorer performances in the immediate and delayed recall conditions. The authors found that the Organization score in the copy condition mediated the difference between the OCD group and the healthy group in immediate recall. The direct effect of diagnosis (OCD or healthy) on the immediate recall condition of the ROCF was also significant. This study indicates that people with OCD have poor memory function and organizational deficits.     

Alpha amplitude and phase locking in obsessive-compulsive disorder during working memory

Alpha event-related desynchronization (ERD) and synchronization are known to reflect brain activation and inhibition, respectively. Alpha phase locking seems to reflect the timing in the cortical process. In a previous study, lower alpha ERD was related to working memory in obsessive-compulsive disorder (OCD) patients than in controls during the retention and retrival phases, but not in the encoding phase. However, memory deficits in OCD patients are known to be related to executive failure during the encoding phase. Thus, focusing on the encoding phase, we tested the level of alpha amplitude and phase locking in OCD patients according to memory load. The EEGs of fifteen OCD patients and fifteen controls were recorded during a Sternberg working memory task. The behavioral performance of the OCD patients was normal. However, the OCD group yielded significantly lower ERD and stronger phase locking. As memory load rose, ERD and phase locking significantly increased in both groups. A difference in event-related alpha oscillation was observed in the encoding phase. Lower alpha modulation in the OCD patient simplied abnormality of the excitatory/inhibitory process in the brain, and increased phase locking might reflect excessive attentional excitability.     

The neural organization of semantic memory: Electrophysiological activity suggests feature-based segregation

Despite decades of research, it remains controversial whether semantic knowledge is anatomically segregated in the human brain. To address this question, we recorded event-related potentials (ERPs) while participants viewed pictures of animals and tools. Within the 200-600-ms epoch after stimulus presentation, animals (relative to tools) elicited an increased anterior negativity that, based on previous ERP studies, we interpret as associated with semantic processing of visual object attributes. In contrast, tools (relative to animals) evoked an enhanced posterior left-lateralized negativity that, according to prior research, might reflect accessing knowledge of characteristic motion and/or more general functional properties of objects. These results support the hypothesis of the neuroanatomical knowledge organization at the level of object features: the observed neurophysiological activity was modulated by the features that were most salient for object recognition. The high temporal resolution of ERPs allowed us to demonstrate that differences in processing animals and tools occurred specifically within the time-window encompassing semantic analysis.     

The relationship between obsessive-compulsive disorder and anxiety and affective disorders: results from the Johns Hopkins OCD Family Study

OBJECTIVE: This study investigates the relationship of specific anxiety and affective disorders to obsessive-compulsive disorder (OCD) in a blind, controlled family study. METHOD: Eighty case and 73 control probands, as well as 343 case and 300 control first-degree relatives of these probands, participated in the study. Subjects were examined by psychologists or psychiatrists using the Schedule for Affective Disorder and Schizophrenia-Lifetime Anxiety version (SADS-LA). Two experienced psychiatrists independently reviewed all clinical materials, and final diagnoses were made according to DSM-IV criteria, by consensus procedure. RESULTS: Except for bipolar disorder, all anxiety and affective disorders investigated were more frequent in case than control probands. Substance dependence disorders were not more frequent. Generalized anxiety disorder (GAD), panic disorder, agoraphobia, separation anxiety disorder (SAD) and recurrent major depression were more common in case than control relatives. These disorders occurred more frequently if the relative was diagnosed with OCD. Only GAD and agoraphobia were more frequent in case relatives independent of OCD. CONCLUSION: GAD and agoraphobia share a common familial aetiology with OCD. The other anxiety and affective disorders, when comorbid with OCD, may emerge as a consequence of the OCD or as a more complex syndrome.     

Gender in obsessive-compulsive disorder and obsessive-compulsive spectrum disorders

Summary Background: There is increasing recognition that obsessive-compulsive disorder (OCD) and putative OCD spectrum disorders (OCSDs) are not homogenous entities. Gender may provide an important window onto the heterogeneity of these various disorders. Methods: A MEDLINE review of gender issues in OCD and putative OCD spectrum disorders (excluding eating disorders) was undertaken (1965–2000). These included demographic variables, clinical phenomenology, etiological factors, and treatment implications. Results: OCD differs from other anxiety disorders in having an approximately equal male:female gender ratio. OCSDs (e.g. body dysmorphic disorder) may have an equal gender ratio, may be more common in women (e.g. trichotillomania, hypochondriasis) or may be more common in men (e.g. Tourette's disorder). Etiological factors may differ across gender; an association between perinatal or early brain injury and OCD or Tourette's appears particularly important in males, while OCD and trichotillomania may also begin during pregnancy or shortly after childbirth with exacerbation of symptoms during menstruation. It is not clear that anti-androgens are effective in OCD, nor that gender predicts response to serotonin reuptake inhibitors in this disorder. Conclusion: There is a relative scarcity of literature addressing gender issues in OCD and putative OCSDs. That literature which does exist is not entirely conclusive, but raises a number of interesting questions for future research.     

Impact of comorbid depressive symptoms on nonverbal memory and visuospatial performance in obsessive-compulsive disorder

Introduction. Recent research has suggested that some executive dysfunctions in obsessive-compulsive disorder (OCD) represent an epiphenomenon of comorbid depressive symptoms. The present study investigated whether the impact of comorbid depressive symptoms on cognitive dysfunction in OCD extends to nonverbal memory impairment. Methods. A total of 32 OCD patients and 20 healthy controls took part in the study. Participants were administered a neurocognitive battery with a focus on nonverbal memory and visuospatial functions. Results. While evidence was provided that neurocognitive processes necessitating visuospatial transformation and visuoconstruction are deficient in OCD patients regardless of comorbid depressive symptoms, nonverbal memory dysfunctions were only apparent for patients with elevated scores in the Hamilton Depression (HDRS) Rating Scale (total score S 8). Correlations with subscores of the HDRS revealed that core depressive symptoms are related to nonverbal memory deficits in OCD. Mental rotation, middle discrimination, and position discrimination were found to be unaffected in OCD. Y-BOCS scores, length of illness, onset of illness, number of hospital admissions, and checking compulsions were not associated with neurocognitive disturbances. Conclusions. Nonverbal memory is disturbed in only a subgroup of OCD patients displaying elevated HDRS scores (HDRS S 8). It is claimed but awaits further empirical testing that differences in depression profile across OCD studies have contributed to inconsistencies in prior investigations on neurocognitive functioning in OCD. Our results are questioning the hypothesis that nonverbal deficits are a causal factor for the development of checking compulsions.     

Association between symptom severity and internal capsule volume in obsessive-compulsive disorder

Neurobiological models support an involvement of white matter tracts in the pathophysiology of obsessive-compulsive disorder (OCD), but there has been little systematic evaluation of white matter volumes in OCD using magnetic resonance imaging (MRI). We investigated potential differences in the volume of the cingulum bundle (CB) and anterior limb of internal capsule (ALIC) in OCD patients (n = 19) relative to asymptomatic control subjects (n = 15). White matter volumes were assessed using a 1.5T MRI scanner. Between-group comparisons were carried out after spatial normalization and image segmentation using optimized voxel-based morphometry. Correlations between regional white matter volumes in OCD subjects and symptom severity ratings were also investigated. We found significant global white matter reductions in OCD patients compared to control subjects. The voxel-based search for regional abnormalities (with covariance for total white matter volumes) showed no specific white matter volume deficits in brain portions predicted a priori to be affected in OCD (CB and ALIC). However, large clusters of significant positive correlation with OCD severity scores were found bilaterally on the ALIC. These findings provide evidence of OCD-related ALIC abnormalities and suggest a connectivity dysfunction within frontal-striatal-thalamic-cortical circuits. Further studies are warranted to better define the role of such white matter alterations in the pathophysiology of OCD, and may provide clues for a more effectively targeting of neurosurgical treatments for OCD.     

Thought disorder in patients with obsessive-compulsive disorder

We examined the presence of disordered thinking/perception in patients with obsessive-compulsive disorder (OCD). Recently, an obsession model has been proposed, which classifies obsessions into two different subtypes: autogenous obsessions and reactive obsessions (Lee & Kwon, 2003). Based on this model, we hypothesized that OCD patients primarily displaying autogenous obsessions as opposed to reactive obsessions would display more severely disordered thinking/perception. We compared 15 OCD patients primarily displaying autogenous obsessions (AOs), 14 OCD patients primarily displaying reactive obsessions (ROs), 32 patients with schizophrenia (SPRs), and 28 patients with other anxiety disorders (OADs) with respect to thought disorders as assessed by the Comprehensive System of the Rorschach Inkblot Test. Results indicated that both AOs and SPRs displayed more severe thought disorders compared to ROs or OADs. Theoretical and clinical implications are discussed.     

Depression in comorbid obsessive-compulsive disorder and posttraumatic stress disorder

Previous findings suggested a unique role that depression symptoms might play in the comorbid relationship between obsessive-compulsive disorder (OCD) and posttraumatic stress disorder (PTSD). However, the nature of this role remains unclear. Thus, the current study examined ways in which OCD and PTSD symptoms vary as a function of depression, as well as the mediating role of depression in the OCD-PTSD relationship, in 104 individuals seeking treatment for refractory OCD. Findings revealed that depressed individuals in the treatment-refractory OCD sample report higher levels of overall obsessing and greater severity of PTSD. In addition, depression appeared to mediate the relation between OCD and PTSD. Implications of findings are discussed.     

The relationship between acute stress disorder and posttraumatic stress disorder following cancer

In this study, the authors investigated the relationship between acute stress disorder (ASD) and posttraumatic stress disorder (PTSD) following cancer diagnosis. Patients who were recently diagnosed with 1st onset head and neck or lung malignancy (N=82) were assessed for ASD within the initial month following their diagnosis and reassessed (n=63) for PTSD 6 months following their cancer diagnosis. At the initial assessment, 28% of patients had ASD, and 32% displayed subsyndromal ASD. At follow-up, PTSD was diagnosed in 53% of patients who had been diagnosed with ASD and in 11% of those who had not met criteria for ASD; 36% of patients with PTSD did not initially display ASD. In this study, the authors question the use of the ASD diagnosis to identify recently diagnosed patients at risk of PTSD.     

The relationship between anorexia nervosa and body dysmorphic disorder

Anorexia nervosa (AN) and body dysmorphic disorder (BDD) are severe body image disorders that highly impair individuals in their daily functioning. They are discrete but overlapping nosological entities. In this review, we examine similarities between AN and BDD with regard to clinical, personality and demographic aspects, such as comorbidity, phenomenology, and treatment outcome. The review suggests that the two disorders are highly comorbid, and show similar ages of onset, illness trajectories, and comparable clinical and personality characteristics. However, important differences emerge in their responsiveness to psychosocial and psychopharmacological treatment, which are discussed. Clinical implications of these findings are summarized and directions for future research are delineated, with a focus on how current treatment components from each disorder may inform new interventions for both disorders.