Comorbidity, age of onset and suicidality in obsessive-compulsive disorder (OCD): An international collaboration.

OBJECTIVES: To collate data from multiple obsessive-compulsive disorder (OCD) treatment centers across seven countries and five continents, and to report findings in relation to OCD comorbidity, age of onset of OCD and comorbid disorders, and suicidality, in a large clinical and ethnically diverse sample, with the aim of investigating cultural variation and the utility of the psychiatric diagnostic classification of obsessive-compulsive and related disorders. METHODS: Researchers in the field of OCD were invited to contribute summary statistics on current and lifetime psychiatric comorbidity, age of onset of OCD and comorbid disorders and suicidality in their patients with OCD. RESULTS: Data from 3711 adult patients with primary OCD came from Brazil (n=955), India (n=802), Italy (n=750), South Africa (n=565), Japan (n=322), Australia (n=219), and Spain (n=98). The most common current comorbid disorders were major depressive disorder (28.4%; n=1055), obsessive-compulsive personality disorder (24.5%, n=478), generalized anxiety disorder (19.3%, n=716), specific phobia (19.2%, n=714) and social phobia (18.5%, n=686). Major depression was also the most commonly co-occurring lifetime diagnosis, with a rate of 50.5% (n=1874). OCD generally had an age of onset in late adolescence (mean=17.9years, SD=1.9). Social phobia, specific phobia and body dysmorphic disorder also had an early age of onset. Co-occurring major depressive disorder, generalized anxiety disorder and psychotic disorders tended to have a later age of onset than OCD. Suicidal ideation within the last month was reported by 6.4% (n=200) of patients with OCD and 9.0% (n=314) reported a lifetime history of suicide attempt. CONCLUSIONS: In this large cross-continental study, comorbidity in OCD was common. The high rates of comorbid major depression and anxiety disorders emphasize the need for clinicians to assess and monitor for these disorders. Earlier ages of onset of OCD, specific phobia and social phobia may indicate some relatedness between these disorders, but this requires further study. Although there do not appear to be significant cultural variations in rates or patterns of comorbidity and suicidality, further research using similar recruitment strategies and controlling for demographic and clinical variables may help to determine whether any sociocultural factors protect against suicidal ideation or psychiatric comorbidity in patients with OCD.

Poor stimulus discriminability as a common neuropsychological deficit between ADHD and reading ability in young children: a moderated mediation model.

BACKGROUND: Attention deficit hyperactivity disorder (ADHD) is frequently associated with poorer reading ability; however, the specific neuropsychological domains linking this co-occurrence remain unclear. This study evaluates information-processing characteristics as possible neuropsychological links between ADHD symptoms and RA in a community-based sample of children and early adolescents with normal IQ (⩾70). METHOD: The participants (n = 1857, aged 6-15 years, 47% female) were evaluated for reading ability (reading single words aloud) and information processing [stimulus discriminability in the two-choice reaction-time task estimated using diffusion models]. ADHD symptoms were ascertained through informant (parent) report using the Development and Well-Being Assessment (DAWBA). Verbal working memory (VWM; digit span backwards), visuospatial working memory (VSWM, Corsi Blocks backwards), sex, socioeconomic status, and IQ were included as covariates. RESULTS: In a moderated mediation model, stimulus discriminability mediated the effect of ADHD on reading ability. This indirect effect was moderated by age such that a larger effect was seen among younger children. CONCLUSION: The findings support the hypothesis that ADHD and reading ability are linked among young children via a neuropsychological deficit related to stimulus discriminability. Early interventions targeting stimulus discriminability might improve symptoms of inattention/hyperactivity and reading ability.

The suicidality continuum in a large sample of obsessive-compulsive disorder (OCD) patients.

BACKGROUND: Obsessive-compulsive disorder (OCD) has a chronic course leading to huge impact in the patient's functioning. Suicidal thoughts and attempts are much more frequent in OCD subjects than once thought before. AIM: To empirically investigate whether the suicidal phenomena could be analyzed as a suicidality severity continuum and its association with obsessive-compulsive (OC) symptom dimensions and quality of life (QoL), in a large OCD sample. METHODS: Cross-sectional study with 548 patients diagnosed with OCD according to the DSM-IV criteria, interviewed in the Brazilian OCD Consortium (C-TOC) sites. Patients were evaluated by OCD experts using standardized instruments including: Yale-Brown Obsessive-Compulsive Scale (YBOCS); Dimensional Yale-Brown Obsessive-Compulsive Scale (DYBOCS); Beck Depression and Anxiety Inventories; Structured Clinical Interview for DSM-IV (SCID); and the SF-36 QoL Health Survey. RESULTS: There were extremely high correlations between all the suicidal phenomena. OCD patients with suicidality had significantly lower QoL, higher severity in the "sexual/religious", "aggression" and "symmetry/ordering" OC symptom dimensions, higher BDI and BA scores and a higher frequency of suicide attempts in a family member. In the regression analysis, the factors that most impacted suicidality were the sexual dimension severity, the SF-36 QoL Mental Health domain, the severity of depressive symptoms and a relative with an attempted suicide history. CONCLUSIONS: Suicidality could be analyzed as a severity continuum and patients should be carefully monitored since they present with suicidal ideation. Lower QoL scores, higher scores on the sexual dimension and a family history of suicide attempts should be considered as risk factors for suicidality among OCD patients.

Separation anxiety disorder in adult patients with obsessive-compulsive disorder: prevalence and clinical correlates.

OBJECTIVE: Individuals with obsessive-compulsive disorder (OCD) and separation anxiety disorder (SAD) tend to present higher morbidity than do those with OCD alone. However, the relationship between OCD and SAD has yet to be fully explored. METHOD: This was a cross-sectional study using multiple logistic regression to identify differences between OCD patients with SAD (OCD+SAD, n=260) and without SAD (OCD, n=695), in terms of clinical and socio-demographic variables. Data were extracted from those collected between 2005 and 2009 via the Brazilian Research Consortium on Obsessive-Compulsive Spectrum Disorders project. RESULTS: SAD was currently present in only 42 (4.4%) of the patients, although 260 (27.2%) had a lifetime diagnosis of the disorder. In comparison with the OCD group patients, patients with SAD+OCD showed higher chance to present sensory phenomena, to undergo psychotherapy, and to have more psychiatric comorbidities, mainly bulimia. CONCLUSION: In patients with primary OCD, comorbid SAD might be related to greater personal dysfunction and a poorer response to treatment, since sensory phenomena may be a confounding aspect on diagnosis and therapeutics. Patients with OCD+SAD might be more prone to developing specific psychiatric comorbidities, especially bulimia. Our results suggest that SAD symptom assessment should be included in the management and prognostic evaluation of OCD, although the psychobiological role that such symptoms play in OCD merits further investigation.

Specificity of basic information processing and inhibitory control in attention deficit hyperactivity disorder.

BACKGROUND: Both inhibitory-based executive functioning (IB-EF) and basic information processing (BIP) deficits are found in clinic-referred attention deficit hyperactivity disorder (ADHD) samples. However, it remains to be determined whether: (1) such deficits occur in non-referred samples of ADHD; (2) they are specific to ADHD; (3) the co-morbidity between ADHD and oppositional defiant disorder/conduct disorder (ODD/CD) has additive or interactive effects; and (4) IB-EF deficits are primary in ADHD or are due to BIP deficits. METHOD: We assessed 704 subjects (age 6-12 years) from a non-referred sample using the Development and Well-Being Assessment (DAWBA) and classified them into five groups: typical developing controls (TDC; n = 378), Fear disorders (n = 90), Distress disorders (n = 57), ADHD (n = 100), ODD/CD (n = 40) and ADHD+ODD/CD (n = 39). We evaluated neurocognitive performance with a Two-Choice Reaction Time Task (2C-RT), a Conflict Control Task (CCT) and a Go/No-Go (GNG) task. We used a diffusion model (DM) to decompose BIP into processing efficiency, speed-accuracy trade-off and encoding/motor function along with variability parameters. RESULTS: Poorer processing efficiency was found to be specific to ADHD. Faster encoding/motor function differentiated ADHD from TDC and from fear/distress whereas a more cautious (not impulsive) response style differentiated ADHD from both TDC and ODD/CD. The co-morbidity between ADHD and ODD/CD reflected only additive effects. All ADHD-related IB-EF classical effects were fully moderated by deficits in BIP. CONCLUSIONS: Our findings challenge the IB-EF hypothesis for ADHD and underscore the importance of processing efficiency as the key specific mechanism for ADHD pathophysiology.

Threat bias in attention orienting: evidence of specificity in a large community-based study.

BACKGROUND: Preliminary research implicates threat-related attention biases in paediatric anxiety disorders. However, major questions exist concerning diagnostic specificity, effects of symptom-severity levels, and threat-stimulus exposure durations in attention paradigms. This study examines these issues in a large, community school-based sample. Method A total of 2046 children (ages 6-12 years) were assessed using the Development and Well Being Assessment (DAWBA), Childhood Behavior Checklist (CBCL) and dot-probe tasks. Children were classified based on presence or absence of 'fear-related' disorders, 'distress-related' disorders, and behavioural disorders. Two dot-probe tasks, which differed in stimulus exposure, assessed attention biases for happy-face and threat-face cues. The main analysis included 1774 children. RESULTS: For attention bias scores, a three-way interaction emerged among face-cue emotional valence, diagnostic group, and internalizing symptom severity (F = 2.87, p < 0.05). This interaction reflected different associations between internalizing symptom severity and threat-related attention bias across diagnostic groups. In children with no diagnosis (n = 1411, mean difference = 11.03, s.e. = 3.47, df = 1, p < 0.001) and those with distress-related disorders (n = 66, mean difference = 10.63, s.e. = 5.24, df = 1, p < 0.05), high internalizing symptoms predicted vigilance towards threat. However, in children with fear-related disorders (n = 86, mean difference = -11.90, s.e. = 5.94, df = 1, p < 0.05), high internalizing symptoms predicted an opposite tendency, manifesting as greater bias away from threat. These associations did not emerge in the behaviour-disorder group (n = 211). CONCLUSIONS: The association between internalizing symptoms and biased orienting varies with the nature of developmental psychopathology. Both the form and severity of psychopathology moderates threat-related attention biases in children.

Obsessive-compulsive disorder and Tourette syndrome: is there a relationship?

The authors describe the main characteristics of Obsessive-Compulsive Disorder, the fourth most frequent psychiatric disease, and Tourette Syndrome. Considered completely separate disorders, there is growing scientific evidence that there is a connection between them. The authors present clinical, genetic and neuroimaging data reinforcing this idea, and call attention to the importance of research in this area, as they believe that the definition of more homogenous subgroups will facilitate the identification of biological marker and predictors of treatment response.