Theory of mind in neurodevelopmental disorders: beyond autistic spectrum disorder

INTRODUCTION

Theory of mind (ToM) is the human ability to perceive, interpret, and attribute the mental states of other people, and the alteration of this cognitive function is a core symptom of autistic spectrum disorder (ASD). In such other neurodevelopmental disorders as childhood-onset obsessive-compulsive disorder (OCD) and Tourette syndrome (TS) that can present with cognitive dysfunctions, ToM has been less extensively studied, especially in the young population. The aim of the study was to compare advanced ToM between groups of young people diagnosed with OCD, TS, or ASD and a control group.

METHODS

Clinical interviews were conducted with male patients aged between 11 and 17 years with a main diagnosis of OCD (n = 19), TS (n = 14), or ASD (n = 18), and a control group (n = 20). We administered instruments for estimating intelligence quotient and severity of psychiatric symptoms, and tasks to evaluate ToM (the "Stories from everyday life" task and the "Reading the mind in the eyes" test).

RESULTS

Young people with TS and with ASD present similar difficulties in solving advanced ToM tasks, whereas patients with childhood-onset OCD present similar results to controls.

CONCLUSIONS

ToM is altered in other neurodevelopmental disorders beyond ASD, such as TS.

Tic disorders and premonitory urges: validation of the Spanish-language version of the Premonitory Urge for Tics Scale in children and adolescents

INTRODUCTION

Most people with persistent tics report an unpleasant sensation (premonitory urge) before the tic. In recent years, interest in these sensory phenomena has increased due to their important role in behavioural therapy. However, instruments for assessing these sensations remain scarce. Among the available instruments, the Premonitory Urge for Tics Scale (PUTS) is the most widely used.

METHODS

We examined the psychometric properties and factor structure of the Spanish-language version of the PUTS in a sample of 72 children and adolescents with Tourette syndrome or persistent tic disorders. We analysed data from the total sample and by age group (children up to 10 years old and children/adolescents over 10).

RESULTS

The PUTS presented good internal consistency and moderate correlations between items on the scale (except for item 1). Divergent validity was good, test-retest reliability was adequate, and a bifactorial structure was identified (one dimension related to mental phenomena reported in obsessive-compulsive disorder, and another related to the quality and frequency of premonitory urges). These results were replicated in both age groups, with lower divergent validity and test-retest reliability in the younger group.

CONCLUSIONS

The Spanish-language version of the PUTS is a valid, reliable tool for assessing premonitory urges in both children and adolescents, especially after the age of 10.

Theory of mind in neurodevelopmental disorders: Beyond autistic spectrum disorder

INTRODUCTION

Theory of mind (ToM) is the human ability to perceive, interpret, and attribute the mental states of other people, and the alteration of this cognitive function is a core symptom of autistic spectrum disorder (ASD). In such other neurodevelopmental disorders as childhood-onset obsessive-compulsive disorder (OCD) and Tourette syndrome (TS) that can present with cognitive dysfunctions, ToM has been less extensively studied, especially in the young population. The aim of the study was to compare advanced ToM between groups of young people diagnosed with OCD, TS, or ASD and a control group.

METHODS

Clinical interviews were conducted with male patients aged between 11 and 17 years with a main diagnosis of OCD (n=19), TS (n=14), or ASD (n=18), and a control group (n=20). We administered instruments for estimating intelligence quotient and severity of psychiatric symptoms, and tasks to evaluate ToM (the "Stories from everyday life" task and the "Reading the mind in the eyes" test).

RESULTS

Young people with TS and with ASD present similar difficulties in solving advanced ToM tasks, whereas patients with childhood-onset OCD present similar results to controls.

CONCLUSIONS

ToM is altered in other neurodevelopmental disorders beyond ASD, such as TS.

Tic disorders and premonitory urges: validation of the Spanish-language version of the Premonitory Urge for Tics Scale in children and adolescents

INTRODUCTION

Most people with persistent tics report an unpleasant sensation (premonitory urge) before the tic. In recent years, interest in these sensory phenomena has increased due to their important role in behavioural therapy. However, instruments for assessing these sensations remain scarce. Among the available instruments, the Premonitory Urge for Tics Scale (PUTS) is the most widely used.

METHODS

We examined the psychometric properties and factor structure of the Spanish-language version of the PUTS in a sample of 72 children and adolescents with Tourette syndrome or persistent tic disorders. We analysed data from the total sample and by age group (children up to 10 years old and children/adolescents over 10).

RESULTS

The PUTS presented good internal consistency and moderate correlations between items on the scale (except for item one). Divergent validity was good, test-retest reliability was adequate, and a bifactorial structure was identified (one dimension related to mental phenomena reported in obsessive-compulsive disorder, and another related to the quality and frequency of premonitory urges). These results were replicated in both age groups, with lower divergent validity and test-retest reliability in the younger group.

CONCLUSIONS

The Spanish-language version of the PUTS is a valid, reliable tool for assessing premonitory urges in both children and adolescents, especially after the age of 10.

Validation of the Spanish version of the Dimensional Yale-Brown Obsessive-Compulsive Scale (DYBOCS) in children and adolescents

BACKGROUND

Obsessive-compulsive disorder (OCD) is best understood as a complex overlap of obsessive-compulsive (OC) symptom dimensions with specific clinical and etiological characteristics. The Dimensional Yale-Brown Obsessive-Compulsive Scale (DYBOCS) was developed to assess the presence and severity of each of these OC symptom dimensions. Despite showing excellent psychometric properties in adults, the psychometric properties of the DYBOCS have not been widely investigated in children and adolescents.

METHODS

We examined the psychometric properties of the DYBOCS Spanish version in a sample of 97 OCD children and adolescents.

RESULTS

The results of the psychometric analyses were excellent overall. The internal consistency for each OC symptom dimension was high, although somewhat lower than in previous studies with adult samples. The DYBOCS showed overall good convergent and divergent validity. Factors obtained from a principal component analysis corresponded with the five DYBOCS dimensions (aggressive; sexual/religious; contamination; symmetry; and hoarding) and each one accounted for approximately 20% of the variance.

CONCLUSIONS

The DYBOCS is a valid instrument for assessing the frequency and severity of OC symptom dimensions in children and adolescents with OCD. The principal component analysis supported the division of OC symptoms into five dimensions. OCD is a heterogeneous disorder, and a dimensional approach can help to understand its clinical, etiological and treatment response characteristics.

Clinical significance of psychiatric comorbidity in children and adolescents with obsessive-compulsive disorder: subtyping a complex disorder

A promising approach in relation to reducing phenotypic heterogeneity involves the identification of homogeneous subtypes of OCD based on age of onset, gender, clinical course and comorbidity. This study aims to assess the sociodemographic characteristics and clinical features of OCD patients in relation to gender and the presence or absence of another comorbid disorder. The sample comprised 112 children and adolescents of both sexes and aged 8-18 years, all of whom had a diagnosis of OCD. Overall, 67 % of OCD patients had one comorbid diagnosis, 20.5 % had two such diagnoses and 2.6 % had three comorbid diagnoses. The group of OCD patients with a comorbid neurodevelopmental disorder had significantly more family history of OCD in parents (p = .049), as compared with the no comorbidity group and the group with a comorbid internalizing disorder, and they also showed a greater predominance of males (p = .013) than did the group with a comorbid internalizing disorder. The group of OCD patients with internalizing comorbidity had a later age of onset of OCD (p = .001) compared with both the other groups. Although the initial severity was similar in all three groups, the need for pharmacological treatment and for hospitalization due to OCD symptomatology was greater in the groups with a comorbid neurodevelopmental disorder (p = .038 and p = .009, respectively) and a comorbid internalizing disorder (p = .008 and p = .004, respectively) than in the group without comorbidity. Our findings suggest that two subtypes of OCD can be defined on the basis of the comorbid pathology presented. The identification of different subtypes according to comorbidity is potentially useful in terms of understanding clinical variations, as well as in relation to treatment management and the use of therapeutic resources.

1H-MRS of the anterior cingulate cortex in childhood and adolescent obsessive-compulsive disorder: a case-control study

Abnormal glutamate concentrations in the anterior cingulate cortex (ACC) have been identified in children and adults with obsessive-compulsive disorder (OCD). The purpose of the present study was to measure in vivo (1)H-MRS neurometabolite concentrations in the ACC of children and adolescents with OCD, in order to identify metabolite abnormalities compared to healthy controls and to assess their relationship with clinical variables. 3T proton-magnetic resonance spectroscopy was used to probe ACC biochemistry in 47 paediatric and adolescent OCD patients (11-18 years old) compared to 31 healthy subjects of similar age, sex and estimated intellectual quotient. There were no significant differences in the concentration of glutamate plus glutamine (Glx) adjusted for CSF between OCD patients and healthy controls [F1,74=0.00; P=0.943], but there were significant differences in the concentration of Glx adjusted for CSF in paediatric and adolescent OCD patients according to duration of illness (less than or more than 24 months) [F2,73=3.95; P=0.024]. In addition, we found significantly lower levels of myo-inositol adjusted for CSF in the ACC [F1,74=5.686; P=0.02] in patients compared with controls. The present findings do not confirm the hypothesis of differences in Glx concentrations in the ACC between children and adolescents with OCD and healthy controls; however, the observation of differences in the Glx concentration in children and adolescent OCD patients depending on the duration of illness is of interest.

White matter structural alterations in pediatric obsessive-compulsive disorder: relation to symptom dimensions

The aims of this study were to identify gray matter (GM) and white matter (WM) volume abnormalities in pediatric obsessive-compulsive patients, to examine their relationship between these abnormalities and the severity of disorder, and to explore whether they could be explained by the different symptom dimensions.

METHODS

62 child and adolescent OCD patients (11-18years old) and 46 healthy subjects of the same gender and similar age and estimated intellectual quotient were assessed by means of psychopathological scales and magnetic resonance imaging (MRI). Axial three-dimensional T1-weighted images were obtained in a 3T scanner and analyzed using optimized voxel-based morphometry (VBM).

RESULTS

Compared with healthy controls, OCD patients showed lower white matter (WM) volume in the left dorsolateral and cingulate regions involving the superior and middle frontal gyri and anterior cingulate gyrus (t=4.35, p=0.049 FWE (family wise error)-corrected). There was no significant correlation between WM and the severity of obsessive-compulsive symptomatology. There were no regions with lower gray matter (GM) volume in OCD patients than in controls. Compared with healthy controls, only the "harm/checking" OCD dimension showed a cluster with a near significant decrease in WM volume in the right superior temporal gyrus extending into the insula (t=5.61, p=.056 FWE-corrected).

CONCLUSION

The evidence suggests that abnormalities in the dorsolateral prefrontal cortex, anterior cingulate cortex, temporal and limbic regions play a central role in the pathophysiology of OCD. Moreover, regional brain volumes in OCD may vary depending on specific OCD symptom dimensions, indicating the clinical heterogeneity of the condition.

Antineuronal Antibodies in Pediatric OCD and Tourette Syndrome

The objective of our study was to test the autoimmune hypothesis of OCD and TS as disorders related with PANDAS, and find clinical features or specific immunological markers related with them. Child onset OCD in adults has been associated with higher mean ASLO titers, higher frequencies of history of tic disorders, tonsillitis in childhood and compulsive symptoms. Also, two proteins, with molecular weights of 86kDa and 55kDa, have shown antibody binding in sera from 7 patients.The fact that some clinical and biological features related with PANDAS are found in adults and that antineuronal antibodies exist in patients with OCD or TS diagnosis that don't meet PANDAS criteria, lends further evidence that autoimmunity related with OCD is wider than PANDAS.

Subtyping obsessive-compulsive disorder: clinical and immunological findings in child and adult onset

It has been suggested that certain kinds of childhood OCD with specific clinical, biological and immunological characteristics may form a subgroup of OCD. We study the presence of these characteristics in child onset OCD and propose that the disorder be considered as a subtype of adult OCD. Forty adult patients with OCD were divided in two groups according to time of disease onset: 18 early onset and 21 late. Both sets were compared with a control group of 14 psychiatric patients. Child onset OCD was associated with higher mean ASLO titers, higher frequencies of history of tic disorders and tonsillitis in childhood and compulsive symptoms. No differences were found in D8/17 antibody titers or in other autoimmune parameters. The findings suggest that child onset OCD can be considered as a subgroup of adult OCD, although more specific biological markers are needed to identify it.