Evidence of gray matter reduction and dysfunction in chromosome 22q11.2 deletion syndrome

Chromosome 22q11.2 deletion syndrome (22q11DS) is associated with cognitive deficits and morphometric brain abnormalities in childhood and a markedly elevated risk of schizophrenia in adolescence/early adulthood. Determining the relationship between neurocognition and neuroimaging findings would yield crucial information about childhood neurodevelopment and provide a basis for the study of the trajectory that occurs on the pathway to psychosis. We compared morphometric brain findings between non-psychotic children with 22q11DS (n = 22) and healthy controls (n = 16), and examined the association between neurocognitive functioning and morphometric brain findings. Volumetric regional gray matter differences between the 22q11DS and control subjects were measured, and correlations of the regional gray matter volumes and neurocognition were performed. Children with 22q11DS demonstrated reductions in gray matter in several brain regions, chiefly the frontal cortices, the cingulate gyrus and the cerebellum. The volumetric reductions in these salient areas were associated with poor performance in sustained attention, executive function and verbal memory; however, the relation of brain volume with cognitive performance did not differ between the patient and control groups. Thus, children with 22q11DS demonstrate gray matter reductions in multiple brain regions that are thought to be relevant to schizophrenia. The correlation of these volumetric reductions with poor neurocognition indicates that these brain regions may mediate higher neurocognitive functions implicated in schizophrenia.

Adaptation of the wisconsin scales of psychosis proneness to Spanish

INTRODUCTION

Nowadays the study of vulnerability to psychosis and early intervention is an area of great clinical impact and research. The aim of this study was to adapt the Wisconsin Scales of Vulnerability to Psychosis from English to Spanish. A set of five scales (Magical Ideation, Perceptual Aberration, Physical Anhedonia, Revised Social Anhedonia and Ambivalence) assess schizotypal traits in the general population and the possible risk of developing disorders embedded in the psychotic spectrum. Additionally, this tool contains a scale of Hypomaniac Personality to detect risk of affective spectrum psychosis.

METHODOLOGY

The Wisconsin Scales of Vulnerability to Psychosis have been adapted following the back-translation method. The scales were translated to an original Spanish version, which was then translated again into English in order to assess the conceptual and semantic overlap with the original items.

RESULTS

All the items were back-translated and evaluated in respect to the original ones by an expert in the scales, and all of them were rated with a perfect equivalence (Type A) or satisfactory (Type B).

CONCLUSIONS

The Spanish version of the Wisconsin Scales of Vulnerability to Psychosis shows good equivalence with the English one, thus allowing to measure affective and schizotypal traits in samples of Spanish-speaking individuals properly. Future studies should test the reliability and validity of these scales in our environment.

An examination of neuroticism as a moderating factor in the association of positive and negative schizotypy with psychopathology in a nonclinical sample

Personality traits such as neuroticism are associated with schizophrenia and schizotypy. However, studies thus far have not clarified the differential association of neuroticism with individual schizotypy dimensions and the role it plays in the expression of schizophrenia-spectrum psychopathology. 204 nonclinically ascertained participants completed self-report questionnaires assessing neuroticism and the positive and negative schizotypy dimensions, and underwent structured interviews assessing schizophrenia-spectrum psychopathology (psychotic-like experiences, negative symptoms, cluster A personality disorders and traits), mood episodes, substance abuse, and global functioning. Results indicated that neuroticism predicted positive symptoms of schizophrenia and depression, over-and-above the effects of both schizotypy dimensions. Also, neuroticism moderated the association of positive schizotypy with interview measures of psychopathology and functioning. The results of this study are consistent with other research indicating that neuroticism is etiologically relevant for schizophrenia-spectrum psychopathology and that it cannot be considered solely a 'secondary effect' of spectrum disorders. Current psychological models of psychosis can accomodate the finding of neuroticism being a shared vulnerability factor for affective and psychotic disorders.

Neurological soft signs in psychometrically identified schizotypy

Patients with schizophrenia often exhibit structural brain abnormalities, as well as neurological soft signs (NSS), consistent with its conceptualization as a neurodevelopmental disorder. NSS are mild, presumably nonlocalizing, neurological impairments that are inferred from performance deficits in domains such as sensory integration, motor coordination, and motor sequencing. The vulnerability for schizophrenia is presumed to be expressed across a broad continuum of impairment referred to as schizotypy. It is hypothesized that nondisordered people along the schizotypy continuum should exhibit elevated rates of NSS. The present study examined the relation of psychometrically identified positive and negative schizotypy with NSS using the Neurological Evaluation Scale in a nonclinically ascertained sample of young adults (n=177). As hypothesized, negative, but not positive, schizotypy was related to increased NSS in tasks that assessed fine and gross motor coordination, motor sequencing, eye movement abnormalities, and memory recall. However, positive schizotypy was associated with increased NSS in tasks related to sensory integration dysfunction. In general, the positivexnegative schizotypy interaction term was unrelated to individual NSS tasks. The findings support: a) the theory that the vulnerability for schizophrenia is expressed across a broad continuum of subclinical and clinical impairment referred to as schizotypy; b) the multidimensional structure of schizotypy; and c) the notion that schizotypy is an appropriate construct for understanding the etiology and development of schizophrenia-spectrum disorders.

Self-reported ADHD symptoms among college students: item positioning affects symptom endorsement rates

OBJECTIVE

The effect of manipulating item positioning on self-reported ADHD symptoms was examined. We assessed whether listing DSM-IV ADHD symptoms serially or interspersed affected (a) the correlation between ADHD symptoms and (b) the rate of symptom endorsement.

METHOD

In Study 1, an undergraduate sample (n = 102) completed a measure that listed DSM-IV ADHD symptoms serially and a measure that interspersed DSM-IV ADHD items among non-ADHD symptoms. In Study 2, a separate undergraduate sample (n = 240) completed a measure that listed DSM-IV ADHD symptoms serially and another ADHD measure that interspersed DSM-IV ADHD items among non-DSM-IV ADHD items.

RESULTS

Item positioning did not affect the correlation between symptoms, but did reveal a significant bias in the rate of symptom endorsements.

CONCLUSION

These findings suggest that there is significant variability in ADHD symptom endorsements resulting from item positioning. This effect has implications for clinical assessment and epidemiological research of ADHD among college students.

The expression of adult ADHD symptoms in daily life: an application of experience sampling methodology

OBJECTIVE

To use experience sampling method (ESM) to examine the impact of inattentive and hyperactive-impulsive ADHD symptoms on emotional well-being, activities and distress, cognitive impairment, and social functioning assessed in the daily lives of young adults. The impact of subjective appraisals on their experiences is also examined.

METHOD

Participants (n = 206) complete up to 56 in-the-moment assessments of mood and current activities using Personal Digital Assistants for 1 week.

RESULTS

Multilevel modeling techniques reveal that ADHD inattentive and hyperactive-impulsive symptoms differentially relate to daily experiences. Higher inattentive symptoms are associated with indices of general distress, including less positive and more negative mood as well as more concentration problems. Higher hyperactive-impulsive symptoms are associated with reduced sensitivity to contextual factors in perceptions of situations.

CONCLUSION

These findings demonstrate predictive validity for adult self-report of ADHD symptoms in a general population sample and suggest future research directions using ESM.

The dimensional structure of the Wisconsin Schizotypy Scales: factor identification and construct validity

The present study examined the factor structure underlying the Wisconsin Schizotypy Scales and the validity of these dimensions. Confirmatory factor analysis with 6137 nonclinical young adults supported a 2-factor model with positive and negative schizotypy dimensions. As predicted, the schizotypy dimensions were differentially related to psychopathology, personality, and social impairment. Both dimensions were related to schizotypal and paranoid symptoms. Positive schizotypy was uniquely related to psychotic-like experiences, substance abuse, mood disorders, and mental health treatment, whereas negative schizotypy was associated with negative and schizoid symptoms. Both dimensions were associated with poorer overall and social functioning, but negative schizotypy was associated with decreased likelihood of intimate relationships. The findings support the construct validity of a multidimensional model of schizotypy and the use of psychometric inventories to assess these dimensions.

For whom the mind wanders, and when: an experience-sampling study of working memory and executive control in daily life

An experience-sampling study of 124 undergraduates, pretested on complex memory-span tasks, examined the relation between working memory capacity (WMC) and the experience of mind wandering in daily life. Over 7 days, personal digital assistants signaled subjects eight times daily to report immediately whether their thoughts had wandered from their current activity, and to describe their psychological and physical context. WMC moderated the relation between mind wandering and activities' cognitive demand. During challenging activities requiring concentration and effort, higher-WMC subjects maintained on-task thoughts better, and mind-wandered less, than did lower-WMC subjects. The results were therefore consistent with theories of WMC emphasizing the role of executive attention and control processes in determining individual differences and their cognitive consequences.

Schizophrenic-like neurocognitive deficits in children and adolescents with 22q11 deletion syndrome

22q11.2 Deletion Syndrome (22q11DS) is the most common genetic microdeletion syndrome affecting humans. The syndrome is associated with general cognitive impairments and specific deficits in visual-spatial ability, non-verbal reasoning, and planning skills. 22q11DS is also associated with behavioral and psychiatric abnormalities, including a markedly elevated risk for schizophrenia. Research findings indicate that people with schizophrenia, as well as those identified as schizoptypic, show specific cognitive deficits in the areas of sustained attention, executive functioning, and verbal working memory. The present study examined such schizophrenic-like cognitive deficits in children and adolescents with 22q11DS (n = 26) and controls (n = 25) using a cross-sectional design. As hypothesized, 22q11DS participants exhibited deficits in intelligence, achievement, sustained attention, executive functioning, and verbal working memory compared to controls. Furthermore, deficits in attention and executive functioning were more pronounced in the 22q11DS sample relative to general cognitive impairment. These findings suggest that the same pattern of neuropsychological impairment seen in patients with schizophrenia is present in non-psychotic children identified as at-risk for the development of schizophrenia based on a known genetic risk marker.

The relationship of Asperger's characteristics and schizotypal personality traits in a non-clinical adult sample

The study examines the relationship between Asperger's Disorder (AD) and Schizotypal Personality Disorder (SPD), mutually exclusive but similar diagnoses [DSM-IV-TR; American Psychiatric Association (2000). Diagnostic and statistical manual of mental disorders. Washington, DC: Author]. The literature and comparison of diagnostic criteria suggest that the two disorders may overlap: AD social impairment with SPD interpersonal problems and AD communication deficits with SPD disorganized features. Questionnaire measures of AD and SPD were administered to a large non-clinical adult sample. Consistent with expectations, the Asperger's and Schizotypal questionnaires were positively correlated. Further, the social-interpersonal and communication-disorganized areas were positively correlated, though the relationship between social-interpersonal areas is particularly strong. Future research should continue to explore the relationship between AD and schizotypy to confirm current findings and improve understanding of distinctions between the disorders.

Anxiety and depression symptoms in psychometrically identified schizotypy

The neurodevelopmental vulnerability for schizophrenia appears to be expressed across a dynamic continuum of adjustment referred to as schizotypy. This model suggests that nonpsychotic schizotypic individuals should exhibit mild and transient forms of symptoms seen in full-blown schizophrenia. Given that depression and anxiety are reported to be comorbid with schizophrenia, the present study examined the relationship of psychometrically defined schizotypy with symptoms of depression and anxiety in a college student sample (n=1258). A series of confirmatory factor analyses indicated that a three-factor solution of positive schizotypy, negative schizotypy, and negative affect provided the best solution for self-report measures of schizotypy, anxiety, and depression. As hypothesized, the model indicated that symptoms of depression and anxiety are more strongly associated with the positive-symptom dimension of schizotypy than with the negative-symptom dimension. This is consistent with studies of schizophrenic patients and longitudinal findings that positive-symptom schizotypes are at risk for both mood and non-mood psychotic disorders, while negative-symptom schizotypes appear more specifically at risk for schizophrenia-spectrum disorders.

Cognitive correlates of a functional COMT polymorphism in children with 22q11.2 deletion syndrome

Chromosome 22q11.2 deletion syndrome (22q11DS) is a common microdeletion syndrome associated with a markedly elevated risk of schizophrenia in adulthood. Cognitive impairments such as a low IQ and deficits in attention and executive function are common in childhood. The catechol O-methyltransferase (COMT) gene maps within the deleted region and is involved in the degradation of dopamine, a neurotransmitter thought to be important in cognition and the development of schizophrenia. Thus, we examined the correlation between neurocognitive deficits and a common polymorphism Val(158)Met in the COMT gene in a cohort of children with 22q11DS. Our results show that children with 22q11DS who have the Met allele have higher IQ and achievement scores and perform better on measures of prefrontal cognition, such as the Continuous Performance Task, as compared with those with the Val allele. These results confirm that the hemizygous COMT Val(158)Met genotype impacts upon cognition in children with 22q11DS.

Extralimital triradii as a putative marker of schizotypy

Dermatoglyphic anomalies are reported to occur at a higher rate in schizophrenic patients and schizotypic individuals than in the general population, supporting the hypothesis that they are a marker of vulnerability for such conditions. Dermatoglyphic anomalies are hypothesized to indicate severe disruptions in the second trimester of prenatal development, a time period that appears to be etiologically relevant to the development of schizophrenia and related conditions. The present study provides the first examination of extralimital triradii in schizotypic young adults (n=197) and control participants (n=135) identified by the Revised Social Anhedonia Scale [Eckblad, M., Chapman, L.J., Chapman, J.P., Mishlove, M., 1982. The Revised Social Anhedonia Scale. Unpublished test (copies available from T.R. Kwapil, Department of Psychology, University of North Carolina at Greensboro P.O. Box 26164 Greensboro, NC 27402-6164)], the Perceptual Aberration Scale [Chapman, L.J., Chapman, J.P., Raulin, M.L., 1978. Body image aberration in schizophrenia. J. Abnorm. Psychol. 87, 399--407], the Magical Ideation Scale [Eckblad, M.L., Chapman, L.J., 1983. Magical ideation as an indicator of schizotypy. J. Consult. Clin. Psychol. 51, 215--225], and the Physical Anhedonia Scale [Chapman, L.J., Chapman, J.P., Raulin, M.L., 1976. Scales for physical and social anhedonia. J. Abnorm. Psychol. 85, 374--382]. As hypothesized, the schizotypic participants (6.6%) exhibited significantly higher rates of extralimital triradii than control participants (1.5%). These findings strongly encourage the future investigation of extralimital triradii in at-risk and psychotic populations.

Dermatoglyphic anomalies in psychometrically identified schizotypic young adults

Dermatoglyphic anomalies are hypothesized to indicate disruptions in the second trimester of prenatal development, a time period that appears to be critical in the etiology of schizophrenia. The present study examined the presence of dermatoglyphic anomalies in psychometrically identified schizotypic young adults (n = 51) and control participants (n = 63) selected based upon their scores on the Perceptual Aberration [J. Abnorm. Psychology 87 (1978) 399] and Magical Ideation Scales [J. Consult. Clin. Psychol. 51 (1983) 215]. It was hypothesized that schizotypic participants would exhibit higher rates of dermatoglyphic anomalies than control participants. The Perceptual Aberration-Magical Ideation group exhibited lower total and absolute finger ridge counts and less complex pattern types than control participants--findings consistent with anomalies reported in patients with schizophrenia. These findings encourage future examination of these anomalies in individuals at-risk for schizophrenia and related disorders.

The psychometric detection of schizotypy: do putative schizotypy indicators identify the same latent class?

The authors examined whether three indicators of Schizotypy, the Revised Social Anhedonia Scale (RSAS), Magical Ideation Scale (MIS), and Perceptual Aberration Scale (PAS), identify a common latent class or taxon as conceptualized by P. E. Meehl (1962, 1990). The separate and joint latent structures of these scales were evaluated using taxometric methods in two large, independent samples. Replicating prior findings, the RSAS and PAS each identified latent taxa with base rates approximating.10. Results for the taxonicity of the MIS were less consistent. Analyses of joint latent structure indicated that the RSAS-identified taxon was essentially independent of constructs measured by the PAS or MIS. Measures commonly thought to tap the same latent class, conjectured to be schizotypy, do not share this property.

Abnormalities of the corpus callosum in nonpsychotic children with chromosome 22q11 deletion syndrome

Chromosome 22q11 deletion syndrome (22q11DS) is associated with elevated rates of schizophrenia and other psychoses in adulthood. Childhood morphologic brain abnormalities are frequently reported, but the significance of these and their relationship to the development of schizophrenia are unclear. We sought to delineate midline neuroanatomical abnormalities in nonpsychotic children with 22q11DS and their age- and sex-matched controls and compare these to those reported in individuals with schizophrenia. On qualitative analysis, we found a high incidence of midline developmental abnormalities (cavum septum pellucidum, or CSP). On quantitative analysis, the total corpus callosum (CC) area was significantly increased in the patient group and among the subregions, the patients had a significantly larger isthmus. These findings of an increased area of the corpus callosum, specifically the isthmus, have not been reported before in individuals with 22q11DS. We also found a relative lack of the age-related increase in the size of the corpus callosum in the children with 22q11DS. There were no differences in cerebellar vermis measurements between the patient and control groups. Our findings are indicative of frequent midline brain anomalies, including dysgenesis of the corpus callosum, in nonpsychotic children with 22q11DS. Although the increased size of the corpus callosum in our 22q11DS patients is in direct contrast to the decrease seen in schizophrenia, the high frequency of structural midline abnormalities in these nonpsychotic children with 22q11DS is similar to that seen in schizophrenia. Further longitudinal studies on these children will help determine which of these structural abnormalities is/are pertinent to the development of psychosis.

Assessment of psychosis proneness in African-American college students

The present study employed the psychometric high-risk method to investigate psychosis proneness in African-American and Caucasian college students recruited from three sites. The goals of the study were to develop norms for African-American students on the Perceptual Aberration (Chapman, Chapman, & Raulin, 1978), Magical Ideation (Eckblad & Chapman, 1983), Revised Social Anhedonia (Eckblad, Chapman, Chapman, & Mishlove, 1982), and Physical Anhedonia Scales (Chapman, Chapman, & Raulin, 1976), as well as to assess the validity of this research method with African-American students. Structured diagnostic interviews were conducted to assess the concurrent validity of these scales for identifying psychosis proneness. The results supported the use of separate norms for male and female African-American students and provided support for the concurrent validity of this research method with African-American and Caucasian college students.

Psychometric properties and concurrent validity of the schizotypal ambivalence scale

The Schizotypal Ambivalence Scale (SAS) is a 19-item revision of the Intense Ambivalence Scale, which was designed to identify ambivalence described by Meehl as characteristic of schizotypy and schizophrenia. The present study examined the psychometric properties of the SAS in a sample of 997 college students. The study also provided preliminary evidence regarding the concurrent validity of the measure for identifying schizophreniclike symptoms and other forms of psychopathology in a sample of 131 students. The SAS has good internal consistency reliability (.84) and correlates moderately with other psychometric indices of schizotypy. High SAS scores were associated with schizotypal, schizoid, and paranoid symptoms, and with poorer overall functioning (after the removal of variance associated with other schizotypy scales), but were not associated with major depressive disorder or ratings of substance use and abuse.

Dissociative experience in hypothetically psychosis-prone college students

The relationship between dissociative experiences and psychosis proneness was investigated in a sample of 523 college undergraduates. Participants were administered the Dissociative Experiences Scale (DES), the Perceptual Aberration Scale, the Magical Ideation Scale, the Social Anhedonia Scale, and the Physical Anhedonia Scale. As hypothesized, the Perceptual Aberration and Magical Ideation Scales were positively correlated with the DES. The Social Anhedonia Scale had a modest correlation with the DES, but this relationship was largely mediated by the Perceptual Aberration and Magical Ideation Scales. The Physical Anhedonia Scale was uncorrelated with the DES. Exploratory factor analysis of the psychosis-proneness scales and the DES subscales resulted in a three-factor solution: dissociative experiences, positive schizotypy, and negative schizotypy. The DES depersonalization subscale loaded on both the dissociation and positive schizotypy factors.

A ten-year longitudinal study of intense ambivalence as a predictor of risk for psychopathology

The predictive validity of the Intense Ambivalence Scale was examined in a 10-year longitudinal study of 362 psychometrically identified psychosis-prone and control participants. Elevated scores on the Intense Ambivalence Scale predicted psychotic-like and depressive symptoms, and the development of psychotic illnesses at the 10-year follow-up assessment (after the removal of variance for membership in the psychosis-prone and control groups). Elevated scores on the scale were also associated with substance abuse, schizotypal symptoms, and impaired functioning at both the initial and follow-up assessments. The Intense Ambivalence Scale did not differentially enhance the predictive power of the Perceptual Aberration or the Magical Ideation Scales.