Martin Debbané

Psychiatric Disorders and Intellectual Functioning Throughout Development in Velocardiofacial (22q11.2 Deletion) Syndrome

OBJECTIVE Velocardiofacial syndrome (VCFS) is associated with cognitive deficits and high rates of schizophrenia and other neuropsychiatric disorders. We report the data from two large cohorts of individuals with VCFS from Israel and Western Europe to characterize the neuropsychiatric phenotype from childhood to adulthood in a large sample. METHOD Individuals with VCFS (n = 172) aged 5 to 54 years were evaluated with structured clinical interviews for psychiatric disorders and age-appropriate versions of the Wechsler intelligence tests. RESULTS The frequency of psychiatric disorders was high and remarkably similar between samples. Psychotic disorders and depression were uncommon during childhood but increased in rates during adulthood (depressive disorders: 40.7% in young adults [aged 18-24 years]; psychotic disorders: 32.1% in adults [age >24 years]). Cognitive scores were inversely associated with age in subjects with VCFS, including patients without psychosis. Specifically, Verbal IQ (VIQ) scores negatively correlated with age, and the subjects with VCFS and psychotic disorders had significantly lower VIQ scores than nonpsychotic VCFS subjects. CONCLUSIONS Neuropsychiatric deficits in individuals with VCFS seem to follow a developmental pattern. The VIQ scores are negatively associated with age and rates of mood, and psychotic disorders increase dramatically during young adulthood. The data presented here support careful monitoring of psychiatric symptoms during adolescence and young adulthood in VCFS. Prospective longitudinal studies are needed to examine the nature of age-related cognitive changes and their association with psychiatric morbidity in VCFS.

Degrees of separation: A quantitative neuroimaging meta-analysis investigating self-specificity and shared neural activation between self- and other-reflection

In functional neuroimaging studies, self-specificity has been investigated by contrasting other-relevant processing against the self. Our meta-analysis investigates self-specificity with respect to degrees of self-relatedness (SR) of the other (i.e. close and public other). Literature suggests a dorsal-ventral component of self- and other-reflection within the MPFC, which has yet to be analyzed according to varying SR, nor has it been quantified statistically. In the present meta-analysis, we pursued three main objectives. First, we conducted whole-brain ALE meta-analyses using contemporary literature analyzing self>close other and self>public other contrasts to determine self-specific regions sensitive to SR. Next, we conducted ALE and conjunction analyses of studies employing self>control, close other>control, or public other>control contrasts to determine shared regions of activation. Third, we conducted post hoc analyses to quantify any observed dorsal-ventral distinction, employing novel methodology using a surface-based coordinates system. We observed significant activation in the dACC and vACC for self>close other and self>public other, whereas anterior insula was observed only for self>public other. An MPFC dorsal-ventral distinction was observed and quantified whereby public other>control was significantly more dorsal than self>control and close other>control. Our results are discussed with regards to SR. Prospective avenues of research exploiting our methodology are proposed.

Psychotic symptoms in children and adolescents with 22q11.2 deletion syndrome: Neuropsychological and behavioral implications.

Individuals with 22q11.2 deletion syndrome (22q11DS) are at increased risk for developing schizophrenia: half of affected adolescents report transient psychotic experiences and up to 30% of adults are diagnosed with schizophrenia. Prospective studies have shown that psychotic symptoms in childhood are predictive of later schizophreniform disorders. The current study aimed to define the prevalence and correlates of psychotic symptoms (PS) in young children and adolescents with 22q11DS. Forty-three children and adolescents with 22q11DS (mean age = 10.62+/-11.19) participated in this study. The occurrence of PS and their neuropsychological and behavioral correlates were investigated through semi-structured interviews and standardized measures. Psychotic symptoms were reported in 28% of the total sample and 17% of pre-adolescent children, and associated with decreased verbal IQ scores [F(1) = 4.41, p = 0.042]. Compared to young patients without PS, young patients with PS were perceived by their parents as more anxious-depressed [F(1) = 4.76, p = 0.035] and withdrawn [F(1) = 7.63, p = 0.009], with reduced adaptive socialization skills [F(1) = 6.88, p = 0.012]. Results suggest that psychotic manifestations are present earlier than typically reported in youngsters with 22q11DS and are accompanied by reduced verbal IQ performance and decreased adaptative social skills. The symptomatic, neuropsychological and behavioral characteristics observed in the current study may constitute central markers of increased risk for psychosis in 22q11DS.

Sex differences in thickness, and folding developments throughout the cortex

While significant differences in male and female brain structures have commonly been reported, only a few studies have focused on the sex differences in the way the cortex matures over time. Here, we investigated cortical thickness maturation between the age of 6 to 30 years, using 209 longitudinally-acquired brain MRI scans. Significant sex differences in the trajectories of cortical thickness change with age were evidenced using non-linear mixed effects models. Similar statistical analyses were computed to quantify the differences between cortical gyrification changes with age in males and females. During adolescence, we observed a statistically significant higher rate of cortical thinning in females compared to males in the right temporal regions, the left temporoparietal junction and the left orbitofrontal cortex. This finding is interpreted as a faster maturation of the social brain areas in females. Concomitantly, statistically significant sex differences in cortical folding changes with age were observed only in one cluster of the right prefrontal regions, suggesting that the mechanisms underlying cortical thickness and gyrification changes with age are quite distinct. Sexual dimorphism in the developmental course of the cortical maturation may be associated with the different age of onset and clinical presentation of many psychiatric disorders between males and females.

Deviant trajectories of cortical maturation in 22q11.2 deletion syndrome (22q11DS): A cross-sectional and longitudinal study

22q11.2 deletion syndrome (22q11DS) is associated with an increased susceptibility to develop schizophrenia. Despite a large body of literature documenting abnormal brain structure in 22q11DS, cerebral changes associated with brain maturation in 22q11DS remained largely unexplored. To map cortical maturation from childhood to adulthood in 22q11.2 deletion syndrome, we used cerebral MRI from 59 patients with 22q11DS, aged 6 to 40, and 80 typically developing controls; three year follow-up assessments were also available for 32 patients and 31 matched controls. Cross-sectional cortical thickness trajectories during childhood and adolescence were approximated in age bins. Repeated-measures were also conducted with the longitudinal data. Within the group of patients with 22q11DS, exploratory measures of cortical thickness differences related to COMT polymorphism, IQ, and schizophrenia were also conducted. We observed deviant trajectories of cortical thickness changes with age in patients with 22q11DS. In affected preadolescents, larger prefrontal thickness was observed compared to age-matched controls. Afterward, we observed greater cortical loss in 22q11DS with a convergence of cortical thickness values by the end of adolescence. No compelling evidence for an effect of COMT polymorphism on cortical maturation was observed. Within 22q11DS, significant differences in cortical thickness were related to cognitive level in children and adolescents, and to schizophrenia in adults. Deviant trajectories of cortical thickness from childhood to adulthood provide strong in vivo cues for a defect in the programmed synaptic elimination, which in turn may explain the susceptibility of patients with 22q11DS to develop psychosis.

Developing Psychosis and Its Risk States Through the Lens of Schizotypy

Starting from the early descriptions of Kraepelin and Bleuler, the construct of schizotypy was developed from observations of aberrations in nonpsychotic family members of schizophrenia patients. In contemporary diagnostic manuals, the positive symptoms of schizotypal personality disorder were included in the ultra high-risk (UHR) criteria 20 years ago, and nowadays are broadly employed in clinical early detection of psychosis. The schizotypy construct, now dissociated from strict familial risk, also informed research on the liability to develop any psychotic disorder, and in particular schizophrenia-spectrum disorders, even outside clinical settings. Against the historical background of schizotypy it is surprising that evidence from longitudinal studies linking schizotypy, UHR, and conversion to psychosis has only recently emerged; and it still remains unclear how schizotypy may be positioned in high-risk research. Following a comprehensive literature search, we review 18 prospective studies on 15 samples examining the evidence for a link between trait schizotypy and conversion to psychosis in 4 different types of samples: general population, clinical risk samples according to UHR and/or basic symptom criteria, genetic (familial) risk, and clinical samples at-risk for a nonpsychotic schizophrenia-spectrum diagnosis. These prospective studies underline the value of schizotypy in high-risk research, but also point to the lack of evidence needed to better define the position of the construct of schizotypy within a developmental psychopathology perspective of emerging psychosis and schizophrenia-spectrum disorders.

Risk Factors and the Evolution of Psychosis in 22q11.2 Deletion Syndrome: A Longitudinal 2-Site Study

OBJECTIVE 22q11.2 Deletion syndrome (22q11.2DS) is associated with high rates of schizophrenia, other neuropsychiatric disorders, and cognitive deficits. The objectives of this 2-center study were to longitudinally assess the trajectories of psychiatric disorders in 22q11.2DS from childhood to adulthood, and to identify risk factors for their emergence. METHOD A total of 125 children and adults with 22q11.2DS were evaluated at 2 time points, baseline and follow-up (4 years apart), using standardized psychiatric and cognitive measures. RESULTS The rate of mood disorders tended to decrease during childhood and increase during late adolescence. Statistically significant predictors for the presence of a psychotic disorder as well as the severity of positive symptoms at follow-up were identical, and consisted of an anxiety disorder at baseline, lower baseline Full Scale IQ, and a greater decrease in verbal IQ scores between time points. Nine of 10 individuals with an emerging psychotic disorder had an anxiety disorder at baseline. The age of onset for a psychotic disorder was between 14 and 22 years in 82.6% of cases. CONCLUSIONS It is important to evaluate the presence of anxiety disorders in children and adolescents with 22q11.2DS, as they are major risk factors for the emergence of psychotic disorders, which usually occur during late adolescence in this at-risk population.

Congenital heart disease affects local gyrification in 22q11.2 deletion syndrome

22q11.2 deletion syndrome (22q11.2DS) is a common genetic condition associated with cognitive and learning impairments. In this study, we applied a three‐dimensional method for quantifying gyrification at thousands of points over the cortical surface to imaging data from 44 children, adolescents, and young adults with 22q11.2DS (17 males, 27 females; mean age 17y 2mo [SD 9y 1mo], range 6–37y), and 53 healthy participants (21 males, 32 females; mean age 15y 4mo [SD 8y 6mo]; range 6–40y). Several clusters of reduced gyrification were observed, further substantiating the pattern of cerebral alterations presented by children with the syndrome. Comparisons within 22q11.2DS demonstrated an effect of congenital heart disease (CHD) on cortical gyrification, with reduced gyrification at the parieto‐temporo‐occipital junction in patients with CHD, as compared with patients without CHD. Reductions in gyrification can resemble mild polymicrogyria, suggesting early abnormal neuronal proliferation or migration and providing support for an effect of hemodynamic factors on brain development in 22q11.2DS. The results also shed light on the pathophysiology of acquired brain injury in other populations with CHD.

Hippocampal volume reduction in 22q11.2 deletion syndrome

Hippocampal volume reduction and decreased memory skills form a characteristic neurofunctional alteration observed in schizophrenia. Individuals affected with 22q11.2 deletion syndrome (22q11DS), while exhibiting memory deficits throughout development, are also at high risk for developing schizophrenia. The present study sought to investigate hippocampal volume reduction as separate of global grey matter reduction in a large, independent sample of individuals with 22q11DS. Volumetric data from structural magnetic resonance imaging was obtained for 43 individuals affected with 22q11DS, aged 6-39 years of age, as well as for 40 healthy individuals matched for age and gender. Drawing of the amygdala was included to enhance the delineation of the hippocampus, and circumscription of both the amygdala and the hippocampus were executed using an increased resolution matrix. After controlling for total grey volume reductions observed in affected individuals, a significant decrease in hippocampus volume was observed in the 22q11DS group, driven by significant bilateral volumetric reduction of the body of the hippocampus. These results are discussed in reference to memory and cerebral alterations already reported in 22q11DS. Further, the specific implications of hippocampus body volume reduction are outlined in light of its anatomical relationships and its function in memory. Finally, reduction of hippocampal volume in 22q11DS is examined in the context of psychiatric risk status associated to the deletion.

Impaired Activation of Face Processing Networks Revealed by Functional Magnetic Resonance Imaging in 22q11.2 Deletion Syndrome

BACKGROUND 22q11.2 deletion syndrome (22q11DS) is a neurogenetic syndrome associated with a high rate of psychiatric disorders. Previous research has revealed distinctive cognitive deficits, including impaired face processing. However, the neuro-functional substrates underlying these deficits have not been explored. Our aim was to investigate facial and emotional processing in 22q11DS. METHODS During event-related functional magnetic resonance imaging, 15 individuals with 22q11DS were compared with age- and gender-matched healthy control subjects on a simple visual categorization task (faces or houses). Each stimulus was presented twice, and faces had either neutral or emotional (fearful) expressions. RESULTS Abnormal responses to faces were observed in 22q11DS, including a lack of normal face-selectivity in fusiform gyrus. By contrast, responses to houses were comparable across groups, with preserved selectivity in parahippocampal gyrus. Results also revealed a repetition-suppression effect for fearful faces in the right amygdala, which arose in healthy control subjects only, suggesting a lack of amygdala modulation by fear expression in 22q11DS. CONCLUSIONS Our results demonstrate selective anomalies in several brain regions critically implicated in visual and social function in 22q11DS. These findings suggest important new avenues for studying emotional processing and social deficits frequently observed in psychotic patients and establishing their relation to specific phenotypic manifestations in 22q11DS.