Simone A. Roberts

Cognitive and behavioral precursors of schizophrenia

Attentional deficits are well-established characteristics of patients with schizophrenia and their at-risk offspring, suggesting a biological connection between attention and schizophrenia. The goal of this study is to clarify the developmental role of attention in the illness. Data has been collected from 87 subjects at high and low risk for schizophrenia who have participated in the New York High-Risk Project from 1977 to the present. Individuals are considered to be at high risk if either or both of their parents has schizophrenia. Analyses of attention and global behaviors, measured at intervals from about 12 to 26 years of age, indicate (a) attentional deficits can be reliably detected in high-risk children who will develop future schizophrenia-spectrum disorders (the prespectrum [PSP] group); (b) these deficits are stable, enduring over time, and appear to reflect a compromised attentional capacity; (c) attention is not affected by the onset of illness in the PSP group; (d) for all subjects, attention and global behaviors follow independent developmental pathways; and (e) behavioral difficulties, but not attention deficits, appear to be highly sensitive to environmental factors, especially rearing by a mentally ill parent. It is concluded that in PSP individuals impaired attention probably results from prenatal developmental abnormalities (possibly on the cellular level) and is likely to be a marker of a biological vulnerability to schizophrenia. In addition, attentional deficits, as opposed to early behavioral difficulties, are concluded to be a useful first step in screening for youngsters in need of early intervention.

The Relationship Between CAG Repeat Length and Age of Onset Differs for Huntington's Disease Patients with Juvenile Onset or Adult Onset

Age of onset for Huntingtons disease (HD) varies inversely with the length of the disease‐causing CAG repeat expansion in the HD gene. A simple exponential regression model yielded adjusted R‐squared values of 0.728 in a large set of Venezuelan kindreds and 0.642 in a North American, European, and Australian sample (the HD MAPS cohort). We present evidence that a two‐segment exponential regression curve provides a significantly better fit than the simple exponential regression. A plot of natural log‐transformed age of onset against CAG repeat length reveals this segmental relationship. This two‐segment exponential regression on age of onset data increases the adjusted R‐squared values by 0.012 in the Venezuelan kindreds and by 0.035 in the HD MAPS cohort. Although the amount of additional variance explained by the segmental regression approach is modest, the two slopes of the two‐segment regression are significantly different from each other in both the Venezuelan kindreds [F(2, 439) = 11.13, P= 2 × 10−5] and in the HD MAPS cohort [F(2, 688) = 38.27, P= 2 × 10−16]. In both populations, the influence of each CAG repeat on age of onset appears to be stronger in the adult‐onset range of CAG repeats than in the juvenile‐onset range.

Wisconsin Card Sorting deficits in the offspring of schizophrenics in the New York High-Risk Project

It has been suggested that performance on the Wisconsin Card Sorting Test (WCST) may be an indicator of vulnerability to schizophrenia. WCST deficits have been demonstrated in schizophrenic patients and their relatives, but not as yet in their offspring. This study aimed to further establish the indicator potential of WCST deficits by analyzing data collected as part of the New York High-Risk Project (NYHRP), a longitudinal study of attention, cognition and clinical functioning in the offspring of schizophrenic (HRSz, n=73), affective disordered (HRAff, n=61) and normal comparison (NC, n=120) parents. Parental Research Diagnostic Criteria diagnoses were established by semi-structured interview (SADS-L). WCST testing was carried out when offspring were in their mid-20s. HRSz subjects performed significantly more poorly on the WCST than HRAff and NC subjects. High-risk subjects who developed psychotic symptoms prior to or shortly after testing did not differ significantly from HRSz subjects who did not become ill. Thus, WCST performance in the offspring of schizophrenics resembles that of schizophrenic patients and may distinguish HRSz from offspring at risk for nonschizophrenic illness. WCST deficits may be a specific familial indicator of vulnerability, but appear not to distinguish between those subjects at risk for schizophrenia who do or do not become ill.

The New York high-risk project: social and general intelligence in children at risk for schizophrenia

UNLABELLED Social deficits, as well as low performance on intelligence tests, are known early symptoms of schizophrenia. We studied whether impairment of social intelligence can be detected before the outbreak of the disorder. In the New York High-Risk Project, children at risk for schizophrenia (HRSz) or affective disorder (HRAff) and a normal control group (NC) were studied over the past 26 years. The children are now in mid-adulthood, with known psychiatric outcomes. Developmental and clinical data from childhood can now be related to adulthood diagnoses. We compared mean WISC (or WISC-R) and WAIS (or WAIS-R) scores from childhood and adolescence, and change of IQ, between the risk groups, as well as between the adulthood outcomes. We were specifically interested in the development of social intelligence (the Picture Arrangement and Comprehension subtests). We used logistic regression analyses to generate a model predicting adulthood schizophrenia. RESULTS IQ at age 9,7 was lower in children with HRSz than with HRAff. Adulthood schizophrenia, compared with major depressive disorder and no psychiatric diagnosis could not be related conclusively to low IQ. This may be a result of the study design, since children with IQ below 70 or behavioral problems were not eligible as study subjects. There was no evidence of lower scores or more decline in social intelligence related to age or group membership (risk or outcome). Subtest-Scatter, a nondirectional measure of the differences between all subtests and Vocabulary, reflecting a lesser difference between crystallized and fluid intelligence, was identified as a significant predictor of adulthood schizophrenia, in the whole group as well as in the HRSz group alone.

Positive and negative thought disorder and psychopathology in childhood among subjects with adulthood schizophrenia

UNLABELLED The New York High-Risk Project (NYHRP) is a longitudinal study of offspring of parents with schizophrenia or affective disorder and normal controls. Neuropsychological deficits had been observed at about age 9 in subjects with adulthood schizophrenia. We explored whether in these subjects, early signs of clinical schizophrenia-related symptoms, such as thought disorder or behavioral abnormalities, could also be observed. METHODS We rated thought disorder and symptoms from videotaped interviews at age 9, using the Scale for the Assessment of Thought, Language and Communication (TLC), and the Mental Health Assessment Form (MHAF). With factor analyses we examined the structure of the ratings, and from interpretable factors, scales were assembled. MANOVAs were used to examine the effect of parental risk and adulthood psychiatric diagnosis (schizophrenia-related psychosis (SRP), major affective disorder (MAD), no disorder/other (NoDx/other)) as independent variables (IV) on thought disorder and symptoms as dependent variables. RESULTS Global, positive and negative thought disorder, and negative symptoms were significantly higher in subjects with adulthood schizophrenia-related psychosis than both comparison groups. A significant interaction between the two IVs was effective with respect to positive thought disorder. This scale was particularly elevated among subjects with adulthood schizophrenia-related psychosis at parental risk for affective disorder (all of whom had adulthood schizoaffective disorder). CONCLUSIONS We were able to show that global, negative and positive thought disorder and negative symptoms were present in subjects with adulthood schizophrenia already at mid-childhood, years before onset of psychosis. Further, we found a particularly high propensity to positive symptoms in subjects with adulthood schizophrenia who have also an affective component in their symptoms. This association, previously reported in acute schizophrenia, was here observed years before the first psychotic episode.

Early life precursors of psychiatric outcomes in adulthood in subjects at risk for schizophrenia or affective disorders

In the New York High-Risk Project (NYHRP), 186 offspring of schizophrenic, affectively ill, and psychiatrically normal parents have been followed prospectively from 1971-72 to the average age of 27 years in 1990 with the goal of identifying early precursors of later psychopathology. In this report, we use path analyses to examine the relationship of several life-history variables to three pathological outcomes in the offspring: namely, psychosis, psychiatric hospitalization, and psychological dysfunction. The chief direct relationship with these outcomes is the effect of having a schizophrenic parent. The latter effect is also mediated indirectly by IQ.

Thought Disorder in Offspring of Schizophrenic Parents: Findings From the New York High-Risk Project

The goal of the present analyses was to examine the hypothesis that mild forms of thought disorder (TD) may serve as an indicator of genetic liability for schizophrenia. A subset of 232 subjects drawn from the New York High-Risk Project was used to compare individuals at high risk for schizophrenia (ie, offspring of parents with schizophrenia; n = 63) with 2 groups of individuals at low risk for schizophrenia (ie, offspring of parents with affective disorder [n = 52] and offspring of psychiatrically normal parents [n = 117]). Subjects were administered the Rorschach Inkblot Test, and their responses were assessed according to the Thought Disorder Index (TDI). The high-risk offspring displayed significantly more TD than the other 2 groups, as shown by significantly higher TDI scores. Moreover, they had more deviant verbalizations, according to their significantly higher scores on a composite Idiosyncratic Verbalizations score. As expected, the offspring who developed psychosis produced more TD in adolescence than those who did not develop psychosis. In the sample as a whole, TD scores during late adolescence/early adulthood were positively associated with schizotypal features during mid-adulthood. These findings support the assertion that the presence of TD serves as an endophenotypic marker of a schizophrenia diathesis.

The New York High-Risk Project : Comorbidity for axis I disorders is preceded by childhood behavioral disturbance

The relationship between childhood behavioral disturbance and comorbidity for adult psychiatric disorders has not been sufficiently investigated. Subjects of this report (N = 185) were offspring of parents with schizophrenia or affective disorder and of normal parents from the New York High-Risk Project. Data on childhood behavior at the mean age of 9.5 years were obtained in a parent interview at initial assessment in 1971-72. Adulthood outcomes were assessed through standardized interviews, and lifetime axis I diagnoses were based on Research Diagnostic Criteria. Subjects with comorbidity for axis I disorders exhibited significantly more behavioral problems as children, compared with those who developed either one or no psychiatric disorder in adulthood. This association was not biased by gender or parental diagnosis of psychiatric disorder. The findings emphasize that psychiatric comorbidity can be traced back to childhood and underline the importance of longitudinal observations in psychiatric research.

PERSONALITY FEATURES AND DISORDER IN THE SUBJECTS IN THE NEW YORK HIGH-RISK PROJECT.

One hundred and seventy-five offspring of parents in two psychiatrically ill groups and of normal controls in the New York High-Risk Project (NYHRP) were assessed for Axis II personality traits and disorders as defined by the Diagnostic and Statistical Manual of Mental Disorders, Third Edition, Revised (DSM-III-R). These offspring include: subjects at high risk for schizophrenia (HRSz, n = 48), all of whom have a parent with schizophrenic disorder; subjects at high risk for affective disorder (HRAff, n = 40), all of whom have a parent with affective disorder; and subjects at no increased risk for psychiatric illness (NC, n = 87), whose parents are psychiatrically normal. The trained interviewers, who administered a standardized direct interview, were blind to parental clinical status and to previous clinical status of the offspring.The rates for any personality disorder (PD) ranged from 7% to 20%. Comorbidity between Axis I and Axis II disorders was high for all groups.