Judith F. Feldman

Behavioural problems in children who weigh 1000 g or less at birth in four countries.

BACKGROUND The increased survival chances of extremely low-birthweight (ELBW) infants (weighing <1000 g at birth) has led to concern about their behavioural outcome in childhood. In reports from several countries with different assessments at various ages, investigators have noted a higher frequency of behavioural problems in such infants, but cross-cultural comparisons are lacking. Our aim was to compare behavioural problems in ELBW children of similar ages from four countries. METHODS We prospectively studied 408 ELBW children aged 8-10 years, whose parents completed the child behaviour checklist. The children came from the Netherlands, Germany, Canada, and USA. The checklist provides a total problem score consisting of eight narrow-band scales. Of these, two (aggressive and delinquent behaviour) give a broad-band externalising score, three (anxious, somatic, and withdrawn behaviour) give a broad-band internalising score, and three (social, thought, and attention problems) indicate difficulties fitting neither broad-band dimension. For each cohort we analysed scores in ELBW children and those in normal- birthweight controls (two cohorts) or national normative controls (two cohorts). Across countries, we assessed deviations of the ELBW children from normative or control groups. FINDINGS ELBW children had higher total problem scores than normative or control children, but this increase was only significant in European countries. Narrow-band scores were raised only for the social, thought, and attention difficulty scales, which were 0.5-1.2 SD higher in ELBW children than in others. Except for the increase in internalising scores recorded for one cohort, ELBW children did not differ from normative or control children on internalising or externalising scales. INTERPRETATION Despite cultural differences, types of behavioural problems seen in ELBW children were very similar in the four countries. This finding suggests that biological mechanisms contribute to behavioural problems of ELBW children.

Sexual orientation after prenatal exposure to exogenous estrogen

Thirty women aged 17 to 30 years with documented prenatal exposure to the nonsteroidal synthetic estrogen diethylstilbestrol (DES) were compared to thirty women of similar demographic characteristics from the same medical clinic who had a history of abnormal Pap smear findings. A subsample of the DES women were also compared to their DES-unexposed sisters. Sexual orientation in its multiple components was assessed by systematic semistructured interviews. In comparison to both control groups, the DES women showed increased bisexuality and homosexuality. However, about 75% of the DES women were exclusively or nearly exclusively heterosexual. Nonhormonal and hormonal interpretations of these findings are discussed.

Attention and Recognition Memory in the 1st Year of Life: A Longitudinal Study of Preterm and Full-Term Infants.

Several aspects of visual attention and their implications for recognition memory were examined in a longitudinal sample of full-term and preterm (birth weight < 1,750 g) infants seen at 5, 7, and 12 months of age. At all 3 ages, full-terms had shorter look durations, faster shift rates, less off-task behavior, and higher novelty scores than preterms. Both groups followed similar developmental trajectories, with older infants having shorter looks and more shifts. Infants were consistent in attentional style across problems of the same type, across problems that used different types of stimuli (faces and patterns), and across the familiarization and test phases of this paired-comparison design; there was also modest cross-age stability. Shorter looks and higher shift rates during familiarization were related to better recognition memory, with shift rate adding to prediction independently of either peak or mean look. These findings underscore the importance of attention to infant information processing.

Prevalence of Autism Spectrum Disorder in Adolescents Born Weighing <2000 Grams

OBJECTIVE: To estimate the diagnostic prevalence of autism spectrum disorders (ASDs) in a low birth weight (LBW) cohort. METHODS: Participants belonged to a regional birth cohort of infants (N = 1105) born weighing <2000 g between October 1, 1984, and July 3, 1989, and followed up by periodic assessments to 21 years of age. At 16 years (n = 623), adolescents were screened for ASD using a wide net (previous professional diagnosis of an ASD or a score above a liberal cutoff on the Social Communication Questionnaire or the Autism Spectrum Symptoms Questionnaire). At 21 years (n = 189), 60% of screen positives and 24% of screen negatives were assessed for diagnoses of ASD by the Autism Diagnostic Observation Schedule or the Autism Diagnostic Interview–Revised. RESULTS: Samples retained at ages 16 and 21 years were representative of samples assessed at earlier ages except for lower levels of social risk. Of positive screens, 11 of 70 had ASD; of negative screens, 3 of 119 had ASD. The fractions of the 2 screening groups with ASD (14.3% in screen-positives and 2.5% in screen negatives) were weighted by fractions of screen-positives and screen-negatives among the adolescents (18.8% and 81.2%, respectively). This calculation produced an estimated prevalence rate of ASD in the entire cohort of 5% (31 of 623). CONCLUSIONS: The diagnostic prevalence of ASD in this LBW preterm cohort was higher than that reported by the Centers for Disease Control and Prevention for 8-year-olds in the general US population in 2006.

Processing Speed in the 1st Year of Life: A Longitudinal Study of Preterm and Full-Term Infants

Processing speed was assessed at 5, 7, and 12 months in full-term and preterm infants (birth-weight < 1,750 g). Speed was gauged directly in a new task by presenting infants with a series of paired faces, one that remained the same across trials and one that changed; trials continued until infants showed a consistent novelty preference. At all ages, preterms required about 20% more trials and 30% more time than full-terms to reach criterion. Among preterms, slower processing was associated with greater medical risk (e.g., respiratory distress syndrome). Developmental trajectories for speed (and attention) were similar for both groups. Thus, the deficits in processing speed previously found for preterms in childhood are already present in the 1st year of life.

Relation of cranial ultrasound abnormalities in low-birthweight infants to motor or cognitive performance at ages 2, 6, and 9 years.

This study sought to determine whether neonatal cranial ultrasound abnormalities are related to motor and cognitive outcomes in low‐birthweight (LBW, <2000g) children without major motor or cognitive disability. The relation of neonatal cranial ultrasound abnormalities to motor performance and general cognitive ability at ages 2, 6, and 9 years was examined in a prospectively followed regional cohort of LBW children, excluding those with major disability, and controlling for other risk factors. Compared with children without ultrasound abnormalities, children with abnormalities indicative of ischemic white‐matter injury had poorer motor performance at all three ages and, at age 2, lower general cognitive ability. The latter finding was not seen when motor performance was also controlled for. It was concluded that in LBW children without major motor or cognitive disability, ischemic white‐matter injury indicated by neonatal cranial ultrasound abnormalities adversely affected motor performance at ages 2, 6, and 9 years, but not general cognitive ability.

A Cognitive Approach to the Development of Early Language

A controversial issue in the field of language development is whether language emergence and growth is dependent solely on processes specifically tied to language or could also depend on basic cognitive processes that affect all aspects of cognitive competence (domain-general processes). The present article examines this issue using a large battery of infant information-processing measures of memory, representational competence, processing speed, and attention, many of which have been shown to predict general cognition in a cohort of full-terms and preterms. Results showed that various aspects of infant memory and representational competence (a) related to language at both 12 and 36 months, (b) predicted similarly for the two groups, and (c) predicted 36-month language, independently of birth status, 12-month language, and the 12-month Bayley Mental Development Index. Additionally, the results established predictive validity for the MacArthur 12-month language measure. These findings support a domain-general view of language.

Visual Short-Term Memory in the First Year of Life: Capacity and Recency Effects.

A span task was developed to assess the amount of information infants could hold in short-term memory. In this task, infants were presented with up to 4 items in succession and then tested for recognition by successively pairing each item with a novel one. A large sample of full-terms and low-birth-weight preterms (< 1,750 g) was tested longitudinally, at 5, 7, and 12 months of age. Results were similar for both groups: (a) Longer spans were more difficult, especially at the 2 younger ages; (b) memory capacity increased over the 1st year of life--whereas less than 25% of the sample could hold as many as 3-4 items in mind at once at the younger ages, nearly half could do so by 12 months of age; (c) there was a marked recency effect (greater memory for the final item) for spans of 3 and 4 at all ages; and (d) there were modest cross-age correlations, indicating that individual differences in memory capacity showed some stability from age to age.

Information Processing at 1 Year: Relation to Birth Status and Developmental Outcome during the First 5 Years.

As part of a longitudinal study of high-risk preterm infants (birthweight less than 1500 g) and a low socioeconomic status (SES) comparison group of full-term infants, measures of information processing were obtained at 1 year : visual and tactual recognition memory, cross-modal transfer, and object permanence. Of these, cross-modal transfer was the most strongly related to later intelligence, correlating with outcome at 1.5, 2, 3, 4, and 5 years for preterms and from 3-5 years for full-terms (rs=44 to 54) ; relations with outcome were independent of SES, maternal education, medical risk, and early Bayley scores. When this 1-year measure of cross-modal transfer was combined with 7-month visual recognition memory, 35%-51% of the variance in 3-,4-, and 5-year IQ was explained

Olfactory deficits, cognition and negative symptoms in early onset psychosis

BACKGROUND Smell identification deficits (SID) are common in adult schizophrenia, where they are associated with negative symptoms and lower intelligence. However, smell identification has not been examined in adolescents with early onset psychosis, wherein diagnosis is often obscure, and there are few prognostic predictors. METHOD We examined smell identification, diagnosis, neuropsychological performance and symptoms in 26 well characterized adolescents with early onset psychosis, age 11-17 years. RESULTS SID existed in the sample and were more common in patients with schizophrenia and psychotic depression than in patients with psychosis NOS and bipolar disorder. As in adults, SID were significantly associated with greater negative symptoms and lower verbal IQ. However, the associations of verbal IQ (and other verbal tasks) to smell identification in this pediatric sample were explained by the relation of both of these types of variables to negative symptoms. CONCLUSIONS SID existed across this sample of youths with psychotic disorder, and were specifically related to typical characteristics of schizophrenia, such as negative symptoms and lower intelligence, but not to features of bipolar disorder, such as grandiosity. SID is a characteristic of early onset psychosis that may be useful for prognostic purposes.