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N Snidman

Publications and source records attributed to N Snidman.

11 recordsLinked to original sources
PubMed1995

Cardiac function and behavioral reactivity during infancy.

Longitudinal cardiac data from the end of the fetal period to 21 months of age were examined for change and stability over age and relations to the temperamental characteristics of high and low reactivity at 4 months of age and fear to the unfamiliar in the second year. Heart period and power in the cardiac spectra changed dramatically over the first 2 years, and individual differences were not preserved until 9-14 months of age. Sleep heart period at 2 weeks of age and low frequency power at 2 months of age were better predictors of the temperamental categories than later measures of the same variables, suggesting that cardiac function early in life may be an especially sensitive index of temperamental qualities.

Adult↗
PubMed1992

Stable behavioral inhibition and its association with anxiety disorder.

"Behavioral inhibition to the unfamiliar" is a temperamental construct reflecting the tendency to be shy, timid, and constrained in novel situations. Previous work has suggested that it may be associated with anxiety disorders in children. Psychopathology was assessed in children from a nonclinical sample originally identified as behaviorally inhibited or uninhibited at 21 months and followed through 7 1/2 years. Children who remained inhibited at 4, 5 1/2 and 7 1/2 years (Stable Inhibited) had higher rates of anxiety disorders than children who were not consistently inhibited. Their parents had higher rates of multiple childhood anxiety disorders and of continuing anxiety disorder. These results suggest that the association between behavioral inhibition and anxiety disorder is accounted for by children who have stable behavioral inhibition.

Anxiety Disorders↗
PubMed1991

Further evidence of an association between behavioral inhibition and anxiety disorders: results from a family study of children from a non-clinical sample.

Behavioral inhibition to the unfamiliar, identifiable in early childhood and reflecting the tendency to exhibit withdrawal and excessive autonomic arousal to challenge or novelty, has been found to be prevalent in young offspring of parents with panic disorder and agoraphobia and associated with risk for anxiety disorders in these children. Using family study methodology, we now examine psychopathology in first degree relatives of children from a non-clinical longitudinal cohort identified at 21 months of age as inhibited (N = 22) or uninhibited (N = 19) and followed through the age of seven years for a study of preservation of temperamental characteristics in normal children. These assessments were compared with evaluations of the first degree relatives of 20 normal comparison children. Psychiatric assessments of parents (N = 110) and siblings (N = 72) were based on structured interviews conducted blindly to the temperamental classification of the index child. Parents of inhibited children, compared with parents of uninhibited and normal controls, had significantly higher risks for multiple (greater than or equal to 2) anxiety disorders, continuing anxiety disorders (both a childhood and adulthood anxiety disorder in the same parent), social phobia, and childhood avoidant and overanxious disorders. These findings provide additional support for the hypothesis linking behavioral inhibition with risk for anxiety disorder.

Adolescent↗
PubMed1991

Temperamental factors in human development.

The initial dispositions to approach or to avoid unfamiliar events are 2 temperamental characteristics of children--among the many that have been described--that appear to be moderately stable over time and associated with distinct, physiological profiles that may be under partial genetic control. The display of high versus low levels of both motor activity and crying to unfamiliar in 4-month-old infants predicts these 2 temperamental profiles in the 2nd year. This fact implies, but does not prove, that variation in the excitability of those brain areas that mediate motor activity and crying participates in the actualization of the temperamental categories called inhibited and uninhibited to the unfamiliar.

Arousal↗
PubMed1990

Psychiatric correlates of behavioral inhibition in young children of parents with and without psychiatric disorders.

Behavioral inhibition is a laboratory-based temperamental category by the tendency to constrict behavior in unfamiliar situations and assumed to reflect low thresholds of limbic arousal. We previously found behavioral inhibition prevalent in the offspring of parents with panic disorder and agoraphobia. In this report, we examined the psychiatric correlates of behavioral inhibition by evaluating the sample of offspring of parents with panic disorder and agoraphobia, previously dichotomized as inhibited and not inhibited, and an existing epidemiologically derived sample of children, followed by Kagan and colleagues and originally identified at 21 months of age as inhibited or uninhibited. A third group of healthy children was added for comparison. Our findings indicate that inhibited children had increased risk for multiple anxiety, overanxious, and phobic disorders. It is suggested that behavioral inhibition may be associated with risk for anxiety disorders in children.

Agoraphobia↗
PubMed1988

Biological bases of childhood shyness.

The initial behavioral reaction to unfamiliar events is a distinctive source of intraspecific variation in humans and other animals. Two longitudinal studies of 2-year-old children who were extreme in the display of either behavioral restraint or spontaneity in unfamiliar contexts revealed that by 7 years of age a majority of the restrained group were quiet and socially avoidant with unfamiliar children and adults whereas a majority of the more spontaneous children were talkative and interactive. The group differences in peripheral physiological reactions suggest that inherited variation in the threshold of arousal in selected limbic sites may contribute to shyness in childhood and even extreme degrees of social avoidance in adults.

Age Factors↗
PubMed1988

Behavioral inhibition in children of parents with panic disorder and agoraphobia. A controlled study.

To investigate the role of "behavioral inhibition to the unfamiliar" as an early temperamental characteristic of children at risk for adult panic disorder and agoraphobia (PDAG), we compared children of parents with PDAG with those from psychiatric comparison groups. Fifty-six children aged 2 to 7 years, matched for age, socioeconomic status, ethnic background, and ordinal position, were blindly evaluated at the Harvard Infant Study laboratory, Cambridge, Mass. The rates of behavioral inhibition in children of probands with PDAG, with or without comorbid major depressive disorder (MDD), were significantly higher than for our comparison group without PDAG. Further, the data suggest a progression of increasing rates of inhibition from the comparison group without MDD (15.4%), to MDD (50.0%), and to comorbid PDAG and MDD (70%) and PDAG (84.6%). In contrast, the rate of behavioral inhibition in children of probands with MDD did not meaningfully differ from the comparison group without MDD. Behavioral inhibition to the unfamiliar, as defined and measured in the previous work of the Harvard Infant Study program, is highly prevalent in the offspring of adults in treatment for PDAG. These children appear to be at risk for distress and disability in childhood and also perhaps for development of psychiatric disorder in later childhood and aulthood.

Adolescent↗
PubMed1988

Childhood derivatives of inhibition and lack of inhibition to the unfamiliar.

Behavioral and physiological assessments of 41 7 1/2-year-old children who had been selected to be inhibited or uninhibited at 21 months and observed again at 4 and 5 1/2 years revealed that each of the 2 original behavioral profiles predicted theoretically reasonable derivatives. A majority of the formerly shy, timid children became quiet and socially avoidant in unfamiliar social situations, while a majority of the formerly sociable children became talkative and interactive with peers and adults. Absolute heart-rate and cortisol level at 7 1/2 years were not as discriminating of the 2 behavioral groups as they had been 2 years earlier.

Arousal↗
PubMed1987

The physiology and psychology of behavioral inhibition in children.

Longitudinal study of 2 cohorts of children selected in the second or third year of life to be extremely cautious and shy (inhibited) or fearless and outgoing (uninhibited) to unfamiliar events revealed preservation of these 2 behavioral qualities through the sixth year of life. Additionally, more of the inhibited children showed signs of activation in 1 or more of the physiological circuits that usually respond to novelty and challenge, namely, the hypothalamic-pituitary-adrenal axis, the reticular activating system, and the sympathetic arm of the autonomic nervous system. It is suggested that the threshold of responsivity in limbic and hypothalamic structures to unfamiliarity and challenge is tonically lower for inhibited than for uninhibited children.

Arousal↗
PubMedDate not supplied

Temperament and allergic symptoms.

Two independent studies of the first and second degree relatives of extremely shy versus sociable children revealed greater prevalence of hayfever and social anxiety among the relatives of the former group of children. These data, which are in accord with other research, imply a genetically mediated relation between social anxiety and selected atopic allergies.

Adult↗