Biomedical subjects

S A Mednick

Publications and source records attributed to S A Mednick.

At least 19 recordsLinked to original sources

PubMed2005

Breastfeeding and risk of schizophrenia in the Copenhagen Perinatal Cohort.

OBJECTIVE: The aim was to study whether early weaning from breastfeeding may be associated with increased risk of schizophrenia. METHOD: The current sample comprises 6841 individuals from the Copenhagen Perinatal Cohort of whom 1671 (24%) had been breastfed for 2 weeks or less (early weaning) and 5170 (76%) had been breastfed longer. Maternal schizophrenia, parental social status, single mother status and gender were included as covariates in a multiple regression analysis of the effect of early weaning on the risk of hospitalization with schizophrenia. RESULTS: The sample comprised 93 cases of schizophrenia (1.4%). Maternal schizophrenia was the strongest risk factor and a significant association between single mother status and elevated offspring risk of schizophrenia was also observed. Early weaning was significantly related to later schizophrenia in both unadjusted and adjusted analyses (adjusted odds ratio 1.73 with 95% CI: 1.13-2.67). CONCLUSION: No or <2 weeks of breastfeeding was associated with elevated risk of schizophrenia. The hypothesis of some protective effect of breastfeeding against the risk of later schizophrenia is supported by our data.

Adult↗

PubMed2004

Prediction of mortality at age 40 in Danish males at high and low risk for alcoholism.

OBJECTIVE: This prospective high-risk study examined the influence of father's alcoholism and other archival-generated measures on premature death. METHOD: Sons of alcoholic fathers (n = 223) and sons of non-alcoholic fathers (n = 106) have been studied from birth to age 40. Archival predictors of premature death included father's alcoholism, childhood developmental data, and diagnostic information obtained from the Psychiatric Register and alcoholism clinics. RESULTS: By age 40, 21 of the 329 subjects had died (6.4%), a rate that is more than two times greater than expected. Sons of alcoholic fathers were not more likely to die by age 40. Premature death was associated with physical immaturity at 1-year of age and psychiatric/alcoholism treatment. No significant interactions were found between risk and archival measures. CONCLUSION: Genetic vulnerability did not independently predict death at age 40. Death was associated with developmental immaturities and treatment for a psychiatric and/or substance abuse problem.

Adult↗

PubMed2001

Male criminals with organic brain syndrome: two distinct types based on age at first arrest.

OBJECTIVE: This study examined whether criminals with organic brain syndrome could be divided into two distinct types. The authors proposed that early starters (onset of criminal activity by age 18) would display a persistent, long-lasting pattern of deviance that was largely independent of their brain disorder, whereas late starters (onset at age 19 or after) would exhibit deviant behaviors that began late in life and were more directly related to their brain disorder. METHOD: Subjects were 1,130 male criminal offenders drawn from a birth cohort of all individuals born between January 1, 1944, and December 31, 1947, in Denmark. The main study group included all men with both a history of criminal arrest and a hospitalization for organic brain syndrome (N=565). In addition, for a subset of analyses, the authors examined a randomly selected, same-size comparison group of men with a history of criminal arrest who were not hospitalized for organic brain syndrome. Data were available on all arrests and all psychiatric hospitalizations for individuals in this cohort through the age of 44. RESULTS: Among those with organic brain syndrome, early starters were significantly more likely than late starters to 1) be arrested before the onset of organic brain syndrome, 2) show a higher rate of offending before but not after the onset of organic brain syndrome, 3) be both recidivists and violent recidivists, and 4) have a diagnosis of antisocial personality disorder. CONCLUSIONS: Male criminals with organic brain syndrome can be meaningfully divided into two distinct types on the basis of age at first arrest. Early starters show a more global, persistent, and stable pattern of offending than late starters. These results have implications for treatment and risk assessment.

Adult↗

PubMed2001

Early educational and health enrichment at age 3-5 years is associated with increased autonomic and central nervous system arousal and orienting at age 11 years: evidence from the Mauritius Child Health Project.

Little is known about the effects of environmental enrichment on psychophysiological measures of arousal and orienting in humans. This study tests the hypothesis that early educational and health enrichment is associated with long-term increases in psychophysiological orienting and arousal. One hundred children were experimentally assigned to a two-year enriched nursery school intervention at ages 3-5 years and matched at age 3 years on psychophysiological measures, gender, and ethnicity to 100 comparisons who received the normal educational experience. Children were retested 6-8 years later at age 11 years on skin conductance (SC) and electroencephalogram (EEG) measures of arousal and attention during pre- and postexperimental rest periods and during the continuous performance task. Nursery enrichment was associated with increased SC amplitudes, faster SC rise times, faster SC recovery times, and less slow-wave EEG during both rest and CPT conditions. This is believed to be the first study to show that early environmental enrichment is associated with long-term increases in psychophysiological orienting and arousal in humans. Results draw attention to the important influence of the early environment in shaping later psychophysiological functioning.

Arousal↗

PubMed2000

Major mental disorders and criminal violence in a Danish birth cohort.

BACKGROUND: This epidemiological investigation was designed to examine the relationships between each of the major mental disorders and criminal violence. Specifically, we assessed whether a significant relationship exists between violence and hospitalization for a major mental disorder, and whether this relationship differs for schizophrenia, affective psychoses, and organic brain syndromes. METHODS: Subjects were drawn from a birth cohort of all individuals born between January 1, 1944, and December 31, 1947, in Denmark (N = 358 180). Because of the existence of accurate and complete national registers, data were available on all arrests for violence and all hospitalizations for mental illness that occurred for individuals in this cohort through the age of 44 years. RESULTS: There was a significant positive relationship between the major mental disorders that led to hospitalization and criminal violence (odds ratios 2.0-8.8 for men and 3.9-23.2 for women). Persons hospitalized for a major mental disorder were responsible for a disproportionate percentage of violence committed by the members of the birth cohort. Men with organic psychoses and both men and women with schizophrenia were significantly more likely to be arrested for criminal violence than were persons who had never been hospitalized, even when controlling for demographic factors, substance abuse, and personality disorders. CONCLUSIONS: Individuals hospitalized for schizophrenia and men hospitalized with organic psychosis have higher rates of arrests for violence than those never hospitalized. This relationship cannot be fully explained by demographic factors or comorbid substance abuse.

Adult↗

PubMed2000

Three-factor model of schizotypal personality: invariance across culture, gender, religious affiliation, family adversity, and psychopathology.

Whilst the syndrome approach to schizotypy has recently demonstrated differential correlates of a three-factor model of schizotypal personality, variations in the nature of these factors question a basic assumption of this approach. This study tested competing models of the factor structure of schizotypal personality using the Schizotypal Personality Questionnaire (SPQ) in a sample of 1,201 Mauritians. Factor invariance across gender, ethnicity, family adversity, and religion and across a psychopathologically select group was also assessed. Results suggest that a three-factor model, Cognitive-Perceptual Deficits, Interpersonal Deficits, and Disorganization, underlies individual differences across widely varying groups. Other competing three-factor schizotypal personality models did not fit the data better. It is argued that the three-factor Disorganized model is a well-replicated model of DSM schizotypal personality in community samples but possibly not in some clinical samples.

Adult↗

PubMed1999

Maternal smoking during pregnancy and adult male criminal outcomes.

BACKGROUND: Perinatal risk factors are related to persistent and violent criminal outcomes. Prenatal maternal smoking may represent an additional perinatal risk factor for adult criminal outcomes. Our study examines maternal smoking during pregnancy as a predictor of offspring crime in the context of a prospective, longitudinal design. METHODS: Subjects were a birth cohort of 4169 males born between September 1959 and December 1961 in Copenhagen, Denmark. During the third trimester of pregnancy, mothers self-reported the number of cigarettes smoked daily. When the male offspring were 34 years of age, their arrest histories were checked in the Danish National Criminal Register. Additional data were collected concerning maternal rejection, socioeconomic status, maternal age, pregnancy and delivery complications, use of drugs during pregnancy, paternal criminal history, and parental psychiatric hospitalization. RESULTS: Results indicate a dose-response relationship between amount of maternal prenatal smoking and arrests for nonviolent and violent crimes. Maternal prenatal smoking was particularly related to persistent criminal behavior rather than to arrests confined to adolescence. These relationships remained significant after potential demographic, parental, and perinatal risk confounds were controlled for. CONCLUSIONS: Maternal prenatal smoking predicts persistent criminal outcome in male offspring. This relationship has not been accounted for by related parental characteristics or perinatal problems. Potential physiologic or central nervous system mediators between maternal smoking during pregnancy and offspring criminal outcomes need further study.

Adolescent↗

PubMed1999

Prenatal teratogens and the development of adult mental illness.

Our findings in the Helsinki Influenza Study and the Danish Forty Year Study lead us to conclude that a 2nd-trimester maternal influenza infection may increase risk for adult schizophrenia or adult major affective disorder. More recently we have also reported an increase of unipolar depression among offspring who were exposed prenatally to a severe earthquake (7.8 on the Richter scale) in Tangshan, China. Among the earthquake-exposed males (but not the females), we observed a significantly greater depression response for those individuals exposed during the 2nd trimester of gestation. These findings suggest that maternal influenza infection and severe maternal stress may operate (in different ways) as teratogens, disrupting the development of the fetal brain and increasing risk for developing schizophrenia or depression in adulthood.

Adult↗

PubMed1999

Skin-conductance orienting deficits and increased alcoholism in schizotypal criminals.

This study tested the interaction hypothesis that a subgroup of criminals with schizotypal personality would show skin-conductance orienting deficits and increased alcoholism. In a prospective, longitudinal study of alcoholism in 134 males, schizotypy was assessed during adolescence, skin-conductance orienting was assessed at ages 18-20 years, and criminal offending and alcohol abuse were assessed at ages 30-33 years. A significant interaction between schizotypy and criminality indicated that schizotypal criminals were characterized by autonomic orienting deficits. Furthermore, the rate of alcoholism in schizotypal criminals (54.8%) was significantly higher than in criminals (23.8%), schizotypal noncriminals (13.9%), and comparisons (21.7%). It is argued that schizotypal criminals are a relatively distinct group and that prefrontal dysfunction may underlie both orienting deficits and alcoholism in this group.

Acoustic Stimulation↗

PubMed1999

MMPI variables predictive of schizophrenia in the Copenhagen High-Risk Project: a 25-year follow-up.

Moldin et al. (1) have identified a cluster of Minnesota Multiphasic Personality Inventory (MMPI) scales that discriminate adolescents at risk for schizophrenia from those not at risk. The present study examines how well Moldin's scales predict schizophrenic decompensation in a sample of 207 Danish adolescents at high genetic risk for schizophrenia. Subjects were assessed using a modified, 304-item MMPI in 1962 (mean age= 15.1 years) and diagnosed in 10-year and 25-year follow-ups. Premorbidly, schizophrenic subjects (n=31) scored higher than subjects with no mental illness on the frequency (F) and psychoticism (PSY) scales. When paranoid and non-paranoid preschizophrenics were separated, three scales (F, Pz (paranoid schizophrenia) and PSY) significantly discriminated paranoid preschizophrenics. Discriminant function analyses confirmed these results. It is concluded that the MMPI may be useful for identifying schizophrenia premorbidly.

Adolescent↗

PubMed1998

Fearlessness, stimulation-seeking, and large body size at age 3 years as early predispositions to childhood aggression at age 11 years.

BACKGROUND: Previous cross-sectional research in Western societies has linked adolescent stimulation-seeking, fearlessness, and body size to antisocial behavior. However, it is unclear how early in life these factors exert their influence, and nothing is known about their specificity to aggressive behavior per se. This study tests the hypotheses that stimulation-seeking, fearlessness, and increased body size at age 3 years predict aggression at age 11 years. METHODS: Behavioral measures of stimulation-seeking and fearlessness, together with height and weight, were measured at age 3 years and related to ratings of aggression at age 11 years in 1130 male and female Indian and Creole children from the island of Mauritius. RESULTS: Aggressive children at age 11 years were characterized by increased measures of stimulation-seeking, fearlessness, height, and weight at age 3 years. Stimulation-seeking and height were independently related to aggression, whereas the fearlessness-aggression relationship was mediated by height. Large body size at age 3 years but not 11 years was related to increased aggression at age 11 years, indicating a critical period in development for the influence of body size on aggression. CONCLUSIONS: Results (1) implicate large body size, stimulation-seeking, and fearlessness in the development of childhood aggression; (2) suggest that there may be a critical period in development in which biological processes influence later aggression; and (3) highlight the importance of early processes in the etiology of aggression.

Age Factors↗

PubMed1998

Mental illness and criminal violence.

This article examines the relationship between criminal violence and mental illness. Our data suggest that mentally ill persons tend to have an increased risk for committing violent offenses, and that the violent offending by these individuals tends to be recidivistic. Our findings suggest that parents who have both committed violent offenses and experienced a psychiatric hospitalization increase the risk of violent offending among their offspring. We propose the hypothesis that mentally ill parents transmit a biological characteristic which may genetically predispose their child towards criminal violence. Prenatal disturbances during critical periods of fetal development may provide clues regarding the etiology of criminal violence.

Adult↗

PubMed1998

School teacher ratings predictive of psychiatric outcome 25 years later.

BACKGROUND: The current study examines teacher ratings as a tool for identifying students at risk of developing psychosis. Follow-up and follow-back studies have shown that teachers are capable of identifying individuals who later develop serious mental illness. METHOD: We examine the long-term outcomes for individuals at genetic risk who were identified as showing markedly deviant behaviour and those identified who did not show markedly deviant behaviour. RESULTS: Teachers were able to correctly anticipate 35% of students who developed schizophrenia. Furthermore, those identified as showing markedly deviant behaviour had poorer clinical and psychiatric outcomes 10 and 25 years later than those identified as not behaving with marked deviance. Their ratings also differentiated, within the group of people with schizophrenia, which individuals would show evidence of poorer functioning 25 years later. These results were replicated in a group of students not at genetic risk of schizophrenia. Within this low-risk group, teachers were able to predict which students would develop psychotic disorders. CONCLUSIONS: Teacher ratings were particularly useful in predicting clinical and psychiatric outcomes 10 and 25 years later. The applicability of these findings in early intervention and treatment research is discussed.

Adolescent↗

PubMed1997

Structural brain abnormalities in schizophrenia: a family study.

Structural brain abnormalities such as ventricular enlargement are robust correlates of schizophrenia, but the degree of difference compared with unrelated normal controls is only moderate (< 1 standard deviation), and only 40% of patients have values on these measures that fall outside of the normal distribution. Family studies can help to clarify the meaning of this overlap by controlling for some of the non-schizophrenia-related genetic variation in neuroanatomical traits. Computerized tomographic scans of the brain were used to measure ventricular and sulcal cerebrospinal fluid (CSF) to brain ratios (VBR and SBR) for each hemisphere in 16 pairs of discordant siblings from the Copenhagen Schizophrenia High-Risk Project. Schizophrenics' values for VBR and SBR exceeded those of their nonschizophrenic siblings in 75% of the pairs; on average, patients' values on these measures were 1 and 5 standard deviations larger, respectively, than those of their nonschizophrenic siblings. Sulcal and left hemisphere effects were significantly more pronounced than ventricular and right hemisphere effects. After controlling for between-family variation, structural brain abnormalities appear to be more prevalent and more pronounced in schizophrenia than has previously been assumed, with relatively greater deviation observed for cortical and left hemisphere measures of CSF space enlargement.

Adult↗

PubMed1997

Adult major affective disorder after prenatal exposure to an influenza epidemic.

BACKGROUND: We have previously reported an increase in schizophrenia diagnoses in a population exposed during the second trimester to the 1957 influenza epidemic. These basic findings together with a fair number of replications have been interpreted as supporting a neurodevelopmental contribution to the origins of schizophrenia. Recent neuroimaging findings suggest that affective illness may also have a neurodevelopmental origin. We examined the hypothesis that exposure to an influenza epidemic during the second trimester would increase the risk for adult major affective disorder. METHODS: The subjects had been exposed as fetuses to the type A2/Singapore influenza epidemic in greater Helsinki, Finland. Control subjects were born in the 6 years before the epidemic. RESULTS: We found a significant (P < .001) increase in the proportion of hospital diagnoses for major affective disorder for individuals exposed to the influenza epidemic during their second trimester of fetal development compared with control subjects (13% vs 2%). This second-trimester effect seems somewhat stronger in men (16% vs 2%) (P < .001), although the rates of major affective disorder in women (8% vs 3%) (P > .05) were similar. The second-trimester effect remained when we estimated population-based rates (2.1 vs 0.6 per 1000) (P < .05) of major affective disorder. Additional analyses revealed that the increase of major affective disorder among subjects in the index group who were exposed during the second trimester was due to a significant (P < .002) elevation of unipolar forms, although a similar though not significant (P > .05) elevation was observed for the bipolar forms of major affective disorder. CONCLUSIONS: These data are consistent with the hypothesis concerning the possible neurodevelopmental contribution to the origins of some forms of major affective disorder, especially unipolar depressive disorder. These encouraging findings, if replicated, may suggest that some mental disorders may stem, in part, from a disturbance in the development of the fetal brain during the second trimester.

Adult↗

PubMed1997

Heart rate and skin conductance in behaviorally inhibited Mauritian children.

This study tested predictions that inhibited versus uninhibited children exhibit higher heart rate (HR) and skin conductance (SC) arousal. Mauritian children (N = 1,795) were tested at age 3 and classified as inhibited, middle, or uninhibited on the basis of social behavior. HR level and several SC measures were obtained immediately before or during a tone task. Inhibited children displayed significantly higher HR and SC levels and longer SC latency relative to uninhibited children. Results remained regardless of ethnicity, gender, height, weight, respiratory complaints, or crying behavior. Findings suggest that HR and SC levels may be early indicators of inhibited or uninhibited behavior at age 3 and support the notion of heightened sympathetic reactivity due to limbic arousal in inhibited children.

Arousal↗

PubMed1997

Childhood behavior precursors of schizotypal personality disorder.

No study has yet reported specifically on the early behavior of individuals later diagnosed with schizotypal personality disorder (SPD). This study examines prospectively collected teacher reports on school behavior as a means of assessing childhood precursors of SPD. Thirty-six DSM-III-R diagnosed schizotypal subjects were compared with four other groups: 31 schizophrenia patients, 37 diagnosed as nonpsychotic mentally ill, 68 who were not mentally ill but had mothers with schizophrenia, and 60 who were not mentally ill and had normal parents. These individuals were compared on a teachers' school report questionnaire obtained when the subjects averaged 15.1 years old. Those who later developed SPD were found to be more passive and unengaged and more hypersensitive to criticisms compared with the nonschizophrenia groups. Similar results were found when males and females were examined separately, except that males who developed SPD were found to be less disruptive and hyperexcitable compared with males with schizophrenia; females with SPD did not differ from females with schizophrenia. A receiver operating characteristic analysis found these factors to predict 73.5 percent of future SPDs; the ability of these factors to predict future SPDs is comparable for males and females. These findings suggest that preschizotypal traits may be identified in late childhood or adolescence.

Adolescent↗

PubMed1997

Low resting heart rate at age 3 years predisposes to aggression at age 11 years: evidence from the Mauritius Child Health Project.

OBJECTIVE: Previous studies indicate that low resting heart rate is probably the best-replicated biological correlate of childhood antisocial and aggressive behavior. Nevertheless, there have been few longitudinal tests of this relationship, little control over potential confounds and mediators, and no test of its cross-cultural generalizability. This study tests the hypothesis that low resting heart rate at age 3 years predicts aggression at age 11 years. METHOD: Resting heart rate at age 3 years was assessed in 1,795 male and female children from Mauritius. Aggressive and nonaggressive forms of antisocial behavior were assessed at age 11 years using the Child Behavior Checklist. RESULTS: Aggressive children had lower heart rates than nonaggressive children (p < .001). Conversely, those with low heart rates were more aggressive than those with high heart rates (p < .003). There were no interactions with gender or ethnicity. Evidence was found for specificity of low heart rate to aggressive forms of antisocial behavior. Group differences in heart rate were not attributable to 11 biological, psychological, and psychiatric mediators and confounds. CONCLUSIONS: It is concluded that low resting heart rate, a partly heritable trait reflecting fearlessness and stimulation-seeking, is an important, diagnostically specific, well-replicated, early biological marker for later aggressive behavior.

Aggression↗