Biomedical subjects

S A Mednick

Publications and source records attributed to S A Mednick.

At least 37 records · Page 2Linked to original sources

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↗

PubMed1997

Effects of child-rearing by schizophrenic mothers: a 25-year follow-up.

We conducted a 25-year follow-up study of 50 children of schizophrenic mothers, consisting of 25 children reared by their mothers and 25 children reared apart. The children's adult psychiatric status was evaluated in a 3-h structured interview employing a battery of syndrome check-lists and scales. A slightly higher incidence of psychopathology (including schizophrenia-spectrum disorders) was found among the reared-apart subjects. This may possibly be attributed to their greater genetic predisposition, as suggested by their mothers' more severe illnesses. Lifetime diagnoses do not provide evidence that psychopathology in offspring at genetic risk is increased by rearing by a schizophrenic mother.

Adolescent↗

PubMed1997

Psychophysiological protective factors for male subjects at high risk for criminal behavior.

OBJECTIVE: This study examines the role of elevated autonomic nervous system reactivity in protecting individuals at high risk for criminal behavior from antisocial outcomes. The authors hypothesized that subjects with criminal fathers who did not become criminals themselves were biologically protected from such an outcome because of, in part, heightened responsiveness of the autonomic nervous system. METHOD: Ninety-four male subjects were placed into one of four study groups: criminal with criminal father (N = 26), noncriminal with criminal father (N = 24), criminal with noncriminal father (N = 20), and noncriminal with noncriminal father (N = 24). Skin conductance and heart rate data were gathered in an orienting paradigm. RESULTS: Skin conductance and heart rate orienting reactivity were found to be significantly higher in the group of noncriminal subjects with criminal fathers than in the other three groups. CONCLUSIONS: For subjects at high risk for criminal behavior, heightened autonomic nervous system responsiveness appears to be associated with lower likelihood of criminal outcome.

Adolescent↗

PubMed1997

Interaction between birth complications and early maternal rejection in predisposing individuals to adult violence: specificity to serious, early-onset violence.

OBJECTIVE: The authors previously reported that birth complications interact with early maternal rejection in predisposing individuals to violence at age 18 years. This study extended the follow-up period for violent offending from 18 years to 34 years, thus increasing the sample of violent offenders threefold and allowing more detailed analyses on onset and type of violence, the form of maternal rejection, and the effect of maternal mental illness. METHOD: Complications in the births of 4,269 males in Denmark, maternal rejection of these individuals before the age of 1 year, and their histories of criminal offenses at age 34 years were assessed. RESULTS: The biosocial interaction previously observed held for violent but not nonviolent crime, was specific to more serious forms of violence and not threats of violence, held for early-onset but not late-onset violence, and was not accounted for by psychiatric illness in the mothers. Being reared in a public care institution in the first year of life and the mother's attempt to abort the fetus were the key aspects of maternal rejection that interacted with birth complications in predisposing a subject to violence. CONCLUSIONS: These findings 1) indicate that the mechanisms underlying early-onset, serious violence differ from those for less serious, late-onset violence, 2) implicate very early factors in the development of violence, 3) highlight the potential importance of integrating psychosocial with biological factors in understanding and preventing violence, and 4) suggest that interventions to reduce birth complications and maternal rejection may help reduce violence.

Adolescent↗

PubMed1996

Rhesus incompatibility as a risk factor for schizophrenia in male adults.

BACKGROUND: Rhesus (Rh) incompatibility is a cause of hemolytic disease of the fetus and newborn. Hemolytic disease results from the transplacentally transmitted maternal antibodies against Rh factor D and can cause permanent neurological damage in the affected newborn. This study examines the hypothesis that Rh incompatibility may be a risk factor for schizophrenia. METHODS: A sample of 1867 male subjects was divided into two groups, 535 Rh incompatible and 1332 Rh compatible, and compared on rate of schizophrenia. RESULTS: The rate of schizophrenia was significantly higher in the Rh-incompatible group (2.1%) compared with the Rh-compatible group (0.8%) (P < .03). In addition, since the risk for Rh hemolytic disease increases with second and later Rh incompatible pregnancies, it is noteworthy that the second- and later-born incompatible offspring exhibited a significantly higher rate of schizophrenia than second- and later-born compatible offspring (P < .05). Also, as predicted, the rate of schizophrenia among firstborn incompatible subjects was not significantly different from that of firstborn compatible subjects (1.1% vs 0.7%). CONCLUSION: Rh incompatibility may be a risk factor for schizophrenia.

Adult↗

PubMed1996

The electroencephalogram after alcohol administration in high-risk men and the development of alcohol use disorders 10 years later.

BACKGROUND: In 1979 through 1980, electroencephalographic (EEG) responses to an alcohol challenge in 19 year-old sons of alcoholics as well as in sons of nonalcoholic control subjects were examined. The familial risk status of the subjects and greater EEG sensitivity to alcohol were hypothesized to predict the development of alcoholism 10 years later. METHODS: In 1990 through 1992, diagnostic interviews were completed to ascertain alcohol and other substance use disorders in these subjects and to update their family history. RESULTS: Updated family history of alcoholism predicted the development of substance dependence. Density of alcoholic relatives (the number of alcoholic relatives divided by the number of known relatives) was positively related to the severity of alcohol use disorders in the probands. Contrary to expectation, a greater EEG response at age 19 years was not related to the later development of alcohol dependence. Instead, the opposite was observed: a smaller EEG alpha frequency response to alcohol at age 19 years was related to the development of alcohol dependence and high quantity and frequency of alcohol consumption 10 years later. CONCLUSIONS: Lower EEG response to a small dose of alcohol may be associated with the later development of alcohol dependence. This result is based on a small number of subjects and should be interpreted with caution. Although this result is opposite to our 1980 hypothesis, it is consistent with much of the recent literature.

Adult↗

PubMed1996

Mental disorder and crime. Evidence from a Danish birth cohort.

BACKGROUND: Evidence has accumulated since the mid 1960s from a number of different countries indicating an association between mental disorder and crime and particularly between the major mental disorders and violence. Registries in Denmark were used to identify a birth cohort and to document all psychiatric admissions and all criminal proceedings of the 324401 members of this cohort up to the age of 43 years. METHODS: Persons who had been admitted to a psychiatric ward were assigned to a diagnostic category according to a hierarchy of principal discharge diagnoses. They were compared with persons never admitted to a psychiatric ward as to the prevalence, type, and frequency of criminal convictions. RESULTS: Women and men who had been hospitalized in psychiatric wards were more likely to have been convicted of a criminal offense than persons with no history of psychiatric hospitalization. The offenders who were hospitalized committed all types and, on average, as many offenses as did the never-hospitalized group of the same sex. CONCLUSIONS: These findings confirm those from 2 other post-World War II Scandinavian birth cohorts that have found an association between psychiatric hospitalization and criminal convictions. They also concur with findings that patients discharged from psychiatric wards are more likely than other persons living in the same community to commit crimes and with results from North America showing elevated rates of major mental disorders among incarcerated offenders. Generalization of these findings is limited to nations with similar criminal justice, mental health, and social welfare systems.

Adult↗

PubMed1996

High rates of violence, crime, academic problems, and behavioral problems in males with both early neuromotor deficits and unstable family environments.

BACKGROUND: It is commonly assumed that individuals with both biological and psychosocial deficits are more likely to become criminal, but there is surprisingly little empirical support for this assumption. We test the hypothesis that a group with biosocial risk factors are more likely to develop behavioral and academic problems in adolescence and violent criminal offending in adult-hood compared with groups with only biological or only social risk factors. METHODS: Hypotheses were tested on a sample of 397 male subjects, using obstetric and early neuromotor measures collected in the first year of life; family, social, demographic, and behavioral measures at age 17 to 19 years; and criminal data at 20 to 22 years of age. RESULTS: Cluster analysis of the risk factors indicated a group with obstetric risk factors only, a group with poverty risk factors only, and a biosocial group with both early neuromotor deficits and unstable family environments. The biosocial group had more than double the adult violence, theft, and total crime rates of the other 2 groups and had significantly more behavioral and academic problems in adolescence. CONCLUSIONS: When early neuromotor deficits and negative family factors cluster together, individuals are particularly likely to become criminal and violent compared with those with only poverty or only obstetric risk factors. Because this biosocial group accounted for 70.2% of all crimes committed in the entire sample, early interventions that tackle these deficits might significantly reduce violence.

Achievement↗

PubMed1996

Assessing the role of genetics in crime using adoption cohorts.

The role of genetics in criminal behaviour can be assessed through family, twin and adoption studies. This paper discusses the major findings of adoption studies that have focused on criminal outcome. Results from adoption studies have consistently revealed a relationship between biological parent criminal behaviour and adoptee criminal outcome. This finding has been noted in the case of property crime, but not in the case of violent crime. Violent crime in adopted-away offspring is not related to violent crime in biological parents. Findings from the Danish Adoption Cohort suggest that violent crime may be genetically related to other types of behavioural deviance. In the Danish Adoption Cohort, there is an increased rate of schizophrenia in the adopted-away offspring of biological fathers who are convicted of violent crimes. This father violence-adoptee schizophrenia relationship cannot be accounted for by the potential confounding factors of rearing social status, age at transfer, knowledge of family history of crime, or biological parents' mental illness.

Adoption↗

PubMed1996

Risk factors of psychosis: identifying vulnerable populations premorbidly.

This article reviews premorbid indicators of psychosis that may be relevant to primary intervention. These risk markers are divided into two categories: (1) precursors related to early etiological factors (family psychiatric history, perinatal and obstetric complications, neurobehavior deficits, early parental separation, institutionalization, and poor family function) and (2) precursors signaling latent mental illness (personality measurements indicating proneness to psychosis, and teacher ratings indicating emotional lability, social anxiety, social withdrawal, passivity, poor peer relations, and disruptive and aggressive behavior). Because teacher ratings have been shown to be powerful predictors of adult mental breakdown, part of this article focuses on a specific study that assesses such ratings as predictors of psychosis in a high-risk population. Risk indicators may also provide clues about protective factors relevant for primary prevention.

Adolescent↗

PubMed1995

The stability of inhibited/uninhibited temperament from ages 3 to 11 years in Mauritian children.

Stability of inhibited/uninhibited temperament was assessed using 1,795 Mauritian children tested at ages 3, 8, and 11 years. Children were divided into uninhibited, middle, and inhibited groups at each age based on social behavior. Results indicated that, relative to uninhibited children (1) those inhibited at age 3 obtained larger inhibition scores at age 8 (p < .0001), (2) those inhibited at age 8 obtained larger inhibition scores at age 11 (p < .002), and (3) those remaining inhibited from ages 3 to 8 obtained larger inhibition scores at age 11 (p < .002). Relative to children who changed classification from ages 3 to 8, those remaining inhibited obtained larger inhibition scores (p < .05) and those remaining uninhibited obtained smaller inhibition scores (p < .015) at age 11. Inhibition scores tended to be higher in females by age 11. Results remained regardless of ethnicity. The results provide some support that inhibited/uninhibited temperament remains stable from ages 3 to 8 and may continue to age 11. The results suggest cross-cultural generalizability of these findings with implications regarding the development of anxiety disorders in the Mauritian population.

Anxiety Disorders↗

PubMed1995

Assessing the predictive value of teacher reports in a high risk sample for schizophrenia: a ROC analysis.

We examined teachers' reports to determine early patterns of school behavior that identify children who were diagnosed schizophrenic in adulthood. High risk subjects (n = 207) in the Copenhagen High Risk for schizophrenia project were examined on a 25-item questionnaire completed by teachers. A likelihood ratio approach was used to create a classification index relating school report to DSM-IIIR diagnoses made 31 years later. A standard receiver operating characteristic (ROC) analysis was used to evaluate the efficacy of the classification indices for distinguishing preschizophrenics from children who later developed schizotypal disorder, other nonpsychotic disorders, and no mental illness. Different items predicted schizophrenia in males and females. To a significantly greater degree than their controls, preschizophrenic males were lonely and rejected, behaved inappropriately, were disciplinary problems, emotionally high strung, and were more likely to have repeated a grade; preschizophrenic females were nervous and passive. Both preschizophrenic males and females were judged by teachers to be vulnerable to future psychotic problems. These findings are consistent with our preliminary findings, as well as with other research. They highlight the ability of teachers to identify school behaviors that may be used to select future schizophrenics for early intervention.

Adolescent↗

PubMed1995

The latent structure of schizotypy: I. Premorbid indicators of a taxon of individuals at risk for schizophrenia-spectrum disorders.

A taxometric analysis (R. R. Golden & P. E. Meehl, 1979) was conducted to test the hypotheses that liability for schizophrenia-spectrum disorders is dichotomously distributed and that this liability can be detected premorbidly with behavioral indicators analogous to many of the criteria for schizotypal personality disorder. Behaviors were assessed in 207 offspring of schizophrenic mothers and 104 matched offspring of normal parents in 1962, when participants' mean age was 15 years. Diagnoses on the basis of the Diagnostic and Statistical Manual of Mental Disorders (3rd ed., rev.; American Psychiatric Association, 1987) were made in 1986-1989, when participants were nearly through the risk period for developing schizophrenia. The aggregation of indicators was consistent with a bimodal latent liability distribution. Membership in the schizotypal class was a sensitive and specific predictor of the emergence of schizophrenia-spectrum disorders in adulthood.

Adolescent↗

PubMed1994

Impaired autonomic nervous system-habituation in those at genetic risk for schizophrenia.

BACKGROUND: Schizophrenia has been associated with habituation of skin conductance activity. Skin conductance data from the Copenhagen High Risk Project were analyzed. We hypothesized that genetic risk for schizophrenia and development of schizophrenia later in life are related to impaired habituation of autonomic nervous system activity. METHODS: Data were collected in 1962, when subjects averaged 15 years of age and had not yet qualified for a psychiatric diagnosis. Nonspecific fluctuations in electrodermal activity were monitored during a rest period free of sensory stimulation. RESULTS: We found that an increasing level of genetic risk for schizophrenia was related to impaired habituation of autonomic nervous system activity over time. Individuals with two schizophrenia-spectrum parent evidenced no habituation, those with one spectrum parent evidence some habituation, and those with normal parents evidenced rapid habituation. Subjects who developed schizophrenia in adulthood evidenced significant deficits in habitation in adolescence. CONCLUSIONS: These results suggest that impaired habituation of spontaneous autonomic nervous system activity may represent a behavioral marker of the genetic predisposition to schizophrenia.

Adolescent↗

PubMed1994

Developmental brain abnormalities in the offspring of schizophrenic mothers. II. Structural brain characteristics of schizophrenia and schizotypal personality disorder.

BACKGROUND: We examined differences in ventricular and sulcal cerebrospinal fluid-to-brain ratios as a function of lifetime psychiatric diagnosis in the offspring of schizophrenic mothers (high-risk sample) and in the offspring of normal parents (low-risk sample). METHODS: We used a cohort analytic study of 17 high-risk individuals with schizophrenia, 31 high-risk individuals with schizotypal personality disorder, 33 high-risk individuals with nonschizophrenia-spectrum psychiatric disorders, 45 high-risk individuals with no disorders, 31 low-risk individuals with psychiatric disorders of all types, and 46 low-risk individuals with no disorders, evaluated initially in 1962 when they were a mean age of 15 years, and reexamined from 1986 through 1989 with psychiatric interviews and computed tomographic scans of the brain. RESULTS: High-risk individuals with schizophrenia and schizotypal personality disorder evidenced an equivalent degree of cortical sulcal enlargement, and both groups evidenced significantly greater sulcal enlargement than did high-risk individuals with nonschizophrenia-spectrum disorders and no disorders and low-risk individuals with psychiatric disorders and no disorders. High-risk individuals with schizophrenia evidenced significantly greater ventricular enlargement than did high-risk and low-risk subjects with other disorders and no disorders, including those with schizotypal personality disorder. These differences were independent of age, gender, history of substance dependence, and history of organic brain syndromes and head injuries. CONCLUSIONS: Among the offspring of schizophrenic parents, cortical abnormalities are expressed equally across the range of syndromes in the schizophrenia spectrum. Subcortical abnormalities (ie, ventricular enlargement) are more pronounced in the more severe syndrome (ie, schizophrenia).

Adult↗

PubMed1994

Birth complications combined with early maternal rejection at age 1 year predispose to violent crime at age 18 years.

BACKGROUND: This study tests the bisocial interaction hypothesis that birth complications when combined with early maternal rejection of the infant predispose to adult violent crime. METHODS: This hypothesis was tested using a cohort of 4269 consecutive live male births on whom measures of birth complications (age 0), early maternal rejection (age 1 year), and violent crime (age 18 years) were collected. RESULTS: A significant interaction (P < .0001) between birth complications and early maternal rejection indicated that those who suffered both birth complications and early child rejection were most likely to become violent offenders in adulthood. While only 4.5% of the subjects had both risk factors, this small group accounted for 18% of all violent crimes. The effect was specific to violence and was not observed for nonviolent criminal offending. CONCLUSIONS: To our knowledge, this is the first study to show that birth complications in combination with early child rejection predispose to violent crime. The findings illustrate the critical importance of integrating biological with social measures to fully understand how violence develops and also suggest that prenatal, perinatal, and early postnatal health care interventions could significantly reduce violence.

Adult↗

PubMed1994

The influence of parental socioeconomic status on CT studies of schizophrenia.

A sample of 19 DSM-III-R schizophrenics and 94 controls with no mental illness from the Copenhagen high-risk project was used to test the hypothesis that social class of origin is related to adult CT measures of ventricular, sulcal, Sylvian fissure and anterior interhemispheric fissure enlargement, cerebellar pathology, and brain volume. The schizophrenics and controls were divided into high and low SES-of-origin. No significant differences emerged between the high and low SES-of-origin subjects within the schizophrenic and control groups on any of the six CT measures.

Adolescent↗

PubMed1994

Learning theory approach to the deterrence of criminal recidivism.

Data on punishment and criminal arrests in a total birth cohort of men in Denmark (N = 28,879) was used to test the following hypotheses derived from learning theory: (a) the imposition of sanctions reduces rates of subsequent criminal arrest; (b) the more severe the sanction received for an arrest, the lower the rate of recidivism; (c) different types of sanctions have similar effects on recidivism; (d) the higher the proportion of sanctions received for past arrests, the lower the rates of future arrest; (e) continuous sanctions reduce arrest rates more than intermittent sanctions; and (f) discontinuation of punishment results in recovery of criminal arrests. Results support the above hypotheses, except Hypothesis b; our results suggest that sanctions have similar effects on recidivism regardless of their severity.

Adult↗