Mild Traumatic Brain Injury Does Not Significantly Affect Midlife Cognitive Functioning Within the General Population: Findings From a Prospective Longitudinal Birth Cohort Study.

OBJECTIVE: To determine whether differences exist in mid-adulthood cognitive functioning in people with and without history of mild traumatic brain injury (mTBI). SETTING: Community-based study. PARTICIPANTS: People born between April 1, 1972, and March 31, 1973, recruited into the Dunedin Multidisciplinary Health and Development Longitudinal Study, who completed neuropsychological assessments in mid-adulthood. Participants who had experienced a moderate or severe TBI or mTBI in the past 12 months were excluded. DESIGN: Longitudinal, prospective, observational study. MAIN MEASURES: Data were collected on sociodemographic characteristics, medical history, childhood cognition (between 7 and 11 years), and alcohol and substance dependence (from 21 years of age). mTBI history was determined from accident and medical records (from birth to 45 years of age). Participants were classified as having 1 mTBI and more in their lifetime or no mTBI. The Wechsler Adult Intelligence Scale (WAIS-IV) and Trail Making Tests A and B (between 38 and 45 years of age) were used to assess cognitive functioning. T tests and effect sizes were used to identify any differences on cognitive functioning domains between the mTBI and no mTBI groups. Regression models explored the relative contribution of number of mTBIs and age of first mTBI and sociodemographic/lifestyle variables on cognitive functioning. RESULTS: Of the 885 participants, 518 (58.5%) had experienced at least 1 mTBI over their lifetime, with a mean number of 2.5 mTBIs. The mTBI group had significantly slower processing speed ( P < .01, d = 0.23) in mid-adulthood than the no TBI controls, with a medium effect size. However, the relationship no longer remained significant after controlling for childhood cognition, sociodemographic and lifestyle factors. No significant differences were observed for overall intelligence, verbal comprehension, perceptual reasoning, working memory, attention, or cognitive flexibility. Childhood cognition was not linked to likelihood of sustaining mTBI later in life. CONCLUSION: mTBI histories in the general population were not associated with lower cognitive functioning in mid-adulthood once sociodemographic and lifestyle factors were taken into account.

Predicting the counterproductive employee in a child-to-adult prospective study.

The present research tested the relations between a battery of background factors and counterproductive work behaviors in a 23-year longitudinal study of young adults (N = 930). Background information, such as diagnosed adolescent conduct disorder, criminal conviction records, intelligence, and personality traits, was assessed before participants entered the labor force. These background factors were combined with work conditions at age 26 to predict counterproductive work behaviors at age 26. The results showed that people diagnosed with childhood conduct disorder were more prone to commit counterproductive work behaviors in young adulthood and that these associations were partially mediated by personality traits measured at age 18. Contrary to expectations, criminal convictions that occurred prior to entering the workforce were unrelated to counterproductive work behaviors. Job conditions and personality traits had independent effects on counterproductive work behaviors, above and beyond background factors.

Findings from the Pittsburgh Youth Study: cognitive impulsivity and intelligence as predictors of the age-crime curve.

OBJECTIVE: This article first summarizes key research findings from the Pittsburgh Youth Study from 1987 to the present, and focuses on delinquency in 1,517 young men who have been followed up from late childhood into their 20s. Second, the article addresses how indicators of self-control prospectively predict later offending, and whether the prediction shows individual difference in the age-crime curve, particularly the up-slope, peak, and down-slope of that curve. METHOD: Longitudinal analyses were conducted on a sample of boys in the middle sample of the Pittsburgh Youth Study (n = 422), whose cognitive impulsivity and intelligence were assessed at about age 12 years. Criminal records on the sample were until age 28. RESULTS: The results show that cognitive impulsivity and intelligence, measured between ages 12 and 13 by means of psychometric tests, predicted the age-crime curve. The age-arrest curve was substantially higher in boys with high cognitive impulsivity and in boys with low IQ. However, there was a significant interaction between cognitive impulsivity and intelligence. For boys with high IQ, cognitive impulsivity was associated with a greater escalation in the prevalence of offending during early adolescence, followed by a more rapid decline in offending as boys entered early adulthood with a slight subsequent increase in criminal offending then occurring late 20. In contrast, there was no evidence that cognitive impulsivity independently influenced criminal offending at any developmental period for boys with low IQ. CONCLUSIONS: The results are discussed in terms of interventions to reduce individuals' delinquency from childhood through early adulthood and lower the age-crime curve for populations. However, the association was complex because it was moderated by both age and intelligence.