This five-year extension is designed to take the Iowa Adoption Studies in a new important direction--the assessment of cognitive deficits associated with illicit substance use. Evidence from 25+ years of studies on over 900 adoptees has demonstrated the importance of an antisocial pathway to substance abuse in which a biological risk for antisocial personality interacts with environmental risk factors to predict adult drug abuse. Recently this group has discovered that a biological risk for antisocial personality and substance abuse predicts lower school achievement, as measured by the Iowa Test of Basic Skills (ITBS), during the early grades of our adoptees (prior to exposure to illicit drugs). We argue that this finding is important to the evaluation of the cognitive deficits associated with illicit substance use. Primarily, we argue that cognitive deficits due to antisocial tendencies, which are highly co-morbid with illicit substance use and have a biological component, must be taken into consideration. We propose to use a sizeable sample of subjects from the Iowa Adoption Studies who have just been reinterviewed. An estimated 400 individuals, all with [TBS scores, will be given a battery of neurocognitive tests in years 1-3 of this 5-year extension and will assess the following cognitive constructs: attention, executive function, memory, global functioning, verbal, non-verbal, and reaction time (single and choice). The subject's use of substances (alcohol, illicit drugs), their psychiatric history (both Axis I and Axis II), and information on physical health covering the interval from their last interview will also be obtained. Facial photos of adoptees will be taken to evaluate facial stigmata of fetal alcohol exposure (FAE). Intrauterine alcohol exposure (FAE) will be measured by facial stigmata plus birth weight and length. Physical health assessments will also be used as co-variates on cognitive outcome. Multivariate statistical models will determine analyses examining cognitive deficits attributable to illicit substance use. Our basic hypothesis is that total substance use over the lifetime is the important variable to assess as a cause of cognitive decline among substance users. However, the influence of total use must be tempered by controlling for variables such as early life cognitive functioning prior to use and other variables that are confounded with substance use and cognitive skills which includes the following: childhood ADHD, CD symptoms, adult ASPD symptoms, FAE, and health problems. Results will provide information useful to both drug prevention (by identifying new early risk factors for adult drug abuse) and treatment (by identifying cognitive deficits which decrease treatment efficiency).
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