Title

The relationship of P300 features to neuropsychological performance in male adolescents at risk for substance dependence

Date of Completion

January 2005

Keywords

Psychology, Clinical|Psychology, Physiological

Degree

Ph.D.

Abstract

Decrements in P300 response to cognitive stimuli have long been established in adult psychiatric populations, including individuals with Alzheimer's disease, schizophrenia, and substance dependence disorders, and in offspring with family history of substance dependence and adolescents with conduct disorder. Cognitive deficits associated with decrements in P300 include poorer attention, memory, and executive skills as compared to individuals with no such abnormalities. Subsequently, the P300 has been named "a biological marker" and is an index of the orienting response in the human brain. However, consensus has not been reached regarding the cognitive deficits associated with familial and behavioral factors. Furthermore, there is no report on the examination of anomalies in P300 as a predisposing factor to cognitive deficits in these populations. ^ The primary goal of this project was to evaluate the relationship between low and high P300 amplitude and latency values and cognitive functioning in male adolescents. It was hypothesized that individuals with lower amplitudes and longer latencies would perform worse on the oddball paradigm test and neuropsychological measures than individuals with higher amplitudes and shorter latencies. It was also hypothesized that conduct-disordered behavior is related to deficits in verbal, reasoning, and inhibition abilities, regardless of the P300 values. ^ One hundred and forty eight male adolescents were recruited from the community. They were grouped by family history of substance dependence, self-reported conduct disordered behavior, and amplitude and latency values. Higher anterior amplitude was related to better performance and longer posterior latency predicted longer response time on a measure of inhibition (Stroop Test), and lower posterior amplitude was related to shorter evaluation time when making an incorrect response (oddball task). Finally, presence of CD symptoms predicted performance on tasks of verbal reasoning, word knowledge, logical reasoning and planning, and visuospatial and construction skills. ^ It was concluded that conduct disorder symptoms play a larger role in cognitive abilities than familial history of substance dependence or P300 amplitude and latency values. However, use of a clinical population and inclusion of a female sample would provide a better understanding of the effects of electrophysiological abnormalities on cognitive functioning. ^