Principles of Neurobehavioral Teratology

This article considers how experience can influence the developing and mature brain and proposes a new categorization scheme based upon the type of information stored and the brain mechanisms that appear to be involved in storing it. In this scheme, experience-expectant information storage refers to incorporation of environmental information that is ubiquitous in the environment and common to all species members, such as the basic elements of pattern perception. Experience-expectant processes appear to have evolved as a neural preparation for incorporating specific information: in many sensory systems, synaptic connections between nerve cells are overproduced, and a subsequent selection process occurs in which aspects of sensory experience determine the pattern of connections that remains. Experience-dependent information storage refers to incorporation of environmental information that is idiosyncratic, or unique to the individual, such as learning about one's specific physical environment or vocabulary. The neural basis of experience-dependent processes appears to involve active formation of new synaptic connections in response to the events providing the information to be stored. Although these processes probably do not occur entirely independently of one another in development, the categories offer a new view more in accord with neural mechanisms than were terms like "critical" or "sensitive period."

To study patterns of co-occurrence of lifetime DSM-III-R alcohol disorders in a household sample. Data came from the National Comorbidity Survey (NCS), a nationally representative household survey. Diagnoses were based on a modified version of the Composite International Diagnostic Interview. Respondents with lifetime NCS/DSM-III-R alcohol abuse or dependence had a high probability of carrying at least 1 other lifetime NCS/DSM-III-R diagnosis. Retrospective reports have suggested that most lifetime co-occurring alcohol disorders begin at a later age than at least 1 other NCS/DSM-III-R disorder. Earlier disorders are generally stronger predictors of alcohol dependence than alcohol abuse and stronger among women than men. Lifetime co-occurrence is positively, but weakly, associated with the persistence of alcohol abuse among men and of alcohol dependence among both men and women. Caution is needed in interpreting the results due to the fact that diagnoses were made by nonclinicians and results are based on retrospective reports of the age at onset. Within the context of these limitations, though, these results show that alcohol abuse and dependence are often associated with other lifetime DSM-III-R disorders and suggest that, at least in recent cohorts, the alcohol use disorders are usually temporally secondary. Prospective data and data based on clinically confirmed diagnoses are needed to verify these findings.