Lexical decision as an endophenotype for reading comprehension: an exploration of an association.

Based on numerous suggestions in the literature, we evaluated lexical decision (LD) as a putative endophenotype for reading comprehension by investigating heritability estimates and segregation analyses parameter estimates for both of these phenotypes. Specifically, in a segregation analysis of a large sample of families, we established that there is little to no overlap between genes contributing to LD and reading comprehension and that the genetic mechanism behind LD derived from this analysis appears to be more complex than that for reading comprehension. We conclude that in our sample, LD is not a good candidate as an endophenotype for reading comprehension, despite previous suggestions from the literature. Based on this conclusion, we discuss the role and benefit of the endophenotype approach in studies of complex human cognitive functions.

Risk factors for HIV, hepatitis B, and hepatitis C among persons with severe mental illness.

OBJECTIVE: Previous reports have indicated that persons with severe mental illness have an elevated risk of contracting HIV, hepatitis B, and hepatitis C compared with the general population. This study extends earlier findings by examining the factors that are most predictive of serologic status among persons with severe mental illness. METHOD: S: A total of 969 persons with severe mental illness from five sites in four states were approached to take part in an assessment involving testing for blood-borne infections and a one-time standardized interview containing questions about sociodemographic characteristics, substance use, risk behaviors for sexually transmitted diseases, history of sexually transmitted diseases, and health care. RESULTS: The greater the number of risk behaviors, the greater was the likelihood of infection, both for persons in more rural locations (New Hampshire and North Carolina), where the prevalence of infection was lower, and those in urban locations (Hartford, Connecticut; Bridgeport, Connecticut; and Baltimore, Maryland), where the prevalence was higher. Although no evidence was found that certain behaviors increase a person's risk of one blood-borne infection while other behaviors increase the risk of a different infection, it is conceivable that more powerful research designs would reveal some significant differences among the risks. CONCLUSION: S: Clinicians should be attentive to these risk factors so as to encourage appropriate testing, counseling, and treatment.