The relationship between blood lead, bone lead and child intelligence.

We report associations between serial measures of blood lead and intelligence in children age 10-12 years, half heavily exposed to lead from the prenatal period onward, and half relatively unexposed. For a subsample, we examine bone lead-IQ associations, comparing them with bone lead associations. Both blood and bone lead levels were associated with intelligence decrements, small relative to the contribution of social factors. For each doubling of Tib-Pb, Full Scale, Performance, and Verbal IQ decreased by an estimated 5.5, 6.2, and 4.1 points, respectively. Bone lead-IQ associations were stronger than those for blood lead, which nonetheless provide robust analogues. Current BPb, easy to obtain, provides a useful means for assessing Pb exposure/IQ associations.     

Is IQ in Childhood Associated with Suicidal Thoughts and Attempts? Findings from The Mater University Study of Pregnancy and Its Outcomes

This study explores associations of IQ at age 14 with adult symptoms of suicidal thoughts and attempts at age 21. Analysis was based on the Mater University Study of Pregnancy and its outcomes, an Australian prospective birth cohort study started in Brisbane Australia in 1981. We assessed associations with suicide thoughts, plans, and attempts. We used two measures of IQ: the Raven's Standard Progressive Matrices and the Wide Range Achievement Test. In multivariable analyses, there was an inverse association between Raven's IQ and suicide thoughts, plans, and attempts, but no strong evidence of an association between the WRAT3 and the three suicidal items. Specific aspects of intelligence may be associated with suicidal thoughts, plans, and attempts.