BRAIN AGING IN A SAMPLE OF NORMAL EGYPTIANS COGNITION, EDUCATION, ADDICTION AND SMOKING

The impact of duration of education, cannabis addiction and smoking on cognition and brain aging is studied in 211 normal Egyptian volunteer s with mean age 46.4+/-3.6 years (range: 20-76 years). Subjects were c lassified into two groups: Gr I(non-addicts) with 174 subjects, mean a ge 49.9+/-3.8 years (range 20-76 years), smokers and non-smokers, educ ated and non-educated and Gr II (cannabis addicts) with 37 subjects, m ean age 43.6+/-2.6 years (range 20-72 years) all smokers, educated and non-educated. Outcome measures included the Paced Auditory Serial Add ition test (PASAT) for testing attention and the Trailmaking test A, a nd B (TMa and TMb) for testing psychomotor performance. Age correlated positively with score of Trailmaking test (TMb) in the non-addict gro up and in the addict group (TMa and TMb). Years of education correlate d negatively with scores of Trialmaking test (TMb) in the non-addict g roup (Gr I) but not the addict group (Or II). However, in both groups mean scores of the Trailmaking test (TMa) were significantly lower in subjects with a primary level of education than those with higher leve ls of education. No significant difference was detected between male s mokers and nonsmokers of Gr I (non-addicts) regarding any of the neuro psychological tests. Yet, smokers and the non-educated group had poore r attention compared to non-smokers of the same group. Cannabis addict s (Gr II) had significantly poorer attention than non-addict normal vo lunteers (Or I). It is concluded that impairment of psychomotor perfor mance is age related whether in normal non-addicts or in cannabis addi cts. A decline in attention was detected in cannabis addicts and has b een considered a feature of pathological aging. Education in early lif e as well as the duration of education are neuroprotectors for brain a ging more so in the non-addict than addict group. Though cigarette smo king per se has no effect on cognitive abilities in normal aging, it b ecomes evident that its association with lack of education impairs att ention. (C) 1997 Elsevier Science B.V.