Caffeine: Is it Dangerous to Health?

Behavioral disinhibition induced by tryptophan depletion in nonalcoholic young men with multigenerational family histories of paternal alcoholism

OBJECTIVE

A deficit in serotonergic neurotransmission has been linked to impulsive behavior, as well as to disorders characterized by disinhibition. The present study tested the hypothesis that young men at high risk for alcoholism demonstrate greater behavioral disinhibition after acute dietary depletion of tryptophan, the amino acid precursor of serotonin.

METHOD

A double-blind, placebo-comparison, between-subjects study design was used. Nonalcoholic young men with a multigenerational paternal family history of alcoholism (N = 13) or with no family history of alcoholism (N = 15) in two previous generations were administered mixtures of tryptophan-deficient amino acid to achieve plasma tryptophan depletion. Comparison subjects with a multigenerational paternal family history of alcoholism (N = 1) and comparison subjects with no family history of alcoholism (N = 18) were given a balanced mixture. Five hours after this, all were tested on a modified Taylor task and a go/ no-go task measuring aggressive response and disinhibition, respectively.

RESULTS

Plasma tryptophan levels were reduced by 89% in both groups. Tryptophan depletion had no effect on aggressive response. In contrast, tryptophan-depleted individuals with a family history of alcoholism made more commission errors (responses to stimuli associated with punishment or loss of reward) than did tryptophan-depleted individuals with no family history of alcoholism and those receiving the balanced (comparison) mixture of amino acid in either group.

CONCLUSIONS

Low serotonin levels may be implicated in the high disinhibition or impulsivity observed in some individuals with a genetic vulnerability to alcohol abuse or dependence.

Cerebral palsy: evaluation of a model of risk

The purpose of this study was to assess a model of risk for cerebral palsy (CP) in preschool children. The research was structured as a retrospective case-control study in which cases (n = 112) were children with CP while controls (n = 153) were either friend referrals or population-based. Data were collected via structured telephone interviews. While significant associations with CP were found on univariate analyses for a number of variables, only four variables--birth weight/gestational age, 5-min APGAR, medication for miscarriage, and urinary tract infection during pregnancy--were found predictive in multivariate analysis. These variables accounted for 36% of the log-likelihood explained by the model.

Psychological problems associated with drug therapy in childhood asthma

Ten studies designed to evaluate the psychological and behavioral effects of the antiasthma agent theophylline in children have been carried out to date. In this review, we evaluate the strengths and weaknesses of those investigations and discuss whether theophylline is responsible for learning disabilities or behavioral disorders such as hyperactivity. We also discuss the similarities between studies of theophylline and those of other xanthines, such as caffeine, to suggest that some persons appear to have a heightened response to these substances and would benefit from closer monitoring, not only of serum drug levels but also of their consumption of food and beverages that contain caffeine. In addition, we describe strategies for examining whether a functional relationship exists between theophylline use and behavioral and psychological changes in children.