Bromocriptine reduces cigarette smoking.

AIMS: Animal studies have shown that nicotine releases dopamine, a neurotransmitter implicated in drug reinforcement. We hypothesized that bromocriptine would decrease smoking behavior in humans. DESIGN: The study was conducted double blind and subjects' order of dose exposure was randomized. PARTICIPANTS: The smoking behavior of 20 heavy smokers was recorded for 5 hours after ingesting placebo or one of two doses of bromocriptine (2.50 mg, 3.75 mg) over three sessions (one dose per session). FINDINGS: There was a significant negative linear trend by dosage indicating shorter total puffing time with increasing bromocriptine dosages (p < 0.02). Other significant negative linear trends by increasing dosage include fewer number of puffs, fewer number of cigarettes smoked and mean latency to smoke after 3 hours (expected CMAX on the drug (all ps < 0.05). There was a negative significant linear trend showing decreased plasma nicotine (p < 0.02) and cotinine (p < 0.005) with increasing dosages of bromocriptine. Shiffman/Jarvik Withdrawal Scale (SJWS) cigarette craving subscale scores decreased significantly across increasing dosages (linear trend p < 0.02). There was a significant negative linear trend (p < 0.05) on the Profile of Mood States (POMS) Vigor and Depression subscales, with subjects reporting decreased vigor and depression with increasing bromocriptine doses. No other mood effects were observed. CONCLUSION: These results support the hypothesis that dopaminergic mechanisms mediate cigarette smoking reinforcement.

Nicotine blood levels and subjective craving for cigarettes.

This study examined cigarette craving and blood nicotine levels in 11 male heavy smokers who were observed during 16 h of tobacco abstinence. Subjects rated their urge to smoke on a new brief 10-item questionnaire, Urge to Smoke (UTS), Schuh and Stitzer's four-item Visual Analog Scale (SSI), and a Strength of Urge to Smoke (SUTS) item. Testing occurred: 1) after 16 h (1700 h the night before to 0900 h the next morning) of abstinence from smoking; 2) after an ad lib smoking period following the 16 h abstinence; 3) every hour during 6 hours of abstinence; 4) and finally, after the 6 h abstinence, another ad lib smoking period. Thus, subjects smoked twice in each session. Blood plasma nicotine levels were measured before, after, and every 2 h during the 6-h abstinence period for a total of six measures. Blood pressure and heart rate were measured prior to each blood draw. There was a significant negative correlation between blood nicotine levels and craving for cigarettes on all craving questionnaires (rs = -0.55 to -0.78; ps < 0.002). Carbon monoxide was shown to correlate highly with nicotine blood levels (rs = 0.83 to 0.98 across subjects; ps < 0.001). Results are consistent with the hypothesis that "urge to smoke" reflects nicotine seeking in continuing smokers.

Family relationships and children's emotional adjustment as correlates of maternal and paternal differential treatment: a replication with toddler and preschool siblings.

Recent behavioral genetic research emphasizes the nonshared family environment as an important contributor to psychological differences between siblings raised in the same family. Most studies of nonshared sibling experiences have examined the effects of differential maternal and paternal treatment separately and have not examined family-level processes. This study attempted to replicate the findings of McHale, Crouter, McGuire, and Updegraff and also of Volling in which relations between family patterns of differential parental treatment, child outcomes, and family functioning were examined. Questionnaire data were collected from 60 maritally intact families with toddler and preschool siblings. Congruence in mothers' and fathers' reports of differential treatment (i.e., similar treatment from both mother and father) was most frequent. Parents' reports of differential enjoyment were related to differential favoritism, whereas their reports of differential discipline were not. Both mothers and fathers were more likely to discipline the older sibling than the younger toddler. Sibling and marital harmony characterized families in which the father disciplined the older sibling more and mothers disciplined the two children equally. Incongruent patterns of differential favoritism (i.e., one parent treats the children equally while the other favors one child) were associated with marital distress. Preschool siblings exhibited greater internalizing and externalizing symptoms when both mothers and fathers disciplined them more than their younger sibling. The findings of this study with very young siblings differ in some respects from those with older children and suggest that future research needs to examine differential parental treatment as a developmental process across childhood.