Objective We utilized the amyloid imaging ligand Pittsburgh Compound B (PiB) to determine the presence of Alzheimer's disease (AD) pathology in different mild cognitive impairment (MCI) subtypes and to relate increased PiB binding to other markers of early AD and longitudinal outcome. Methods Twenty‐six patients with MCI (13 single‐domain amnestic‐MCI [a‐MCI], 6 multidomain a‐MCI, and 7 nonamnestic MCI) underwent PiB imaging. Twenty‐three had clinical follow‐up (21.2 ± 16.0 [standard deviation] months) subsequent to their PiB scan. Results Using cutoffs established from a control cohort, we found that 14 (54%) patients had increased levels of PiB retention and were considered “amyloid‐positive.” All subtypes were associated with a significant proportion of amyloid‐positive patients (6/13 single‐domain a‐MCI, 5/6 multidomain a‐MCI, 3/7 nonamnestic MCI). There were no obvious differences in the distribution of PiB retention in the nonamnestic MCI group. Predictors of conversion to clinical AD in a‐MCI, including poorer episodic memory, and medial temporal atrophy, were found in the amyloid‐positive relative to amyloid‐negative a‐MCI patients. Longitudinal follow‐up demonstrated 5 of 13 amyloid‐positive patients, but 0 of 10 amyloid‐negative patients, converted to clinical AD. Further, 3 of 10 amyloid‐negative patients “reverted to normal.” Interpretation These data support the notion that amyloid‐positive patients are likely to have early AD, and that the use of amyloid imaging may have an important role in determining which patients are likely to benefit from disease‐specific therapies. In addition, our data are consistent with longitudinal studies that suggest a significant percentage of all MCI subtypes will develop AD. Ann Neurol 2009;65:557–568

The aim of this study was to describe smoking prevalence and smoking behavior in a multiethnic low-income HIV/AIDS population. A cross-sectional survey design was used. The study site was Thomas Street Clinic, an HIV/AIDS care facility serving a medically indigent and ethnically diverse population. Demographic, disease status, behavioral, and psychosocial variables were assessed by participant self-report. Surveys were collected from 348 study participants. Demographic composition of the sample was 78% male, 25% White, 44% Black, and 29% Hispanic. Study participants had a mean age of 40.2 years (SD=7.8). The HIV exposure profile of the sample was diverse: 46% men who have sex with men, 35% heterosexual contact, and 11% injection drug use. Prevalence of current cigarette smoking in the sample was 46.9%. Among participants with a lifetime history of smoking 100 or more cigarettes (62.8%), only 26.6% were currently abstinent, lower than the 48.8% rate seen in the general population. Multiple logistic regression analysis indicated that race/ethnicity, education level, age, and heavy drinking were significantly associated with smoking status. Hispanics were less likely than Whites were to smoke, younger participants were less likely than older participants were to be current smokers, and heavy drinkers were more likely to be current smokers than were those who were not heavy drinkers. As education level increased, the likelihood of smoking decreased and the likelihood of quitting increased. The high smoking prevalence in this HIV/AIDS population demonstrates the need for smoking cessation interventions targeted to the special needs of this patient group.

R. Eisenberger's (1992) learned industriousness theory states that individuals display differing degrees of persistence depending on their history of reinforcement for effortful behavior. These differences may influence the development, maintenance, and cessation of addictive behaviors. In cross-sectional studies, E. P. Quinn, T. H. Brandon, and A. L. Copeland (1996) found that cigarette smokers were less persistent than nonsmokers, and R. A. Brown, C. W. Lejuez, C. W. Kahler, and D. R. Strong (2002) found that smokers who had previously abstained for 3 months were more persistent than those who had never quit. The present study extended these findings by using a prospective design. A pretreatment measure of task persistence (mirror tracing) completed by 144 smokers predicted sustained abstinence throughout 12 months of follow-up. Moreover, persistence predicted outcome independent of other significant predictors: gender, nicotine dependence, negative affect, and self-efficacy.

These results suggest that individuals living with HIV/AIDS are receptive to, and can be helped by, smoking cessation treatment. In addition, smoking cessation treatment tailored to the special needs of individuals living with HIV/AIDS, such as counseling delivered by cellular telephone, can significantly increase smoking abstinence rates over that achieved by usual care.

This study compared 2 minimal interventions for reducing relapse in ex-smokers. One intervention involved 12-month access to a telephone hot line. In the other intervention, 8 relapse-prevention booklets were mailed to participants over 1 year. The 2 interventions were crossed in a 2 x 2 factorial design, yielding control, hot-line-only, mailings-only, and combined conditions. The criterion of at least 1 week of abstinence at baseline was met by 584 participants, 446 of whom also completed a 12-month assessment. Repeated mailings, but not the hot line, reduced relapse for those participants who had been abstinent for less than 3 months at baseline. At follow-up, 12% of those in the mailings conditions were smoking again compared with 35% in the nonmailing conditions. As predicted, both interventions were effective at attenuating the association between depressive symptoms and poor outcome found in the control condition.

Smoking-related cues tend to produce urges and cardiac responses in smokers. This reactivity has been assumed to reflect prior classical conditioning. However, little direct evidence exists supporting the notion that environmental cues can be classically conditioned to cigarette smoking. In this study, 8 smokers received 22 daily trials during which 2 cue complexes (comprising visual, olfactory, and auditory stimuli) were paired with smoking (CS+ trials) and not smoking (CS- trials). Reactivity to the environmental cues, as measured by self-report of urge and pulse rate, increased across CS+ trials, diverging from responses in the CS- trials. Reactivity was stronger among light smokers and those who verbalized awareness of smoking contingencies. Findings indicate that environmental cues can be classically conditioned to smoking.

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Background One problem with assessing effects of smoking cessation interventions on withdrawal symptoms is that symptoms are affected by whether participants abstain from smoking during trials. Those who enter a randomized trial but do not change smoking behavior might not experience withdrawal related symptoms. Purpose We present a tutorial of how one can use a principal stratification sensitivity analysis to account for abstinence in the estimation of smoking cessation intervention effects. The paper is intended to introduce researchers to principal stratification and describe how they might implement the methods. Methods We provide a hypothetical example that demonstrates why estimating effects within observed abstention groups is problematic. We demonstrate how estimation of effects within groups defined by potential abstention that an individual would have in either arm of a study can provide meaningful inferences. We describe a sensitivity analysis method to estimate such effects, and use it to investigate effects of a combined behavioral and nicotine replacement therapy intervention on withdrawal symptoms in a female prisoner population. Results Overall, the intervention was found to reduce withdrawal symptoms but the effect was not statistically significant in the group that was observed to abstain. More importantly, the intervention was found to be highly effective in the group that would abstain regardless of intervention assignment. The effectiveness of the intervention in other potential abstinence strata depends on the sensitivity analysis assumptions. Limitations We make assumptions to narrow the range of our sensitivity parameter estimates. While appropriate in this situation, such assumptions might not be plausible in all situations. Conclusions A principal stratification sensitivity analysis provides a meaningful method of accounting for abstinence effects in the evaluation of smoking cessation interventions on withdrawal symptoms. Smoking researchers have previously recommended analyses in subgroups defined by observed abstention status in the evaluation of smoking cessation interventions. We believe that principal stratification analyses should replace such analyses as the preferred means of accounting for post-randomization abstinence effects in the evaluation of smoking cessation programs.