Time-varying processes involved in smoking lapse in a randomized trial of smoking cessation therapies

Time-varying effect modeling with intensive longitudinal data: Examining dynamic links among craving, affect, self-efficacy and substance use during addiction recovery

Time-varying effect modeling (TVEM), a statistical technique for modeling dynamic patterns of change, presents new opportunities to study biobehavioral health processes. TVEM is particularly useful when applied to intensive longitudinal data (ILD) because it permits highly flexible modeling of outcomes over continuous time, as well as of associations between variables and moderation effects. TVEM coupled with ILD is ideal for the study of addiction. This article provides a general overview of using TVEM, particularly when applied to ILD, to better enable addiction scientists to conduct novel analyses that are important to realizing the dynamics of addiction-related processes. It presents an empirical example using ecological momentary assessment data from participants throughout their first 90 days of addiction recovery to estimate the (1) associations between morning craving and same-day recovery outcomes, (2) association between morning positive and negative affect and same-day recovery outcomes and (3) time-varying moderation effects of affect on the association between morning craving and recovery outcomes. We provide a didactic overview in implementing and interpreting the aims and results, including equations, computer syntax and reference resources. Our results highlight how affect operates as both a time-varying risk and protective factor on recovery outcomes, particularly when considered in combination with experiences of craving (i.e. dynamic moderation). We conclude by discussing our results, recent innovations and future directions of TVEM for advancing addiction science, including how 'time' can be operationalized to probe new research questions.

Different doses, durations and modes of delivery of nicotine replacement therapy for smoking cessation

BACKGROUND

Nicotine replacement therapy (NRT) aims to replace nicotine from cigarettes. This helps to reduce cravings and withdrawal symptoms, and ease the transition from cigarette smoking to complete abstinence. Although there is high-certainty evidence that NRT is effective for achieving long-term smoking abstinence, it is unclear whether different forms, doses, durations of treatment or timing of use impacts its effects.

OBJECTIVES

To determine the effectiveness and safety of different forms, deliveries, doses, durations and schedules of NRT, for achieving long-term smoking cessation.

SEARCH METHODS

We searched the Cochrane Tobacco Addiction Group trials register for papers mentioning NRT in the title, abstract or keywords, most recently in April 2022.

SELECTION CRITERIA

We included randomised trials in people motivated to quit, comparing one type of NRT use with another. We excluded studies that did not assess cessation as an outcome, with follow-up of fewer than six months, and with additional intervention components not matched between arms. Separate reviews cover studies comparing NRT to control, or to other pharmacotherapies.

DATA COLLECTION AND ANALYSIS

We followed standard Cochrane methods. We measured smoking abstinence after at least six months, using the most rigorous definition available. We extracted data on cardiac adverse events (AEs), serious adverse events (SAEs) and study withdrawals due to treatment.  MAIN RESULTS: We identified 68 completed studies with 43,327 participants, five of which are new to this update. Most completed studies recruited adults either from the community or from healthcare clinics. We judged 28 of the 68 studies to be at high risk of bias. Restricting the analysis only to those studies at low or unclear risk of bias did not significantly alter results for any comparisons apart from the preloading comparison, which tested the effect of using NRT prior to quit day whilst still smoking.  There is high-certainty evidence that combination NRT (fast-acting form plus patch) results in higher long-term quit rates than single form (risk ratio (RR) 1.27, 95% confidence interval (CI) 1.17 to 1.37; I2 = 12%; 16 studies, 12,169 participants). Moderate-certainty evidence, limited by imprecision, indicates that 42/44 mg patches are as effective as 21/22 mg (24-hour) patches (RR 1.09, 95% CI 0.93 to 1.29; I2 = 38%; 5 studies, 1655 participants), and that 21 mg patches are more effective than 14 mg (24-hour) patches (RR 1.48, 95% CI 1.06 to 2.08; 1 study, 537 participants). Moderate-certainty evidence, again limited by imprecision, also suggests a benefit of 25 mg over 15 mg (16-hour) patches, but the lower limit of the CI encompassed no difference (RR 1.19, 95% CI 1.00 to 1.41; I2 = 0%; 3 studies, 3446 participants). Nine studies tested the effect of using NRT prior to quit day (preloading) in comparison to using it from quit day onward. There was moderate-certainty evidence, limited by risk of bias, of a favourable effect of preloading on abstinence (RR 1.25, 95% CI 1.08 to 1.44; I2 = 0%; 9 studies, 4395 participants). High-certainty evidence from eight studies suggests that using either a form of fast-acting NRT or a nicotine patch results in similar long-term quit rates (RR 0.90, 95% CI 0.77 to 1.05; I2 = 0%; 8 studies, 3319 participants). We found no clear evidence of an effect of duration of nicotine patch use (low-certainty evidence); duration of combination NRT use (low- and very low-certainty evidence); or fast-acting NRT type (very low-certainty evidence). Cardiac AEs, SAEs and withdrawals due to treatment were all measured variably and infrequently across studies, resulting in low- or very low-certainty evidence for all comparisons. Most comparisons found no clear evidence of an effect on these outcomes, and rates were low overall. More withdrawals due to treatment were reported in people using nasal spray compared to patches in one study (RR 3.47, 95% CI 1.15 to 10.46; 1 study, 922 participants; very low-certainty evidence) and in people using 42/44 mg patches in comparison to 21/22 mg patches across two studies (RR 4.99, 95% CI 1.60 to 15.50; I2 = 0%; 2 studies, 544 participants; low-certainty evidence).

AUTHORS' CONCLUSIONS

There is high-certainty evidence that using combination NRT versus single-form NRT and 4 mg versus 2 mg nicotine gum can result in an increase in the chances of successfully stopping smoking. Due to imprecision, evidence was of moderate certainty for patch dose comparisons. There is some indication that the lower-dose nicotine patches and gum may be less effective than higher-dose products. Using a fast-acting form of NRT, such as gum or lozenge, resulted in similar quit rates to nicotine patches. There is moderate-certainty evidence that using NRT before quitting may improve quit rates versus using it from quit date only; however, further research is needed to ensure the robustness of this finding. Evidence for the comparative safety and tolerability of different types of NRT use is limited. New studies should ensure that AEs, SAEs and withdrawals due to treatment are reported.

In the Presence of Parents: Parental Heterosexism and Momentary Negative Affect and Substance Craving Among Sexual Minority Youth

PURPOSE

We examined the influence of parental heterosexism on in vivo negative affect and substance craving among sexual minority youth (SMY) who use nicotine and other substances, and if that relation was strengthened when in the presence of their parent(s).

METHODS

SMY (n = 42, ages 15-19) completed baseline assessments, including experiences of parental heterosexism (PH), and a 30-day ecological momentary assessment. Ecological momentary assessment reports included affective states (i.e., anger, anxiety, depression), substance craving (i.e., nicotine, cannabis, alcohol), and other contextual factors (e.g., presence of parents). Multilevel logistic regression models evaluated the study hypotheses.

RESULTS

PH was associated with greater odds of reporting in-the-moment anger, depression, cannabis craving, and alcohol craving. Parental presence was associated with lower odds of reporting anxiety or depression, and greater odds of reporting nicotine craving. There was a significant interaction when predicting the odds of reporting anxiety. For SMY low in PH, parental presence was related to lower odds of reporting anxiety. As PH increased, parental presence had diminishing associations with the odds of reporting anxiety.

DISCUSSION

Parenting behaviors can serve as protective and risk factors for negative affect and substance craving among SMY. Improving family-based interventions for SMY may be integral for enhancing healthy development and reducing health disparities.

Time-Varying Mediation of Pharmacological Smoking Cessation Treatments on Smoking Lapse via Craving, Cessation Fatigue, and Negative Mood

INTRODUCTION

The addictive nature of nicotine makes smoking cessation an extremely challenging process. With prolonged exposure, tobacco smoking transforms from being a positive reinforcer to a negative one, as smoking is used to mitigate aversive withdrawal symptoms. Studying the variations in withdrawal symptoms, especially during their peak in the first week of a quit attempt, could help improve cessation treatment for the future. The time-varying mediation model effectively studies whether altering withdrawal symptoms act as mediators in the pathway between treatment and cessation.

AIMS AND METHODS

This secondary data analysis of a randomized clinical smoking cessation trial of three pharmacotherapy regimens (nicotine patch, varenicline, and nicotine patch + mini-lozenge) analyzes ecological momentary assessment (EMA) data from the first 4 weeks post-target quit day (TQD). We assess whether withdrawal symptoms (eg, negative mood, cessation fatigue, and craving) mediate the pathway between pharmacotherapy and daily smoking status and whether this effect varies over time.

RESULTS

We found a statistically significant time-varying mediation effect of varenicline on smoking status through craving, which shows decreasing risk of lapse via reduction in craving. We did not find significant time-varying mediation effects through negative mood and cessation fatigue.

CONCLUSIONS

This study supports the importance of craving suppression in the smoking cessation process. It also helped identify specific timepoints when withdrawal symptoms increased that would likely benefit from targeted cessation intervention strategies.

IMPLICATIONS

This study aimed to understand the underlying dynamic mechanisms of the smoking cessation process using a new analytical approach that capitalizes on the intensive longitudinal data collected via EMAs. The findings from this study further elucidate the smoking cessation process and provide insight into behavioral intervention targets and the timing of such interventions through the estimation of time-varying mediation effects.

A Person- and Time-Varying Vector Autoregressive Model to Capture Interactive Infant-Mother Head Movement Dynamics

Head movement is an important but often overlooked component of emotion and social interaction. Examination of regularity and differences in head movements of infant-mother dyads over time and across dyads can shed light on whether and how mothers and infants alter their dynamics over the course of an interaction to adapt to each others. One way to study these emergent differences in dynamics is to allow parameters that govern the patterns of interactions to change over time, and according to person- and dyad-specific characteristics. Using two estimation approaches to implement variations of a vector-autoregressive model with time-varying coefficients, we investigated the dynamics of automatically-tracked head movements in mothers and infants during the Face-Face/Still-Face Procedure (SFP) with 24 infant-mother dyads. The first approach requires specification of a confirmatory model for the time-varying parameters as part of a state-space model, whereas the second approach handles the time-varying parameters in a semi-parametric ("mostly" model-free) fashion within a generalized additive modeling framework. Results suggested that infant-mother head movement dynamics varied in time both within and across episodes of the SFP, and varied based on infants' subsequently-assessed attachment security. Code for implementing the time-varying vector-autoregressive model using two R packages, dynr and mgcv, is provided.

Causes of smoking relapse in the 12 months after smoking cessation treatment: Affective and cigarette dependence-related factors

Despite advances in smoking cessation treatments, smoking relapse remains common. Experiencing positive or negative affect and cigarette dependence are the most common causes of relapse; however, little is known about the characteristics that increase the risk of relapse from these causes among current treatment-seeking smokers. Thus, this study aimed to identify the most frequent causes of relapse and the individual characteristics that increase the risk of relapse from these causes during a 12-month period after smoking cessation. Participants included 121 treatment-seeking smokers who quit smoking at the end of treatment and relapsed during a 12-month follow-up period (60.3% female;Mage = 42.57, SD = 11.07). Results indicated that the most frequent smoking relapse situations occurred when smokers experienced positive (e.g., being relaxed; 43.0%) or negative (e.g., being angry; 37.2%) affect or cigarette dependence-related situations (e.g., craving; 19.8%). At an individual level, males with a higher level of education and without a psychopharmaceutical prescription had a higher risk of relapsing in positive-affect situations. Smoking the first cigarette at an older age increased the risk of relapse in negative-affect situations. Finally, being younger and less motivated to quit at pretreatment increased the likelihood of relapse in cigarette dependence-related situations. These findings provide detailed information about smoking relapse situations and identify a set of characteristics that might help to improve current relapse-prevention interventions.

Time-varying effects of 'optimized smoking treatment' on craving, negative affect and anhedonia

AIMS

To identify when smoking cessation treatments affect craving, negative affect and anhedonia, and how these symptoms relate to abstinence, to help evaluate the effects of particular intervention components in multi-component treatments and accelerate treatment refinement.

DESIGN

Secondary analysis of data from a two-arm randomized controlled trial.

SETTING

Seven primary care clinics in Wisconsin, United States.

PARTICIPANTS

Adult primary care patients who smoked daily (n = 574).

INTERVENTION AND COMPARATOR

Intervention was abstinence-optimized treatment (A-OT, n = 276) comprising 3 weeks of nicotine mini-lozenges pre-target quit day (TQD), 26 weeks of combination nicotine patch and mini-lozenges post-TQD and extensive psychosocial support. The comparator was recommended usual care (RUC, n = 298), comprising brief counseling and 8 weeks of nicotine patch post-TQD.

MEASUREMENTS

Time-varying effect models examined dynamic effects of A-OT (versus RUC) on the primary outcomes of nightly cigarette craving, negative affect and anhedonia from 1 week pre- to 2 weeks post-TQD. Exploratory models examined within-person relations between nicotine medication use and same-day symptom ratings. Secondary logistic regression analyses examined associations between post-TQD craving, negative affect and anhedonia and 1-month post-TQD abstinence.

FINDINGS

A-OT significantly suppressed pre- and post-TQD craving (β = -0.27 to -0.46 across days) and post-TQD anhedonia (β = -0.24 to -0.38 across days), relative to RUC. Within individuals, using patches was associated with lower negative affect in RUC (β = -0.42 to -0.52), but not in A-OT. Using more mini-lozenges was associated with greater craving (β = 0.04-0.07) and negative affect (β = 0.03-0.05) early, and with lower anhedonia (β = -0.06 to -0.12) later. Greater post-TQD craving (OR = 0.68) and anhedonia (OR = 0.85) predicted lower odds of abstinence 1 month post-TQD.

CONCLUSION

Time-varying effect models showed that a multi-component treatment intervention for smoking cessation suppressed significant withdrawal symptoms more effectively than recommended usual care among daily adult smokers motivated to quit. The intervention reduced craving pre- and post-target quit day (TQD) and anhedonia post-TQD.

A time-varying model of the dynamics of smoking lapse

OBJECTIVE

The majority of smokers who make a quit attempt experience their first lapse within the first week of quitting, yet limited research to date has examined how the strength and direction of the relationship between smoking risk factors and lapse may change over longer periods of time. Time-varying effect modeling (TVEM) was used to address this gap.

METHOD

A diverse sample (N = 325) of adult smokers completed ecological momentary assessments of risk factors for lapse for 28 days after quitting. TVEM was used to examine the relationship between risk factors (abstinence self-efficacy, positive affect, positive coping expectancies, smoking expectancies, motivation, negative affect, stress, and urge) and lapse for 28 days postquit.

RESULTS

Some associations were stable (e.g., negative affect, motivation), whereas others varied over time. Abstinence self-efficacy, positive affect, and positive coping expectancies were most strongly associated with lapse between Days 3 and 8 postquit. The association of urge with lapse was strongest between Days 4 and 10, as well as near the end of the quit attempt. Stress was also most strongly associated with lapse near the beginning and end of the postquit period and was the only predictor associated with lapse on quit date. The strength of the association between smoking expectancies and lapse increased over time.

CONCLUSION

There may be periods during a quit attempt when certain risk factors are more strongly related to lapse. This work has relevance for tailoring interventions designed to deliver intervention components in particular contexts or times of need. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Very Low Nicotine Content Cigarettes Disrupt the Feedback Loop of Affective States and Smoking Behavior

INTRODUCTION

Smoking to reduce negative affect has been identified as a key motivational feature of tobacco use. Our recent work suggests that smoking very low nicotine content (VLNC) cigarettes reduces the relationship between negative affect and smoking behavior over a 6-week period. Here, we sought to extend our findings by evaluating whether a gradual or immediate approach to switching to VLNC cigarettes led to a differential reduction in the relationship between affect and smoking behavior over a longer (20-week) period.

AIMS AND METHODS

Participants (n = 1250) were adult smokers from 10 US sites randomized to one of three groups: gradual nicotine reduction (15.5, 11.7, 5.2, 2.4, and 0.4 mg of nicotine per gram of tobacco [mg/g]), immediate nicotine reduction (0.4 mg/g), or standard nicotine content cigarettes (15.5 mg/g; control), for 20 weeks. We examined whether the relationship between affect-both negative and positive-and cigarettes per day differed as a function of reduction group.

RESULTS

We found that both negative and positive affect were associated with cigarette consumption in the control group, but not in the gradual or immediate reduction groups across the 20 weeks of exposure.

CONCLUSIONS

Our results extend previous findings that switching to VLNC cigarettes disrupts the relationship between affect and cigarette consumption by showing that either gradually or immediately reducing cigarette nicotine content achieves this disruption. These findings provide further evidence that switching to VLNC cigarettes reduces nicotine-related reinforcement of cigarette smoking.

IMPLICATIONS

These findings support the notion that switching to very low nicotine content cigarettes reduces the association between affect and smoking behavior, and that either a gradual or immediate nicotine reduction approach achieves this reduction. This provides further evidence that switching to very low nicotine content cigarettes weakens reinforcement mechanisms associated with nicotine dependence.

The Time-Varying Relations Between Risk Factors and Smoking Before and After a Quit Attempt

Introduction

Intensive longitudinal data (ILD) collected with ecological momentary assessments (EMAs) can provide a rich resource for understanding the relations between risk factors and smoking in the time surrounding a cessation attempt.

Methods

Participants (N = 142) were smokers seeking treatment at a safety-net hospital smoking cessation clinic who were randomly assigned to receive standard clinic care (ie, counseling and cessation medications) or standard care plus small financial incentives for biochemically confirmed smoking abstinence. Participants completed EMAs via study provided smartphones several times per day for 14 days (1 week prequit through 1 week postquit). EMAs assessed current contextual factors including environmental (eg, easy access to cigarettes, being around others smoking), cognitive (eg, urge to smoke, stress, coping expectancies, cessation motivation, cessation self-efficacy, restlessness), behavioral (ie, recent smoking and alcohol consumption), and affective variables. Temporal relations between risk factors and smoking were assessed using a logistic time-varying effect model.

Results

Participants were primarily female (57.8%) and Black (71.8%), with an annual household income of <$20000 per year (71.8%), who smoked 17.6 cigarettes per day (SD = 8.8). Individuals assigned to the financial incentives group had decreased odds of smoking compared with those assigned to usual care beginning 3 days before the quit attempt and continuing throughout the first week postquit. Environmental, cognitive, affective, and behavioral variables had complex time-varying impacts on smoking before and after the scheduled quit attempt.

Conclusions

Knowledge of time-varying effects may facilitate the development of interventions that target specific psychosocial and behavioral variables at critical moments in the weeks surrounding a quit attempt.

Implications

Previous research has examined time-varying relations between smoking and negative affect, urge to smoke, smoking dependence, and certain smoking cessation therapies. We extend this work using ILD of unexplored variables in a socioeconomically disadvantaged sample of smokers seeking cessation treatment. These findings could be used to inform ecological momentary interventions that deliver treatment resources (eg, video- or text-based content) to individuals based upon critical variables surrounding their attempt.

Everyday discrimination indirectly influences smoking cessation through post-quit self-efficacy

BACKGROUND

Although studies have shown an association between discrimination and current smoking, the influence of discrimination on smoking cessation is an understudied area in tobacco research. The current study evaluated the influence of everyday discrimination on smoking cessation and examined self-efficacy as a potential mediator of this association.

METHODS

Participants (N = 146), who were recruited from a safety-net hospital in Dallas County, Texas, from 2011 to 2013, completed a self-report measure of perceived discrimination one week before the scheduled quit attempt and self-efficacy for quitting was assessed one day after the scheduled quit date. Biochemically-verified 7-day point prevalence abstinence was assessed weekly, through the fourth week after the scheduled quit date. Structural equation modeling was used to evaluate the indirect effect of perceived discrimination on smoking cessation via self-efficacy for quitting.

RESULTS

Analyses indicated significant indirect effect of discrimination on smoking cessation through self-efficacy at Weeks 1 (B = .09, SE = .04, p = .02) and 4 (B = .07, SE = .03, p = .03). A higher frequency of discrimination was associated with lower self-efficacy one day after the scheduled quit date, and lower self-efficacy increased the likelihood of smoking one and four weeks after the scheduled quit attempt.

CONCLUSIONS

Findings suggest that perceptions of discrimination reduce the likelihood of smoking cessation via diminished self-efficacy. Future research is needed to identify intervention strategies to reduce the frequency of discrimination experiences and attenuate the negative impact of discrimination and low self-efficacy on smoking cessation.

Different doses, durations and modes of delivery of nicotine replacement therapy for smoking cessation

BACKGROUND

Nicotine replacement therapy (NRT) aims to replace nicotine from cigarettes to ease the transition from cigarette smoking to abstinence. It works by reducing the intensity of craving and withdrawal symptoms. Although there is clear evidence that NRT used after smoking cessation is effective, it is unclear whether higher doses, longer durations of treatment, or using NRT before cessation add to its effectiveness.

OBJECTIVES

To determine the effectiveness and safety of different forms, deliveries, doses, durations and schedules of NRT, for achieving long-term smoking cessation, compared to one another.

SEARCH METHODS

We searched the Cochrane Tobacco Addiction Group trials register, and trial registries for papers mentioning NRT in the title, abstract or keywords. Date of most recent search: April 2018.

SELECTION CRITERIA

Randomized trials in people motivated to quit, comparing one type of NRT use with another. We excluded trials that did not assess cessation as an outcome, with follow-up less than six months, and with additional intervention components not matched between arms. Trials comparing NRT to control, and trials comparing NRT to other pharmacotherapies, are covered elsewhere.

DATA COLLECTION AND ANALYSIS

We followed standard Cochrane methods. Smoking abstinence was measured after at least six months, using the most rigorous definition available. We extracted data on cardiac adverse events (AEs), serious adverse events (SAEs), and study withdrawals due to treatment. We calculated the risk ratio (RR) and the 95% confidence interval (CI) for each outcome for each study, where possible. We grouped eligible studies according to the type of comparison. We carried out meta-analyses where appropriate, using a Mantel-Haenszel fixed-effect model.

MAIN RESULTS

We identified 63 trials with 41,509 participants. Most recruited adults either from the community or from healthcare clinics. People enrolled in the studies typically smoked at least 15 cigarettes a day. We judged 24 of the 63 studies to be at high risk of bias, but restricting the analysis only to those studies at low or unclear risk of bias did not significantly alter results, apart from in the case of the preloading comparison. There is high-certainty evidence that combination NRT (fast-acting form + patch) results in higher long-term quit rates than single form (RR 1.25, 95% CI 1.15 to 1.36, 14 studies, 11,356 participants; I² = 4%). Moderate-certainty evidence, limited by imprecision, indicates that 42/44 mg are as effective as 21/22 mg (24-hour) patches (RR 1.09, 95% CI 0.93 to 1.29, 5 studies, 1655 participants; I² = 38%), and that 21 mg are more effective than 14 mg (24-hour) patches (RR 1.48, 95% CI 1.06 to 2.08, 1 study, 537 participants). Moderate-certainty evidence (again limited by imprecision) also suggests a benefit of 25 mg over 15 mg (16-hour) patches, but the lower limit of the CI encompassed no difference (RR 1.19, 95% CI 1.00 to 1.41, 3 studies, 3446 participants; I² = 0%). Five studies comparing 4 mg gum to 2 mg gum found a benefit of the higher dose (RR 1.43, 95% CI 1.12 to 1.83, 5 studies, 856 participants; I² = 63%); however, results of a subgroup analysis suggest that only smokers who are highly dependent may benefit. Nine studies tested the effect of using NRT prior to quit day (preloading) in comparison to using it from quit day onward; there was moderate-certainty evidence, limited by risk of bias, of a favourable effect of preloading on abstinence (RR 1.25, 95% CI 1.08 to 1.44, 9 studies, 4395 participants; I² = 0%). High-certainty evidence from eight studies suggests that using either a form of fast-acting NRT or a nicotine patch results in similar long-term quit rates (RR 0.90, 95% CI 0.77 to 1.05, 8 studies, 3319 participants; I² = 0%). We found no evidence of an effect of duration of nicotine patch use (low-certainty evidence); 16-hour versus 24-hour daily patch use; duration of combination NRT use (low- and very low-certainty evidence); tapering of patch dose versus abrupt patch cessation; fast-acting NRT type (very low-certainty evidence); duration of nicotine gum use; ad lib versus fixed dosing of fast-acting NRT; free versus purchased NRT; length of provision of free NRT; ceasing versus continuing patch use on lapse; and participant- versus clinician-selected NRT. However, in most cases these findings are based on very low- or low-certainty evidence, and are the findings from single studies.AEs, SAEs and withdrawals due to treatment were all measured variably and infrequently across studies, resulting in low- or very low-certainty evidence for all comparisons. Most comparisons found no evidence of an effect on cardiac AEs, SAEs or withdrawals. Rates of these were low overall. Significantly more withdrawals due to treatment were reported in participants using nasal spray in comparison to patch in one trial (RR 3.47, 95% CI 1.15 to 10.46, 922 participants; very low certainty) and in participants using 42/44 mg patches in comparison to 21/22 mg patches across two trials (RR 4.99, 95% CI 1.60 to 15.50, 2 studies, 544 participants; I² = 0%; low certainty).

AUTHORS' CONCLUSIONS

There is high-certainty evidence that using combination NRT versus single-form NRT, and 4 mg versus 2 mg nicotine gum, can increase the chances of successfully stopping smoking. For patch dose comparisons, evidence was of moderate certainty, due to imprecision. Twenty-one mg patches resulted in higher quit rates than 14 mg (24-hour) patches, and using 25 mg patches resulted in higher quit rates than using 15 mg (16-hour) patches, although in the latter case the CI included one. There was no clear evidence of superiority for 42/44 mg over 21/22 mg (24-hour) patches. Using a fast-acting form of NRT, such as gum or lozenge, resulted in similar quit rates to nicotine patches. There is moderate-certainty evidence that using NRT prior to quitting may improve quit rates versus using it from quit date only; however, further research is needed to ensure the robustness of this finding. Evidence for the comparative safety and tolerability of different types of NRT use is of low and very low certainty. New studies should ensure that AEs, SAEs and withdrawals due to treatment are both measured and reported.

Does cessation fatigue predict smoking-cessation milestones? A longitudinal study of current and former smokers

OBJECTIVE

Long-term abstinence can be undermined by cessation fatigue-an exhaustion of coping resources attributable to quitting smoking/staying quit. The current study examines the predictive validity of a Cessation Fatigue Scale (CFS; three subscales). Among current smokers, we hypothesized higher fatigue would predict longer latency to both quit initiation and achieving 7-day point prevalence abstinence (7-day PPA). Among recent quitters, we expected higher cessation fatigue would confer greater lapse/relapse risk. Lower rates of abstinence at 2-month follow-up were expected for those with higher fatigue.

METHOD

Current smokers motivated to quit in the next month (n = 301) and recent quitters (n = 242) were assessed biweekly over the course of 2 months. Retention rates were high (>85%). Cox and logistic regression analyses tested hypotheses.

RESULTS

Among smokers, greater emotional exhaustion predicted longer delay to achieving 7-day PPA (HR = .53, 95% CI [.40, -.68], p < .001) and lower likelihood of 7-day PPA at 2-month follow-up (OR = .27, 95% CI [.16, -.46], p < .001), even after controlling for nicotine dependence and motivation to quit. Among recent quitters, emotional exhaustion progressively increased over the first 6 weeks since quit initiation. Elevated exhaustion was associated with greater lapse (HR = 1.65, 95% CI [1.06, 2.56], p < .05) and relapse (HR = 2.33, 95% CI [1.37, 3.97], p < .01) risk, and lower likelihood of 7-day PPA at 2-month follow-up (OR = .39, 95% CI [.16, .94], p < .05), even after controlling for nicotine withdrawal and motivation to quit.

CONCLUSIONS

Cessation fatigue, as measured by the CFS's emotional exhaustion subscale, prospectively predicted important cessation milestones. Findings suggest that cessation fatigue is a novel process that undermines smoking cessation and a viable target for intervention. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Effects of varenicline on subjective craving and relative reinforcing value of cigarettes

BACKGROUND

Varenicline is an FDA approved medication for the treatment of nicotine dependence. While the efficacy and safety of this medication have been demonstrated, success rates remain low, and efforts to understand mechanisms of efficacy are in progress. A behavioral economics framework is one unique way to examine how demand for a drug changes under different circumstances. Therefore, the current randomized placebo-controlled, cross-over study aimed to examine effects of varenicline on subjective cigarette craving and objective demand for cigarettes measured by a hypothetical behavioral economic task as well as associations between subjective craving and objective demand.

METHOD

Non-treatment seeking (n = 37) daily smokers (>10 cigarettes per day) completed a measure of subjective craving for cigarettes and the Cigarette Purchase Task following overnight nicotine abstinence. Participants completed these measures after 10 days on varenicline (1 mg twice per day) and matched placebo.

RESULTS

Analyses revealed a significant reduction in subjective craving for cigarettes while on varenicline (p = 0.01), as compared to placebo, and a sex effect such that females exhibited greater craving than males (p = 0.03). However, there were no medication × sex effects (p = 0.84). Analyses of objective demand for cigarettes found varenicline reduced maximum expenditure (Omax) (p = 0.03). Subjective craving was also associated with various indices of demand.

CONCLUSION

Results demonstrated varenicline's efficacy in attenuating subjective craving and objective demand for cigarettes and highlight the partial overlap between dimensions of acute drug motivation, namely subjective craving and behavioral economic indices of cigarette demand.

Cigarette Nicotine Content as a Moderator of the Relationship Between Negative Affect and Smoking

Introduction

Research suggests a strong association between negative affect (NA) and smoking. However, little is known about the association between NA and smoking among individuals who switch to reduced-nicotine cigarettes. The goal of this study was to examine the extent to which cigarette nicotine content moderates the relationship between NA and smoking over time.

Methods

Seven hundred and seventeen participants, 237 in the normal nicotine content (NNC; 15.8 mg/g and usual brand) cigarette group and 480 in the very low nicotine content (VLNC; 2.4 mg/g nicotine or less) cigarette group, participated in a randomized trial that examined the effects of cigarette nicotine content on smoking behavior over 6 weeks. We used parallel process latent growth curve modeling to estimate the relationship between changes in NA and changes in the numbers of cigarettes smoked per day (CPD), from baseline to 6 weeks, as a function of cigarette nicotine content.

Results

The relationship between NA and investigational CPD reduced over time for those in the VLNC group, but not for those in the NNC group. There was no significant relationship between change in PA and CPD over time for either cigarette group.

Conclusions

Smoking VLNC cigarettes disrupts the relationship between smoking and negative affect, which may help reduce nicotine dependence.

Implications

This study suggests that the association between NA and smoking behavior is reduced over time among those that smoked reduced-nicotine content cigarettes. This provides additional evidence that smoking reduced-nicotine content cigarettes may help reduce nicotine dependence.

Intergenerational Continuity in Depression: The Importance of Time-Varying Effects, Maternal Co-morbid Health Risk Behaviors and Child's Gender

Intergenerational continuity in depressive symptoms is well established between mother and child, but there are still important facets of this relationship that are underexplored. We examine intergenerational continuity in depressive symptoms between mother-child dyads as a flexible function of child age and account for the potential moderating role of maternal co-morbid health risk behaviors. Using prospective, self-report data collected yearly from 413 mother-child dyads (210 mother-son dyads and 203 mother-daughter dyads) between child ages 12-17, the results indicate that the effect of maternal depressive symptoms on daughters' depressive symptoms steadily increases throughout adolescence whereas the effect of maternal depressive symptoms on sons' depressive symptoms is relatively small, stable, and non-significant during mid-adolescence before increasing in effect in later adolescence. A positive interactive effect between maternal depressive symptoms and intimate partner violence is observed for sons and maternal depressive symptoms and substance use for daughters. A negative interactive effect of maternal depressive symptoms and substance use is observed among sons. Overall, this study identifies particular subgroups for whom intervention programming is most beneficial and suggests targeting health risk behaviors of mothers to lessen the impact of maternal depressive symptoms on offspring.

Bayesian variable selection for multistate Markov models with interval-censored data in an ecological momentary assessment study of smoking cessation

The application of sophisticated analytical methods to intensive longitudinal data, collected with ecological momentary assessments (EMA), has helped researchers better understand smoking behaviors after a quit attempt. Unfortunately, the wealth of information captured with EMAs is typically underutilized in practice. Thus, novel methods are needed to extract this information in exploratory research studies. One of the main objectives of intensive longitudinal data analysis is identifying relations between risk factors and outcomes of interest. Our goal is to develop and apply expectation maximization variable selection for Bayesian multistate Markov models with interval-censored data to generate new insights into the relation between potential risk factors and transitions between smoking states. Through simulation, we demonstrate the effectiveness of our method in identifying associated risk factors and its ability to outperform the LASSO in a special case. Additionally, we use the expectation conditional-maximization algorithm to simplify estimation, a deterministic annealing variant to reduce the algorithm's dependence on starting values, and Louis's method to estimate unknown parameter uncertainty. We then apply our method to intensive longitudinal data collected with EMA to identify risk factors associated with transitions between smoking states after a quit attempt in a cohort of socioeconomically disadvantaged smokers who were interested in quitting.

A time-varying effect model of the dynamic association between alcohol use and consequences over the first two years of college

College students experience myriad negative consequences from alcohol misuse. The strength of the association between level of alcohol use and consequences may change across the initial years of college, as students develop tolerance or learn to avoid negative effects of drinking. Time varying effect models (TVEM) allow for statistical examination of the changing strength of associations between two variables as they unfold across time. Goals of the present study were to test the hypothesis that the association between weekly quantity of alcohol use and the odds of an alcohol consequence that week would decrease in strength from the first week of freshman year to the end of sophomore year, and to examine gender differences in the association between use and consequences over time. Participants (N=812 college student drinkers, 60% female) completed 36 assessments of alcohol use and consequences across two years (every other week). TVEM models revealed that the proportion of those for whom alcohol use led to a consequence declined across time. Aside from the first few weeks of college, the association between alcohol use and odds of a consequence was consistently stronger for women than men. Among men, the odds of a consequence declined relatively steadily over time. Among women, the strength of this association was more dynamic. This study provides initial insight into the complex relationship between drinking and consequences. Future research focusing on understanding factors that explain the decreasing association between use and consequences with time can contribute to college student alcohol education and interventions.

Emergence of electronic cigarette use in US adolescents and the link to traditional cigarette use

BACKGROUND

Electronic cigarettes (e-cigarettes) are increasingly used by US adolescents and may be a gateway to traditional cigarette use. We examine rates of both products by age and examine differences in age-varying rates by sex and race/ethnicity.

METHODS

Data are from the 2014 National Youth Tobacco Survey, a national sample of US middle and high school students (n=22.007); students ages 11-19 were included. Past 30-day e-cigarette and traditional cigarette use were examined as a function of age; sex and race/ethnicity were included as moderators. The age-varying association between e-cigarette and traditional cigarette use was also examined.

RESULTS

Rates of e-cigarette use increase faster than traditional cigarette use from ages 13-16. Compared to females, males had higher rates of e-cigarette use from ages 14-17.5 and traditional cigarette use from ages 15-18. Between ages 12-14, more Hispanic adolescents used e-cigarettes compared to White or Black adolescents; after age 14 Hispanics and Whites reported similar rates, peaking at twice the rate for Blacks. Hispanic adolescents report greater traditional cigarette use versus Whites between ages 12-13, but lower rates between ages 15-18. E-cigarette use was strongly associated with traditional cigarette use, particularly during early adolescence [OR>40 before age 12].

CONCLUSIONS

Young Hispanic adolescents are at elevated risk for use of e-cigarettes and traditional cigarettes during early adolescence. During early adolescence, youth using e-cigarettes are more likely to smoke traditional cigarettes compared to youth not using e-cigarettes. The study of age-varying effects holds promise for advancing understanding of disparities in health risk behaviors.

A time-varying effect model for examining group differences in trajectories of zero-inflated count outcomes with applications in substance abuse research

This study proposes a time-varying effect model for examining group differences in trajectories of zero-inflated count outcomes. The motivating example demonstrates that this zero-inflated Poisson model allows investigators to study group differences in different aspects of substance use (e.g., the probability of abstinence and the quantity of alcohol use) simultaneously. The simulation study shows that the accuracy of estimation of trajectory functions improves as the sample size increases; the accuracy under equal group sizes is only higher when the sample size is small (100). In terms of the performance of the hypothesis testing, the type I error rates are close to their corresponding significance levels under all settings. Furthermore, the power increases as the alternative hypothesis deviates more from the null hypothesis, and the rate of this increasing trend is higher when the sample size is larger. Moreover, the hypothesis test for the group difference in the zero component tends to be less powerful than the test for the group difference in the Poisson component. Copyright © 2016 John Wiley & Sons, Ltd.

Depressive Symptoms and Cigarette Demand as a Function of Induced Stress

INTRODUCTION

Depressed smokers may disproportionately value cigarettes as compared to other reinforcers in the context of increases in negative affect (NA). Thus, cigarette demand may be an important construct for understanding the relationship between depression, NA change, and tobacco use. The aim of the current study was to examine the interaction between depressive symptoms and change in NA as a function of induced mood as a predictor of cigarette demand.

METHODS

Participants included 73 young adult daily smokers (41.70% female, 73.60% White, age M (SD) = 19.70 (1.15)) who attended two experimental sessions: one stress and one neutral. During each session, participants completed ratings of depressive symptoms, NA, and cigarette demand.

RESULTS

We examined the predictive utility of depressive symptoms, change in NA as a result of a stressor, and the interaction between depressive symptoms and NA change on demand indices. Separate models were constructed by session. Results indicated significant interactive effects between depressive symptoms and change in NA for predicting intensity, breakpoint, and P max during the stress session. Specifically, change in NA moderated the relationship between depression and demand indices such that among individuals high in NA change, depressive symptoms were positively related to P max and breakpoint, whereas among individuals low in NA change, depressive symptoms were positively related to intensity.

CONCLUSIONS

When exposed to stress, cigarettes may become more valuable for individuals with depressive symptoms.

IMPLICATIONS

This study contributes to the literature attempting to understand the complex relationships between depression, stress-related changes in NA, and tobacco use. This study suggests that one mechanism that may be important to the relationship between depression and tobacco use is cigarette demand. Specifically, for individuals with elevated depressive symptoms, certain aspects of cigarette demand may be higher (intensity, breakpoint, and P max) when exposed to stress, which may contribute to tobacco use being maintained over time.

Time-varying effect modeling to address new questions in behavioral research: Examples in marijuana use

Time-varying effect modeling (TVEM), a statistical approach that enables researchers to estimate dynamic associations between variables across time, holds enormous potential to advance behavioral research. TVEM can address innovative questions about processes that unfold across different levels of time. We present a conceptual introduction to the approach and demonstrate 4 innovative ways to approach time in TVEM to advance research on the etiology of marijuana use. First, we examine changes in associations across historical time to understand how the link between marijuana use attitudes and marijuana use behavior has shifted from 1976 to present; gender differences in the relevance of attitudes diminished over time and were no longer significant after 2004. Second, we examine age-varying associations between heavy episodic drinking and marijuana use across developmental time and demonstrate that this dynamic association is substantially stronger during ages 14 to 16 compared with later ages. Third, we explore the complex association between age of onset of marijuana use and adult marijuana use to identify precise age ranges during which the onset of use is most risky, and demonstrate how this complex association is more salient for males. Finally, we examine changes in marijuana use as a function of time relative to the birth of first child and show how this transition is more crucial for females. All empirical examples in this methodological demonstration rely on existing data from cross-sectional or panel studies. We conclude with thoughts on future directions for the application and further development of TVEM in behavioral research. (PsycINFO Database Record

Attentional bias to negative affect moderates negative affect's relationship with smoking abstinence

OBJECTIVE

To examine whether initial orienting (IO) and inability to disengage (ITD) attention from negative affective stimuli moderate the association of negative affect with smoking abstinence during a quit attempt.

METHOD

Data were from a longitudinal cohort study of smoking cessation (N = 424). A negative affect modified Stroop task was administered 1 week before and on quit day to measure IO and ITD. Ecological Momentary Assessments were used to create negative affect intercepts and linear slopes for the week before quitting and on quit day. Quit day and long-term abstinence measures were collected.

RESULTS

Continuation ratio logit model analyses found significant interactions for prequit negative affect slope with prequit ITD, odds ratio (OR) = 0.738 (0.57, 0.96), p = .02, and for quit day negative affect intercept with quit day ITD, OR = 0.62 (0.41, 950), p = .03, predicting abstinence. The Prequit Negative Affect Intercept × Prequit IO interaction predicting quit day abstinence was significant, OR = 1.42 (1.06, 1.90), p = .02, as was the Quit Day Negative Affect Slope × Quit Day IO interaction predicting long-term abstinence, OR = 1.45 (1.02, 2.08), p = .04.

CONCLUSION

The hypothesis that the association of negative affect with smoking abstinence would be moderated by ITD was generally supported. Among individuals with high ITD, negative affect was inversely related to abstinence, but unrelated to abstinence among individuals with lower levels of ITD. Unexpectedly, among individuals with low IO, negative affect was inversely related to abstinence, but unrelated to abstinence among individuals with higher levels of ITD. (PsycINFO Database Record

Time-varying effects of families and peers on adolescent marijuana use: Person-environment interactions across development

Studies have demonstrated that the effects of two well-known predictors of adolescent substance use, family monitoring and antisocial peers, are not static but change over the course of adolescence. Moreover, these effects may differ for different groups of youth. The current study uses time-varying effect modeling to examine the changes in the association between family monitoring and antisocial peers and marijuana use from ages 11 to 19, and to compare these associations by gender and levels of behavioral disinhibition. Data are drawn from the Raising Healthy Children study, a longitudinal panel of 1,040 youth. The strength of association between family monitoring and antisocial peers and marijuana use was mostly steady over adolescence, and was greater for girls than for boys. Differences in the strength of the association were also evident by levels of behavioral disinhibition: youth with lower levels of disinhibition were more susceptible to the influence of parents and peers. Stronger influence of family monitoring on girls and less disinhibited youth was most evident in middle adolescence, whereas the stronger effect of antisocial peers was significant during middle and late adolescence. Implications for the timing and targeting of marijuana preventive interventions are discussed.

Two-stage model for time varying effects of zero-inflated count longitudinal covariates with applications in health behaviour research

This study proposes a two-stage approach to characterize individual developmental trajectories of health risk behaviors and delineate their time-varying effects on short-term or long-term health outcomes. Our model can accommodate longitudinal covariates with zero-inflated counts and discrete outcomes. The longitudinal data of a well-known study of youth at high risk for substance abuse are presented as a motivating example to demonstrate the effectiveness of the model in delineating critical developmental periods of prevention and intervention. Our simulation study shows that the performance of the proposed model improves as the sample size or number of time points increases. When there are excess zeros in the data, the regular Poisson model cannot estimate either the longitudinal covariate process or its time-varying effect well. This result, therefore, emphasizes the important role that the proposed model plays in handling zero-inflation in the data.

Age-varying associations between substance use behaviors and depressive symptoms during adolescence and young adulthood

BACKGROUND

Substance use and depression often co-occur, complicating treatment of both substance use and depression. Despite research documenting age-related trends in both substance use and depression, little research has examined how the associations between substance use behaviors and depression changes across the lifespan.

METHODS

This study examines how the associations between substance use behaviors (daily smoking, regular heavy episodic drinking (HED), and marijuana use) and depressive symptoms vary from adolescence into young adulthood (ages 12-31), and how these associations differ by gender. Using data from the National Longitudinal Study of Adolescent to Adult Health (Add Health), we implemented time-varying effect models (TVEM), an analytic approach that estimates how the associations between predictors (e.g., substance use measures) and an outcome (e.g., depressive symptoms) vary across age.

RESULTS

Marijuana use and daily smoking were significantly associated with depressive symptoms at most ages from 12 to 31. Regular HED was significantly associated with depressive symptoms during adolescence only. In bivariate analyses, the association with depressive symptoms for each substance use behavior was significantly stronger for females at certain ages; when adjusting for concurrent substance use in a multivariate analysis, no gender differences were observed.

CONCLUSIONS

While the associations between depressive symptoms and both marijuana and daily smoking were relatively stable across ages 12-31, regular HED was only significantly associated with depressive symptoms during adolescence. Understanding age and gender trends in these associations can help tailor prevention efforts and joint treatment methods in order to maximize public health benefit.

New methods shed light on age of onset as a risk factor for nicotine dependence

INTRODUCTION

Early onset of substance use is a risk factor for later drug use, abuse, and dependence. This study examines how the rate of nicotine dependence differs as a function of age of onset of regular smoking in continuous time, in order to identify critical age periods that are most predictive of later dependence for males and females.

METHODS

Time-varying effect modeling (TVEM) can reveal specific ages of onset that confer greatest risk for adult nicotine dependence. The rate of dependence in adulthood is modeled as a flexible function of age of onset using a subset of adults (N = 15,748) from the National Epidemiologic Survey on Alcohol and Related Conditions who ever smoked regularly.

RESULTS

The peak risk of adult nicotine dependence coincides with onset of regular use at approximately 10 years old, with an elevated risk persisting to 20 years. The risk of dependence is significantly higher for females compared to males for onset of regular use between ages 9 and 18.

CONCLUSIONS

Results suggest that the risk of adult nicotine dependence is highest when onset of regular smoking occurs at around 10 years, though the associated risk is high for ages of onset into young adulthood. Early onset of regular use is a relatively stronger risk factor for adolescent females than males. Smoking prevention programs should focus on late childhood through early adolescence, particularly among females. TVEM provides a more nuanced understanding of the risk associated with different ages of onset of health risk behaviors.

A time-varying effect model for studying gender differences in health behavior

This study proposes a time-varying effect model that can be used to characterize gender-specific trajectories of health behaviors and conduct hypothesis testing for gender differences. The motivating examples demonstrate that the proposed model is applicable to not only multi-wave longitudinal studies but also short-term studies that involve intensive data collection. The simulation study shows that the accuracy of estimation of trajectory functions improves as the sample size and the number of time points increase. In terms of the performance of the hypothesis testing, the type I error rates are close to their corresponding significance levels under all combinations of sample size and number of time points. Furthermore, the power increases as the alternative hypothesis deviates more from the null hypothesis, and the rate of this increasing trend is higher when the sample size and the number of time points are larger.

Trends Among U.S. High School Seniors in Recent Marijuana Use and Associations With Other Substances: 1976-2013

PURPOSE

The purpose of this study was to describe historical trends in rates of recent substance use and associations between marijuana and other substances, among U.S. high school seniors by race and gender.

METHODS

Data from Monitoring the Future (1976-2013; N = 599,109) were used to estimate historical trends in alcohol use, heavy episodic drinking (HED), cigarette use, and marijuana use. We used time-varying effect models to flexibly estimate changes in associations of substance use behaviors.

RESULTS

Past-month marijuana use rates peaked in the 1970s, declined through 1990, then rose again to reach levels of use of more than 20% for both black and white participants. Recent years show increasing disparities across groups such that males, and in particular black youth, are on a trajectory toward higher use. This rise in marijuana use is particularly concerning among black youth, with rates far exceeding those for cigarette use and HED. The association of marijuana use with both cigarette use and HED is particularly high in recent years among black adolescents.

CONCLUSIONS

Substance use recently declined among high school seniors, except for marijuana use, particularly among black youth. The increasing association between marijuana and other substances among black adolescents suggests future amplification in critical health disparities.

Modeling naturalistic craving, withdrawal, and affect during early nicotine abstinence: A pilot ecological momentary assessment study

Despite the critical role of withdrawal, craving, and positive affect (PA) and negative affect (NA) in smoking relapse, relatively little is known about the temporal and predictive relationship between these constructs within the first day of abstinence. This pilot study aims to characterize dynamic changes in withdrawal, craving, and affect over the course of early abstinence using ecological momentary assessment. Beginning immediately after smoking, moderate and heavy smoking participants (n = 15 per group) responded to hourly surveys assessing craving, withdrawal, NA, and PA. Univariate and multivariate multilevel random coefficient modeling was used to describe the progression of craving, withdrawal/NA, and PA and to test correlations between these constructs at the subject level over the course of early abstinence. Heavy smokers reported greater craving from 1-4 hr of abstinence and greater withdrawal/NA after 3 or more hours as compared with moderate smokers. Level of withdrawal/NA was strongly positively associated with craving, and PA was negatively correlated with craving; however, the temporal dynamics of these correlations differed substantially. The association between withdrawal/NA and craving decreased over early abstinence, whereas the reverse was observed for PA. These findings can inform experimental studies of nicotine abstinence as well as their clinical applications to smoking cessation efforts. In particular, these results help to elucidate the role of PA in nicotine abstinence by demonstrating its independent association with nicotine craving over and above withdrawal/NA. If supported by future studies, these findings can refine experimental methods and clinical approaches for smoking cessation.

Withdrawal: Expanding a Key Addiction Construct

Withdrawal is an essential component of classical addiction theory; it is a vital manifestation of dependence and motivates relapse. However, the traditional conceptualization of withdrawal as a cohesive collection of symptoms that emerge during drug deprivation and decline with either the passage of time or reinstatement of drug use, may be inadequate to explain scientific findings or fit with modern theories of addiction. This article expands the current understanding of tobacco withdrawal by examining: (1) withdrawal variability; (2) underlying causes of withdrawal variability, including biological and person factors, environmental influences, and the influence of highly routinized behavioral patterns; (3) new withdrawal symptoms that allow for enhanced characterization of the withdrawal experience; and (4) withdrawal-related cognitive processes. These topics provide guidance regarding the optimal assessment of withdrawal and illustrate the potential impact modern withdrawal conceptualization and assessment could have on identifying treatment targets.

Predictors of multiple sexual partners from adolescence through young adulthood

PURPOSE

To examine time-varying associations between predictors of recent multiple sexual partners from middle adolescence through young adulthood.

METHODS

We examined whether the odds of multiple partners in the past year were differentially predicted by substance use and depression over time, using data from a nationally representative longitudinal study (N = 11,963, 52.2% female, 18.3% African-American, 11.9% Hispanic, 3.5% Asian, 2.6% other race, M age at Wave I = 16.1 years, SD = 1.8). Data were analyzed using the time-varying effect model, which estimates associations between predictors and an outcome as a function of near-continuous time.

RESULTS

The proportion of participants having multiple partners increased over time, leveling off at around 30% after age 20. Significant positive associations between substance use and multiple partners were strongest early in adolescence and decreased sharply by around age 18. The significant positive association between depression and sexual behavior weakened with age, remaining significant in young adulthood for women but not men.

CONCLUSIONS

These findings suggest that factors associated with having multiple recent sexual partners change from middle adolescence through young adulthood. The time-varying effect model can be used to identify risk factors that are especially salient at different ages, thus identifying which age periods may hold the greatest promise for intervention.