Negative mood reverses devaluation of goal-directed drug-seeking favouring an incentive learning account of drug dependence

Value-based decision-making in regular alcohol consumers following experimental manipulation of alcohol value

BACKGROUND

Devaluation of alcohol leads to reductions in alcohol choice and consumption; however, the cognitive mechanisms that underpin this relationship are not well-understood. In this study we applied a computational model of value-based decision-making (VBDM) to decisions made about alcohol and alcohol-unrelated cues following experimental manipulation of alcohol value.

METHOD

Using a pre-registered within-subject design, thirty-six regular alcohol consumers (≥14 UK units per week) completed a two-alternative forced choice task where they chose between two alcohol images (in one block) or two soft drink images (in a different block) after watching videos that emphasised the positive (alcohol value), and separately, the negative (alcohol devalue) consequences of alcohol. On each block, participants pressed a key to select the image depicting the drink they would rather consume. A drift-diffusion model (DDM) was fitted to reaction time and choice data to estimate evidence accumulation (EA) processes and response thresholds during the different blocks in each experimental condition.

FINDINGS

In the alcohol devalue condition, soft drink EA rates were significantly higher compared to alcohol EA rates (p = 0.04, d = 0.31), and compared to soft drink EA rates in the alcohol value condition (p = 0.01, d = 0.38). However, EA rates for alcoholic drinks and response thresholds (for either drink type) were unaffected by the experimental manipulation.

CONCLUSIONS

In line with behavioural economic models of addiction that emphasise the important role of alternative reinforcement, experimentally manipulating alcohol value is associated with changes in the internal cognitive processes that precede soft drink choice.

Is Abstinence from Alcohol and Smoking Associated with Less Anxiety and Depressive Symptoms Among People with HIV?

Achieving abstinence from alcohol, tobacco, or both may improve mental health, but is understudied in people with HIV (PWH). The St PETER HIV randomized clinical trial compared varenicline, cytisine, and nicotine replacement therapy on alcohol and smoking behavior among 400 PWH in Russia. The primary exposure was thirty-day point prevalence abstinence (PPA) from (1) alcohol, (2) smoking, (3) both, or (4) neither and was assessed at 1, 3, 6 and 12-months as were the study outcomes of anxiety (GAD-7) and depressive (CES-D) symptoms. The primary aim was to examine the association between smoking and/or alcohol abstinence and subsequent symptoms of depression and anxiety. Primary analysis used repeated measures generalized linear modeling to relate PPA with mental health scores across time. In secondary analyses, Kruskal-Wallis tests related PPA with mental health scores at each timepoint. Primary analyses did not identify significant differences in anxiety or depressive symptoms between exposure groups over time. Secondary analyses found CES-D scores across PPA categories were similar at 1-month (11, 10, 11, 11) and 6-months (10, 10, 11, 11) but differed at 3-months (9, 11, 10, 12; p = 0.035) and 12-months (10, 6, 11, 10; p = 0.019). GAD-7 scores did not vary across PPA categories at any time point. While abstinence was associated with fewer depressive symptoms at times, findings were not consistent during follow-up, perhaps reflecting intermittent relapse. PWH with polysubstance use and mental health comorbidity are complex, and larger samples with sustained abstinence would further elucidate effects of abstinence on mental health.

The moderating role of mental health on the association between COVID-related stress, isolation, and economic hardship and using substances to cope

Since young adulthood is a vulnerable period for adverse mental health experiences and high-risk substance use, it is critical to understand the impact of the COVID-19 pandemic on young adult mental health and substance use behaviors. Therefore, we determined whether the relationship between COVID-related stressors and using substances to cope with COVID-related social distancing and isolation was moderated by depression and anxiety among young adults. Data were from the Monitoring the Future (MTF) Vaping Supplement (total N = 1244). Logistic regressions assessed the relations between COVID-related stressors, depression, anxiety, demographic characteristics, and interactions between depression/anxiety and COVID-related stressors with vaping more, drinking more, and using marijuana to cope with COVID-related social distancing and isolation. Greater COVID-related stress due to social distancing was associated with vaping more to cope among those with more depression symptoms and drinking more to cope among those with more symptoms of anxiety. Similarly, COVID-related economic hardships were associated with using marijuana to cope among those with more symptoms of depression. However, feeling less COVID-related isolation and social distancing stress was linked to vaping and drinking more to cope, respectively, among those with more symptoms of depression. These findings suggest that the most vulnerable young adults are seeking substances to cope with the pandemic, while potentially experiencing co-occurring depression and anxiety along with COVID-related stressors. Therefore, intervention programs to support young adults who are struggling with their mental health in the aftermath of the pandemic as they transition into adulthood are critical.

The absence of association between anorexia nervosa and smoking: converging evidence across two studies

Previous studies have found increased smoking prevalence amongst adults with anorexia nervosa (AN) compared to the general population. The current investigation explored bidirectional associations between AN and smoking behaviour (initiation and heaviness), to address questions surrounding causation. In Study One, logistic regression models with variance robust standard errors assessed longitudinal associations between AN and smoking, using data from adolescent participants of the Avon Longitudinal Study of Parents and Children (N = 5100). In Study Two, two-sample Mendelian randomisation (MR) tested possible causal effects using summary statistics from publicly available genome-wide association studies (GWAS). Study One provided no clear evidence for a predictive effect of AN on subsequent smoking behaviour, or for smoking heaviness/initiation predicting later AN. MR findings did not support causal effects between AN and smoking behaviour, in either direction. Findings do not support predictive or causal effects between AN and smoking behaviour. Previously reported associations may have been vulnerable to confounding, highlighting the possibility of smoking and AN sharing causal risk factors.

Pathways to the persistence of drug use despite its adverse consequences

The persistence of drug taking despite its adverse consequences plays a central role in the presentation, diagnosis, and impacts of addiction. Eventual recognition and appraisal of these adverse consequences is central to decisions to reduce or cease use. However, the most appropriate ways of conceptualizing persistence in the face of adverse consequences remain unclear. Here we review evidence that there are at least three pathways to persistent use despite the negative consequences of that use. A cognitive pathway for recognition of adverse consequences, a motivational pathway for valuation of these consequences, and a behavioral pathway for responding to these adverse consequences. These pathways are dynamic, not linear, with multiple possible trajectories between them, and each is sufficient to produce persistence. We describe these pathways, their characteristics, brain cellular and circuit substrates, and we highlight their relevance to different pathways to self- and treatment-guided behavior change.

Value-based cognition and drug dependency

Value-based decision-making is thought to play an important role in drug dependency. Achieving elevated levels of euphoria or ameliorating dysphoria/pain may motivate goal-directed drug consumption in both drug-naïve and long-time users. In other words, drugs become viewed as the preferred means of attaining a desired internal state. The bias towards choosing drugs may affect one's cognition. Observed biases in learning, attention and memory systems within the brain gradually focus one's cognitive functions towards drugs and related cues to the exclusion of other stimuli. In this narrative review, the effects of drug use on learning, attention and memory are discussed with a particular focus on changes across brain-wide functional networks and the subsequent impact on behaviour. These cognitive changes are then incorporated into the cycle of addiction, an established model outlining the transition from casual drug use to chronic dependency. If drug use results in the elevated salience of drugs and their cues, the studies highlighted in this review strongly suggest that this salience biases cognitive systems towards the motivated pursuit of addictive drugs. This bias is observed throughout the cycle of addiction, possibly contributing to the persistent hold that addictive drugs have over the dependent. Taken together, the excessive valuation of drugs as the preferred means of achieving a desired internal state affects more than just decision-making, but also learning, attentional and mnemonic systems. This eventually narrows the focus of one's thoughts towards the pursuit and consumption of addictive drugs.

Quantifying value-based determinants of drug and non-drug decision dynamics

RATIONALE

A growing body of research suggests that substance use disorder (SUD) may be characterized as disorders of decision making. However, drug choice studies assessing drug-associated decision making often lack more complex and dynamic conditions that better approximate contexts outside the laboratory and may lead to incomplete conclusions regarding the nature of drug-associated value.

OBJECTIVES

The current study assessed isomorphic (choice between identical food options) and allomorphic (choice between remifentanil [REMI] and food) choice across dynamically changing reward probabilities, magnitudes, and differentially reward-predictive stimuli in male rats to better understand determinants of drug value. Choice data were analyzed at aggregate and choice-by-choice levels using quantitative matching and reinforcement learning (RL) models, respectively.

RESULTS

Reductions in reward probability or magnitude independently reduced preferences for food and REMI commodities. Inclusion of reward-predictive cues significantly increased preference for food and REMI rewards. Model comparisons revealed that reward-predictive stimuli significantly altered the economic substitutability of food and REMI rewards at both levels of analysis. Furthermore, model comparisons supported the reformulation of reward value updating in RL models from independent terms to a shared, relative term, more akin to matching models.

CONCLUSIONS

The results indicate that value-based quantitative choice models can accurately capture choice determinants within complex decision-making contexts and corroborate drug choice as a multidimensional valuation process. Collectively, the present study indicates commonalities in decision-making for drug and non-drug rewards, validates the use of economic-based SUD therapies (e.g., contingency management), and implicates the neurobehavioral processes underlying drug-associated decision-making as a potential avenue for future SUD treatment.

Value, drug addiction and the brain

Over the years, various models have been proposed to explain the psychology and biology of drug addiction, built primarily around the habit and compulsion models. Recent research indicates drug addiction may be goal-directed, motivated by excessive valuation of drugs. Drug consumption may initially occur for the sake of pleasure but may transition to a means of escaping withdrawal, stress and negative emotions. In this hypothetical paper, we propose a value-based neurobiological model for drug addiction. We posit that during dependency, the value-based decision-making system in the brain is not inactive but has instead prioritized drugs as the reward of choice. In support of this model, we consider the role of valuation in choice, its influence on pleasure and punishment, and how valuation is contrasted in impulsive and compulsive behaviours. We then discuss the neurobiology of value, beginning with the dopaminergic system and its relationship with incentive salience before moving to brain-wide networks involved in valuation, control and prospection. These value-based neurobiological components are then integrated into the cycle of addiction as we consider the development of drug dependency from a valuation perspective. We conclude with a discussion of cognitive interventions utilizing value-based decision-making, highlighting not just advances in recalibrating the valuation system to focus on non-drug rewards, but also areas for improvement in refining this approach.

Smoking behavior and symptoms of depression and anxiety among young adult backpackers: Results from a short longitudinal study

Levels of smoking and smoking initiation have been found to increase during the transition to adulthood. Symptoms of depression and anxiety may both precede or follow smoking behavior, yet there is equivocal evidence regarding the direction of this relationship. The aim of the current study was to examine the direction of this relationship in a group of young adult backpackers who traveled to social environments which are permissive of smoking. The current study involved a quasi-experimental design examining 199 (52% men, mean age 24.27, SD = 1.05 years at time 1) young adults, before, during and following a backpacking experience of at least six months. Regression analyses was used to examine the association between smoking and symptoms of depression and anxiety over time. Relative to smoking levels before the journey, a significant transient increase in smoking was found during the journey. The increase in smoking during the journey predicted increases in both depressive and anxiety symptoms following the journey. The reverse direction models were not significant. Our study suggests that social contexts which are permissive of smoking, such as backpacking, increase young adult smoking behavior. Mood symptoms did not contribute to the observed increase in smoking behavior but, inversely, increases in smoking contributed to heightened mood symptoms. Additional longitudinal studies are needed to explore the role that smoking behavior plays in young adults' mental health.

Goal-Directed and Habitual Control in Smokers

Introduction

Harmful behavior such as smoking may reflect a disturbance in the balance of goal-directed and habitual control. Animal models suggest that habitual control develops after prolonged substance use. In this study, we investigated whether smokers (N = 49) differ from controls (N = 46) in the regulation of goal-directed and habitual behavior. It was also investigated whether individual differences in nicotine dependence levels were associated with habitual responding.

Methods

We used two different multistage instrumental learning tasks that consist of an instrumental learning phase, subsequent outcome devaluation, and a testing phase to measure the balance between goal-directed and habitual responding. The testing phases of these tasks occurred after either appetitive versus avoidance instrumental learning. The appetitive versus aversive instrumental learning stages in the two different tasks modeled positive versus negative reinforcement, respectively.

Results

Smokers and nonsmoking controls did not differ on habitual versus goal-directed control in either task. Individual differences in nicotine dependence within the group of smokers, however, were positively associated with habitual responding after appetitive instrumental learning. This effect seems to be due to impaired stimulus-outcome learning, thereby hampering goal-directed task performance and tipping the balance to habitual responding.

Conclusions

The current finding highlights the importance of individual differences within smokers. For future research, neuroimaging studies are suggested to further unravel the nature of the imbalance between goal-directed versus habitual control in severely dependent smokers by directly measuring activity in the corresponding brain systems.

Implications

Goal-directed versus habitual behavior in substance use and addiction is highly debated. This study investigated goal-directed versus habitual control in smokers. The findings suggest that smokers do not differ from controls in goal-directed versus habitual control. Individual differences in nicotine dependence within smokers, however, were positively associated with habitual responding after appetitive instrumental learning. This effect seems to be due to impaired stimulus-outcome learning, thereby hampering goal-directed task performance and tipping the balance to habitual responding. These findings add to the ongoing debate on habitual versus goal-directed control in addiction and emphasize the importance of individual differences within smokers.

Relative expected value of drugs versus competing rewards underpins vulnerability to and recovery from addiction

Behavioural economic theories of addiction contend that greater expected value of drug relative to alternative non-drug rewards is the core mechanism underpinning vulnerability to and recovery from addiction. To evaluate this claim, we exhaustively review studies with human drug users that have measured concurrent choice between drugs vs. alternative rewards, and explored individual differences. These studies show that drug choice can be modulated by drug cues, drug devaluation, imposition of costs/punishment and negative mood induction. Regarding individual differences, dependence severity was reliably associated with overall drug preference, and self-reported drug use to cope with negative affect was reliably associated with greater sensitivity to mood induced increases in drug choice. By contrast, there were no reliable individual differences in sensitivity to the effect of drug cues, drug devaluation or punishment on drug choice. These findings provide insight into the mechanisms that underpin vulnerability to dependence: vulnerability is conferred by greater relative value ascribed to drugs, and relative drug value is further augmented by negative affective states in those who report drug use coping motives. However, dependence does not appear to be characterised by abnormal cue-reactivity, habit learning or compulsion. We then briefly review emerging literature which demonstrates that therapeutic interventions and recovery from addiction might be attributed to changes in the expected relative value of drug versus alternative rewards. Finally, we outline a speculative computational account of the distortions in decision-making that precede action selection in addiction, and we explain how this account provides a blueprint for future research on the determinants of drug choice, and mechanisms of treatment and recovery from addiction. We conclude that a unified economic decision-making account of addiction has great promise in reconciling diverse addiction theories, and neuropsychological evaluation of the underlying decision mechanisms is a fruitful area for future research and treatment.

Addiction is driven by excessive goal-directed drug choice under negative affect: translational critique of habit and compulsion theory

Drug addiction may be a goal-directed choice driven by excessive drug value in negative affective states, a habit driven by strong stimulus-response associations, or a compulsion driven by insensitivity to costs imposed on drug seeking. Laboratory animal and human evidence for these three theories is evaluated. Excessive goal theory is supported by dependence severity being associated with greater drug choice/economic demand. Drug choice is demonstrably goal-directed (driven by the expected value of the drug) and can be augmented by stress/negative mood induction and withdrawal-effects amplified in those with psychiatric symptoms and drug use coping motives. Furthermore, psychiatric symptoms confer risk of dependence, and coping motives mediate this risk. Habit theory of addiction has weaker support. Habitual behaviour seen in drug-exposed animals often does not occur in complex decision scenarios, or where responding is rewarded, so habit is unlikely to explain most human addictive behaviour where these conditions apply. Furthermore, most human studies have not found greater propensity to habitual behaviour in drug users or as a function of dependence severity, and the minority that have can be explained by task disengagement producing impaired explicit contingency knowledge. Compulsion theory of addiction also has weak support. The persistence of punished drug seeking in animals is better explained by greater drug value (evinced by the association with economic demand) than by insensitivity to costs. Furthermore, human studies have provided weak evidence that propensity to discount cost imposed on drug seeking is associated with dependence severity. These data suggest that human addiction is primarily driven by excessive goal-directed drug choice under negative affect, and less by habit or compulsion. Addiction is pathological because negative states powerfully increase expected drug value acutely outweighing abstinence goals.

Does acute stress influence the Pavlovian-to-instrumental transfer effect? Implications for substance use disorders

RATIONAL

The ability of conditioned stimuli to affect instrumental responding is a robust finding from animal as well as human research and is assumed as a key factor regarding the development and maintenance of addictive behaviour.

OBJECTIVES

While it is well known that stress is an important factor for relapse after treatment, little is known about the impact of stress on conditioned substance-associated stimuli and their influence on instrumental responding.

METHODS

We administered in the present study a Pavlovian-to-instrumental transfer (PIT) paradigm with stimuli associated with smoking- and chocolate-related rewards using points in a token economy to light to moderate smokers who also indicated to like eating chocolate. After completion of the first two phases of the PIT paradigm (i.e. Pavlovian training and instrumental trainings), participants were randomly allocated to the socially evaluated cold pressor test or a control condition before the final phase of the PIT paradigm, the transfer phase, was administered.

RESULTS

The presentation of a smoking-related stimulus enhanced instrumental responding for a smoking-related reward (i.e. 'smoking-PIT' effect) and presentation of a chocolate-related stimulus for a chocolate-related reward (i.e. 'chocolate-PIT' effect) in participants aware of the experimental contingencies as indicated by expectancy ratings. However, acute stress did not change (i.e. neither enhanced nor attenuated) the 'smoking-PIT' effect or the 'chocolate-PIT' effect, and no overall effect of acute stress on tobacco choice was observed in aware participants.

CONCLUSIONS

The established role of stress in addiction appears not to be driven by an augmenting effect on the ability of drug stimuli to promote drug-seeking.

Withdrawal from escalated cocaine self-administration impairs reversal learning by disrupting the effects of negative feedback on reward exploitation: a behavioral and computational analysis

Addiction is regarded as a disorder of inflexible choice with behavior dominated by immediate positive rewards over longer-term negative outcomes. However, the psychological mechanisms underlying the effects of self-administered drugs on behavioral flexibility are not well understood. To investigate whether drug exposure causes asymmetric effects on positive and negative outcomes we used a reversal learning procedure to assess how reward contingencies are utilized to guide behavior in rats previously exposed to intravenous cocaine self-administration (SA). Twenty-four rats were screened for anxiety in an open field prior to acquisition of cocaine SA over six daily sessions with subsequent long-access cocaine SA for 7 days. Control rats (n = 24) were trained to lever-press for food under a yoked schedule of reinforcement. Higher rates of cocaine SA were predicted by increased anxiety and preceded impaired reversal learning, expressed by a decrease in lose-shift as opposed to win-stay probability. A model-free reinforcement learning algorithm revealed that rats with high, but not low cocaine escalation failed to exploit previous reward learning and were more likely to repeat the same response as the previous trial. Eight-day withdrawal from high cocaine escalation was associated, respectively, with increased and decreased dopamine receptor D2 (DRD2) and serotonin receptor 2C (HTR2C) expression in the ventral striatum compared with controls. Dopamine receptor D1 (DRD1) expression was also significantly reduced in the orbitofrontal cortex of high cocaine-escalating rats. These findings indicate that withdrawal from escalated cocaine SA disrupts how negative feedback is used to guide goal-directed behavior for natural reinforcers and that trait anxiety may be a latent variable underlying this interaction.

Negative Mood Induction Increases Choice of Heroin Versus Food Pictures in Opiate-Dependent Individuals: Correlation With Self-Medication Coping Motives and Subjective Reactivity

Acute growth in negative affect is thought to play a major role in triggering relapse in opiate-dependent individuals. Consistent with this view, three lab studies have demonstrated that negative mood induction increases opiate craving in opiate-dependent individuals. The current study sought to confirm these effects with a behavioral measure of heroin seeking, and test whether the effect is associated with self-reported opiate use to cope with negative affect and subjective reactivity to mood induction. Participants were heroin-dependent individuals engaged with treatment services (n = 47) and control participants (n = 25). Heroin users completed a questionnaire assessing reasons for using heroin: negative affect, social pressure, and cued craving. Baseline heroin choice was measured by preference to enlarge heroin versus food thumbnail pictures in two-alternative forced-choice trials. Negative mood was then induced by depressive statements and music before heroin choice was tested again. Subjective reactivity was indexed by negative and positive mood reported at the pre-induction to post-test timepoints. Heroin users chose heroin images more frequently than controls overall ( p = .001) and showed a negative mood-induced increase in heroin choice compared to control participants (interaction p < .05). Mood-induced heroin choice was associated with self-reported heroin use to cope with negative affect ( p < .05), but not social pressure ( p = .39) or cued craving ( p = .52), and with subjective mood reactivity ( p = .007). These data suggest that acute negative mood is a trigger for heroin seeking in heroin-dependent individuals, and this effect is pronounced in those who report using heroin to cope with negative affect, and those who show greater subjective reactivity to negative triggers. Interventions should seek to target negative coping motives to build resilience to affective triggers for relapse.

Negative mood-induced alcohol-seeking is greater in young adults who report depression symptoms, drinking to cope, and subjective reactivity

Acute negative mood powerfully motivates alcohol-seeking behavior, but it remains unclear whether sensitivity to this effect is greater in drinkers who report depression symptoms, drinking to cope, and subjective reactivity. To examine these questions, 128 young adult alcohol drinkers (ages 18-25) completed questionnaires of alcohol use disorder symptoms, depression symptoms, and drinking to cope with negative affect. Baseline alcohol choice was measured by preference to enlarge alcohol versus food thumbnail images in two-alternative forced-choice trials. Negative mood was then induced by depressive statements and music, before alcohol choice was tested. Subjective reactivity was indexed by increased sadness pre- to post-mood induction. Baseline alcohol choice correlated with alcohol dependence symptoms (p = .001), and drinking coping motives (ps ≤ .01). Mood induction increased alcohol choice and subjective sadness overall (ps < .001). The mood-induced increase in alcohol choice was associated with depression symptoms (p = .007), drinking to cope (ps ≤ .03), and subjective reactivity (p = .007). The relationship between mood-induced alcohol choice and drinking to cope remained significant after covarying for other drinking motives. Furthermore, the three predictors (depression, drinking to cope, and subjective reactivity) accounted for unique variance in mood-induced alcohol choice (ps ≥ .03), and collectively accounted for 18% of the variance (p < .001). These findings validate the pictorial alcohol choice task as sensitive to the relative value of alcohol and acute negative mood. The findings also accord with the core prediction of negative reinforcement theory that sensitivity to the motivational impact of negative mood on alcohol-seeking behavior may be an important mechanism that links depression and alcohol dependence. (PsycINFO Database Record

Cancer Patients Enrolled in a Smoking Cessation Clinical Trial: Characteristics and Correlates of Smoking Rate and Nicotine Dependence

Introduction

A substantial proportion of cancer patients continue to smoke after their diagnosis but few studies have evaluated correlates of nicotine dependence and smoking rate in this population, which could help guide smoking cessation interventions.

Aim

This study evaluated correlates of smoking rate and nicotine dependence among 207 cancer patients.

Methods

A cross-sectional analysis using multiple linear regression evaluated disease, demographic, affective, and tobacco-seeking correlates of smoking rate and nicotine dependence. Smoking rate was assessed using a timeline follow-back method. The Fagerström Test for Nicotine Dependence measured levels of nicotine dependence.

Results

A multiple linear regression predicting nicotine dependence showed an association with smoking to alleviate a sense of addiction from the Reasons for Smoking scale and tobacco-seeking behavior from the concurrent choice task (p < .05), but not with affect measured by the HADS and PANAS (p > .05). Multiple linear regression predicting prequit showed an association with smoking to alleviate addiction (p < .05). ANOVA showed that Caucasian participants reported greater rates of smoking compared to other races.

Conclusions

The results suggest that behavioral smoking cessation interventions that focus on helping patients to manage tobacco-seeking behavior, rather than mood management interventions, could help cancer patients quit smoking.

Depressive statements prime goal-directed alcohol-seeking in individuals who report drinking to cope with negative affect

BACKGROUND

Most variants of negative reinforcement theory predict that acute depressed mood can promote alcohol-seeking behaviour, but the precise mechanisms underpinning this effect remain contested. One possibility is that mood-induced alcohol-seeking is due to the formation of a stimulus-response (S-R) association, enabling depressed mood to elicit alcohol-seeking automatically. A second possibility is that depressed mood undergoes incentive learning, enabling it to enhance the expected value of alcohol and thus promote goal-directed alcohol-seeking.

OBJECTIVES

These two explanations were distinguished using a human outcome-revaluation procedure.

METHODS

One hundred and twenty-eight alcohol drinkers completed questionnaires of alcohol use disorder, drinking to cope with negative affect and depression symptoms. Participants then learned that two responses earned alcohol and food points respectively (baseline) in two alternative forced choice trials. At test, participants rated the valence of randomly sampled negative and positive mood statements and, after each statement, chose between the alcohol- and food-seeking responses in extinction.

RESULTS

The percentage of alcohol- versus food-seeking responses was increased significantly in trials containing negative statements compared to baseline and positive statement trials, in individuals who reported drinking to cope with negative affect (p = .004), but there was no such interaction with indices of alcohol use disorder (p = .87) or depression symptoms (p = .58).

CONCLUSIONS

Individuals who drink to cope with negative affect are more sensitive to the motivational impact of acute depressed mood statements priming goal-directed alcohol-seeking. Negative copers' vulnerability to alcohol dependence may be better explained by excessive affective incentive learning than by S-R habit formation.

Current major depression is associated with greater sensitivity to the motivational effect of both negative mood induction and abstinence on tobacco-seeking behavior

BACKGROUND

Although depression and smoking commonly co-occur, the mechanisms underpinning this association are poorly understood. One hypothesis is that depression promotes tobacco dependence, persistence and relapse by increasing sensitivity to acute negative mood and abstinence induced tobacco-seeking behavior.

METHODS

Twenty nine daily smokers of >10 cigarettes per day, nine with major depression and 20 without, completed two laboratory sessions one week apart, smoking as normal prior to session 1 (sated session), and 6h abstinent prior to session 2 (abstinent session). In both sessions, tobacco-seeking was measured at baseline by preference to view smoking versus food images. Negative mood was then induced by negative ruminative statements and sad music, before tobacco-seeking was measured again at test.

RESULTS

In the sated session, negative mood induction produced a greater increase in tobacco choice from baseline to test in depressed (p<0.001, η_p²=0.782) compared to non-depressed smokers (p=0.045, η_p²=0.216, interaction: p=0.046, η_p²=0.150). Abstinence also produced a greater increase in baseline tobacco choice between the sated and abstinent sessions in depressed (p=0.002, η_p²=0.771) compared to non-depressed smokers (p=0.22, η_p²=0.089, interaction: p=0.023, η_p²=0.189). These mood and abstinence induced increases in tobacco choice were positively associated with depression symptoms across the sample as a whole (ps≤0.04, η_p²≥0.159), and correlated with each other (r=0.67, p<0.001).

CONCLUSIONS

Current major depression or depression symptoms may promote tobacco dependence, persistence and relapse by increasing sensitivity to both acute negative mood and abstinence induced tobacco-seeking behavior. Treatments should seek to break the association between adverse states and smoking to cope.

Cigarette smoking and depression comorbidity: systematic review and proposed theoretical model

BACKGROUND AND AIMS

Despite decades of research on co-occurring smoking and depression, cessation rates remain consistently lower for depressed smokers than for smokers in the general population, highlighting the need for theory-driven models of smoking and depression. This paper provides a systematic review with a particular focus upon psychological states that disproportionately motivate smoking in depression, and frame an incentive learning theory account of smoking-depression co-occurrence.

METHODS

We searched PubMed, Scopus, PsychINFO and CINAHL to December 2014, which yielded 852 papers. Using pre-established eligibility criteria, we identified papers focused on clinical issues and motivational mechanisms underlying smoking in established, adult smokers (i.e. maintenance, quit attempts and cessation/relapse) with elevated symptoms of depression. Two reviewers determined independently whether papers met review criteria. We included 297 papers in qualitative synthesis.

RESULTS

Our review identified three primary mechanisms that underlie persistent smoking among depressed smokers: low positive affect, high negative affect and cognitive impairment. We propose a novel application of incentive learning theory which posits that depressed smokers experience greater increases in the expected value of smoking in the face of these three motivational states, which promotes goal-directed choice of smoking behavior over alternative actions.

CONCLUSIONS

The incentive learning theory accounts for current evidence on how depression primes smoking behavior and provides a unique framework for conceptualizing psychological mechanisms of smoking maintenance among depressed smokers. Treatment should focus upon correcting adverse internal states and beliefs about the high value of smoking in those states to improve cessation outcomes for depressed smokers.

The propositional basis of cue-controlled reward seeking

Two experiments examined the role of propositional and automatic (ideomotor) processes in cue-elicited responding for rewarding outcomes (beer and chocolate). In a training phase, participants earned either chocolate or beer points by making one of two button-press responses. Rewards were indicated by the presentation of chocolate and beer pictures. On test, each trial began with a picture of beer or chocolate, or a blank screen, and choice of the beer versus chocolate response was assessed in the presence of these three pictures. Participants tended to choose the beer and chocolate response in the presence of the beer and chocolate pictures, respectively. In Experiment 1, instructions signalling that the pictures did not indicate which response would be rewarded significantly reduced the priming effect. In Experiment 2, instructions indicating that the pictures signified which response would not be rewarded resulted in a reversed priming effect. Finally, in both experiments, the priming effect correlated with self-reported beliefs that the cues signalled which response was more likely to be reinforced. These results suggest that cue-elicited response selection is mediated by a propositional belief regarding the efficacy of the response–outcome relationship, rather than an automatic ideomotor mechanism.