Risk/reward decision-making in schizophrenia: a preliminary examination of the influence of tobacco smoking and relationship to Wisconsin Card Sorting Task performance

Comparison of decision-making under ambiguity in patients with temporal lobe and frontal lobe epilepsy

OBJECTIVE

The effect of the frontal lobe on cognitive functions is a subject that has been studied frequently. However, cognitive impairments that can be seen in frontal lobe epilepsy are less addressed. In previous studies on decision-making disorders in patients with epilepsy, patients with temporal lobe epilepsy (TLE) were frequently studied, and it was reported that decision-making disorders could be encountered in this patient group. In this study, we aimed to compare the decision-making performance of patients with cryptogenic frontal lobe epilepsy (FLE) and TLE in ambiguous situations.

METHODS

Twenty patients with TLE (mean age: 34.10 ± 11.71 years) and 20 patients with FLE (mean age: 32.25 ± 11.92 years) were enrolled in the study and their cognitive performance was compared with 20 healthy controls (mean age: 33.15 ± 13.66 years). Neuropsychological tests were performed on the participants for sleep, depression, anxiety, impulsivity, intelligence, attention, language functions, memory and learning, and frontal axis functions. Decision-making performance in ambiguous situations was studied using the Iowa Gambling Task (IGT).

RESULTS

Iowa Gambling Task performances of patients with FLE and TLE were found to be worse than in healthy controls (p = 0.049). Although there was no statistically significant difference when the decision-making of patients with TLE and FLE was compared, it was observed that patients with FLE chose higher risk cards compared with those with TLE. The performances of the neuropsychological subgroup tests of patients with TLE and FLE in attention, language functions, memory and learning, and frontal axis functions were found to be significantly worse than in healthy subjects.

CONCLUSION

Decision-making in patients with TLE and FLE in ambiguous situations is similarly impaired compared with healthy controls.

The Prominent Deck B Phenomenon in Schizophrenia: An Empirical Study on Iowa Gambling Task

Background: The Iowa Gambling Task (IGT) was established to evaluate emotion-based decision-making ability under uncertain circumstances in clinical populations, including schizophrenia (Sz). However, there remains a lack of stable behavioral measures regarding discrimination for decision-making performance in IGT between schizophrenic cases and healthy participants. None of the Sz-IGT studies has specifically verified the prominent deck B (PDB) phenomenon gradually revealed in other populations. Here, we provided a global review and empirical study to verify these Sz-IGT issues. Methods: Seeking reliable and valid behavioral measures, we reviewed 38 studies using IGT to investigate decision-making behavior in Sz groups. The IGT, the Wisconsin Card Sorting Test (WCST), and clinical symptoms evaluations were administered to 61 schizophrenia or schizoaffective cases diagnosed by psychiatrists and 62 demographically matched healthy participants. Results: There were no valid behavioral measures in IGT that could significantly identify the decision-making dysfunction of Sz. However, Sz cases, on average, made more choices from disadvantageous deck B relative to other decks, particularly in the later learning process (block 3-5). Compared to the control group, the Sz group was more impaired on the WCST. The high-gain frequency decks B and D showed significant correlations with WCST but no correlation between clinical symptoms and IGT/WCST. Conclusions: Gain-loss frequency (GLF) has a dominant and stable impact on the decision-making process in both Sz and control groups. PDB phenomenon is essentially challenging to be observed on the ground of the expected value (EV) viewpoint approach on the IGT in both populations. Consequently, caution should be exercised when launching the IGT to assess the decision-making ability of Sz under a clinical scenario.

Risky decision-making and delusion proneness: An initial examination

Delusion proneness is an individual-differences characteristic, existing on a continuum from no delusional thoughts to a diagnosis of schizophrenia. Previous research found individuals high in delusion proneness request less information to make decisions, potentially making a decision without sufficient information (jumping to conclusions). The present study examined risky decision-making as a function of delusion proneness. Participants (n = 102) completed the Peters Delusions Inventory to assess delusion proneness, and the Iowa Gambling Task (IGT) and Game of Dice Task (GDT) to assess risky decision-making. Although no significant results emerged on the GDT, those scoring higher in delusion proneness decided more advantageously on the IGT than those scoring lower in delusion proneness. Exploratory analyses indicated no significant relationship between gender and task performance. The present study provides further insight into risky decision making as a function of delusion proneness.

The concept of exposure when selecting comparison groups for determining individual susceptibility to addiction to cigarette smoking

Smoking is a leading cause of preventable death. The effect of tobacco is even more contundent in people with mental illness and, in general, cigarette smoking addiction is influenced by genetic factors. The opioid system is involved in the mesolimbic reward system, which is of great importance in addictive behaviors, such as smoking and is influenced by genes such as the OPRM1. The aim of this study was to evaluate if selecting a comparison group that include light smokers versus people that never smoked impacts the results of genetic association studies. In addition, to evaluate the genetic association in different groups of smokers by analyzing independent covariates such as mental illness and clinical dental data. All subjects were participants of the Dental Registry and DNA Repository project. Genotyping was carried out using TaqMan chemistry for two markers in OPRM1 (rs553202 and rs7755635). Logistic regression analyses were performed as implemented in PLINK. The established value for alpha was 5%, and the Hardy-Weinberg equilibrium was evaluated by the chi-square test with one degree of freedom for each marker. 1,897 patients were included, which were allocated to eight distinct groups, according to the frequency and quantity of cigarettes smoked and mental illness status. There was no significant association between the two markers in OPRM1 and smoking. When mental illness and dental clinical data (tooth loss, dental caries, and periodontitis) were used as covariates, there were associations between heavy smoking and OPRM1, when non-smokers were used as comparison. We did not have diet or microbiome data to consider for these dental analyses and suggest that these kinds of data should be always incorporated in the future. Significant results were found only when the covariables mental illness and oral clinical data were added to the analysis.

Goal-directed planning and action impairments in schizophrenia evaluated in a virtual environment

Planning and executing goal-directed behaviours are critical final steps in translating motivation into action. Amotivation is a key feature of schizophrenia, but its impact on goal-directed functioning has not been extensively studied in an objective and ecologically valid manner. To address this, we investigated goal-directed planning and action in schizophrenia using a virtual reality task, the Multitasking in the City Test (MCT). The MCT was administered to 49 outpatients with schizophrenia and 55 healthy controls, and required participants to complete a series of errands in a virtual city. Ability to complete the task as directed was assessed by a performance score based on errands completed and errors committed. Task efficiency was evaluated by the total distance travelled, and an index of path efficiency comparing an optimal route with the traversed route. Schizophrenia participants had lower performance scores, travelled farther, and had reduced path efficiency compared to healthy controls. Greater distance travelled and lower path efficiency in schizophrenia were related to amotivation. Path efficiency in schizophrenia was also related to neurocognition, including planning ability; notably, this relationship appeared to be independent of the relationship with amotivation. Individuals with schizophrenia demonstrated impaired goal-directed planning and action in the context of a simulated everyday errands task, both in terms of reduced capacity to complete errands and reduced efficiency in doing so. The latter may manifest as diminished real-world motivated and functional behaviour in patients with schizophrenia and indicates a specific deficit in the execution of planned behaviour.

Deciphering reward-based decision-making in schizophrenia: A meta-analysis and behavioral modeling of the Iowa Gambling Task

BACKGROUND

Patients with schizophrenia (SZP) have been reported to exhibit impairments in reward-based decision-making, but results are heterogeneous with multiple potential confounds such as age, intelligence level, clinical symptoms or medication, making it difficult to evaluate the robustness of these impairments.

METHODS

We conducted a meta-analysis of studies comparing the performance of SZP and healthy controls (HC) in the Iowa Gambling Task (IGT) as well as comprehensive analyses based on subject-level data (n = 303 SZP, n = 188 HC) to investigate reward-based decision-making in SZP. To quantify differences in the influence of individual deck features (immediate gain, gain frequency, net loss) between SZP and HC, we additionally employed a least-squares model.

RESULTS

SZP showed statistically significant suboptimal decisions as indicated by disadvantageous deck choices (d from 0.51 to −0.62) and lower net scores (d from −0.35 to −1.03) in a meta-analysis of k = 29 samples (n = 1127 SZP, n = 1149 HC) and these results were confirmed in a complementary subject-level analysis. Moreover, decision-making in SZP was characterized by a relative overweighting of immediate gain and net losses and an underweighting of gain frequency. Moderator analyses revealed that in part, decision-making in the IGT was moderated by intelligence level, medication and general symptom scores.

CONCLUSION

Our results indicate robust impairments in reward-based decision-making in SZP and suggest that decreased cognitive resources, such as working memory, may contribute to these alterations.

Decision-making ability in psychosis: a systematic review and meta-analysis of the magnitude, specificity and correlates of impaired performance on the Iowa and Cambridge Gambling Tasks

To identify factors which may help or hinder decision-making ability in people with psychosis, we did a systematic review and meta-analysis of their performance on the Iowa and Cambridge Gambling Tasks. Analysis of 47 samples found they had moderately poorer performance than healthy individuals (N = 4264, g = -0.57, 95% confidence interval (CI) -0.66 to -0.48). Few studies (k = 8) used non-psychotic clinical comparator groups, although very low-quality evidence (k = 3) found people with bipolar disorder may perform better. Negative symptoms (k = 13, N = 648, r = -0.17, 95% CI -0.26 to -0.07) and lower IQ (k = 11, N = 525, r = 0.20, 95% CI 0.29-0.10), but not positive symptoms (k = 10, N = 512, r = -0.01, 95% CI -0.11 to 0.08), each had small-moderate associations with poorer decision-making. Lower quality evidence suggested general symptoms, working memory, social functioning, awareness of emotional responses to information, and attentional bias towards gain are associated with decision-making, but not education, executive functioning or overall symptoms. Meta-regression suggested an inverse association between decision-making and depression severity (k = 6, Q = 6.41, R2 100%, p = 0.01). Those taking first-generation (k = 6, N = 305, g = -0.17, 95% CI -0.40 to 0.06, p = 0.147) or low-dose antipsychotics (k = 5, N = 442, g = -0.19, 95% CI -0.44 to 0.06, p = 0.139) had unimpaired decision-making. Although meta-regression found no linear association between dose and performance, non-reporting of the dose was common and associated with larger impairments (k = 46, Q = 4.71, R2 14%, p = 0.03). Those supporting people with psychosis to make decisions, including treatment decisions, should consider the potential effect of these factors. Interventionist-causal trials are required to test whether reducing antipsychotic dose and treating anxiety and depression can improve decision-making in this group.

Steeper discounting of delayed rewards in schizophrenia but not first-degree relatives

Excessive discounting of future rewards has been related to a variety of risky behaviors and adverse clinical conditions. Prior work examining delay discounting in schizophrenia suggests an elevated discount rate. However, it remains uncertain whether this reflects the disease process itself or an underlying genetic vulnerability, whether it is selective for delay discounting or reflects pervasive changes in decision-making, and whether it is driven by specific clinical dimensions such as cognitive impairment. Here we investigated delay discounting, as well as loss aversion and risk aversion, in three groups: schizophrenia (SZ), unaffected first-degree family members (FM), and controls without a family history of psychosis (NC). SZ had elevated discounting, without changes in loss aversion or risk aversion. Contrary to expectations, the FM group did not show an intermediate phenotype in discounting. Higher discount rates correlated with lower cognitive performance on verbal reasoning, but this did not explain elevated discount rates in SZ. Group differences were driven primarily by the non-smoking majority of the sample. This study provides further evidence for elevated discounting in schizophrenia, and demonstrates that steeper discounting is not necessarily associated with familial risk, cannot be wholly accounted for by cognitive deficits, and is not attributable to smoking-related impulsivity.

The habenula in psychiatric disorders: More than three decades of translational investigation

The habenula is an epithalamic structure located at the center of the dorsal diencephalic conduction system, a pathway involved in linking forebrain to midbrain regions. Composed of a medial and lateral subdivisions, the habenula receives inputs from the limbic system and basal ganglia mainly through the stria medullaris (SM), and projects to midbrain regions through the fasciculus retroflexus (FR). An increasing number of studies have implicated this structure in psychiatric disorders associated with dysregulated reward circuitry function, notably mood disorders, schizophrenia, and substance use disorder. However, despite significant progress in research, the mechanisms underlying the relationship between the habenula and the pathophysiology of psychiatric disorders are far from being fully understood, and still need further investigation. This review provides a closer look at key findings from animal and human studies illustrating the role of the habenula in mood disorders, schizophrenia, and substance use disorder, and discusses the clinical potential of using this structure as a therapeutic target.

Ambiguity aversion in schizophrenia: An fMRI study of decision-making under risk and ambiguity

When making decisions in everyday life, we often have to choose between uncertain outcomes. Economic studies have demonstrated that healthy people tend to prefer options with known probabilities (risk) than those with unknown probabilities (ambiguity), which is referred to as "ambiguity aversion." However, it remains unclear how patients with schizophrenia behave under ambiguity, despite growing evidence of their altered decision-making under uncertainty. In this study, combining economic tools and functional magnetic resonance imaging (fMRI), we assessed the attitudes toward risk/ambiguity and investigated the neural correlates during decision-making under risk/ambiguity in schizophrenia. Although no significant difference in attitudes under risk was observed, patients with schizophrenia chose ambiguity significantly more often than the healthy controls. Attitudes under risk and ambiguity did not correlate across patients with schizophrenia. Furthermore, unlike in the healthy controls, activation of the left lateral orbitofrontal cortex was not increased during decision-making under ambiguity compared to under risk in schizophrenia. These results suggest that ambiguity aversion, a well-established subjective bias, is attenuated in patients with schizophrenia, highlighting the need to distinguish between risk and ambiguity when assessing decision-making under these situations. Our findings, comprising important clinical implications, contribute to improved understanding of the mechanisms underlying altered decision-making in patients with schizophrenia.

Conceptual Knowledge Influences Decision Making Differently in Individuals with High or Low Cognitive Flexibility: An ERP Study

OBJECTIVE

Studies using the Iowa Gambling Task (IGT) have distinguished between good and bad decision makers and have provided an explanation for deficits in decision making. Previous studies have demonstrated a link between Wisconsin Card Sorting Test (WCST) performance and IGT performance, but the results were not consistent and failed to explain why WCST performance can predict IGT performance. The present study aimed to demonstrate that WCST performance can predict IGT performance and to identify the cognitive component of the WCST that affects IGT performance using event-related potentials (ERPs).

METHODS

In this study, 39 healthy subjects (5 subjects were excluded) were divided into a high group and a low group based on their global score on the WCST. A single-choice version of the IGT was used to eliminate the impact of retrieval strategies on the choice evaluation process and interference due to uncorrelated decks. Differences in the underlying neural mechanisms and explicit knowledge between the two groups during the three stages of the decision-making process were described.

RESULTS

Based on the information processing perspective, we divided the decision-making process into three stages: choice evaluation, response selection, and feedback processing. The behavioral results showed that the highly cognitively flexible participants performed better on the IGT and acquired more knowledge of the task. The ERP results showed that during the choice evaluation stage, the P300 recorded from central and parietal regions when a bad deck appeared was larger in the high group participants than in the low group participants. During the response selection stage, the effect of choice type was significant only in the frontal region in the high group, with a larger effect for passing. During the feedback evaluation stage, a larger FRN was evoked for a loss than for a win in the high group, whereas the FRN effect was absent in the low group.

CONCLUSION

Compared with the participants with low cognitive flexibility, the participants with high cognitive flexibility performed better on the IGT, acquired more knowledge of the task, and displayed more obvious somatic markers. The low group participants showed reduced working memory abilities during the choice evaluation stage. The appropriate somatic markers reflected by the DPN is formed only when conceptual knowledge is gained in the response selection stage. The absence of an FRN effect in the subjects who performed poorly on the WCST suggests a significant deficit in feedback learning and reward prediction.

Nicotine-dopamine-transporter interactions during reward-based decision making

Our everyday-life comprises a multitude of decisions that we take whilst trying to maximize advantageous outcomes, limit risks and update current needs. The cognitive processes that guide decision making as well as the brain circuits they are based on are only poorly understood. Numerous studies point to a potential role of dopamine and nicotine in decision making but less is known about their interactions. Here, 26 healthy male subjects performed the Iowa Gambling Task (IGT) in two sessions following the administration of either nicotine or placebo. Striatal dopamine transporter (DAT) binding was measured by single-photon emission computed tomography (SPECT). Results indicate that lower DAT levels were associated with better performance in the IGT (p=0.0004). Cognitive modelling analysis using the prospect valence learning (PVL) model indicated that low DAT subjects' performance deteriorated following nicotine administration as indicated by an increased learning rate and a decreased response consistency. Our results shed light on the neurochemistry underlying reward-based decision making in humans by demonstrating a significant interaction between nicotine and the DAT. The observed interaction is consistent with the hypothesized associations between DAT expression and extracellular dopamine levels, suggestive of an inverted U-shape relationship between baseline dopamine and magnitude in response to a pro-dopaminergic compound. Our findings are of particular interest in the context of psychiatric disorders where aberrant decision making represents a part of the core symptomatology, such as addiction, schizophrenia or depression.

Decision-making deficits in patients with chronic schizophrenia: Iowa Gambling Task and Prospect Valence Learning model

PURPOSE

Decision-making is the process of forming preferences for possible options, selecting and executing actions, and evaluating the outcome. This study used the Iowa Gambling Task (IGT) and the Prospect Valence Learning (PVL) model to investigate deficits in risk-reward related decision-making in patients with chronic schizophrenia, and to identify decision-making processes that contribute to poor IGT performance in these patients.

MATERIALS AND METHODS

Thirty-nine patients with schizophrenia and 31 healthy controls participated. Decision-making was measured by total net score, block net scores, and the total number of cards selected from each deck of the IGT. PVL parameters were estimated with the Markov chain Monte Carlo sampling scheme in OpenBugs and BRugs, its interface to R, and the estimated parameters were analyzed with the Mann-Whitney U-test.

RESULTS

The schizophrenia group received significantly lower total net scores compared to the control group. In terms of block net scores, an interaction effect of group × block was observed. The block net scores of the schizophrenia group did not differ across the five blocks, whereas those of the control group increased as the blocks progressed. The schizophrenia group obtained significantly lower block net scores in the fourth and fifth blocks of the IGT and selected cards from deck D (advantageous) less frequently than the control group. Additionally, the schizophrenia group had significantly lower values on the utility-shape, loss-aversion, recency, and consistency parameters of the PVL model.

CONCLUSION

These results indicate that patients with schizophrenia experience deficits in decision-making, possibly due to failure in learning the expected value of each deck, and incorporating outcome experiences of previous trials into expectancies about options in the present trial.

Evaluating the relationship between cannabis use and IQ in youth and young adults at clinical high risk of psychosis

Among people with psychosis, those with a history of cannabis use show better cognitive performance than those who are cannabis naïve. It is unknown whether this pattern is present in youth at clinical high risk (CHR) of psychosis. We evaluated relationships between IQ and cannabis use while controlling for use of other substances known to impact cognition in 678 CHR and 263 healthy control (HC) participants. IQ was estimated using the Vocabulary and Block Design subtests of the Wechsler Abbreviated Scale of Intelligence. Drug and alcohol use severity and frequency were assessed with the Alcohol and Drug Use Scale, and we inquired participants' age at first use. CHR were further separated into early and late age at onset of cannabis use sub-groups, and low-, moderate- and high-frequency sub-groups. No significant differences in IQ emerged between CHR or HC cannabis users vs. non-users, or between use frequency groups. CHR late-onset users showed significantly higher IQ than CHR early-onset users. Age at onset of cannabis use was significantly and positively correlated with IQ in CHR only. Results suggest that age at onset of cannabis may be a more important factor for IQ than use current use or use frequency in CHR.

Similarities and Differences in Decision-Making Impairments between Autism Spectrum Disorder and Schizophrenia

Although individuals with autism spectrum disorders (ASD) and schizophrenia (SCH) share overlapping characteristics and may perform similarly on many cognitive tasks, cognitive dysfunctions common to both disorders do not necessarily share the same underlying mechanisms. Decision-making is currently a major research interest for both ASD and SCH. The aim of the present study was to make direct comparisons of decision-making and disorder-specific underlying neuropsychological mechanisms between the two disorders. Thirty-seven participants with ASD, 46 patients with SCH, and 80 healthy controls (HC) were assessed with the Iowa Gambling Task (IGT), which measures decision-making under ambiguity, and the Game of Dice Task (GDT), which measures decision-making under risk. The results revealed that both the ASD and SCH groups had deficits for both the IGT and the GDT compared with the HC. More importantly, in the IGT, participants with ASD displayed a preference for deck A, indicating that they had more sensitivity to the magnitude of loss than to the frequency of loss, whereas patients with SCH displayed a preference for deck B, indicating that they showed more sensitivity to the frequency of loss than to the magnitude of loss. In the GDT, the impaired performance might be due to the deficits in executive functions in patients with SCH, whereas the impaired performance might be due to the deficits in feedback processing in participants with ASD. These findings demonstrate that there are similar impairments in decision-making tasks between ASD and SCH; however, these two disorders may have different impairment mechanisms.

Negative affective states and cognitive impairments in nicotine dependence

Smokers have substantial individual differences in quit success in response to current treatments for nicotine dependence. This observation may suggest that different underlying motivations for continued tobacco use across individuals and nicotine cessation may require different treatments in different individuals. Although most animal models of nicotine dependence emphasize the positive reinforcing effects of nicotine as the major motivational force behind nicotine use, smokers generally report that other consequences of nicotine use, including the ability of nicotine to alleviate negative affective states or cognitive impairments, as reasons for continued smoking. These states could result from nicotine withdrawal, but also may be associated with premorbid differences in affective and/or cognitive function. Effects of nicotine on cognition and affect may alleviate these impairments regardless of their premorbid or postmorbid origin (e.g., before or after the development of nicotine dependence). The ability of nicotine to alleviate these symptoms would thus negatively reinforce behavior, and thus maintain subsequent nicotine use, contributing to the initiation of smoking, the progression to dependence and relapse during quit attempts. The human and animal studies reviewed here support the idea that self-medication for pre-morbid and withdrawal-induced impairments may be more important factors in nicotine addiction and relapse than has been previously appreciated in preclinical research into nicotine dependence. Given the diverse beneficial effects of nicotine under these conditions, individuals might smoke for quite different reasons. This review suggests that inter-individual differences in the diverse effects of nicotine associated with self-medication and negative reinforcement are an important consideration in studies attempting to understand the causes of nicotine addiction, as well as in the development of effective, individualized nicotine cessation treatments.

Drift diffusion model of reward and punishment learning in schizophrenia: Modeling and experimental data

In this study, we tested reward- and punishment learning performance using a probabilistic classification learning task in patients with schizophrenia (n=37) and healthy controls (n=48). We also fit subjects' data using a Drift Diffusion Model (DDM) of simple decisions to investigate which components of the decision process differ between patients and controls. Modeling results show between-group differences in multiple components of the decision process. Specifically, patients had slower motor/encoding time, higher response caution (favoring accuracy over speed), and a deficit in classification learning for punishment, but not reward, trials. The results suggest that patients with schizophrenia adopt a compensatory strategy of favoring accuracy over speed to improve performance, yet still show signs of a deficit in learning based on negative feedback. Our data highlights the importance of applying fitting models (particularly drift diffusion models) to behavioral data. The implications of these findings are discussed relative to theories of schizophrenia and cognitive processing.

Effects of disrupting medial prefrontal cortex GABA transmission on decision-making in a rodent gambling task

RATIONALE

Decision-making is a complex cognitive process that is mediated, in part, by subregions of the medial prefrontal cortex (PFC). Decision-making is impaired in a number of psychiatric conditions including schizophrenia. Notably, people with schizophrenia exhibit reductions in GABA function in the same PFC areas that are implicated in decision-making. For example, expression of the GABA-synthesizing enzyme GAD67 is reduced in the dorsolateral PFC of people with schizophrenia.

OBJECTIVES

The goal of this experiment was to determine whether disrupting cortical GABA transmission impairs decision-making using a rodent gambling task (rGT).

METHODS

Rats were trained on the rGT until they reached stable performance and then were implanted with guide cannulae aimed at the medial PFC. Following recovery, the effects of intra-PFC infusions of the GABAA receptor antagonist bicuculline methiodide (BMI) or the GABA synthesis inhibitor L-allylglycine (LAG) on performance on the rGT were assessed.

RESULTS

Intracortical infusions of BMI (25 ng/μl/side), but not LAG (10 μg/μl/side), altered decision-making. Following BMI infusions, rats made fewer advantageous choices. Follow-up experiments suggested that the change in decision-making was due to a change in the sensitivity to the punishments, rather than a change in the sensitivity to reward magnitudes, associated with each outcome. LAG infusions increased premature responding, a measure of response inhibition, but did not affect decision-making.

CONCLUSIONS

Blocking GABAA receptors, but not inhibiting cortical GABA synthesis, within the medial PFC affects decision-making in the rGT. These data provide proof-of-concept evidence that disruptions in GABA transmission can contribute to the decision-making deficits in schizophrenia.

Dissecting negative symptoms in schizophrenia: opportunities for translation into new treatments

Among the constellation of symptoms that characterize schizophrenia, negative symptoms have emerged as a critical feature linked to the functional impairment experienced by affected individuals. Despite advances in our understanding of the role of negative symptoms in the illness, effective treatments for these debilitating symptoms have remained elusive. In this review we explore the contemporary conceptualization of negative symptoms in schizophrenia, including the identification of two key subdomains of diminished expression and amotivation, and clarifications around hedonic capacity. We then explore strategies for clinical assessments of negative symptoms, followed by findings using objective paradigms for evaluating discrete aspects of these negative symptoms in clinical populations and animal models, both for symptoms of diminished expression and within the multifaceted motivation system. We conclude with a consideration of current strategies for drug development for these negative symptoms, the role of heterogeneity in the clinical presentation of symptoms in schizophrenia and opportunities for personalized assessment and treatment approaches, as well as a commentary on current clinical drug trial design and the role of environmental opportunities for novel treatments to effect change and improve outcomes for affected individuals.

Mechanisms Underlying Motivational Deficits in Psychopathology: Similarities and Differences in Depression and Schizophrenia

Motivational and hedonic impairments are core aspects of a variety of types of psychopathology. These impairments cut across diagnostic categories and may be critical to understanding major aspects of the functional impairments accompanying psychopathology. Given the centrality of motivational and hedonic systems to psychopathology, the Research Domain Criteria (RDoC) initiative includes a "positive valence" systems domain that outlines a number of constructs that may be key to understanding the nature and mechanisms of motivational and hedonic impairments in psychopathology. These component constructs include initial responsiveness to reward, reward anticipation or expectancy, incentive or reinforcement learning, effort valuation, and action selection. Here, we review behavioral and neuroimaging studies providing evidence for impairments in these constructs in individuals with psychosis versus in individuals with depressive pathology. There are important differences in the nature of reward-related and hedonic deficits associated with psychosis versus depression that have major implications for our understanding of etiology and treatment development. In particular, the literature strongly suggests the presence of impairments in in-the-moment hedonics or "liking" in individuals with depressive pathology, particularly among those who experience anhedonia. Such deficits may propagate forward and contribute to impairments in other constructs that are dependent on hedonic responses, such as anticipation, learning, effort, and action selection. Such hedonic impairments could reflect alterations in dopamine and/or opioid signaling in the striatum related to depression or specifically to anhedonia in depressed populations. In contrast, the literature points to relatively intact in-the-moment hedonic processing in psychosis, but provides much evidence for impairments in other components involved in translating reward to action selection. Particularly, individuals with schizophrenia exhibit altered reward prediction and associated striatal and prefrontal activation, impaired reward learning, and impaired reward-modulated action selection.

Hyper-coupling between working memory task-evoked activations and amplitude of spontaneous fluctuations in first-episode schizophrenia

Working memory (WM) deficit is an important component of impaired cognition in schizophrenia. However, between-studies inconsistencies as to the specific functional substrate imply that inter-individual variability (IIV) in the WM performance is associated with IIV in brain activity in schizophrenia. To examine the neural substrate of this WM IIV, we studied whether the neural mechanisms that underlie individual differences in WM capacity are the same in schizophrenia patients and healthy people. We correlated the IIV of the task-evoked brain activity and task performance during an n-back WM task with the IIV of the moment-to-moment variability in intrinsic resting-state activity, as measured by the amplitude of low-frequency fluctuations (ALFFs) and further compared this relationship between 17 patients with first-episode schizophrenia (FES) and 18 healthy controls. Between-group comparisons of the correlation patterns indicated aberrant ALFF-WM activation correlations and ALFF-WM performance correlations in the FES patients, but no significant changes were detected in any single measurement of these three characteristics. Specifically, we found increased positive ALFF-WM activation correlations in the bilateral lateral prefrontal cortices, posterior parietal cortices and fusiform gyri in the FES patients. We also observed significant increases in positive ALFF-WM performance correlations in the bilateral ventromedial prefrontal cortices in the FES patients. This hyper-coupling between the ALFF and fMRI measures during a WM task may indicate that it was difficult for the patients to detach themselves from one state to transition to another and suggests that the inefficient cortical function in schizophrenia stems from the intrinsic functional architecture of the brain.

The motivation and pleasure dimension of negative symptoms: neural substrates and behavioral outputs

A range of emotional and motivation impairments have long been clinically documented in people with schizophrenia, and there has been a resurgence of interest in understanding the psychological and neural mechanisms of the so-called "negative symptoms" in schizophrenia, given their lack of treatment responsiveness and their role in constraining function and life satisfaction in this illness. Negative symptoms comprise two domains, with the first covering diminished motivation and pleasure across a range of life domains and the second covering diminished verbal and non-verbal expression and communicative output. In this review, we focus on four aspects of the motivation/pleasure domain, providing a brief review of the behavioral and neural underpinnings of this domain. First, we cover liking or in-the-moment pleasure: immediate responses to pleasurable stimuli. Second, we cover anticipatory pleasure or wanting, which involves prediction of a forthcoming enjoyable outcome (reward) and feeling pleasure in anticipation of that outcome. Third, we address motivation, which comprises effort computation, which involves figuring out how much effort is needed to achieve a desired outcome, planning, and behavioral response. Finally, we cover the maintenance emotional states and behavioral responses. Throughout, we consider the behavioral manifestations and brain representations of these four aspects of motivation/pleasure deficits in schizophrenia. We conclude with directions for future research as well as implications for treatment.

The cognitive processes underlying affective decision-making predicting adolescent smoking behaviors in a longitudinal study

This study investigates the relationship between three different cognitive processes underlying the Iowa Gambling Task (IGT) and adolescent smoking behaviors in a longitudinal study. We conducted a longitudinal study of 181 Chinese adolescents in Chengdu City, China. The participants were followed from 10th to 11th grade. When they were in the 10th grade (Time 1), we tested these adolescents' decision-making using the IGT and working memory capacity using the Self-ordered Pointing Test (SOPT). Self-report questionnaires were used to assess school academic performance and smoking behaviors. The same questionnaires were completed again at the 1-year follow-up (Time 2). The Expectancy-Valence (EV) Model was applied to distill the IGT performance into three different underlying psychological components: (i) a motivational component which indicates the subjective weight the adolescents assign to gains vs. losses; (ii) a learning-rate component which indicates the sensitivity to recent outcomes vs. past experiences; and (iii) a response component which indicates how consistent the adolescents are between learning and responding. The subjective weight to gains vs. losses at Time 1 significantly predicted current smokers and current smoking levels at Time 2, controlling for demographic variables and baseline smoking behaviors. Therefore, by decomposing the IGT into three different psychological components, we found that the motivational process of weight gain vs. losses may serve as a neuropsychological marker to predict adolescent smoking behaviors in a general youth population.

Comorbid substance use disorder in schizophrenia: a selective overview of neurobiological and cognitive underpinnings

Although individuals with schizophrenia show a lifetime prevalence of 50% for suffering from a comorbid substance use disorder, substance abuse usually represents an exclusion criterion for studies on schizophrenia. This implies that surprisingly little is known about a large group of patients who are particularly difficult to treat. The aim of the present work is to provide a brief and non-exhaustive overview of the current knowledgebase about neurobiological and cognitive underpinnings for dual diagnosis schizophrenia patients. Studies published within the last 20 years were considered using computerized search engines. The focus was on nicotine, caffeine, alcohol, cannabis and cocaine being among the most common substances of abuse. All drugs of abuse target dopaminergic, glutamatergic and GABAergic transmission which are also involved in the pathophysiology of schizophrenia. Current literature suggests that neurocognitive function might beless disrupted in substance-abusing compared to non-abusing schizophrenia patients, but in particular the neuroimaging database on this topic is sparse. Detrimental effects on brain structure and function were shown for patients for whom alcohol is the main substance of abuse. It is as yet unclear whether this finding might be an artifact of age differences of patient subgroups with different substance abuse patterns. More research is warranted on the specific neurocognitive underpinnings of schizophrenia patients abusing distinct psychoactive substances. Treatment programs might either benefit from preserved cognitive function as a resource or specifically target cognitive impairment in different subgroups of addicted schizophrenia patients.

Cigarette smoking modulates medication-associated deficits in a monetary reward task in patients with schizophrenia

Imaging studies of reward processing have demonstrated a mesolimbic-mesocortical dopaminergic dysfunction in schizophrenia. Such studies on reward processing in patients and also in healthy controls showed that differential activations of dopaminergic brain areas are associated with adaptive changes in response speed related to different reward values. Given this relationship, we investigated reward processing on the behavioural level in a larger sample of 49 medicated patients with a diagnosis of schizophrenia (ICD-10 F20) and 49 healthy controls. Subjects were instructed to react by button press upon two different stimuli in order to retain a 60 % chance winning a previously announced high (1$) or low (20¢) amount of money paid to participants after the experiment. Concordant with previous reports on deficits in reward processing, acceleration of reaction times in patients upon low rewards differed significantly (p < 0.05) from healthy controls in our present behavioural study. This effect was pronounced in the non-smoking subgroup of patients (n = 24). In this subgroup, we also observed a significant (p < 0.05) positive correlation with medication type (relatively high vs. low D2 receptor affinity) and with the PANSS score, the latter with a trend to significance (p = 0.08). Our study demonstrates that reaction time measures in a monetary reward task might constitute a feasible behavioural proxy for dopaminergic dysfunction and its different dimensions regarding psychopathology but also medication in patients with schizophrenia. In line with clinical observations, our findings support the notion that smoking modulates medication-associated side effects on reward processing in patients with schizophrenia.

Medial prefrontal cortex lesions impair decision-making on a rodent gambling task: reversal by D1 receptor antagonist administration

Decision-making is a complex cognitive process that is impaired in a number of psychiatric disorders. In the laboratory, decision-making is frequently assessed using "gambling" tasks that are designed to simulate real-life decisions in terms of uncertainty, reward and punishment. Here, we investigate whether lesions of the medial prefrontal cortex (PFC) cause impairments in decision-making using a rodent gambling task (rGT). In this task, rats have to decide between 1 of 4 possible options: 2 options are considered "advantageous" and lead to greater net rewards (food pellets) than the other 2 "disadvantageous" options. Once rats attained stable levels of performance on the rGT they underwent sham or excitoxic lesions of the medial PFC and were allowed to recover for 1 week. Following recovery, rats were retrained for 5 days and then the effects of a dopamine D1-like receptor antagonist (SCH23390) or a D2-like receptor antagonist (haloperidol) on performance were assessed. Lesioned rats exhibited impaired decision-making: they made fewer advantageous choices and chose the most optimal choice less frequently than did sham-operated rats. Administration of SCH23390 (0.03 mg/kg), but not haloperidol (0.015-0.03 mg/kg) attenuated the lesion-induced decision-making deficit. These results indicate that the medial PFC is important for decision-making and that excessive signaling at D1 receptors may contribute to decision-making impairments.

A further evaluation of decision-making under risk and under ambiguity in schizophrenia

Abnormal decision-making has been described as a key-concept to understand some behavioral disturbances in schizophrenia. However, whether schizophrenia patients display impairments in profitable decision-making on experimental designs is still controversial (1) to assess performance on decision-making paradigms under ambiguity and under risk conditions in a large sample of schizophrenia patients and (2) to study the impact of clinical variables on decision-making performance in schizophrenia. The Iowa gambling task (IGT) and the game of dice task (GDT) were administered to assess, respectively, decision-making under ambiguity and under risk in 63 schizophrenia patients and 67 healthy controls. In addition, clinical variables (e.g., schizophrenic symptoms, self-reported depression, and impulsivity) were evaluated using appropriate questionnaires the same day. Pharmacological treatments were reported. Schizophrenia patients had impaired performances on both IGT and GDT tasks. No correlation between the decision-making tasks performance and clinical variables was found. Lower gains on the GDT were associated with executive dysfunctioning in schizophrenia. These findings give evidence that schizophrenia patients display impairments in both decision-making under ambiguity and under risk.

Correlations between executive function, decision-making and impulsivity are disrupted in schizophrenia versus controls

Schizophrenia (n=68) and control (n=62) participants matched on cigarette smoking history were assessed on executive function, decision-making and impulsivity tasks. In controls, executive function and decision-making correlated positively with each other and negatively with impulsivity. There were no inter-task correlations in schizophrenia participants. The significance of these findings is discussed.

Effects of acute administration of nicotinic and muscarinic cholinergic agonists and antagonists on performance in different cost-benefit decision making tasks in rats

RATIONALE

Alterations in cost-benefit decision making accompany numerous neuropsychiatric conditions, including schizophrenia, attention deficit hyperactivity disorder, and addiction. Central cholinergic systems have been linked to the etiology and/or treatment of many of these conditions, but little is known about the role of cholinergic signaling in cost-benefit decision making.

OBJECTIVES

The goal of these experiments was to determine how cholinergic signaling is involved in cost-benefit decision making, using a behavioral pharmacological approach.

METHODS

Male Long-Evans rats were trained in either "probability discounting" or "delay discounting" tasks, in which rats made discrete-trial choices between a small food reward and a large food reward associated with either varying probabilities of omission or varying delays to delivery, respectively. The effects of acute administration of different doses of nicotinic and muscarinic acetylcholine receptor agonists and antagonists were assessed in each task.

RESULTS

In the probability discounting task, acute nicotine administration (1.0 mg/kg) significantly increased choice of the large risky reward, and control experiments suggested that this was due to robust nicotine-induced impairments in behavioral flexibility. In the delay discounting task, the muscarinic antagonists scopolamine (0.03, 0.1, and 0.3 mg/kg) and atropine (0.3 mg/kg) both significantly increased choice of the small immediate reward. Neither mecamylamine nor oxotremorine produced reliable effects on either of the decision making tasks.

CONCLUSIONS

These data suggest that cholinergic receptors play multiple roles in decision making contexts which include consideration of reward delay or probability. These roles should be considered when targeting these receptors for therapeutic purposes.

[Decision-making and schizophrenia]

Abnormalities involving the prefrontal cortex (PFC) have long been postulated to underpin the pathophysiology of schizophrenia. Investigations of PFC integrity have focused mainly on the dorsolateral PFC (DLPFC) and abnormalities in this region have been extensively documented. However, defects in schizophrenia may extend to other prefrontal regions, including the ventromedial PFC (VMPFC), and evidence of VMPFC abnormalities comes from neuropathological, structural and functional studies. Patients with acquired brain injury to the VMPFC display profound disruption of social behaviour and poor judgment in their personal lives. The Iowa Gambling Task (IGT) was developed to assess decision-making in these neurological cases : it presents a series of 100 choices from four card decks that differ in the distribution of rewarding and punishing outcomes. Whilst healthy volunteers gradually develop a preference for the two "safe" decks over the course of the task, patients with VMPFC lesions maintain a preference for the two "risky" decks which are associated with high reinforcement in the short term, but significant long-term debt. Interestingly, damage to VMPFC may cause both poor performance on the IGT and lack of insight concerning the acquired personality modification. Recently, our group reported a trait-related decisionmaking impairment in the three phases of bipolar disorder. In a PET study, VMPFC dysfunction was shown in bipolar manic patients impaired on a decision-making task and an association between decision-making cognition and lack of insight was described in mania. A quantitative association between grey matter volume of VMPFC and memory impairment was previously reported in schizophrenia. Research suggests that lack of insight is a prevalent feature in schizophrenia patients, like auditory hallucinations, paranoid or bizarre delusions, and disorganized speech and thinking. Because schizophrenia is associated with significant social or occupational dysfunction, previous research assessed decision-making function but indicates conflicting results. Thirteen studies have reported impaired IGT performance in patients with schizophrenia and, in seven reports, no significant differences in IGT performance between patient and healthy control groups were found. Those discrepancies may relate to multiple factors. First, most of the studies included small sample size and negative findings may be due to the large variance of net scores. Second, as suggested by Rodríguez-Sánchez et al., there is a wide disparity in performance by control subjects across studies. Third, intelligence quotient (IQ) score and level of education may be correlated with IGT performance, which may explain IGT performance differences in studies that did not control for educational or IQ score. Fourth, only two studies have systematically controlled for substance use disorder, a potential confounder. Fifth, only two studies assessed the impact of antipsychotic (AP) class on performance. Sixth, to our knowledge, no study assessed the impact of AP dosage on decision-making ability, while AP dose-reduction and dopamine increase, might lead to improvements, in cognitive functions in schizophrenia and in IGT performance in bipolar disorder, respectively. Finally, discrepancies between studies may be related to the heterogeneity of diagnostic groups. Two of the negative studies included schizophrenia and schizoaffective disorder while positive studies have generally included only patients with schizophrenia. Nevertheless, some studies that included only patients with schizophrenia failed to find differences between groups. Thus, further research should assess decision-making in schizophrenia by testing a large group of patients with homogeneity of diagnostic, in comparison with a large group of control subjects. Authors should control for IQ or level of education, substance use disorder and smoking status. While it is now accepted that DLPFC defects in schizophrenia may extend to VMPFC, future investigations should test for an association between memory, insight ability and IGT performance and assess the impact of antipsychotic dosage upon performance.

Schizophrenia and risk-taking: impaired reward but preserved punishment processing

Risky decision-making is subserved by the frontostriatal system, which includes a network of interconnected brain regions known to be dysfunctional in patients with schizophrenia. This study aimed to investigate whether and to what extent patients with schizophrenia display a different pattern of risk-taking behavior relative to matched healthy controls. The Balloon Analogue Risk Task (BART) and the Risky-Gains Task were used as naturalistic measures of risk-taking behavior in 25 patients with schizophrenia and 25 controls. Results of the BART revealed that patients behaved more conservatively, and this in turn led to suboptimal risky decision-making. Consistently, patients behaved more conservatively in the Risky-Gains Task. Interestingly, however, they adjusted the pattern of risk-taking following a punished trial similar to controls. These findings indicate that patients have impaired reward but preserved punishment processing. This study complements previous studies on decision-making in schizophrenia and suggests specific rather than widespread abnormalities along the frontostriatal system in schizophrenia.

The utility of rat models of impulsivity in developing pharmacotherapies for impulse control disorders

High levels of impulsive behaviours are a clinically significant symptom in a range of psychiatric disorders, such as attention deficit hyperactivity disorder, bipolar disorder, personality disorders, pathological gambling and substance abuse. Although often measured using questionnaire assessments, levels of different types of impulsivity can also be determined using behavioural tests. Rodent analogues of these paradigms have been developed, and similar neural circuitry has been implicated in their performance in both humans and rats. In the current review, the methodology underlying the measurement of different aspects of impulsive action and choice are considered from the viewpoint of drug development, with a focus on the continuous performance task (CPT), stop-signal task (SST), go/no-go and delay-discounting paradigms. Current issues impeding translation between animal and human studies are identified, and comparisons drawn between the acute effects of dopaminergic, noradrenergic and serotonergic compounds across species. Although the field could benefit from a more systematic determination of different pharmacological agents across paradigms, there are signs of strong concordance between the animal and human data. However, the type of impulsivity measured appears to play a significant role, with the SST and delay discounting providing more consistent effects for dopaminergic drugs, while the CPT and SST show better predictive validity so far for serotonergic and noradrenergic compounds. Based on the available data, it would appear that these impulsivity models could be used more widely to identify potential pharmacotherapies for impulse control disorders. Novel targets within the glutamatergic and serotonergic system are also suggested.

Relationship between measures of inhibitory processes in patients with schizophrenia: role of substance abuse disorders

Disruption of prepulse inhibition of the startle response (PPI) has been widely identified in patients with schizophrenia, as well as impairment in many domains of cognitive functioning. However, there is some controversy regarding the relationship between PPI and the different neuropsychological tasks assessing inhibition. This controversy may be due to the influence of other variables, such as substance abuse. We aimed to determine whether differences in inhibition in schizophrenia subjects were related to their pattern of substance use and whether there was a correlation between the changes in each process. PPI and neuropsychological functioning were studied in three groups of subjects with schizophrenia (N=73): tobacco dependents (ToD; n=22), multiple substance abusers (MSUD; n=31) and non-substance abusers (non-SUD; n=20). All subjects were assessed using PPI and neuropsychological tests (Stroop and Wisconsin Card Sorting Test [WCST]). ToD showed better pre-attentive inhibitory function compared to the other two groups, and MSUD showed lower resistance to interference. Furthermore, significant correlations were found between PPI, Stroop, and WCST. Our data suggest that there is a relationship between the different tasks assessing inhibition in schizophrenia, being affected by substance abuse history. We also found differences in inhibition capacity depending on substance abuse in patients with schizophrenia.

General functioning predicts reward and punishment learning in schizophrenia

Previous studies investigating feedback-driven reinforcement learning in patients with schizophrenia have provided mixed results. In this study, we explored the clinical predictors of reward and punishment learning using a probabilistic classification learning task. Patients with schizophrenia (n=40) performed similarly to healthy controls (n=30) on the classification learning task. However, more severe negative and general symptoms were associated with lower reward-learning performance, whereas poorer general psychosocial functioning was correlated with both lower reward- and punishment-learning performances. Multiple linear regression analyses indicated that general psychosocial functioning was the only significant predictor of reinforcement learning performance when education, antipsychotic dose, and positive, negative and general symptoms were included in the analysis. These results suggest a close relationship between reinforcement learning and general psychosocial functioning in schizophrenia.

Goal representations and motivational drive in schizophrenia: the role of prefrontal-striatal interactions

The past several years have seen a resurgence of interest in understanding the psychological and neural bases of what are often referred to as "negative symptoms" in schizophrenia. These aspects of schizophrenia include constructs such as asociality, avolition (a reduction in the motivation to initiate or persist in goal-directed behavior), and anhedonia (a reduction in the ability to experience pleasure). We believe that these dimensions of impairment in individuals with schizophrenia reflect difficulties using internal representations of emotional experiences, previous rewards, and motivational goals to drive current and future behavior in a way that would allow them to obtain desired outcomes, a deficit that has major clinical significance in terms of functional capacity. In this article, we review the major components of the systems that link experienced and anticipated rewards with motivated behavior that could potentially be impaired in schizophrenia. We conclude that the existing evidence suggests relatively intact hedonics in schizophrenia, but impairments in some aspects of reinforcement learning, reward prediction, and prediction error processing, consistent with an impairment in "wanting." As of yet, there is only indirect evidence of impairment in anterior cingulate and orbital frontal function that may support value and effort computations. However, there are intriguing hints that individuals with schizophrenia may not be able to use reward information to modulate cognitive control and dorsolateral prefrontal cortex function, suggesting a potentially important role for cortical-striatal interactions in mediating impairment in motivated and goal-directed behavior in schizophrenia.

Volume reduction and altered sulco-gyral pattern of the orbitofrontal cortex in first-episode schizophrenia

BACKGROUND

Although clinical and neuropsychological findings have implicated functional deficits of the orbitofrontal cortex (OFC) in schizophrenia, structural magnetic resonance imaging (MRI) studies of this region have yielded inconsistent findings. In addition, it remains elusive whether the OFC morphology in first-episode patients is related to their clinical features.

METHOD

MR images were acquired from 42 (24 males, 18 females) first-episode schizophrenia patients and 35 (20 males, 15 females) age-, gender-, and parental socio-economic status (SES)-matched healthy subjects. The OFC sub-regions (orbital gyrus and straight gyrus) were measured on contiguous 1-mm-thick coronal slices. The OFC sulco-gyral pattern was also evaluated for each subject. Furthermore, the relationships between OFC morphology and clinical measures were examined.

RESULTS

The volumes of the bilateral orbital gyri were significantly reduced in schizophrenia patients compared with healthy subjects, whereas the volumes of the straight gyri did not show differences between the groups. Among the schizophrenia patients, the volume of the left orbital gyrus was inversely correlated with their SES and illness duration. The OFC sulco-gyral patterns were significantly different between the patients and controls in the right hemisphere.

CONCLUSION

This study demonstrated morphologic abnormalities of the OFC in first-episode schizophrenia patients, which may have reflected neurodevelopmental aberrations and neurodegenerative changes during the first episode of the illness. Our findings also suggest that such brain structural changes are related to the social dysfunction observed in schizophrenia.

Prefrontal cognitive dysfunction is associated with tobacco dependence treatment failure in smokers with schizophrenia

BACKGROUND

Patients with schizophrenia have higher rates of smoking (58-88%) than in the general population ( approximately 22%), and are more refractory to smoking cessation. These patients also exhibit numerous neurocognitive deficits, some of which may be ameliorated by cigarette smoking. The neurocognitive benefits derived from nicotine may, in turn, contribute to elevated rates of smoking and smoking persistence in schizophrenia. The present study examined the relationship between neurocognitive function and smoking cessation in schizophrenia.

METHODS

Treatment-seeking smokers with schizophrenia (N=58) participated in a 10-week placebo-controlled trial of sustained-release (SR) bupropion plus transdermal nicotine patch. Neuropsychological performance was evaluated in a subset of patients (n=31), prior to pharmacological treatment, using a neurocognitive battery.

RESULTS

Subjects were compared as a function of endpoint smoking status (Quit versus Not Quit), assessed by end of trial 7-day point prevalence abstinence, confirmed by CO level (< 10 ppm) on demographic traits, smoking, and clinical outcomes. While there were no significant baseline differences between quitters and non-quitters, non-quitters exhibited significantly greater deficits in performance on Trail Making Test, Part B (p=0.01) and on Digit Span backwards (p=0.04) compared to quitters. No associations were found between quit status and performance on other neuropsychological measures.

CONCLUSIONS

Our findings extend results of previous studies which suggest deficits in frontal executive function are associated with smoking cessation failure in schizophrenia. This may have implications for the development of tailored smoking cessation treatments in this population.