Self-awareness deficits associated with lower treatment motivation in cocaine addiction.

BACKGROUND: Individuals with cocaine use disorder (CUD) often display behaviours that are paradoxically misaligned with their situation. Typical examples include poor treatment motivation and inconsistent self-reported craving. These behaviours may reflect impairments in the awareness of one's own behaviour. OBJECTIVES: We examined whether impaired self-awareness of addiction-related frontostriatal dysfunction (i.e., symptoms of apathy, disinhibition, and executive dysfunction) was associated with treatment motivation and craving. METHODS: Sixty-five outpatients with CUD (57 male) and their informants (those who knew the patient well) completed parallel self and informant versions of the Frontal Systems Behaviour Scale. Self-awareness was indexed through the discrepancy between self and informant scores in the three sub-scales; apathy, disinhibition and executive dysfunction. The University Rhode Island Change Assessment Scale assessed treatment motivation. Self-reported craving was assessed using a visual analogue scale. Multiple linear regression models examined associations between self-awareness and treatment motivation and craving, adjusting for sociodemographic factors and lifetime drug use. RESULTS: We found an inverse relationship between self-awareness of symptoms of disinhibition and treatment motivation maintenance. Although impaired awareness of disinhibition was also correlated with craving, this association was not significant after adjusting for sociodemographic factors and drug use. The apathy and executive dysfunction awareness scores were not associated with treatment motivation or craving. CONCLUSION: We show that people with lower insight into their disinhibition problems (e.g., impulsivity, mood instability) have more problems maintaining motivation when initiating treatment. Findings suggest that self-awareness interventions could be useful to prevent premature treatment dropout and improve addiction treatment outcomes.

Brain substrates of social decision-making in dual diagnosis: cocaine dependence and personality disorders.

Cocaine dependence frequently co-occurs with personality disorders, leading to increased interpersonal problems and greater burden of disease. Personality disorders are characterised by patterns of thinking and feeling that divert from social expectations. However, the comorbidity between cocaine dependence and personality disorders has not been substantiated by measures of brain activation during social decision-making. We applied functional magnetic resonance imaging to compare brain activations evoked by a social decision-making task-the Ultimatum Game-in 24 cocaine dependents with personality disorders (CDPD), 19 cocaine dependents without comorbidities and 19 healthy controls. In the Ultimatum Game participants had to accept or reject bids made by another player to split monetary stakes. Offers varied in fairness (in fair offers the proposer shares ~50 percent of the money; in unfair offers the proposer shares <30 percent of the money), and participants were told that if they accept both players get the money, and if they reject both players lose it. We contrasted brain activations during unfair versus fair offers and accept versus reject choices. During evaluation of unfair offers CDPD displayed lower activation in the insula and the anterior cingulate cortex and higher activation in the lateral orbitofrontal cortex and superior frontal and temporal gyri. Frontal activations negatively correlated with emotion recognition. During rejection of offers CDPD displayed lower activation in the anterior cingulate cortex, striatum and midbrain. Dual diagnosis is linked to hypo-activation of the insula and anterior cingulate cortex and hyper-activation of frontal-temporal regions during social decision-making, which associates with poorer emotion recognition.

Neural correlates of impaired self-awareness of apathy, disinhibition and dysexecutive deficits in cocaine-dependent individuals.

Cocaine addiction is characterized by impaired self-awareness about cognitive and motivational deficits, leading to poor treatment outcomes. However, there is still limited understanding of the neurophysiological underpinnings of this impairment. We aimed to establish if impaired self-awareness is underpinned by brain structural phenotypes among cocaine-dependent individuals (CDI). Sixty-five CDI and 65 designated informants completed the Frontal Systems Behavior Scale, and a subsample of 40 CDI were scanned via magnetic resonance imaging. We applied multiple regression models to establish the association between levels of self-awareness indexed by Frontal Systems Behavior Scale's discrepancy scores (i.e. informant ratings minus self-reports of apathy, disinhibition and dysexecutive deficits) and gray matter volumes indexed by magnetic resonance imaging voxel-based measures within five brain regions of interest: anterior cingulate cortex, orbitofrontal cortex (OFC), striatum, insula and dorsolateral prefrontal cortex (DLPFC). We also examined the neural underpinnings of underestimation versus overestimation of deficits, by splitting the CDI group according to the positive or negative value of their discrepancy scores. We found that poorer self-awareness of apathy deficits was associated with greater gray matter volume in the dorsal striatum, and poorer self-awareness of disinhibition deficits was associated with greater gray matter volume in the OFC in the whole sample. More underestimation and more overestimation of executive deficits were linked to lower DLPFC volume. We show that impaired self-awareness of cognitive and motivational deficits in cocaine addiction has a neural underpinning, implicating striatum, OFC and DLPFC structural phenotypes.

The effects of healing abutments of different size and anatomic shape placed immediately in extraction sockets on peri-implant hard and soft tissues. A pilot study in foxhound dogs.

OBJECTIVES: The aim of this animal study was to compare the effects of narrow, concave-straight and wide anatomic healing abutments on changes to soft tissues and crestal bone levels around implants immediately placed into extraction sockets in foxhound dogs. MATERIALS AND METHODS: Forty-eight titanium implants (Bredent Medical GMBH, Germany) of the same dimensions were placed in six foxhound dogs. They were divided into two groups (n = 24): test (implants with anatomic abutment) and control (implants with concave-straight abutment). The implants were inserted randomly in the post extraction sockets of P2 , P3 , P4, and M1 bilaterally in six dogs. After eight and twelve weeks, the animals were sacrificed and samples extracted containing the implants and the surrounding soft and hard tissues. Soft tissue and crestal bone loss (CBL) were evaluated by histology and histomorphometry. RESULTS: All implants were clinically and histologically osseointegrated. Healing patterns were examined microscopically at eight and twelve weeks. After eight and twelve weeks, for hard tissues, the distance from the implant shoulder to the first bone-to-implant contact (IS-C) was higher for control group in the lingual aspect with statistical significance (P < 0.05). For soft tissues (STL), the distance from the top of the peri-implant mucosa to the apical portion of the junction epithelium (PM-Je) was significantly less on the lingual aspect in the test group (with wider abutment) at eight and twelve weeks (P < 0.05). The distance from the top of the apical portion of the junction epithelium to the first bone-to-implant contact (Je-C) was significantly higher in the test group (wider abutment) in the lingual aspect at eight and twelve weeks (P < 0.05). There was no connective tissue contact with any abutment surface. CONCLUSIONS: Within the limitations of this animal study, anatomic healing abutments protect soft and hard tissues and reduce crestal bone resorption compared with concave-straight healing abutments.

Increased corticolimbic connectivity in cocaine dependence versus pathological gambling is associated with drug severity and emotion-related impulsivity.

Neural biomarkers for the active detrimental effects of cocaine dependence (CD) are lacking. Direct comparisons of brain connectivity in cocaine-targeted networks between CD and behavioural addictions (i.e. pathological gambling, PG) may be informative. This study therefore contrasted the resting-state functional connectivity networks of 20 individuals with CD, 19 individuals with PG and 21 healthy individuals (controls). Study groups were assessed to rule out psychiatric co-morbidities (except alcohol abuse and nicotine dependence) and current substance use or gambling (except PG). We first examined global connectivity differences in the corticolimbic reward network and then utilized seed-based analyses to characterize the connectivity of regions displaying between-group differences. We examined the relationships between seed-based connectivity and trait impulsivity and cocaine severity. CD compared with PG displayed increased global functional connectivity in a large-scale ventral corticostriatal network involving the orbitofrontal cortex, caudate, thalamus and amygdala. Seed-based analyses showed that CD compared with PG exhibited enhanced connectivity between the orbitofrontal and subgenual cingulate cortices and between caudate and lateral prefrontal cortex, which are involved in representing the value of decision-making feedback. CD and PG compared with controls showed overlapping connectivity changes between the orbitofrontal and dorsomedial prefrontal cortices and between amygdala and insula, which are involved in stimulus-outcome learning. Orbitofrontal-subgenual cingulate cortical connectivity correlated with impulsivity and caudate/amygdala connectivity correlated with cocaine severity. We conclude that CD is linked to enhanced connectivity in a large-scale ventral corticostriatal-amygdala network that is relevant to decision making and likely to reflect an active cocaine detrimental effect.

Neural substrates of cognitive flexibility in cocaine and gambling addictions.

BACKGROUND: Individuals with cocaine and gambling addictions exhibit cognitive flexibility deficits that may underlie persistence of harmful behaviours. AIMS: We investigated the neural substrates of cognitive inflexibility in cocaine users v. pathological gamblers, aiming to disambiguate common mechanisms v. cocaine effects. METHOD: Eighteen cocaine users, 18 pathological gamblers and 18 controls performed a probabilistic reversal learning task during functional magnetic resonance imaging, and were genotyped for the DRD2/ANKK Taq1A polymorphism. RESULTS: Cocaine users and pathological gamblers exhibited reduced ventrolateral prefrontal cortex (PFC) signal during reversal shifting. Cocaine users further showed increased dorsomedial PFC (dmPFC) activation relative to pathological gamblers during perseveration, and decreased dorsolateral PFC activation relative to pathological gamblers and controls during shifting. Preliminary genetic findings indicated that cocaine users carrying the DRD2/ANKK Taq1A1+ genotype may derive unique stimulatory effects on shifting-related ventrolateral PFC signal. CONCLUSIONS: Reduced ventrolateral PFC activation during shifting may constitute a common neural marker across gambling and cocaine addictions. Additional cocaine-related effects relate to a wider pattern of task-related dysregulation, reflected in signal abnormalities in dorsolateral and dmPFC.

Cocaine use severity and cerebellar gray matter are associated with reversal learning deficits in cocaine-dependent individuals.

Cocaine addiction involves persistent deficits to unlearn previously rewarded response options, potentially due to neuroadaptations in learning-sensitive regions. Cocaine-targeted prefrontal systems have been consistently associated with reinforcement learning and reversal deficits, but more recent interspecies research has raised awareness about the contribution of the cerebellum to cocaine addiction and reversal. We aimed at investigating the link between cocaine use, reversal learning and prefrontal, insula and cerebellar gray matter in cocaine-dependent individuals (CDIs) varying on levels of cocaine exposure in comparison with healthy controls (HCs). Twenty CDIs and 21 HCs performed a probabilistic reversal learning task (PRLT) and were subsequently scanned in a 3-Tesla magnetic resonance imaging scanner. In the PRLT, subjects progressively learn to respond to one predominantly reinforced stimulus, and then must learn to respond according to the opposite, previously irrelevant, stimulus-reward pairing. Performance measures were errors after reversal (reversal cost), and probability of maintaining response after errors. Voxel-based morphometry was conducted to investigate the association between gray matter volume in the regions of interest and cocaine use and PRLT performance. Severity of cocaine use correlated with gray matter volume reduction in the left cerebellum (lobule VIII), while greater reversal cost was correlated with gray matter volume reduction in a partially overlapping cluster (lobules VIIb and VIII). Right insula/inferior frontal gyrus correlated with probability of maintaining response after errors. Severity of cocaine use detrimentally impacted reversal learning and cerebellar gray matter.

Re-appraisal of negative emotions in cocaine dependence: dysfunctional corticolimbic activation and connectivity.

Cocaine dependence is associated with pronounced elevations of negative affect and deficient regulation of negative emotions. We aimed to investigate the neural substrates of negative emotion regulation in cocaine-dependent individuals (CDI), as compared to non-drug-using controls, using functional magnetic resonance imaging (fMRI) during a re-appraisal task. Seventeen CDI abstinent for at least 15 days and without other psychiatric co-morbidities and 18 intelligence quotient-matched non-drug-using controls participated in the study. Participants performed the re-appraisal task during fMRI scanning: they were exposed to 24 blocks of negative affective or neutral pictures that they should Observe (neutral pictures), Maintain (sustain the emotion elicited by negative pictures) or Suppress (regulate the emotion elicited by negative pictures through previously trained re-appraisal techniques). Task-related activations during two conditions of interest (Maintain>Observe and Suppress>Maintain) were analyzed using the general linear model in SPM8 software. We also performed psychophysiological interaction (PPI) seed-based analyses based on one region from each condition: the dorsolateral prefrontal cortex (dlPFC-Maintain>Observe) and the inferior frontal gyrus (IFG-Suppress>Maintain). Results showed that cocaine users had increased right dlPFC and bilateral temporoparietal junction activations during Maintain>Observe, whereas they showed decreased right IFG, posterior cingulate cortex, insula and fusiform gyrus activations during Suppress>Maintain. PPI analyses showed that cocaine users had increased functional coupling between the dlPFC and emotion-related regions during Maintain>Observe, whereas they showed decreased functional coupling between the right IFG and the amygdala during Suppress>Maintain. These findings indicate that CDI have dysfunctional corticolimbic activation and connectivity during negative emotion experience and re-appraisal.

Do comorbid personality disorders in cocaine dependence exacerbate neuroanatomical alterations? A structural neuroimaging study.

Cocaine dependence (CD) is highly comorbid with personality disorders, with implications for poorer treatment response. The neurobiological mechanisms of this comorbidity are unclear. We aimed to test the role of comorbid personality disorders in the neuroanatomy of CD. We examined 4 groups using high-resolution structural neuroimaging, psychological questionnaires and cognitive tests: CD (n = 19), CD and personality disorder type B (CD + B, n = 21), CD and personality disorder C (CD + C, n = 13) and 21 controls. We compared groups in neuroanatomy and hypothesised that (i) CD would show altered striatal areas ascribed to reward processing (i.e., accumbens, caudate and putamen), (ii) CD + B and CD + C would show altered areas supporting emotional regulation/social valuation and anxiety/avoidance (i.e., OFC and amygdala). The CD + B group had larger caudate volumes than CD (p = .01, d = 0.94) and reduced lateral OFC thickness than CD + C (p = .056, d = 0.71). Exploratory correlations showed that altered neural integrity of the OFC and of the caudate nucleus in these groups exacerbated with worse personality disorder severity and impulsivity scores. CD with and without comorbid personality disorders may have partially distinct underlying mechanisms and targets for treatment.

Melatonin stimulates the growth of new bone around implants in the tibia of rabbits.

This study evaluated the effect of the topical application of melatonin in accelerating bone formation associated with implants 2 months after their application to the tibiae of rabbits. Twenty New Zealand rabbits were used. Twenty implants treated with melatonin and 20 control implants without melatonin were placed in the proximal metaphyseal area of each tibia. Studies of new bone formation were subsequently made at 15, 30, 45 and 60 days. Cortical width and cortical length of new bone formation were measured. Following implantation, an anteroposterior and lateral radiologic study was carried out. Collected samples were sectioned at 5 µm and stained using hematoxylin-eosin, Masson's trichromic and Gordon-Switt reticulin stains. After a 60 day treatment period, melatonin increased the length of cortical bone (95.13±0.42%) versus that around control implants (62.91±1.45%). Related to the perimeter of cortical bone of the tibiae, melatonin induced new bone 88.35±1.56% versus 60.20±1.67% in the control implants. Melatonin regenerated the width and length of cortical bone around implants in tibiae of rabbits more quickly than around control implants without the addition of melatonin.

Evaluation of Motivation for the Treatment of Drug Addicts with Personality Disorders.

Lack of motivation for the treatment of drug addiction is associated with dropout and relapses. Further, personality disorders (PD) have traditionally been linked to low motivation and therapeutic failure. Thus, the present study aims to analyze the structure of the Motivation for Treatment Questionnaire (MTQ-8), as well as to determine differences in motivation due to the presence of PD and the impact of psychological adjustment on motivation. The sample included 125 patients (84% male) who started a treatment for their addiction to cocaine and alcohol. Rasch analysis was applied for the first objective, and means contrast and regression analysis for the others. The two subscales of the MTQ-8 fit the Rasch model, with appropriate psychometric characteristics when merging Items 5 and 7. The presence of PD was not associated with reduced motivation. Motivation for treatment was greater when abstinence was less than three weeks, and psychological distress predicted motivation for treatment. The present study confirms that MTQ-8 subscales are suitable for measuring motivation for treatment and readiness for change in drug-dependent patients. It is noted that the presence of PD should not be associated with a lower level of motivation, and that psychological distress influences motivation.

Dysfunctional Personality Beliefs Linked to Emotion Recognition Deficits in Individuals With Cocaine Addiction and Personality Disorders.

Background: Facial emotion recognition is impaired in addiction and personality disorders. Dysfunctional personality beliefs reflect negative interpersonal schemas that may underpin emotion recognition deficits. We aimed to examine the association between personality beliefs and emotion recognition among participants with cocaine use disorder including those with comorbid personality disorders. Methods: We recruited 70 participants with cocaine use disorder aged between 19 and 52 who had used 14 g of cocaine over 4.8 years on average. Thirty-eight participants had an additional personality disorder (11 Borderline, 7 Histrionic, 5 Antisocial, 10 Avoidant, and 5 Obsessive-Compulsive). Dysfunctional beliefs were indicated with the Personality Belief Questionnaire, and facial emotion recognition was indicated with the Ekman's Test. We applied correlations/multiple regressions to test the relationship between beliefs and emotion recognition. Results: Personality beliefs reflecting paranoid, borderline, and antisocial schemas were negatively associated with emotion recognition. Antisocial beliefs were associated with poorer recognition of fear, and paranoid beliefs with poorer recognition of disgust. Antisocial beliefs were significantly associated with emotion recognition after adjusting for cocaine use. Conclusion: Dysfunctional personality beliefs are associated with poorer emotion recognition in cocaine addiction. Personality-related negative schemas about the self and others can impact social cognition and interaction during cocaine treatment.

Metaanalysis of filler materials in periapical surgery.

OBJECTIVE: To evaluate the success and failure, apical sealing and biocompatibility of silver amalgam, IRM, SuperEBA and MTA as retrograde filler materials. STUDY DESIGN: A metaanalysis is made of filler materials in periapical surgery, evaluating a total of 30 articles published in recent years. RESULTS: Percentage success with silver amalgam was 76.5% and slightly inferior to that afforded by IRM. Performance in turn increased considerably when the materials used were SuperEBA or MTA. As regards marginal leakage, MTA with a mean leakage time of 65.5 days afforded the best results, followed by SuperEBA, IRM and silver amalgam. MTA was the most biocompatible of the materials studied, with practically no inflammatory response, while inflammation proved mild or moderate with SuperEBA, mild with IRM, and moderate to severe in the case of silver amalgam. Tissue regeneration was only observed with MTA, in the same way as cement appositioning. Bone neoformation was observed with all four filler materials. CONCLUSIONS: MTA appears to be an ideal material, though the results obtained require confirmation by in vivo studies.

Complications in the treatment of mandibular condylar fractures: Surgical versus conservative treatment.

OBJECTIVES: In the present article, we aim to review the main intra- and post-operative complications associated with two different therapeutic approaches for treating mandibular condylar fractures: conservative (CTR) and surgical treatment (ORIF, Open Reduction and Internal Fixation). MATERIAL AND METHODS: We have carried out a retrospective, meta-analytic, observational study using literature review, covering the period between 2000- September 2017. The data obtained were processed using statistical software SPSS v.0.18 and R v.2.11.1. The chi-squared test was used for comparison of relative frequencies for independent samples. RESULTS: A total of 2458 patients with 2810 fractures were collected for study. Patients treated with CTR and ORIF were an average of 29 years old, of those treated with CTR, 72.37% and 27.63% were male or female respectively and, of those treated with ORIF, 70.36% and 29.64% were male or female respectively. The main complications suffered by CTR and ORIF patients were: asymmetry (10.2%/6.4%), residual pain (6.5%/5.6%), temporomandibular joint and articular imbalance (15.9%/10.3%) and malocclusion (11.1%/4.0%), respectively. We only found significant differences between CTR and ORIF in the number of cases of temporomandibular joint and articular imbalance and malocclusion. Facial nerve damage was found exclusively among ORIF patients (8.6%) of which 8.3% were temporary and 0.3% permanent. CONCLUSIONS: The complications associated with either technique are minimal and infrequent, resulting in successful outcomes with minimal morbidity. CTR are associated with complications deriving from delayed mobilization leading to functional limitation, whereas the main complication associated with ORIF treatment was facial nerve damage.

Self-deception as a mechanism for the maintenance of drug addiction.

BACKGROUND: This study was aimed at: (i) examining levels of self-deception in substance dependent individuals following addiction treatment, and (ii) examining the association between participants’ levels of self-deception and (a) personality disorders, (b) addiction-related beliefs, (c) duration of abstinence, and (d) estimates of craving. METHOD: We administered self-report questionnaires of self-deception and mixtification, and core beliefs related to addiction and craving. The sample comprised 79 outpatients who were consecutively recruited at the Centro Provincial de Drogodependencias in Granada: 87.3% were males and the mean age was 37.68 years old. Thirty-four percent of participants were diagnosed with comorbid personality disorders. RESULTS: Results showed that individuals with substance dependence exhibit elevated scores of self-deception, particularly in the domains of active denial, selective amnesia, projection, and confabulation. Individuals with comorbid personality disorders display greater levels of self-deception compared to individuals without dual diagnosis. CONCLUSIONS: Moreover, there is a significant association between levels of self-deception and addiction-related beliefs and craving. In addition, there is a negative association between levels of self-deception and duration of abstinence.

Cocaine-specific neuroplasticity in the ventral striatum network is linked to delay discounting and drug relapse.

AIMS: To contrast functional connectivity on ventral and dorsal striatum networks in cocaine dependence relative to pathological gambling, via a resting-state functional connectivity approach; and to determine the association between cocaine dependence-related neuroadaptations indexed by functional connectivity and impulsivity, compulsivity and drug relapse. DESIGN: Cross-sectional study of 20 individuals with cocaine dependence (CD), 19 individuals with pathological gambling (PG) and 21 healthy controls (HC), and a prospective cohort study of 20 CD followed-up for 12 weeks to measure drug relapse. SETTING AND PARTICIPANTS: CD and PG were recruited through consecutive admissions to a public clinic specialized in substance addiction treatment (Centro Provincial de Drogodependencias) and a public clinic specialized in gambling treatment (AGRAJER), respectively; HC were recruited through community advertisement in the same area in Granada (Spain). MEASUREMENTS: Seed-based functional connectivity in the ventral striatum (ventral caudate and ventral putamen) and dorsal striatum (dorsal caudate and dorsal putamen), the Kirby delay-discounting questionnaire, the reversal-learning task and a dichotomous measure of cocaine relapse indicated with self-report and urine tests. FINDINGS: CD relative to PG exhibit enhanced connectivity between the ventral caudate seed and subgenual anterior cingulate cortex, the ventral putamen seed and dorsomedial pre-frontal cortex and the dorsal putamen seed and insula (P≤0.001, kE=108). Connectivity between the ventral caudate seed and subgenual anterior cingulate cortex is associated with steeper delay discounting (P≤0.001, kE=108) and cocaine relapse (P≤0.005, kE=34). CONCLUSIONS: Cocaine dependence-related neuroadaptations in the ventral striatum of the brain network are associated with increased impulsivity and higher rate of cocaine relapse.

The value of impulsivity to define subgroups of addicted individuals differing in personality dysfunction, craving, psychosocial adjustment, and wellbeing: a latent class analysis.

High impulsivity is common to substance and gambling addictions. Despite these commonalities, there is still substantial heterogeneity on impulsivity levels within these diagnostic groups, and variations in impulsive levels predict higher severity of symptoms and poorer outcomes. We addressed the question of whether impulsivity scores can yield empirically driven subgroups of addicted individuals that will exhibit different clinical presentations and outcomes. We applied latent class analysis (LCA) to trait (UPPS-P impulsive behavior scale) and cognitive impulsivity (Stroop and d2 tests) scores in three predominantly male addiction diagnostic groups: Cocaine with Personality Disorders, Cocaine Non-comorbid, and Gambling and analyzed the usefulness of the resulting subgroups to differentiate personality beliefs and relevant outcomes: Craving, psychosocial adjustment, and quality of life. In accordance with impulsivity scores, the three addiction diagnostic groups are best represented as two separate classes: Class 1 characterized by greater trait impulsivity and poorer cognitive impulsivity performance and Class 2 characterized by lower trait impulsivity and better cognitive impulsivity performance. The two empirically derived classes showed significant differences on personality features and outcome variables (Class 1 exhibited greater personality dysfunction and worse clinical outcomes), whereas conventional diagnostic groups showed non-significant differences on most of these measures. Trait and cognitive impulsivity scores differentiate subgroups of addicted individuals with more versus less severe personality features and clinical outcomes.

Executive functions in cocaine-dependent patients with Cluster B and Cluster C personality disorders.

OBJECTIVE: Cocaine dependence often co-occurs with personality disorders from Clusters B and C, which are inherently associated with some of the executive dysfunctions found in addiction. We address the question of whether the comorbidity between cocaine dependence and different types of personality disorders is associated with differential profiles of executive deficits compatible with their personality dysfunction. We predicted that the comorbidity with Cluster B disorders would be associated with inhibition and shifting deficits, whereas the comorbidity with Cluster C disorders would be associated with working memory deficits. METHOD: We tested 107 participants (22 cocaine users with Cluster B disorders, 15 cocaine users with Cluster C disorders, 36 cocaine users without comorbidities, and 34 controls) using tests of working memory, attention, inhibition, and shifting. Groups were statistically matched on IQ and had no Axis I comorbidities (other than substance-related). Based on the performance of the control group, we obtained z-score composite measures of working memory, attention/inhibition, shifting, and global executive impairment. We tested group differences in these composite measures using univariate analyses of variance and Sidak tests corrected for multiple comparisons. RESULTS: Cocaine users with Cluster B disorders had poorer attention/inhibition, whereas cocaine users with comorbid Cluster C disorders had poorer working memory. Cluster B and noncomorbid cocaine users (but not Cluster C users) differed from controls on the global executive impairment measure. CONCLUSION: The comorbidity between cocaine dependence and personality disorders from Clusters B and C is associated with executive function deficits that are compatible with their respective personality dysfunctions.

Monetary delay discounting in gambling and cocaine dependence with personality comorbidities.

BACKGROUND: Cocaine addiction and pathological gambling are commonly associated with steeper (impulsive) discounting of delayed rewards, which promotes ongoing drug and gambling behaviors. However, it is yet unclear whether impulsive delay discounting is a stable trait in cocaine and gambling disorders during abstinence, and whether it is significantly impacted by dysfunctional personality beliefs. METHODS: The aim of this study was to compare the delay discounting rates of four groups: 47 cocaine users with comorbid personality disorders, 41 cocaine users without psychiatric comorbidities, 28 pathological gamblers without psychiatric comorbidities, and 36 healthy comparison individuals. We also examined the association between dysfunctional personality beliefs and delay discounting rates. Participants completed the Kirby Delay Discounting Questionnaire and the Beck Personality Belief Questionnaire as part of a larger battery. RESULTS: We used non-parametric tests to compare discounting rates between the groups, and bivariate correlation analyses to examine the association between beliefs and discounting rates within each of the groups. We found that discounting rates were significantly higher in individuals with disordered gambling compared to controls. Specifically in cocaine users with Cluster B personality disorders, higher discounting rates were associated with the intensity of "dependent" dysfunctional beliefs (e.g., "I am needy and weak"). Conclusion:We conclude that impulsive delay discounting is increased in gambling relative to controls and linked to personality beliefs in cocaine users with Cluster B personality disorders.

A MAOA gene*cocaine severity interaction on impulsivity and neuropsychological measures of orbitofrontal dysfunction: preliminary results.

BACKGROUND: Based on previous evidence of a MAOA gene*cocaine use interaction on orbitofrontal cortex volume attrition, we tested whether the MAOA low activity variant and cocaine use severity are interactively associated with impulsivity and behavioral indices of orbitofrontal dysfunction: emotion recognition and decision-making. METHODS: 72 cocaine dependent individuals and 52 non-drug using controls (including healthy individuals and problem gamblers) were genotyped for the MAOA gene and tested using the UPPS-P Impulsive Behavior Scale, the Iowa Gambling Task and the Ekman's Facial Emotions Recognition Test. To test the main hypothesis, we conducted hierarchical multiple regression analyses including three sets of predictors: (1) age, (2) MAOA genotype and severity of cocaine use, and (3) the interaction between MAOA genotype and severity of cocaine use. UPPS-P, Ekman Test and Iowa Gambling Task's scores were the outcome measures. We computed the statistical significance of the prediction change yielded by each consecutive set, with 'a priori' interest in the MAOA*cocaine severity interaction. RESULTS: We found significant effects of the MAOA gene*cocaine use severity interaction on the emotion recognition scores and the UPPS-P's dimensions of Positive Urgency and Sensation Seeking: Low activity carriers with higher cocaine exposure had poorer emotion recognition and higher Positive Urgency and Sensation Seeking. CONCLUSION: Cocaine users carrying the MAOA low activity show a greater impact of cocaine use on impulsivity and behavioral measures of orbitofrontal cortex dysfunction.