Serotonin Signaling in Hippocampus during Initial Cocaine Abstinence Drives Persistent Drug Seeking

The initiation of abstinence after chronic drug self-administration is stressful. Cocaine-seeking behavior on the first day of the absence of the expected drug (Extinction Day 1, ED1) is reduced by blocking 5-HT signaling in dorsal hippocampal cornu ammonis 1 (CA1) in both male and female rats. We hypothesized that the experience of ED1 can substantially influence later relapse behavior and that dorsal raphe (DR) serotonin (5-HT) input to CA1 may be involved. We inhibited 5-HT1A/1B receptors (WAY-100635 plus GR-127935), or DR input (chemogenetics), in CA1 on ED1 to test the role of this pathway on cocaine-seeking persistence 2 weeks later. We also inhibited 5-HT1A or 5-HT1B receptors in CA1 during conditioned place preference (CPP) for cocaine, to examine mechanisms involved in the persistent effects of ED1 manipulations. Inhibition of DR inputs, or 5-HT1A/1B signaling, in CA1 decreased drug seeking on ED1 and decreased cocaine seeking 2 weeks later revealing that 5-HT signaling in CA1 during ED1 contributes to persistent drug seeking during abstinence. In addition, 5-HT1B antagonism alone transiently decreased drug-associated memory performance when given prior to a CPP test, whereas similar antagonism of 5-HT1A alone had no such effect but blocked CPP retrieval on a test 24 h later. These CPP findings are consistent with prior work showing that DR inputs to CA1 augment recall of the drug-associated context and drug seeking via 5-HT1B receptors and prevent consolidation of the updated nondrug context via 5-HT1A receptors. Thus, treatments that modulate 5-HT-dependent memory mechanisms in CA1 during initial abstinence may facilitate later maintenance of abstinence.

Decoding cocaine-induced proteomic adaptations in the mouse nucleus accumbens

Cocaine use disorder (CUD) is a chronic neuropsychiatric condition that results from enduring cellular and molecular adaptations. Among substance use disorders, CUD is notable for its rising prevalence and the lack of approved pharmacotherapies. The nucleus accumbens (NAc), a region that is integral to the brain's reward circuitry, plays a crucial role in the initiation and continuation of maladaptive behaviors that are intrinsic to CUD. Leveraging advancements in neuroproteomics, we undertook a proteomic analysis that spanned membrane, cytosolic, nuclear, and chromatin compartments of the NAc in a mouse model. The results unveiled immediate and sustained proteomic modifications after cocaine exposure and during prolonged withdrawal. We identified congruent protein regulatory patterns during initial cocaine exposure and reexposure after withdrawal, which contrasted with distinct patterns during withdrawal. Pronounced proteomic shifts within the membrane compartment indicated adaptive and long-lasting molecular responses prompted by cocaine withdrawal. In addition, we identified potential protein translocation events between soluble-nuclear and chromatin-bound compartments, thus providing insight into intracellular protein dynamics after cocaine exposure. Together, our findings illuminate the intricate proteomic landscape that is altered in the NAc by cocaine use and provide a dataset for future research toward potential therapeutics.

Contingency management plus acceptance and commitment therapy for initial cocaine abstinence: Results of a sequential multiple assignment randomized trial (SMART)

BACKGROUND

This study tested an adaptive intervention for optimizing abstinence outcomes over phases of treatment for cocaine use disorder using a SMART design. Phase 1 assessed whether 4 weeks of contingency management (CM) improved response with the addition of Acceptance and Commitment Therapy (ACT). Phase 2 assessed pharmacological augmentation with modafinil (MOD) vs. placebo (PLA) for individuals not achieving abstinence during Phase 1.

METHOD

For Phase 1 of treatment, participants (N=118) were randomly allocated to ACT+CM or Drug Counseling (DC+CM), the comparison condition. At week 4, treatment response was defined as the submission of six consecutive cocaine-negative urine drug screens (UDS). Phase 1 non-responders were re-randomized to MOD or PLA as adjunct to their initial treatment. Phase 1 responders continued receiving their initial treatment. Primary outcomes included response rate and proportion of cocaine-negative UDS for Phase 1 and 2. Analyses used Bayesian inference with 80% pre-specified as the posterior probability (PP) threshold constituting moderate evidence that an effect exists.

RESULTS

Phase 1 response was higher in the ACT+CM group (24.5%) compared to the DC+CM group (17.5%; PP = 84.5%). In Phase 2, the proportion of cocaine-negative UDS among Phase 1 responders did not differ by initial treatment (PP = 61.8%) but remained higher overall compared to Phase 1 non-responders (PPs > 99%). No evidence of an effect favoring augmentation with MOD was observed.

DISCUSSION

Adding ACT to CM increased abstinence initiation. Initial responders were more likely to remain abstinent compared to initial non-responders, for whom modafinil was not an effective pharmacotherapy augmentation strategy.

Percentage of negative urine drug screens as a clinically meaningful endpoint for RCTs evaluating treatment for cocaine use

BACKGROUND

This study examined a threshold based on the percentage of cocaine-negative (CN) urine drug screens (UDS) collected during treatment as a potential meaningful endpoint for clinical trials. We hypothesized that individuals providing at least 75% CN UDS would have better long-term outcomes than those providing less than 75% CN UDS.

METHODS

Two separate pooled datasets of randomized clinical trials conducted at different institutions were used for analyses: one composed of eight trials (N = 760) and the other composed of three trials (N = 416), all evaluating behavioral and/or pharmacological treatments for cocaine use. UDS were collected at least once per week (up to three times per week) during the 8- or 12-week treatment period across all trials, with substance use and psychosocial functioning measured up to 12 months following treatment. Chi-squares and ANOVAs compared within-treatment and follow-up outcomes between the groups.

RESULTS

Compared to those who did not achieve the threshold, participants who achieved the 75%-CN threshold were retained in treatment longer and had a longer period of continuous abstinence, and were more likely to report problem-free functioning. Additionally, participants who achieved the 75%-CN threshold were more likely to report sustained abstinence and better psychosocial functioning throughout a follow-up period up to 12 months than those who did not achieve the threshold.

CONCLUSIONS

A threshold of 75%-CN UDS is associated with short- and long-term clinical benefits. Future clinical trials may consider this a meaningful threshold for defining treatment responders.

Cocaine Use May Moderate the Associations of HIV and Female Sex with Neurocognitive Impairment in a Predominantly African American Population Disproportionately Impacted by HIV and Substance Use

HIV-associated neurocognitive disorders (HAND) remain a major challenge for people with HIV in the antiretroviral therapy era. Cocaine use may trigger/exacerbate HAND among African American (AA) adults, especially women. Between 2018 and 2019, 922 adults, predominantly AAs, with/without HIV and with/without cocaine use in Baltimore, Maryland, were enrolled in a study investigating the association of HIV and cocaine use with neurocognitive impairment (NCI). Neurocognitive performance was assessed with the NIH Toolbox Cognition Battery (NIHTB-CB). NCI was considered to be present if the fully adjusted standard score for at least two cognitive domains was 1.0 standard deviation below the mean. Although the overall analysis showed HIV and female sex were associated with NCI, the associations were dependent on cocaine use. Neither HIV [adj prevalence ratio (PR): 1.12, confidence interval (95% CI): 0.77-1.64] nor female sex (adj PR: 1.07, 95% CI: 0.71-1.61) was associated with NCI among cocaine nonusers, while both HIV (adj PR: 1.39, 95% CI: 1.06-1.81) and female sex (adj PR: 1.53, 95% CI: 1.18-1.98) were associated with NCI in cocaine users. HIV was associated with two NIHTB-CB measures overall. In addition, HIV was associated with a lower dimensional change card sort score (an executive function measure) in cocaine users and not in nonusers. Cognitive performance was poorer in female than in male cocaine users. The adverse effect of HIV on cognitive performance predominantly affected cocaine users. However, cocaine use may moderate the impact of HIV and female sex on cognitive performance, highlighting the importance of reducing cocaine use in NCI prevention among the AA population.

Impulsivity and Treatment Outcomes in Individuals with Cocaine Use Disorder: Examining the Gap between Interest and Adherence

Background: Impulsivity is implicated in the development and maintenance of Cocaine Use Disorder (CUD). Less work has examined impulsivity's role on interest in initiating treatment, treatment adherence, or treatment response. No pharmacotherapies are approved for CUD, so efforts to understand and bolster the effects of psychotherapy are important in guiding and refining treatment. The present study examined the impact of impulsivity on interest in treatment, treatment initiation, treatment adherence, and treatment outcomes in individuals with CUD. Methods: Following the completion of a larger study on impulsivity and CUD participants were offered 14 sessions of (12 weeks) Cognitive Behavioral Relapse Prevention (CBT-RP). Before starting treatment, participants completed seven self-report and four behavioral measures of impulsivity. Sixty-eight healthy adults (36% female) with CUD (aged 49.4 ± 7.9) expressed an interest in treatment. Results: Greater scores on several self-report measures of impulsivity, and fewer difficulties with delayed gratification were associated with increased interest in treatment in both males and females. 55 participants attended at least 1 treatment session, while 13 participants did attend a single session. Individuals who attended at least one treatment session scored lower on measures of lack of perseverance and procrastination. Still, measures of impulsivity did not reliably predict session attendance nor the frequency of cocaine-positive urine samples throughout treatment. Males attended nearly twice as many treatment sessions as females despite nonsignificant associations between impulsivity in males and the number of sessions attended. Conclusions: Greater impulsivity in individuals with CUD was associated with expressing an interest in treatment, but not treatment adherence or response.

Transgenerational Cycle of Traumatization and HIV Risk Exposure among Crack Users

The aim of this manuscript is to understand the impact of childhood sexual abuse on the development of Post-Traumatic Stress Disorder (PTSD), Human Immunodeficiency Virus (HIV) exposure. and parental neglect in crack cocaine users, considering the role of gender. This study is a secondary database analysis of a sample from a multicenter cross-sectional study with 715 crack cocaine users receiving outpatient treatment in public mental health networks in six Brazilian capitals. Prevalence ratios were estimated by Poisson regression. In crack cocaine users with childhood sexual abuse, traumatic experiences seem to remain fixed through the development of Post Traumatic Stress Disorder (PTSD) in adulthood. Crack cocaine users with childhood abuse and PTSD in adulthood showed more sexual risk behaviors, including outcomes such as HIV (PR = 3.6 p < 0.001 for childhood abuse and PR = 3.7 p < 0.001 for PTSD). Furthermore, this traumatic trajectory affects the functional ability of crack cocaine users, especially women, to work thus impacting their inclusion and sense of social belonging. Such a chain seems to be reflected in the establishment of a circle of transgenerational transmission, to the extent that subjects with a history of abuse and PTSD reported more parental neglect towards their children. This study reinforces the importance of preventive public policies regarding early socio-emotional vulnerabilities and the need to support families, especially women, to avoid HIV and self-destructive outcomes such as crack cocaine use.

Towards a machine-learning assisted diagnosis of psychiatric disorders and their operationalization in preclinical research: Evidence from studies on addiction-like behaviour in individual rats

Over the last few decades, there has been a progressive transition from a categorical to a dimensional approach to psychiatric disorders. Especially in the case of substance use disorders, interest in the individual vulnerability to transition from controlled to compulsive drug taking warrants the development of novel dimension-based objective stratification tools. Here we drew on a multidimensional preclinical model of addiction, namely the 3-criteria model, previously developed to identify the neurobehavioural basis of the individual's vulnerability to switch from controlled to compulsive drug taking, to test a machine-learning assisted classifier objectively to identify individual subjects as vulnerable/resistant to addiction. Datasets from our previous studies on addiction-like behaviour for cocaine or alcohol were fed into a variety of machine-learning algorithms to develop a classifier that identifies resilient and vulnerable rats with high precision and reproducibility irrespective of the cohort to which they belong. A classifier based on K-median or K-mean-clustering (for cocaine or alcohol, respectively) followed by artificial neural networks emerged as a highly reliable and accurate tool to predict if a single rat is vulnerable/resilient to addiction. Thus, each rat previously characterized as displaying 0-criterion (i.e., resilient) or 3-criteria (i.e., vulnerable) in individual cohorts was correctly labelled by this classifier. The present machine-learning-based classifier objectively labels single individuals as resilient or vulnerable to developing addiction-like behaviour in a multisymptomatic preclinical model of addiction-like behaviour in rats. This novel dimension-based classifier increases the heuristic value of these preclinical models while providing proof of principle to deploy similar tools for the future of diagnosis of psychiatric disorders.

Effects of Human Immunodeficiency Virus Infection and Former Cocaine Dependence on Neuroanatomical Measures and Neurocognitive Performance

Evidence from animal research, postmortem analyses, and magnetic resonance imaging (MRI) investigations indicate substantial morphological alteration in brain structure as a function of human immunodeficiency virus (HIV) or cocaine dependence (CD). Although previous research on HIV+ active cocaine users suggests the presence of deleterious morphological effects in excess of either condition alone, a yet unexplored question is whether there is a similar deleterious interaction in HIV+ individuals with CD who are currently abstinent. To this end, the combinatorial effects of HIV and CD history on regional brain volume, cortical thickness, and neurocognitive performance was examined across four groups of participants in an exploratory study: healthy controls (n = 34), HIV-negative individuals with a history of CD (n = 21), HIV+ individuals with no history of CD (n = 20), HIV+ individuals with a history of CD (n = 15). Our analyses revealed no statistical evidence of an interaction between both conditions on brain morphometry and neurocognitive performance. While descriptively, individuals with comorbid HIV and a history of CD exhibited the lowest neurocognitive performance scores, using Principle Component Analysis of neurocognitive testing data, HIV was identified as the primary driver of neurocognitive impairment. Higher caudate volume was evident in CD+ participants relative to CD- participants. Findings indicate no evidence of compounded differences in neurocognitive function or structural measures of brain integrity in HIV+ individuals in recovery from CD relative to individuals with only one condition.

Cue-induced cocaine craving enhances psychosocial stress and vice versa in chronic cocaine users

Stress and craving, it has been found, contribute to the development and maintenance of and relapse in cocaine use disorder. Chronic cocaine users (CU), previous research has shown, display altered physiological responses to psychosocial stress and increased vegetative responding to substance-related cues. However, how psychosocial stress and cue-induced craving interact in relation to the CU's physiological responses remains largely unknown. We thus investigated the interaction between acute psychosocial stress and cocaine-cue-related reactivity in 47 CU and 38 controls. In a crossed and balanced design, the participants were randomly exposed to a video-based cocaine-cue paradigm and the Trier Social Stress Test (TSST) or vice versa to investigate possible mutually augmenting effects of both stressors on physiological stress responses. Over the course of the experimental procedure, plasma cortisol, ACTH, noradrenaline, subjective stress, and craving were assessed repeatedly. To estimate the responses during the cocaine-cue paradigm and TSST, growth models and discontinuous growth models were used. Overall, though both groups did not differ in their endocrinological responses to the TSST, CU displayed lower ACTH levels at baseline. The TSST did not elevate craving in CU, but when the cocaine-cue video was shown first, CU displayed an enhanced cortisol response to the subsequent TSST. In CU, cocaine-cues robustly evoked craving but no physiological stress response, while cue-induced craving was intensified after the TSST. Taken together, though CU did not show an altered acute stress response during the TSST, stress and craving together seemed to have mutually augmenting effects on their stress response.

Emotion recognition in individuals with cocaine use disorder: the role of abstinence length and the social brain network

RATIONALE

Emotion recognition is impaired in drug addiction. However, research examining the effects of cocaine use on emotion recognition yield mixed evidence with contradictory results potentially reflecting varying abstinence durations.

OBJECTIVES

Therefore, we investigated emotion recognition and its neural correlates in individuals with cocaine use disorder (CUD) parsed according to abstinence duration.

METHODS

Emotion recognition performance was compared between current cocaine users (CUD + , n = 28; cocaine-positive urine), short-term abstainers (CUD-ST, n = 23; abstinence < 6 months), long-term abstainers (CUD-LT, n = 20; abstinence ≥ 6 months), and controls (n = 45). A sample subset (n = 73) underwent structural magnetic resonance imaging to quantify regional gray matter volume (GMV) using voxel-based morphometry.

RESULTS

CUD + demonstrated greater difficulty recognizing happiness than CUD-ST and controls, and sadness and fear compared to controls (p < 0.01). For fear, CUD-ST also performed worse than controls (p < 0.01), while no differences emerged between CUD-LT and controls. Whole-brain analysis revealed lower GMV in the bilateral cerebellum in CUD + compared to CUD-LT and controls; a similar pattern was observed in the amygdala (CUD +  < CUD-LT) (p_FWE < 0.01). Collapsed across all participants, poorer recognition for happiness was associated with lower right cerebellar GMV (p_FWE < 0.05).

CONCLUSIONS

Emotion recognition is impaired with current cocaine use, and selective deficits (in fear) may persist with up to 6 months of abstinence. Lower cerebellar GMV may underlie deficits in positive emotion recognition. Interventions targeting emotional-social-cognitive deficits, especially among active users, may enhance treatment success for individuals with CUD.

Ibudilast attenuates cocaine self-administration and prime- and cue-induced reinstatement of cocaine seeking in rats

Ibudilast is a non-selective phosphodiesterase (PDE) inhibitor and glial cell modulator which has shown great promise for the treatment of drug and alcohol use disorders in recent clinical studies. However, it is unknown whether and how ibudilast affects cocaine seeking behavior. Here we show that systemic administration of ibudilast dose-dependently reduced cocaine self-administration under fixed- and progressive-ratio reinforcement schedules in rats and shifted cocaine dose-response curves downward. In addition, ibudilast decreased cocaine prime- and cue-induced reinstatement of cocaine seeking. These results indicate that ibudilast was effective in reducing the reinforcing effects of cocaine and relapse to cocaine seeking. Chronic cocaine exposure induces cAMP-related neuroadaptations in the reward circuitry of the brain. To investigate potential mechanisms for ibudilast-induced attenuation of cocaine self-administration, we recorded from ventral tegmental area (VTA) dopamine neurons in ex vivo midbrain slices prepared from rats that had undergone saline and cocaine self-administration. We found cocaine self-administration led to a decrease in inhibitory postsynaptic currents (IPSCs), an increase in the AMPAR/NMDAR ratio, and an increase in the excitation to inhibition (E/I) ratio. Ibudilast pretreatments enhanced GABAergic inhibition and did not further change cocaine-induced potentiation of excitation, leading to normalization of the E/I ratio. Restoration of the balance between excitation and inhibition in VTA dopamine neurons may contribute to the attenuation of cocaine self-administration by ibudilast.

A randomised, double-blind, sham-controlled study of left prefrontal cortex 15 Hz repetitive transcranial magnetic stimulation in cocaine consumption and craving

Background

Cocaine use disorder (CUD) is a global health issue with no effective treatment. Repetitive Transcranial Magnetic Stimulation (rTMS) is a recently proposed therapy for CUD.

Methods

We conducted a single-center, randomised, sham-controlled, blinded, parallel-group research with patients randomly allocated to rTMS (15 Hz) or Sham group (1:1) using a computerised block randomisation process. We enrolled 62 of 81 CUD patients in two years. Patients were followed for eight weeks after receiving 15 15 Hz rTMS/sham sessions over the left dorsolateral prefrontal cortex (DLPFC) during the first three weeks of the study. We targeted the DLFPC following the 5 cm method. Cocaine lapses in twice a week urine tests were the primary outcome. The secondary outcomes were craving severity, cocaine use pattern, and psychometric assessments.

Findings

We randomly allocated patients to either an active rTMS group (32 subjects) or a sham treatment group (30 subjects). Thirteen (42%) and twelve (43.3%) of the subjects in rTMS and sham groups, respectively, completed the full trial regimen, displaying a high dropout rate. Ten/30 (33%) of rTMS-treated patients tested negative for cocaine in urine, in contrast to 4/27 of placebo controls (p = 0.18, odd ratio 2.88, CI 0.9–10). The Kaplan-Meier survival curve did not state a significant change between the treated and sham groups in the time of cocaine urine negativisation (p = 0.20). However, the severity of cocaine-related cues mediated craving (VAS peak) was substantially decreased in the rTMS treated group (p<0.03) after treatment at T1, corresponding to the end of rTMS treatment. Furthermore, in the rTMS and sham groups, self-reported days of cocaine use decreased significantly (p<0.03). Finally, psychometric impulsivity parameters improved in rTMS-treated patients, while depression scales improved in both groups.

Conclusions

In CUD, rTMS could be a useful tool for lowering cocaine craving and consumption.

Trial registration

The study number on clinicalTrials.gov is NCT03607591.

Association between alcohol and crack: Prevalence, effects, associated factors and experiences of combined use

Objective

To estimate the prevalence and factors associated with the effect of alcohol on crack cocaine use and to analyze experiences related to combined use. Materials and methods: sequential mixed methods (qualitative and quantitative) research, carried out between August 2014 and August 2015 with people who use crack. In the quantitative approach, a cross-sectional study was conducted with 1,062 participants. Factors associated with “alcohol use with the effect of increasing the effect of crack/crack craving” were estimated by multiple regression. In the qualitative approach, 39 interviews were conducted using Bardin’s content analysis technique.

Results

871 (82.0%) participants reported consuming alcohol, among them, 668 (76.7%) used alcohol combined with crack: 219 (32.8%) reported feeling an effect of reduction in paranoia and/or crack craving and 384 (57.5%) reported feeling an increase in the effect of crack and in the craving to consume the drug. This relationship was also observed in the narratives of the people who use crack, with the possibility of a cyclic effect of consumption of the two substances. Those who related alcohol use to the effect of increasing crack craving (384) were more likely to use alcohol before crack (OR: 1.81; 95%CI: 1.13–2.89); to consume more than 20 stones daily (OR: 1.48; 95%CI: 1.01–2.16); to remain in abstinence from crack for less than one month (OR: 3.20; 95%CI: 1.91–5.35); to use dependence treatment services (OR: 1.85; 95%CI: 1.26–2.71); and to commit physical violence (OR:1.67; 95%CI:1.08–2.56).

Conclusion

The findings of this study indicate that the modulation of the effect of alcohol use on crack cocaine depends on the moment when the drugs are consumed, and the use of alcohol before crack consumption is associated with characteristics that suggest a greater vulnerability to patterns of harmful crack use. Even though combined use is referred to as a way of reducing the negative effects of crack, the damage of this association may be greater than its possible benefits.

Spontaneously Hypertensive Rat substrains show differences in model traits for addiction risk and cocaine self-administration: Implications for a novel rat reduced complexity cross

Forward genetic mapping of F2 crosses between closely related substrains of inbred rodents - referred to as a reduced complexity cross (RCC) - is a relatively new strategy for accelerating the pace of gene discovery for complex traits, such as drug addiction. RCCs to date were generated in mice, but rats are thought to be optimal for addiction genetic studies. Based on past literature, one inbred Spontaneously Hypertensive Rat substrain, SHR/NCrl, is predicted to exhibit a distinct behavioral profile as it relates to cocaine self-administration traits relative to another substrain, SHR/NHsd. Direct substrain comparisons are a necessary first step before implementing an RCC. We evaluated model traits for cocaine addiction risk and cocaine self-administration behaviors using a longitudinal within-subjects design. Impulsive-like and compulsive-like traits were greater in SHR/NCrl than SHR/NHsd, as were reactivity to sucrose reward, sensitivity to acute psychostimulant effects of cocaine, and cocaine use studied under fixed-ratio and tandem schedules of cocaine self-administration. Compulsive-like behavior correlated with the acute psychostimulant effects of cocaine, which in turn correlated with cocaine taking under the tandem schedule. Compulsive-like behavior also was the best predictor of cocaine seeking responses. Heritability estimates indicated that 22 %-40 % of the variances for the above phenotypes can be explained by additive genetic factors, providing sufficient genetic variance to conduct genetic mapping in F2 crosses of SHR/NCrl and SHR/NHsd. These results provide compelling support for using an RCC approach in SHR substrains to uncover candidate genes and variants that are of relevance to cocaine use disorders.

Females develop features of an addiction-like phenotype sooner during withdrawal than males

RATIONALE

Women meet criteria for substance use disorder after fewer years of drug use than men; this accelerated time course, or telescoping effect, has been observed for multiple drugs, including cocaine. Preclinical findings similarly indicate an enhanced vulnerability in females to developing an addiction-like phenotype; however, it is not yet known if this phenotype develops faster in females versus males.

OBJECTIVES

The goal of this study was to determine using a rat model whether two key features of addiction in humans, an enhanced motivation for cocaine and compulsive use, emerge sooner during withdrawal from extended access cocaine self-administration in females versus males.

METHODS

Motivation for cocaine, as assessed under a progressive-ratio reinforcement schedule, was determined prior to and following extended access cocaine self-administration (24 h/day, 96 infusions/day, 10 days) and after 7, 14, or 60 days of withdrawal. Compulsive use, or use despite punishment, was evaluated once progressive-ratio responding stabilized by adding histamine, an aversive stimulus, to the cocaine solutions.

RESULTS

Motivation for cocaine increased from baseline sooner during withdrawal in females than males (at 7 versus 14 days); motivation was also highest in the 60-day group. Histamine decreased progressive-ratio responding for cocaine in both sexes, although effects were greatest in males in the 7-day withdrawal group; males reached the female-level of resistance to histamine punishment by 14 days of withdrawal.

CONCLUSIONS

Female rats developed addition-like features sooner during withdrawal than male rats indicating that the telescoping effect observed in humans is biologically based. Additionally, like drug-seeking/craving, motivation for cocaine and measures of compulsive use incubate over withdrawal.

Extinction vs. Abstinence: A Review of the Molecular and Circuit Consequences of Different Post-Cocaine Experiences

The intravenous cocaine self-administration model is widely used to characterize the neurobiology of cocaine seeking. When studies are aimed at understanding relapse to cocaine-seeking, a post-cocaine abstinence period is imposed, followed by “relapse” tests to assess the ability of drug-related stimuli (“primes”) to evoke the resumption of the instrumental response previously made to obtain cocaine. Here, we review the literature on the impact of post-cocaine abstinence procedures on neurobiology, finding that the prelimbic and infralimbic regions of the prefrontal cortex are recruited by extinction training, and are not part of the relapse circuitry when extinction training does not occur. Pairing cocaine infusions with discrete cues recruits the involvement of the NA, which together with the dorsal striatum, is a key part of the relapse circuit regardless of abstinence procedures. Differences in molecular adaptations in the NA core include increased expression of GluN1 and glutamate receptor signaling partners after extinction training. AMPA receptors and glutamate transporters are similarly affected by abstinence and extinction. Glutamate receptor antagonists show efficacy at reducing relapse following extinction and abstinence, with a modest increase in efficacy of compounds that restore glutamate homeostasis after extinction training. Imaging studies in humans reveal cocaine-induced adaptations that are similar to those produced after extinction training. Thus, while instrumental extinction training does not have face validity, its use does not produce adaptations distinct from human cocaine users.

Initial development of a brief assessment of cocaine demand

Cocaine demand is a behavioral economic measure assessing drug reward value and motivation to use drug. The purpose of the current study was to develop a brief assessment of cocaine demand (BACD). Results from the BACD were compared with self-report measures of cocaine use. Participants consisted of treatment-seeking individuals with cocaine use disorder (N = 22). Results revealed that indices of brief demand were significantly associated with various self-report measures of cocaine use. Overall, these results support the utility of a BACD for assessing cocaine demand.

Effects of cocaine and HIV on decision-making abilities

Our study aimed to understand the impact of cocaine dependence on high-risk decision-making abilities in individuals with the human immunodeficiency virus (HIV) and individuals with cocaine dependence. We recruited 99 participants (27 HIV/Cocaine, 20 HIV Only, 26 Cocaine Only, and 26 Healthy Controls). The Iowa Gambling Task (IGT) was applied to assess decision-making abilities. Independent and interactive effects of HIV status and cocaine dependence were examined using 2 × 2 factorial ANCOVA with premorbid IQ (WRAT-4: WR) as the covariate. We found cocaine dependence had a significant adverse effect on overall IGT performance (p = 0.015). We also found individuals who were HIV-positive tended to have less total money at the end of the game than individuals who were HIV-negative (p = 0.032), suggesting individuals living with HIV had less focus on long-term gains and more focus on short-term gains. Our findings highlight the significant impact of cocaine dependence on decision-making abilities and the difficulty individuals with HIV have in adequately weighing the cost and benefits of their decisions and making appropriate changes for the future.

Beyond abstinence and relapse II: momentary relationships between stress, craving, and lapse within clusters of patients with similar patterns of drug use

RATIONALE

Given that many patients being treated for opioid-use disorder continue to use drugs, identifying clusters of patients who share similar patterns of use might provide insight into the disorder, the processes that affect it, and ways that treatment can be personalized.

OBJECTIVES AND METHODS

We applied hierarchical clustering to identify patterns of opioid and cocaine use in 309 participants being treated with methadone or buprenorphine (in a buprenorphine-naloxone formulation) for up to 16 weeks. A smartphone app was used to assess stress and craving at three random times per day over the course of the study.

RESULTS

Five basic patterns of use were identified: frequent opioid use, frequent cocaine use, frequent dual use (opioids and cocaine), sporadic use, and infrequent use. These patterns were differentially associated with medication (methadone vs. buprenorphine), race, age, drug-use history, drug-related problems prior to the study, stress-coping strategies, specific triggers of use events, and levels of cue exposure, craving, and negative mood. Craving tended to increase before use in all except those who used sporadically. Craving was sharply higher during the 90 min following moderate-to-severe stress in those with frequent use, but only moderately higher in those with infrequent or sporadic use.

CONCLUSIONS

People who share similar patterns of drug-use during treatment also tend to share similarities with respect to psychological processes that surround instances of use, such as stress-induced craving. Cluster analysis combined with smartphone-based experience sampling provides an effective strategy for studying how drug use is related to personal and environmental factors.

Exogenous SO2 donor treatment impairs reconsolidation of drug reward memory in mice

Substance-related and addictive disorders (SRADs) are characterized by compulsive drug use and recurrent relapse. The persistence of pathological drug-related memories indisputably contributes to a high propensity to relapse. Hence, strategies to disrupt reconsolidation of drug reward memory are currently being pursued as potential anti-relapse interventions. Sulfur dioxide (SO2), acting as a potential gaseous molecule, endogenously derives from sulfur amino acid and can exert significant neural regulatory effects. However, the role of SO2 in reconsolidation of drug memory has not been determined. In the present study, we used morphine- or cocaine-induced conditioned place preference (CPP) mouse models with retrieval to investigate the effects of exogenous SO2 donor treatment on reconsolidation of drug reward memory. We found that administration of SO2 donor immediately after the retrieval impaired the expression of morphine or cocaine CPP. Furthermore, the exogenous SO2 donor treatment 6 h post-retrieval or in the absence of retrieval had no effect on drug reward memory and the expression of CPP. SO2 itself did not produce aversive effects nor did it acutely block morphine CPP. Our results indicate that exogenous SO2 impairs reconsolidation of drug reward memory rather than inhibits the expression of drug reward memory. As such, SO2 holds potential for the treatment and prevention of SRADs and should be studied further.

Cannabinoid type 1 receptors in A2a neurons contribute to cocaine-environment association

RATIONALE

Cannabinoid type 1 receptors (CB1Rs) are widely expressed within the brain's reward circuits and are implicated in regulating drug induced behavioral adaptations. Understanding how CB1R signaling in discrete circuits and cell types contributes to drug-related behavior provides further insight into the pathology of substance use disorders.

OBJECTIVE AND METHODS

We sought to determine how cell type-specific expression of CB1Rs within striatal circuits contributes to cocaine-induced behavioral plasticity, hypothesizing that CB1R function in distinct striatal neuron populations would differentially impact behavioral outcomes. We crossed conditional Cnr1^fl/fl mice and striatal output pathway cre lines (Drd1a -cre; D1, Adora2a -cre; A2a) to generate cell type-specific CB1R knockout mice and assessed their performance in cocaine locomotor and associative behavioral assays.

RESULTS

Both knockout lines retained typical locomotor activity at baseline. D1-Cre x Cnr1^fl/fl mice did not display hyperlocomotion in response to acute cocaine dosing, and both knockout lines exhibited blunted locomotor activity across repeated cocaine doses. A2a-cre Cnr1^fl/fl, mice did not express a preference for cocaine paired environments in a two-choice place preference task.

CONCLUSIONS

This study aids in mapping CB1R-dependent cocaine-induced behavioral adaptations onto distinct striatal neuron subtypes. A reduction of cocaine-induced locomotor activation in the D1- and A2a-Cnr1 knockout mice supports a role for CB1R function in the motor circuit. Furthermore, a lack of preference for cocaine-associated context in A2a-Cnr1 mice suggests that CB1Rs on A2a-neuron inhibitory terminals are necessary for either reward perception, memory consolidation, or recall. These results direct future investigations into CB1R-dependent adaptations underlying the development and persistence of substance use disorders.

Effect of Modulation of the Astrocytic Glutamate Transporters' Expression on Cocaine-Induced Reinstatement in Male P Rats Exposed to Ethanol

AIM

Reinforcing properties of ethanol and cocaine are mediated in part through the glutamatergic system. Extracellular glutamate concentration is strictly maintained through several glutamate transporters, such as glutamate transporter 1 (GLT-1), cystine/glutamate transporter (xCT) and glutamate aspartate transporter (GLAST). Previous findings revealed that cocaine and ethanol exposure downregulated GLT-1 and xCT, and that β-lactam antibiotics restored their expression.

METHODS

In this study, we investigated the effect of ampicillin/sulbactam (AMP/SUL) (200 mg/kg, i.p.), a β-lactam antibiotic, on cocaine-induced reinstatement and locomotor activity in male alcohol preferring (P) rats using free choice ethanol (15 and 30%, v/v) and water. We also investigated the effect of co-exposure to ethanol and cocaine (20 mg/kg, i.p.) on GLT-1, xCT and GLAST expression in the nucleus accumbens (NAc) core, NAc shell and dorsomedial prefrontal cortex (dmPFC).

RESULTS

Cocaine exposure decreased ethanol intake and preference. Cocaine and ethanol co-exposure acquired place preference and increased locomotor activity compared to ethanol-exposed rats. GLT-1 and xCT expression were downregulated after cocaine and ethanol co-exposure in the NAc core and shell, but not in dmPFC. AMP/SUL attenuated reinstatement to cocaine as well attenuated the decrease in locomotor activity and ethanol intake and preference. These effects were associated with upregulation of GLT-1 and xCT expression in the NAc core/shell and dmPFC. GLAST expression was not affected after ethanol and cocaine co-exposure or AMP/SUL treatment.

CONCLUSION

Our findings demonstrate that astrocytic glutamate transporters within the mesocorticolimbic area are critical targets in modulating cocaine-seeking behavior while being consuming ethanol.

Role of the GABAa and GABAb receptors of the central nucleus of the amygdala in compulsive cocaine-seeking behavior in male rats

RATIONALE

Compulsive cocaine use, defined as the continued use despite the dire consequences, is a hallmark of cocaine addiction. Thus, understanding the brain mechanism regulating the compulsive cocaine-seeking and cocaine-taking behaviors is essential to understand cocaine addiction and the key to identification of the molecular targets for the development of medications against this condition.

OBJECTIVE

This study aimed to determine how the GABAa and GABAb receptors of the central nucleus of the amygdala (CeA) regulate the compulsive cocaine-seeking behavior.

METHODS

Male Wistar outbred rats were trained to self-administer intravenous cocaine (0.4 mg/kg/infusion) under a chained schedule. The compulsive cocaine-seeking behavior was measured as the cocaine-seeking behavior in the face of footshock punishment. The role of the GABA receptors of CeA in the regulation of such behavior was determined by measuring the dose-dependent effects of the GABAa agonist muscimol or the GABAb agonist baclofen bilaterally microinjected into the CeA on the punished cocaine-seeking behavior.

RESULTS

The cocaine-seeking behavior was inhibited by footshock punishment in an intensity-dependent manner. Both muscimol and baclofen dose-dependently increased the punished cocaine-seeking behavior. However, the potency of muscimol but not baclofen was negatively correlated with the effects of punishment.

CONCLUSION

These data indicate that the CeA GABAa receptors play a key role in the regulation of the compulsive cocaine-seeking behavior and suggest that an increase in the function of the GABAa receptors possibly induced by cocaine or genetic factors may be an important mechanism involved in the development of or vulnerability to the compulsive cocaine use and addiction.

Relapse-Associated Transient Synaptic Potentiation Requires Integrin-Mediated Activation of Focal Adhesion Kinase and Cofilin in D1-Expressing Neurons

Relapse to drug use can be initiated by drug-associated cues. The intensity of cue-induced drug seeking in rodent models correlates with the induction of transient synaptic potentiation (t-SP) at glutamatergic synapses in the nucleus accumbens core (NAcore). Matrix metalloproteinases (MMPs) are inducible endopeptidases that degrade extracellular matrix (ECM) proteins, and reveal tripeptide Arginine-Glycine-Aspartate (RGD) domains that bind and signal through integrins. Integrins are heterodimeric receptors composed of αβ subunits, and a primary signaling kinase is focal adhesion kinase (FAK). We previously showed that MMP activation is necessary for and potentiates cued reinstatement of cocaine seeking, and MMP-induced catalysis stimulates β3-integrins to induce t-SP. Here, we determined whether β3-integrin signaling through FAK and cofilin (actin depolymerization factor) is necessary to promote synaptic growth during t-SP. Using a small molecule inhibitor to prevent FAK activation, we blocked cued-induced cocaine reinstatement and increased spine head diameter (dh). Immunohistochemistry on NAcore labeled spines with ChR2-EYFP virus, showed increased immunoreactivity of phosphorylation of FAK (p-FAK) and p-cofilin in dendrites of reinstated animals compared with extinguished and yoked saline, and the p-FAK and cofilin depended on β3-integrin signaling. Next, male and female transgenic rats were used to selectively label D1 or D2 neurons with ChR2-mCherry. We found that p-FAK was increased during drug seeking in both D1 and D2-medium spiny neurons (MSNs), but increased p-cofilin was observed only in D1-MSNs. These data indicate that β3-integrin, FAK and cofilin constitute a signaling pathway downstream of MMP activation that is involved in promoting the transient synaptic enlargement in D1-MSNs induced during reinstated cocaine by drug-paired cues.SIGNIFICANCE STATEMENT Drug-associated cues precipitate relapse, which is correlated with transient synaptic enlargement in the accumbens core. We showed that cocaine cue-induced synaptic enlargement depends on matrix metalloprotease signaling in the extracellular matrix (ECM) through β3-integrin to activate focal adhesion kinase (FAK) and phosphorylate the actin binding protein cofilin. The nucleus accumbens core (NAcore) contains two predominate neuronal subtypes selectively expressing either D1-dopamine or D2-dopamine receptors. We used transgenic rats to study each cell type and found that cue-induced signaling through cofilin phosphorylation occurred only in D1-expressing neurons. Thus, cocaine-paired cues initiate cocaine reinstatement and synaptic enlargement through a signaling cascade selectively in D1-expressing neurons requiring ECM stimulation of β3-integrin-mediated phosphorylation of FAK (p-FAK) and cofilin.

Mirtazapine reduces the expression of cocaine-induced locomotor sensitization in male and female Wistar rats

BACKGROUND

Epidemiological studies have described that women are more vulnerable to the reinforcing effects of cocaine. In animals, the findings are similar: female rats show higher levels of cocaine self-administration and increased cocaine-induced locomotor activity. In contrast, women with depression respond better to treatment with antidepressants, however their therapeutic response to tetracyclic antidepressants is lower. Several studies have shown that mirtazapine-a tetracyclic antidepressant-decreases the behavioral effects of cocaine in male rats. The objective of this study was to evaluate the efficacy of daily dosing of mirtazapine on cocaine-induced locomotor activity and sensitization in naive female rats compared to male rats.

METHODS

Male and female Wistar rats were daily dosed with 10 mg/kg of cocaine. During extinction, cocaine was withdrawn and the groups received daily mirtazapine (30 mg/kg, i.p.) or saline. Tamoxifen was administered during the antagonism phase. After each administration, locomotor activity for each animal was recorded for 30 min in transparent Plexiglass activity chambers.

RESULTS

In this study, a higher cocaine locomotor response was found in females than in males and the mirtazapine was equally effective in decreasing cocaine-induced locomotor activity and the expression of locomotor sensitization in male and female rats. In addition, co-administration of mirtazapine and tamoxifen enhanced the efficacy of mirtazapine in female rats.

CONCLUSION

The results suggest that mirtazapine may be considered an effective therapeutic option for the treatment of cocaine use disorder in men and women.

The Efficacy of Lidocaine in Disrupting Cocaine Cue-Induced Memory Reconsolidation

RATIONAL

Cue-induced craving memories, linked to drug-seeking behaviors, require key molecular processes for memory reconsolidation. Lidocaine, a sodium channel blocker, inhibits NMDA receptor activation and suppresses nitric oxide and ERK production. These processes are required for memory re-consolidation; inhibiting them may reduce cue-related craving memories in cocaine dependent subjects.

OBJECTIVES

To assess the efficacy of lidocaine in decreasing cue-induced cocaine craving and cocaine use.

METHODS

Treatment-seeking cocaine-dependent participants (n = 33, 25 men) were recruited. Personalized craving and relaxation scripts were developed. Participants were then randomly assigned in a double-blind design to either receive intravenous lidocaine immediately following a cocaine craving script (lidocaine/craving), saline following a craving script (saline/craving), or lidocaine following a relaxation script (lidocaine/relax). One week following the infusion, cue-induced craving was assessed in the same paradigm without an infusion. Cocaine use and craving were assessed for 4 weeks following infusion.

RESULTS

The administration of lidocaine during craving induction (lidocaine/craving) did not decrease cue-induced craving during craving reactivation one week later or craving and cocaine use over the 4-week follow-up period compared to the saline/craving group. There were no significant differences in craving and cocaine use between the lidocaine/relax and saline/craving groups.

CONCLUSION

Lidocaine administered following craving induction did not decrease subsequent cue-induced craving or cocaine use. Blocking the reconsolidation of craving-related memories with pharmacological agents remains an important area of investigation.

Risk-taking and fairness among cocaine-dependent patients in dual diagnoses: Schizophrenia and Anti-Social Personality Disorder

This study reports experimental results from a clinical sample of patients with a cocaine-related disorder and dual diagnosis: Schizophrenia and Anti-Social Personality Disorder. Both types of patients as well as a non-clinical group of students performed two incentivized decision-making tasks. In the first part of the experiment, they performed a lottery-choice task in order to elicit their degree of risk aversion. In the second part, they decided in two modified dictator games aimed at eliciting their aversion to advantageous and disadvantageous inequality. It is found that the Anti-Social Personality Disorder group exhibits no significant differences from the non-clinical sample in either task. However, compared with the students' sample, subjects from the group with schizophrenia show more risk aversion and exhibit more aversion towards disadvantageous inequality.

Cebranopadol reduces cocaine self-administration in male rats: Dose, treatment and safety consideration

As a novel first-in-class potent analgesic acting as an agonist of multiple opioid receptors, cebranopadol showed high efficacy and good tolerability in a broad range of preclinical models and clinical trials related to pain. In the present study, to evaluate the efficacy and safety of cebranopadol as a potential treatment of cocaine dependence, we tested the effects of cebranopadol with single and repeated doses (25, 50, 75, or 100 μg/kg, oral gavage) using rat models of cocaine fixed-ratio (FR) self-administration (SA), cocaine progressive-ratio (PR) SA, and sucrose pellet SA. In single-dosing treatment paradigm, cebranopadol significantly and dose-dependently reduced cocaine SA under FR and PR schedules and suppressed food intake under FR schedule without causing apparent side effects. In repeated-dosing treatment scheme, i.e. daily administration of 25, 50, 75, or 100 μg/kg cebranopadol for a week, the similar reduction in cocaine intake was detected, while non-negligible complications/side effects were observed at repeated high doses (75 and 100 μg/kg). The observed side effects were similar to the common toxic signs elicited by heroin at high doses, although cebranopadol did not fully substitute heroin's discriminative stimulant effects in our drug discriminative tests. These results demonstrated that the most appropriate oral dose of cebranopadol to balance the efficacy and safety is 50 μg/kg. Collectively, although cebranopadol may serve as a new treatment for cocaine dependence, more consideration, cautiousness, and a clear optimal dose window to dissociate its therapeutic effects from opioid side effects/complications in male and female subjects will be necessary to increase its practical clinical utility.

Prediction of attempted suicide in men and women with crack-cocaine use disorder in Brazil

Background

Suicide is a severe health problem, with high rates in individuals with addiction. Considering the lack of studies exploring suicide predictors in this population, we aimed to investigate factors associated with attempted suicide in inpatients diagnosed with cocaine use disorder using two analytical approaches.

Methods

This is a cross-sectional study using a secondary database with 247 men and 442 women hospitalized for cocaine use disorder. Clinical assessment included the Addiction Severity Index, the Childhood Trauma Questionnaire, and the Structured Clinical Interview for the Diagnostic and Statistical Manual of Mental Disorders, totalling 58 variables. Descriptive Poisson regression and predictive Random Forest algorithm were used complementarily to estimate prevalence ratios and to build prediction models, respectively. All analyses were stratified by gender.

Results

The prevalence of attempted suicide was 34% for men and 50% for women. In both genders, depression (PR_M = 1.56, PR_W = 1.27) and hallucinations (PR_M = 1.80, PR_W = 1.39) were factors associated with attempted suicide. Other specific factors were found for men and women, such as childhood trauma, aggression, and drug use severity. The men's predictive model had prediction statistics of AUC = 0.68, Acc. = 0.66, Sens. = 0.82, Spec. = 0.50, PPV = 0.47 and NPV = 0.84. This model identified several variables as important predictors, mainly related to drug use severity. The women's model had higher predictive power (AUC = 0.73 and all other statistics were equal to 0.71) and was parsimonious.

Conclusions

Our findings indicate that attempted suicide is associated with depression, hallucinations and childhood trauma in both genders. Also, it suggests that severity of drug use may be a moderator between predictors and suicide among men, while psychiatric issues shown to be more important for women.

Sex-dependent associations between addiction-related behaviors and the microbiome in outbred rats

BACKGROUND

Multiple factors contribute to the etiology of addiction, including genetics, sex, and a number of addiction-related behavioral traits. One behavioral trait where individuals assign incentive salience to food stimuli ("sign-trackers", ST) are more impulsive compared to those that do not ("goal-trackers", GT), as well as more sensitive to drugs and drug stimuli. Furthermore, this GT/ST phenotype predicts differences in other behavioral measures. Recent studies have implicated the gut microbiota as a key regulator of brain and behavior, and have shown that many microbiota-associated changes occur in a sex-dependent manner. However, few studies have examined how the microbiome might influence addiction-related behaviors. To this end, we sought to determine if gut microbiome composition was correlated with addiction-related behaviors determined by the GT/ST phenotype.

METHODS

Outbred male (N=101) and female (N=101) heterogeneous stock rats underwent a series of behavioral tests measuring impulsivity, attention, reward-learning, incentive salience, and locomotor response. Cecal microbiome composition was estimated using 16S rRNA gene amplicon sequencing. Behavior and microbiome were characterized and correlated with behavioral phenotypes. Robust sex differences were observed in both behavior and microbiome; further analyses were conducted within sex using the pre-established goal/sign-tracking (GT/ST) phenotype and partial least squares differential analysis (PLS-DA) clustered behavioral phenotype.

RESULTS

Overall microbiome composition was not associated to the GT/ST phenotype. However, microbial alpha diversity was significantly decreased in female STs. On the other hand, a measure of impulsivity had many significant correlations to microbiome in both males and females. Several measures of impulsivity were correlated with the genus Barnesiella in females. Female STs had notable correlations between microbiome and attentional deficient. In both males and females, many measures were correlated with the bacterial families Ruminocococcaceae and Lachnospiraceae.

CONCLUSIONS

These data demonstrate correlations between several addiction-related behaviors and the microbiome specific to sex.

Administration of a novel high affinity PICK1 PDZ domain inhibitor attenuates cocaine seeking in rats

Protein interacting with C kinase-1 (PICK1) regulates intra-cellular trafficking of GluA2-containing AMPA receptors, a process known to play a critical role in cocaine-seeking behavior. This suggests that PICK1 may represent a molecular target for developing novel pharmacotherapies to treat cocaine craving-induced relapse. Emerging evidence indicates that inhibition of PICK1 attenuates the reinstatement of cocaine-seeking behavior, an animal model of relapse. Here, we show that systemic administration of TAT-P4-(DATC5)2, a novel high-affinity peptide inhibitor of the PICK1 PDZ domain, dose-dependently attenuated the reinstatement of cocaine seeking in rats at doses that did not produce operant learning deficits or suppress locomotor activity. We also show that systemic TAT-P4-(DATC5)2 penetrated the brain where it was visualized in the nucleus accumbens shell. Consistent with these effects, infusions of TAT-P4-(DATC5)2 directly into the accumbens shell reduced cocaine, but not sucrose, seeking. The effects of TAT-P4-(DATC5)2 on cocaine seeking are likely due, in part, to inhibition of PICK1 in medium spiny neurons (MSNs) of the accumbens shell as TAT-P4-(DATC5)2 was shown to accumulate in striatal neurons and bind PICK1. Taken together, these findings highlight a novel role for PICK1 in the reinstatement of cocaine seeking and support future studies examining the efficacy of peptide inhibitors of PICK1 in animal and human models of cocaine relapse.

The effects of nicotinamide on reinstatement to cocaine seeking in male and female Sprague Dawley rats

RATIONALE

Interventions for psychostimulant use disorders are of significant need. Nicotinamide (NAM) is a small molecule that can oppose cellular adaptations observed following cocaine exposure in the rodent self-administration and reinstatement model of addiction. In addition, utility of NAM against symptoms of withdrawal and vulnerability to relapse to cocaine use has been suggested by case studies and anecdotal reports. However, the empirical effects of NAM on drug-seeking behaviors have not been examined.

OBJECTIVE

The objective of the current study was to investigate the effects of systemic NAM administration on reinstatement to cocaine seeking, using the rat self-administration/extinction/reinstatement model of cocaine addiction.

METHODS

Male and female Sprague Dawley rats were trained to self-administer i.v. cocaine or food pellets for 2 hrs per day for 12 days, followed by 14-17 days of extinction, during which i.p. NAM injections (0-120 mg/kg) were given 30 minutes prior to each extinction or reinstatement session. Rats were tested on cue-, cocaine-, or food-primed reinstatement, as well as locomotor activity.

RESULTS

Chronic NAM administered throughout extinction dose dependently attenuated cue-primed reinstatement in male rats, but not female rats. In contrast, acute NAM given once prior to reinstatement had no effect on reinstatement. Chronic NAM had no effect on locomotor activity or reinstatement to food seeking.

CONCLUSIONS

The specificity of NAM against cue-primed reinstatement indicates that NAM may influence responsiveness to drug-associated cues, specifically in males. Future studies will examine the mechanism(s) by which NAM may exert this effect.

Escalation of drug use in persons dually diagnosed with opioid and cocaine dependence: Gender comparison and dimensional predictors

BACKGROUND

Persons dually diagnosed with opioid and cocaine dependence (OD + CD) present a clinical challenge and are at risk of morbidity and mortality. The time of escalation of heroin and cocaine exposure in persons with OD + CD remain understudied, and the influence of gender and other variables have not been examined. This observational study focused on the time of escalation of heroin and cocaine in volunteers with OD + CD, examining gender and exposure to other drugs (e.g., cannabis or alcohol) as predictors. Ages of first use and of onset of heaviest use of each drug were collected (in whole years). Time of escalation was defined as the interval between age of first use and onset of heaviest use.

VOLUNTEERS

sequentially ascertained adult volunteers recruited from the New York Metropolitan area, of which n = 297 were diagnosed with OD + CD.

METHODS

Instruments administered were the SCID-I diagnostic interview (DSM-IV criteria), BIS-11 impulsiveness scale, and KMSK scales, dimensional measures of maximal exposure to specific drugs.

RESULTS

In volunteers with OD + CD, ages of onset of heaviest use of cannabis (median age = 15) and alcohol (median age = 19) were in adolescence or emerging adulthood and preceded those for heroin and cocaine (median ages = 26 and 25, respectively). Maximal levels of cannabis and alcohol exposure were high, in volunteers with OD + CD. In adjusted Cox regressions, gender was not a significant predictor of time of heroin or cocaine escalation. However, more rapid time of alcohol escalation was a predictor of more rapid time of escalation of both heroin and cocaine, in volunteers with OD + CD.

Pharmacotherapy for Cocaine Use Disorder-a Systematic Review and Meta-analysis

BACKGROUND

Currently, there are no accepted FDA-approved pharmacotherapies for cocaine use disorder, though numerous medications have been tested in clinical trials. We conducted a systematic review and meta-analysis to better understand the effectiveness of pharmacotherapy for cocaine use disorder.

METHODS

We searched multiple data sources (MEDLINE, PsycINFO, and Cochrane Library) through November 2017 for systematic reviews and randomized controlled trials (RCTs) of pharmacological interventions in adults with cocaine use disorder. When possible, we combined the findings of trials with comparable interventions and outcome measures in random-effects meta-analyses. We assessed the risk of bias of individual trials and the strength of evidence for each outcome using standardized criteria. Outcomes included continuous abstinence (3+ consecutive weeks); cocaine use; harms; and study retention. For relapse prevention studies (participants abstinent at baseline), we examined lapse (first cocaine positive or missing UDS) and relapse (two consecutive cocaine positive or missed UDS').

RESULTS

Sixty-six different drugs or drug combinations were studied in seven systematic reviews and 48 RCTs that met inclusion criteria. Antidepressants were the most widely studied drug class (38 RCTs) but appear to have no effect on cocaine use or treatment retention. Increased abstinence was found with bupropion (2 RCTs: RR 1.63, 95% CI 1.02 to 2.59), topiramate (2 RCTs: RR 2.56, 95% CI 1.39 to 4.73), and psychostimulants (14 RCTs: RR 1.36, 95% CI 1.05 to 1.77), though the strength of evidence for these findings was low. We found moderate strength of evidence that antipsychotics improved treatment retention (8 RCTs: RR 1.33, 95% CI 1.03 to 1.75).

DISCUSSION

Most of the pharmacotherapies studied were not effective for treating cocaine use disorder. Bupropion, psychostimulants, and topiramate may improve abstinence, and antipsychotics may improve retention. Contingency management and behavioral interventions along with pharmacotherapy should continue to be explored.

SR REGISTRATION

Prospero CRD42018085667.

Kappa-opioid receptors, dynorphin, and cocaine addiction: a positron emission tomography study

Animal studies indicate that the kappa-opioid receptor/dynorphin system plays an important role in cocaine binges and stress-induced relapse. Our goal was to investigate changes in kappa-opioid receptor (KOR) availability in the human brain using positron emission tomography (PET), before and after a cocaine binge. We also investigated the correlation between KOR and stress-induced cocaine self-administration. PET imaging was performed with the KOR selective agonist [11C]GR103545. Subjects with cocaine-use disorder (CUD) underwent PET scans and performed two types of cocaine self-administration sessions in the laboratory as follows: (1) choice sessions following a cold pressor test, to induce stress, and (2) binge dosing of cocaine. This allowed us investigate the following: (1) the association between KOR binding and a laboratory model of stress-induced relapse and (2) the change in KOR binding following a 3-day cocaine binge, which is thought to represent a change in endogenous dynorphin. A group of matched healthy controls was included to investigate between group differences in KOR availability. A significant association between [11C]GR103545 binding and cocaine self-administration was seen: greater KOR availability was associated with more choices for cocaine. In addition, the 3-day cocaine binge significantly reduced [11C]GR103545 binding by 18% in the striatum and 14% across brain regions. No difference in [11C]GR103545 binding was found between the CUD subjects and matched controls. In the context of previous studies, these findings add to the growing evidence that pharmacotherapies targeting the KOR have the potential to significantly impact treatment development for cocaine-use disorder.

Impairments in reinforcement learning do not explain enhanced habit formation in cocaine use disorder

RATIONALE

Drug addiction has been suggested to develop through drug-induced changes in learning and memory processes. Whilst the initiation of drug use is typically goal-directed and hedonically motivated, over time, drug-taking may develop into a stimulus-driven habit, characterised by persistent use of the drug irrespective of the consequences. Converging lines of evidence suggest that stimulant drugs facilitate the transition of goal-directed into habitual drug-taking, but their contribution to goal-directed learning is less clear. Computational modelling may provide an elegant means for elucidating changes during instrumental learning that may explain enhanced habit formation.

OBJECTIVES

We used formal reinforcement learning algorithms to deconstruct the process of appetitive instrumental learning and to explore potential associations between goal-directed and habitual actions in patients with cocaine use disorder (CUD).

METHODS

We re-analysed appetitive instrumental learning data in 55 healthy control volunteers and 70 CUD patients by applying a reinforcement learning model within a hierarchical Bayesian framework. We used a regression model to determine the influence of learning parameters and variations in brain structure on subsequent habit formation.

RESULTS

Poor instrumental learning performance in CUD patients was largely determined by difficulties with learning from feedback, as reflected by a significantly reduced learning rate. Subsequent formation of habitual response patterns was partly explained by group status and individual variation in reinforcement sensitivity. White matter integrity within goal-directed networks was only associated with performance parameters in controls but not in CUD patients.

CONCLUSIONS

Our data indicate that impairments in reinforcement learning are insufficient to account for enhanced habitual responding in CUD.

Incentive and dopamine sensitization produced by intermittent but not long access cocaine self-administration

The temporal pattern of drug use (pharmacokinetics) has a profound effect on the ability of self-administered cocaine to produce addiction-like behavior in rodents, and to change the brain. To further address this issue, we compared the effects of long access (LgA) cocaine self-administration, which is widely used to model the transition to addiction, with intermittent access (IntA), which is thought to better reflect the pattern of drug use in humans, on the ability of a single, self-administered injection of cocaine to increase dopamine (DA) overflow in the core of the nucleus accumbens (using in vivo microdialysis), and to produce addiction-like behavior. IntA experience was more effective than LgA in producing addiction-like behavior-a drug experience-dependent increase in motivation for cocaine assessed using behavioral economic procedures, and cue-induced reinstatement-despite much less total drug consumption. There were no group differences in basal levels of DA in dialysate [DA], but a single self-administered IV injection of cocaine increased [DA] in the core of the nucleus accumbens to a greater extent in rats with prior IntA experience than those with LgA or limited access experience, and the latter two groups did not differ. Furthermore, high motivation for cocaine was associated with a high [DA] response. Thus, IntA, but not LgA, produced both incentive and DA sensitization. This is consistent with the notion that a hyper-responsive dopaminergic system may contribute to the transition from casual patterns of drug use to the problematic patterns that define addiction.

Patterns of polysubstance use and overdose among people who inject drugs in Baltimore, Maryland: A latent class analysis

BACKGROUND

Opioid-related overdose rates continue to climb. However, little research has examined the reach of overdose education and naloxone trainings among people who inject drugs (PWID). Understanding gaps in coverage is essential to improving the public health response to the ongoing crisis.

METHODS

We surveyed 298 PWID in Baltimore City, MD. We conducted a latent class analysis of drug use indicators and tested for differences by class in past month overdose, having received overdose training, and currently having naloxone.

RESULTS

Three classes emerged: cocaine/heroin injection (40.2%), heroin only injection (32.2%), and multi-drug/multi-route use (27.6%). The prevalence of past month overdose differed marginally by class (p = 0.06), with the multi-drug/multi-route use class having the highest prevalence (22.5%) and the heroin only class having the lowest (4.6%). The prevalence of previous overdose training differed significantly by class (p = 0.02), with the heroin/cocaine class (76.5%) having more training than the other two classes. Training was least common amongst the multi-drug/multi-route class (60.3%), though not statistically different from the heroin only class (63.0%). Classes did not differ significantly in current naloxone possession, although the multi-drug/multi-route class exhibited the lowest prevalence of naloxone possession (37.2%).

CONCLUSIONS

People who inject multiple substances are at high risk for overdose and are also the least likely to receive overdose trainings. The current service landscape does not adequately reach individuals with high levels of structural vulnerability and high levels of drug use and homelessness. Actively including this subgroup into harm reduction efforts are essential for preventing overdose fatalities.

Effects of Social Support and 12-Step Involvement on Recovery among People in Continuing Care for Cocaine Dependence

Background: Social networks that support recovery lead to enhanced treatment outcomes and sobriety regardless if this support stems from family, peer groups or 12-Step programs. Treatment process factors including readiness to change and commitment to abstinence also impact substance use. However, little is understood about the relationship between social support to treatment process factors during and after treatment for substance use disorders. Objectives: To identify the ways in which different social networks foster substance use change in a sample of individuals with cocaine dependence from intensive outpatient programs (IOPs). Methods: Data were drawn from two studies examining adults (N = 489) with cocaine dependence in IOPs for substance use disorders collected between 2004 and 2009. Assessment data were collected at 3- to 6-month intervals from baseline to 24-months and included the University of Rhode Island change assessment questionnaire, timeline followback, thoughts about abstinence, perceived social support - friend, and family versions and analyzed using GEE and mediational analyses. Results: Greater perceived friend social support was associated with greater readiness to change whereas greater perceived familial social support was associated with substance use goal; greater social support from both friends and family were associated with less substance use. Greater AA/NA participation was associated with substance use goal and readiness to change, and less substance use. Substance use goals partially mediated the impact of social support on later substance use. Conclusions/Importance: While peer and familial support are key to sustained recovery, their impact differentially affects treatment process variables. This information could be used to inform social support treatment interventions.

Cannabidiol Treatment Might Promote Resilience to Cocaine and Methamphetamine Use Disorders: A Review of Possible Mechanisms

Currently, there are no approved pharmacotherapies for addiction to cocaine and other psychostimulant drugs. Several studies have proposed that cannabidiol (CBD) could be a promising treatment for substance use disorders. In the present work, the authors describe the scarce preclinical and human research about the actions of CBD on the effects of stimulant drugs, mainly cocaine and methamphetamine (METH). Additionally, the possible mechanisms underlying the therapeutic potential of CBD on stimulant use disorders are reviewed. CBD has reversed toxicity and seizures induced by cocaine, behavioural sensitization induced by amphetamines, motivation to self-administer cocaine and METH, context- and stress-induced reinstatement of cocaine and priming-induced reinstatement of METH seeking behaviours. CBD also potentiated the extinction of cocaine- and amphetamine-induced conditioned place preference (CPP), impaired the reconsolidation of cocaine CPP and prevented priming-induced reinstatement of METH CPP. Observational studies suggest that CBD may reduce problems related with crack-cocaine addiction, such as withdrawal symptoms, craving, impulsivity and paranoia (Fischer et al., 2015). The potential mechanisms involved in the protective effects of CBD on addiction to psychostimulant drugs include the prevention of drug-induced neuroadaptations (neurotransmitter and intracellular signalling pathways changes), the erasure of aberrant drug-memories, the reversion of cognitive deficits induced by psychostimulant drugs and the alleviation of mental disorders comorbid with psychostimulant abuse. Further, preclinical studies and future clinical trials are necessary to fully evaluate the potential of CBD as an intervention for cocaine and methamphetamine addictive disorders.

Longitudinal changes of amygdala functional connectivity in adolescents prenatally exposed to cocaine

BACKGROUND

Prenatal cocaine exposure (PCE) is associated with arousal dysregulation, but interactions between exposure and age are rarely investigated directly with longitudinal study designs. Our previous study had examined task-elicited emotional arousal and noted persistently high amygdala activations in the development of adolescents with PCE. However, while externally imposed emotional arousal could be considered a "state" effect depending on specific task stimuli, it is still unclear whether similar developmental alterations extend to intrinsic functional connectivity (FC), reflecting more of a "trait" effect.

METHODS

We used a longitudinal design and analyzed resting-state functional magnetic resonance imaging data acquired twice from 25 adolescents with PCE and 16 non-exposed controls. Both groups were each scanned first at the mean age of 14.3 and then again at 16.6 years. Seeding in bilateral amygdalae and comparing the 2^nd scan with the 1^st, we examined the interaction effect between PCE and age on FCs in the emotional network.

RESULTS

Compared with the younger age, we observed a generally decreased FC in the emotional network of the control group at the older age, but these FCs were generally increased at the older age in this same network of the PCE group. Additionally, this interaction effect of exposure by age in the right fusiform was positively correlated with the emotional interference imposed by external task stimuli.

CONCLUSIONS

These results provided additional data directly characterizing developmental changes in the emotional network of adolescents with PCE, complementing and extending the notion of a PCE-associated long-term teratogenic effect on arousal regulation.

Patterns of Cocaine Use During Treatment: Associations With Baseline Characteristics and Follow-Up Functioning

OBJECTIVE

Abstinence outcomes are typically prioritized in the treatment of cocaine use disorder while ignoring patterns of low-frequency cocaine use. This study examined patterns of cocaine use frequency during treatment and evaluated how these patterns related to baseline characteristics and functioning outcomes 6 and 12 months after treatment.

METHOD

We used a pooled dataset (N = 720) from seven randomized clinical trials for cocaine use disorder. The Addiction Severity Index (ASI) was used to assess functioning. Repeated-measures latent class analysis was used to derive patterns of cocaine use.

RESULTS

Three patterns were identified: abstinence (10.6%), low-frequency use (approximately 1 day/week; 66.3%), and persistent frequent use (approximately 4 days/week; 23.1%). The low-frequency group was associated with male gender, younger age, and a criminal justice referral. The abstinent group had the highest alcohol problem severity score at baseline. At Month 6, the low-frequency group reported lower problem severity than the persistent frequent use group across multiple ASI areas, including the cocaine use as well as psychological, family, employment, and legal domains. At Month 12, the low-frequency group did not differ from the abstinent group in problem severity on any ASI domain and, relative to the persistent frequent use group, had lower cocaine use and employment problem severity.

CONCLUSIONS

These findings highlight the importance of adopting a harm reduction approach and recognizing the potential clinical benefits associated with nonabstinent outcomes.

Effects of chronic cocaine self-administration and N-acetylcysteine on learning, cognitive flexibility, and reinstatement in nonhuman primates

RATIONALE

Cocaine use disorder (CUD) is associated with cognitive deficits that have been linked to poor treatment outcomes. An improved understanding of cocaine's deleterious effects on cognition may help optimize pharmacotherapies. Emerging evidence implicates abnormalities in glutamate neurotransmission in CUD and drugs that normalize glutamatergic homeostasis (e.g., N-acetylcysteine [NAC]) may attenuate CUD-related relapse behavior.

OBJECTIVES

The present studies examined the impact of chronic cocaine exposure on touchscreen-based models of learning (repeated acquisition) and cognitive flexibility (discrimination reversal) and, also, the ability of NAC to modulate cocaine self-administration and its capacity to reinstate drug-seeking behavior.

METHODS

First, stable repeated acquisition and discrimination reversal performance was established. Next, high levels of cocaine-taking behavior (2.13-3.03 mg/kg/session) were maintained for 150 sessions during which repeated acquisition and discrimination reversal performance was probed periodically. Finally, the effects of NAC treatment were examined on cocaine self-administration and, subsequently, extinction and reinstatement.

RESULTS

Cocaine self-administration significantly impaired performance under both cognitive tasks; however, discrimination reversal was disrupted considerably more than acquisition. Performance eventually approximated baseline levels during chronic exposure. NAC treatment did not perturb ongoing self-administration behavior but was associated with significantly quicker extinction of drug-lever responding. Cocaine-primed reinstatement did not significantly differ between groups.

CONCLUSIONS

The disruptive effects of cocaine on learning and cognitive flexibility are profound but performance recovered during chronic exposure. Although the effects of NAC on models of drug-taking and drug-seeking behavior in monkeys are less robust than reported in rodents, they nevertheless suggest a role for glutamatergic modulators in CUD treatment programs.

Sex-based differences in multidimensional clinical assessments of early-abstinence crack cocaine users

Crack cocaine use disorder (CUD) has been related to sex differences. This work aimed to compare the severity of drug use and the severity of other negative related outcomes in males and females with CUD. A total of 1344 inpatients (798 males and 546 females) with crack cocaine use disorder (CUD) were evaluated by a detailed multidimensional clinical assessment, including addiction severity and trauma exposure. Linear regression predicted higher drug use severity (β = 0.273, p < 0.001) and more problems in domains related to childcare issues (β = 0.321), criminal involvement (β = 0.108), work-related problems (β = 0.281) and social support impairments (β = 0.142) for females, all with p < 0.001. Alcohol problems were predicted to be higher in males (β = -0.206, P < 0.001). Females had higher rates of other mental disorders, particularly trauma and stress-related disorders (OR: 3.206, CI: 2.22, 4.61). Important sex differences also emerged in trauma history and HIV infection prevalence. CUD has a more severe clinical presentation among females facing early abstinence. Sex differences in the CUD course indicate the need for consideration of sex-specific interventions and research.

Cognitive dysfunction in individuals with cocaine use disorder: Potential moderating factors and pharmacological treatments

It is well-documented in the literature that individuals repeatedly exposed to cocaine exhibit cognitive impairment and that cognitive dysfunction is a risk factor for poor treatment outcomes in those with cocaine use disorder (CUD). Specific deficits related to attention, episodic memory, working memory, and executive functioning are the most common deficits noted in this population. Given that cognitive impairment is a risk factor for poor treatment outcomes in those with CUD, identifying possible moderating factors contributing to and/or exacerbating cocaine-related cognitive deficits is of great importance. Some of these factors may include premorbid intellectual functioning, cocaine use patterns, polysubstance use, comorbid emotional symptoms, and sleep dysfunction. It is plausible that by identifying moderating factors impacting cognition, behavioral interventions can then be modified accordingly and/or treatment regimens can be augmented with pharmacological interventions (e.g., cognitive enhancing agents), leading to a reduction in treatment attrition and improved treatment outcomes. The currently available treatments for CUD are mainly behavioral with variable efficacy, and even though there have been great preclinical and clinical research efforts focused on medication development for CUD, there are currently no Food and Drug Administration-approved medications for CUD. A description of some of the several potential moderating factors, along with some pharmacological treatments which have been shown to ameliorate, at least to some extent, cognitive dysfunction in those with CUD are discussed. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

The effect of N-acetylcysteine and working memory training on neural mechanisms of working memory and cue reactivity in regular cocaine users

The current study investigated the combined effects of N-acetylcysteine and working memory (WM) training on behavioral and neural mechanisms of cue reactivity and WM in cocaine users in a randomized, double-blind design. Twenty-four of 38 cocaine-using men completed a 25-day treatment with either 2400 mg/day NAC or placebo. Both groups performed WM-training. During pre- and post-test lab-visits, neural mechanisms of cue reactivity and WM, and cue-induced craving and WM performance were assessed. Additionally, exploratory whole brain analyses were performed. Overall, the hypotheses were not confirmed, possibly due to small sample size, low WM-training adherence and/or ongoing substance use.

The trajectory of crack users to the street situation in the perspective of family members

OBJECTIVES

To understand the family experience regarding the trajectory of crack users for the street situation.

METHODS

Qualitative study using the systemic approach as the theoretical referential and the narrative as methodological referential. We conducted interviews with eleven family members of crack users with street situation experience cared for at a community mental health service. We analyzed the interviews using the inductive content analysis technique.

RESULTS

The family members understood the trajectory of the crack users for the street situation from two perspectives. One before the street situation process, for which they described a problematic childhood, the presence of stressor traumas/events, vulnerabilities in the family environment, and their family members' encounter with the drug world. Moreover, another posterior to the street situation, for which they narrated the perception of alterations in the users, the discovery of crack use, the deepening of the individuals' relationship with the streets, and the adoption of coping strategies.

CONCLUSIONS

It was made evident that the family adopts an explicative model for the behavior of drug use and contact with the streets based on the life history of the crack user family member.

In Cocaine Dependence, Neural Prediction Errors During Loss Avoidance Are Increased With Cocaine Deprivation and Predict Drug Use

BACKGROUND

In substance-dependent individuals, drug deprivation and drug use trigger divergent behavioral responses to environmental cues. These divergent responses are consonant with data showing that short- and long-term adaptations in dopamine signaling are similarly sensitive to state of drug use. The literature suggests a drug state-dependent role of learning in maintaining substance use; evidence linking dopamine to both reinforcement learning and addiction provides a framework to test this possibility.

METHODS

In a randomized crossover design, 22 participants with current cocaine use disorder completed a probabilistic loss-learning task during functional magnetic resonance imaging while on and off cocaine (44 sessions). Another 54 participants without Axis I psychopathology served as a secondary reference group. Within-drug state and paired-subjects' learning effects were assessed with computational model-derived individual learning parameters. Model-based neuroimaging analyses evaluated effects of drug use state on neural learning signals. Relationships among model-derived behavioral learning rates (α+, α-), neural prediction error signals (δ+, δ-), cocaine use, and desire to use were assessed.

RESULTS

During cocaine deprivation, cocaine-dependent individuals exhibited heightened positive learning rates (α+), heightened neural positive prediction error (δ+) responses, and heightened association of α+ with neural δ+ responses. The deprivation-enhanced neural learning signals were specific to successful loss avoidance, comparable to participants without psychiatric conditions, and mediated a relationship between chronicity of drug use and desire to use cocaine.

CONCLUSIONS

Neurocomputational learning signals are sensitive to drug use status and suggest that heightened reinforcement by successful avoidance of negative outcomes may contribute to drug seeking during deprivation. More generally, attention to drug use state is important for delineating substrates of addiction.

Cocaine relapse and health-related quality of life: a 23 weeks study

INTRODUCTION

Cocaine dependence is a disorder where relapses are frequently presented and many factors are involved. Furthermore, cocaine dependence is associated with poor health-related quality of life (HRQoL) outcomes. This study aims to explore perceived HRQoL as an indicator of drug relapse in cocaine-dependent patients (CDP).

SUBJECTS AND METHODS

A longitudinal study was carried out in CDP during 23 weeks. A consecutive sampling method was applied, 39 participants composed the initial sample (mean age 35.6 years), only 15 participants completed outpatient follow-up period. CDP were assessed with psychiatric and HRQoL instruments (SCID-I, SCID-II, BDI, STAI scale and SF-36) in different points of the study. The patients were followed up, and cocaine relapses were assessed. The sample was divided according with the relapse (early vs. late relapse). Data were compared and analyzed in order to evaluate whether HRQoL measure could be related to cocaine relapse.

RESULTS

There are differences in perceived HRQoL measures between CDP with/without early relapse, especially in Mental health and Social functioning dimensions (p<0.05). Furthermore, Late/relapse-patients have higher improvement of HRQoL than patients with early relapse.

CONCLUSIONS

Perceived HRQoL might predict early relapse and could be a possible predictor tool of potential future relapses. More research in this field is needed.