Attention and memory deficits in crack-cocaine users persist over four weeks of abstinence

Neurocognitive and clinical profile of male patients with substance use disorder in early remission phase with and without comorbid depression

Substance Use Disorder (SUD) represents one of the most frequent conditions worldwide which commonly coexists with major depressive disorder (MDD). This comorbidity (SUD + MDD) is one of the most prevalent with patients showing certain social and clinical characteristics that could lead to a worsening of their cognitive performance. However, despite these particularities, only a few studies have addressed the possible differences in cognitive performance between patients with SUD + MDD compared with those with SUD-only patients. Therefore, the aim of this study is to examine the clinical and cognitive profile of patients with SUD + MDD vs. SUD-only who are in early remission phase. For this purpose, 271 male patients underwent a clinical and neuropsychological assessment (SUD + MDD group: N = 101; SUD-only group: N = 170). Results indicated that SUD + MDD patients showed worse cognitive performance than SUD in visuospatial reasoning, verbal memory and learning, recognition, and processing speed even after a 3-month period of abstinence. Furthermore, these patients exhibited more self-reported prefrontal symptoms, as well as worse social and clinical conditions. This study indicates that the neurocognitive and clinical profile of patients with SUD + MDD could represent a risk since their characteristics have been associated with poorer recovery and prognosis. Our results could be helpful in clinical practice highlighting the need for cognitive remediation strategies in these populations, providing information that would allow the implementation of more appropriate treatments and preventive strategies.

Evaluation of oxidative stress and its association with drug therapy in inpatients treated for cocaine dependence

The use of cocaine affects several systems and organs of the human body and the consumption of this substance leads to an increase in the production of reactive oxygen species, and to the reduction of antioxidant defenses. The aim of this study was to evaluate the oxidative stress (OS), biochemical and hematological parameters in patients hospitalized for treatment of cocaine addiction, comparing levels at hospital admission and discharge. Forty patients were included in the study. OS was evaluated using catalase (CAT), superoxide dismutase (SOD), glutathione reductase (GPx), total antioxidant power (FRAP), malondialdehyde (MDA), and sulfhydryl group (GS). The medications used during hospitalization were registered and their influence on the parameters of OS was analyzed. After the hospitalization period, there was an increase in GGT levels, a reduction in SOD activity, and an increase in GPx activity and FRAP levels. Carbamazepine users had higher SOD values and lower FRAP values at hospital discharge. The use of chlorpromazine caused differences in creatinine and gamma-glutamyltransferase (GGT) serum leves, and the levels of glutamic oxalacetic transaminase (TGO), MDA, and FRAP were increased at hospital discharge. Haloperidol and thiamine during hospitalization interfered with alkaline phosphatase levels. The use of risperidone caused an increase in the levels of SOD, and folic acid use was associated with lower levels of GPx and higher levels of glutamic-pyruvic transaminase (TGP) and alkaline phosphatase. Drug rehabilitation treatment was effective in decreasing oxidative damage represented by the reduction of biological markers.

A systematic review of quality of life and health-related quality of life as outcomes in substance and behavioural addictions

ISSUES

Consideration of an individual's quality of life (QoL) can benefit assessment and treatment of addictive disorders, however, uncertainty remains over operationalisation of the construct as an outcome and the appropriateness of existing measures for these populations. This systematic review aimed to identify and evaluate QoL and health-related QoL outcome instruments used in addiction-related risk and harm research and map their conceptualised domains.

APPROACH

Three electronic databases and a specialised assessment library were searched on 1 February 2022 for QoL or health-related QoL outcome instruments used with addiction-related risk and harm populations. PRISMA reporting guidance was followed and included outcome instruments were appraised using mixed methods. Psychometric evidence supporting their use was summarised. The COSMIN risk of bias tool was used to assess validation studies.

KEY FINDINGS

A total of 298 articles (330 studies) used 53 outcome instruments and 41 unique domains of QoL. Eleven instruments' psychometric properties were evaluated. No instrument was assessed for any parameter in at least five studies for meta-analytic pooling. Cronbach's alpha (α) internal consistency was the most widely assessed parameter with the AQoLS, WHOQOL-BREF, ALQoL-9, Q-LES-Q-SF, SF-12, DUQoL, QLI and SF-36 displaying promising statistics (α > 0.70).

IMPLICATIONS AND CONCLUSION

Many instruments have been utilised. However, a significant proportion of studies applied a small number of instruments with minimal high-quality validation evidence supporting their use within addiction-related risk and harm. Promising instruments are recommended, however, the paucity of supporting evidence limits confidence in the reliability and validity of QoL measurement in these populations.

Neuropsychological functioning of patients with major depression or bipolar disorder comorbid to substance use disorders: A systematic review

Major depression disorder (MDD) and bipolar disorder (BD) are usual comorbidities in patients with substance use disorders (SUD), a condition known as dual disorder (DD). MDD, BD and SUD are associated with cognitive impairment, potentially leading to a greater functional impairment in the context of DD.

OBJECTIVES

To review the existing data on the cognitive impairment in DD patients with comorbid MDD or BD, considering the influence of the depressive symptomatology.

METHODS

Following the PRISMA protocol 19 studies were selected from the last 17 years, 13 of which focused on BD, five on MDD and one included both diagnoses.

RESULTS

Studies based in BD+SUD showed that the most affected cognitive domains were attention and executive functions, but not all of them found a greater impairment due to the comorbidity. While fewer studies were found for depression, MDD+SUD works point to a similar impairment cognitive pattern. Furthermore, depression improvement could be associated to better cognitive performance.

LIMITATIONS

More standardized research is needed regarding the influence of depression on cognitive performance of DD patients, especially on those with comorbid MDD. Factors such as main substance, abstinence, or MDD/BD-related variables should be considered. Unstudied factors, like gender or circadian rhythms, are proposed to improve knowledge in this area.

CONCLUSIONS

Current studies suggest that DD could potentiate cognitive impairment in BD, MDD and SUD. However, additional research is needed to improve the understanding of comorbidity to apply more individualized therapies in the treatment of these patients, considering the interference of their neurocognitive functioning.

Cognitive Alterations in Addictive Disorders: A Translational Approach

The cognitive decline in people with substance use disorders is well known and can be found during both the dependence and drug abstinence phases. At the clinical level, cognitive decline impairs the response to addiction treatment and increases dropout rates. It can be irreversible, even after the end of drug abuse consumption. Improving our understanding of the molecular and cellular alterations associated with cognitive decline could be essential to developing specific therapeutic strategies for its treatment. Developing animal models to simulate drug abuse-induced learning and memory alterations is critical to continue exploring this clinical situation. The main aim of this review is to summarize the most recent evidence on cognitive impairment and the associated biological markers in patients addicted to some of the most consumed drugs of abuse and in animal models simulating this clinical situation. The available information suggests the need to develop more studies to further explore the molecular alterations associated with cognitive impairment, with the ultimate goal of developing new potential therapeutic strategies.

Patients with Schizophrenia Showed Worse Cognitive Performance than Bipolar and Major Depressive Disorder in a Sample with Comorbid Substance Use Disorders

Comorbidity of substance use disorders (SUD) and severe mental illness (SMI) is highly frequent in patients, the most common diagnoses being schizophrenia (SZ), bipolar disorder (BD) and major depressive disorder (MDD). Since comorbidity has its own clinical features, and neurocognitive functioning is not always similar to psychiatric symptoms the present study explores the cognitive performance of patients with dual disorders. A neuropsychological battery of tests was used to assess 120 under treatment male patients, 40 for each group considered (SZ + SUD, BD + SUD and MDD + SUD) who were mainly polyconsumers. Significant differences (with premorbid IQ as a covariate) were found among the groups, with SZ + SUD having a worse performance in attention, verbal learning, short term memory and recognition. The consideration of a global Z score for performance evidenced an impaired neurocognitive pattern for SZ + SUD compared with BD + SUD and MDD + SUD. According to norms, all patients showed difficulties in verbal learning, short-term memory and recognition. Our research indicated that the neurocognitive functioning of dual disorder patients was influenced by the comorbid SMI, with SZ + SUD presenting major difficulties. Future studies should thoroughly explore the role of such difficulties as indicators or endophenotypes for dual schizophrenia disorders, and their usefulness for prevention and treatment.

Comparison of the acute effects of Tai chi versus high-intensity interval training on inhibitory control in individuals with substance use disorder

Objective

The purpose of this study is to investigate the effects of a single session of Tai chi (TC) exercise and high-intensity interval training (HIIT) on inhibitory control in individuals with substance use disorder (SUD).

Methods

A total 47 males with methamphetamine dependence were recruited from a compulsory drug rehabilitation center; participation in this study was voluntary. The participants were randomly assigned to the TC group or the HIIT group, and computer-based Go/No-go and Stroop tasks were used to assess inhibitory control in an indoor setting prior to and following exercise. Independent sample t-test was applied for baseline comparison of continuous variables, while analysis of variance was applied to test differences in the effect of each intervention before and after a single session of exercise.

Results

In Go/No-go test, the reaction time of the TC and HIIT groups in the post-test was shorter than that at the baseline, and the response accuracy of the post-test were higher than that of the baseline. In the Stroop task, the reaction time of two groups in the post-test was shorter than that at the baseline; while, greater improvement in response accuracy was observed in HIIT group in the post-test than that of the baseline.

Conclusion

Both TC and HIIT can promote inhibitory control in individuals with SUD. Compared with the TC group, the HIIT group showed greater improvements in response accuracy. These findings demonstrate the potential of TC and HIIT in improving cognition in SUD.

Clinical trial registration

[http://www.chictr.org.cn/], identifier [ChiCTR1900022158].

Attentional function and inhibitory control in different substance use disorders

Attentional function in substance use disorder (SUD) is not well understood. To probe attentional function in SUD as a function of primary substance of abuse, we administered the attentional network task (ANT) to 44 individuals with Cocaine Use Disorder (CoUD), 49 individuals with Cannabis Use Disorder (CaUD), 86 individuals with Opioid Use Disorder (OUD), and 107 controls with no SUD, along with the stop-signal task (SST). The ANT quantifies the effects of (temporal) alerting cues and (spatial) orienting cues to reduce reaction time (RT) to targets, as well as probing how conflicting (target-incongruent) stimuli slow RT. The SST quantifies individuals' ability to inhibit already-initiated motor responses. After controlling for sex representation and age, OUD and CaUD participants showed blunted alerting effects compared to controls, whereas CaUD and CoUD participants showed greater stimulus conflict (flanker) effects. Finally, CoUD participants showed a trend toward increased orienting ability. In SST performance, no SUD group showed a prolonged stop-signal reaction compared to controls. However, the OUD group (and CoUD group at trend level) showed prolonged "go" RT to targets and reduced hit rates. These data indicate differences in attentional function in persons with SUD as a function of the primary substance use.

Anhydroecgonine methyl ester, a cocaine pyrolysis product, contributes to cocaine-induced rat primary hippocampal neuronal death in a synergistic and time-dependent manner

Crack cocaine users are simultaneously exposed to volatilized cocaine and to its main pyrolysis product, anhydroecgonine methyl ester (AEME). Although the neurotoxic effects of cocaine have been extensively studied, little is known about AEME or its combination. We investigated cell death processes using rat primary hippocampal cells exposed to cocaine (2 mM), AEME (1 mM) and their combination (C + A), after 1, 3, 6 and 12 h. Cocaine increased LC3 I after 6 h and LC3 II after 12 h, but reduced the percentage of cells with acid vesicles, suggesting failure in the autophagic flux, which activated the extrinsic apoptotic pathway after 12 h. AEME neurotoxicity did not involve the autophagic process; rather, it activated caspase-9 after 6 h and caspase-8 after 12 h leading to a high percentage of cells in early apoptosis. C + A progressively reduced the percentage of undamaged cells, starting after 3 h; it activated both apoptotic pathways after 6 h, and was more neurotoxic than cocaine and AEME alone. Also, C + A increased the phosphorylation of p62 after 12 h, but there was little difference in LC3 I or II, and a small percentage of cells with acid vesicles at all time points investigated. In summary, the present study provides new evidence for the neurotoxic mechanism and timing response of each substance alone and in combination, indicating that AEME is more than just a biological marker for crack cocaine consumption, as it may intensify and hasten cocaine neurotoxicity.

Salivary Cortisol Levels Are Associated with Craving and Cognitive Performance in Cocaine-Abstinent Subjects: A Pilot Study

Cortisol is a glucocorticoid hormone secreted by the adrenal cortex upon the activation of the hypothalamic-pituitary-adrenal (HPA) axis. Assessment of cortisol in saliva has emerged as a reliable way of evaluating HPA function. We examined the relationships between salivary cortisol levels with both craving and cognitive performance, as a possible biomarker of cocaine addiction. Cognitive performance (attention, declarative and working memory, executive functions and recognition of emotions) was assessed in 14 abstinent cocaine-dependent subjects in outpatient treatment and 13 control participants. Three salivary samples were collected at home by all the participants in the morning, afternoon and at bedtime. Patients showed higher levels of cortisol in the morning, as well as higher area under the curve with respect to the ground (AUCg). Regarding cognitive performance, cocaine-abstinent subjects showed worse performance in attention (d2 test), verbal memory (Spanish Complementary Verbal Learning Test, TAVEC) and executive tests (Tower of Hanoi and phonological fluency test) with respect to the control group. Morning cortisol levels and the AUCg index were negatively associated with the age of onset of drug consumption and the AUCg index was also positively associated with craving in our patients' group. Moreover, morning cortisol levels, as well as the AUCg index, were negatively associated with verbal memory performance. Therefore, our pilot study suggests that salivary cortisol measurements could be a good avenue to predict craving level, as well as cognitive status, especially the declarative memory domain.

Prior cocaine self-administration impairs attention signals in anterior cingulate cortex

Although maladaptive decision-making is a defining feature of drug abuse and addiction, we have yet to ascertain how cocaine self-administration disrupts neural signals in anterior cingulate cortex (ACC), a brain region thought to contribute to attentional control. To address this issue, rats were trained on a reward-guided decision-making task; reward value was manipulated by independently varying the size of or the delay to reward over several trial blocks. Subsequently, rats self-administered either a cocaine (experimental group) or sucrose (control) during 12 consecutive days, after which they underwent a 1-month withdrawal period. Upon completion of this period, rats performed the previously learned reward-guided decision-making task while we recorded from single neurons in ACC. We demonstrate that prior cocaine self-administration attenuates attention and attention-related ACC signals in an intake-dependent manner, and that changes in attention are decoupled from ACC firing. These effects likely contribute to the impaired decision-making-typified by chronic substance abuse and relapse-observed after drug use.

Intranasal Insulin: a Treatment Strategy for Addiction

Addiction to substances such as alcohol, cocaine, opioids, and methamphetamine poses a continuing clinical and public challenge globally. Despite progress in understanding substance use disorders, challenges remain in their treatment. Some of these challenges include limited ability of therapeutics to reach the brain (blood-brain barrier), adverse systemic side effects of current medications, and importantly key aspects of addiction not addressed by currently available treatments (such as cognitive impairment). Inability to sustain abstinence or seek treatment due to cognitive deficits such as poor decision-making and impulsivity is known to cause poor treatment outcomes. In this review, we provide an evidenced-based rationale for intranasal drug delivery as a viable and safe treatment modality to bypass the blood-brain barrier and target insulin to the brain to improve the treatment of addiction. Intranasal insulin with improvement of brain cell energy and glucose metabolism, stress hormone reduction, and improved monoamine transmission may be an ideal approach for treating multiple domains of addiction including memory and impulsivity. This may provide additional benefits to enhance current treatment approaches.

Cocaine Use Disorder Is Associated With Changes in Th1/Th2/Th17 Cytokines and Lymphocytes Subsets

Background: Cocaine is a psychostimulant drug with high addictive proprieties. Evidence suggests that cocaine use leads to critical changes in the immune system, with significant effects on T, B, and natural killer (NK) cells and influencing peripheral levels of cytokines. The presence of abstinence-related symptoms during detoxification treatment is known to influence the prognosis. Here, our aim was to investigate immune profiles in women with cocaine use disorder (CUD) according to withdrawal symptoms severity.

Methods: Blood samples and clinical data were collected at onset of detoxification treatment of 50 women with CUD. The patients were stratified according to Cocaine Selective Severity Assessment (CSSA) scores in low withdrawal (L-W) and high withdrawal (H-W) categories. In addition, we also included a control group with 19 healthy women as reference to immune parameters. Peripheral blood was collected and lymphocyte subsets were phenotyped by multi-color flow cytometry (B cells, CD4⁺ T, CD8⁺ T, NK cells, and different stages of T-cell differentiation). PBMCs from patients and healthy controls were stimulated in vitro with phytohemagglutinin (1%) for 72 h to assess the production of Th1/Th2/Th17 cytokines.

Results: Following stimulation, lymphocytes from women with CUD produced increased levels of Th1/Th2/Th17 cytokines. However, higher levels of IL-2 and IL-17 were observed only in the L-W group, while higher levels of IL-6 were detected in the H-W group compared to controls. H-W group showed lower percentage of early-differentiated Th cells (CD4⁺CD27⁺CD28⁺), elevated percentage of Th cells (CD3⁺CD4⁺), intermediate-differentiated Th cells (CD4⁺CD27⁻CD28⁺), and B cells (CD3⁻CD19⁺). Both CUD groups showed decreased percentages of naïve T cells (CD3⁺CD4⁺CD45RA⁺ and CD3⁺CD8⁺CD45RA⁺).

Conclusion: Our data demonstrated that CUD can lead to increased production of Th1/Th2/Th17 cytokines and lymphocyte changes.

Brain and Cognition for Addiction Medicine: From Prevention to Recovery Neural Substrates for Treatment of Psychostimulant-Induced Cognitive Deficits

Addiction to psychostimulants like cocaine, methamphetamine, and nicotine poses a continuing medical and social challenge both in the United States and all over the world. Despite a desire to quit drug use, return to drug use after a period of abstinence is a common problem among individuals dependent on psychostimulants. Recovery for psychostimulant drug-dependent individuals is particularly challenging because psychostimulant drugs induce significant changes in brain regions associated with cognitive functions leading to cognitive deficits. These cognitive deficits include impairments in learning/memory, poor decision making, and impaired control of behavioral output. Importantly, these drug-induced cognitive deficits often impact adherence to addiction treatment programs and predispose abstinent addicts to drug use relapse. Additionally, these cognitive deficits impact effective social and professional rehabilitation of abstinent addicts. The goal of this paper is to review neural substrates based on animal studies that could be pharmacologically targeted to reverse psychostimulant-induced cognitive deficits such as impulsivity and impairment in learning and memory. Further, the review will discuss neural substrates that could be used to facilitate extinction learning and thus reduce emotional and behavioral responses to drug-associated cues. Moreover, the review will discuss some non-pharmacological approaches that could be used either alone or in combination with pharmacological compounds to treat the above-mentioned cognitive deficits. Psychostimulant addiction treatment, which includes treatment for cognitive deficits, will help promote abstinence and allow for better rehabilitation and integration of abstinent individuals into society.

Insights into the Effects of Crack Abuse on the Human Metabolome Using a NMR Approach

Approximately 255 million people consume illicit drugs every year, among which 18 million use cocaine. A portion of this drug is represented by crack, but it is difficult to estimate the number of users since most are marginalized. However, there are no recognized efficacious pharmacotherapies for crack-cocaine dependence. Inflammation and infection in cocaine users may be due to behavior adopted in conjunction with drug-related changes in the brain. To understand the metabolic changes associated with the drug abuse disorder and identify biomarkers, we performed a ¹H NMR-based metabonomic analysis of 44 crack users' and 44 healthy volunteers' blood serum. The LDA model achieved 98% of accuracy. From the water suppressed ¹H NMR spectra analyses, it was observed that the relative concentration of lactate was higher in the crack group, while long chain fatty acid acylated carnitines were decreased, which was associated with their nutritional behavior. Analyses of the aromatic region of CPMG ¹H NMR spectra demonstrated histidine and tyrosine levels increased in the blood serum of crack users. The reduction of carnitine and acylcarnitines and the accumulation of histidine in the serum of the crack users suggest that histamine biosynthesis is compromised. The tyrosine level points to altered dopamine concentration.