Neuropsychological functioning in opiate-dependent subjects receiving and following methadone maintenance treatment

Case study of invalid to valid shift in cognitive performance following successful treatment of psychogenic nonepileptic seizure events

Patients with psychogenic nonepileptic seizure (PNES) who fail performance validity testing (PVT) may appear to produce non-valid cognitive profiles. Consequently, they may not get referred to treatment and events persist, with worsening disability and high resource utilization. As a result, we report pre- and post-treatment neuropsychological evaluation findings in a 59-year-old woman with a confirmed diagnosis of PNES established using video-EEG monitoring. At pre-treatment baseline neuropsychological evaluation, PNES events occurred weekly to daily. Performance was impaired across PVTs and across multiple cognitive domains. After behavioral intervention specific to PNES, these events substantially reduced in frequency to rare stress-induced flares. Post-treatment neuropsychological evaluation revealed marked improvement of most cognitive and behavioral scores from baseline, and valid PVT scores. We review predisposing, precipitating, and perpetuating factors for PNES and cognitive impairment in this case and discuss the patient's outcome from treatment. Effectively managing PNES events and dissociative tendencies while reducing unnecessary pharmacological interventions appears to have allowed this patient to function closer to her optimal state. This case illustrates the complexity of Functional Neurologic Disorder (FND) clinical presentation and challenges the assumption that suboptimal neuropsychological performance predicts poor treatment engagement and outcome. We showcase the reversibility of PNES and cognitive manifestations of FND using targeted psychotherapeutic interventions, which resulted in reduced disability and associated healthcare costs, as well as re-engagement in life.

Effects of Abstinence From Opioid on Neuropsychological Performance in Men With Opioid Use Disorder: A Longitudinal Study

OBJECTIVES

Impairments in neuropsychological functioning (mainly memory, learning, attention, and executive functioning) among persons with long-term opioid use disorder (OUD) have been widely reported, with few studies suggesting that these are not permanent and can improve with abstinence. Thus, present study aimed to evaluate the neuropsychological functioning in persons with OUD and examine the effects of abstinence on the same over a period 8 weeks.

METHODS

A total of 50 patients with diagnosis of OUD as per the Diagnostic and Statistical Manual of Mental Disorders , Fifth Edition ( DSM-5 ) criteria underwent serial longitudinal neuropsychological assessments for executive functioning, attention and concentration, and verbal and nonverbal memory at baseline, 2 weeks, and 8 weeks of abstinence.

RESULTS

The mean performance scores representative of attention, concentration, verbal memory, and nonverbal memory showed significant improvement in the initial 2 weeks, and executive functioning showed significant improvement by 8 weeks of abstinence (all P 's < 0.01). A significant negative correlation was found between the duration of opioid use and performance on verbal memory tests (0.014), the frequency of intake per day and performance on nonverbal memory and executive functioning tests, and the severity of opioid dependence and performance on nonverbal memory test (0.019).

CONCLUSIONS

Neuropsychological functioning in certain domains was associated with the duration of opioid use, the frequency of daily opioid intake, and the severity of opioid dependence among persons with OUD at baseline. It showed significant improvement in domains of attention, concentration, verbal and nonverbal memory, and executive functions over a period of 8 weeks of abstinence.

Harmful effects of opioid use in pregnancy: A scientific review commissioned by the European Board and College of obstetrics and gynaecology (EBCOG)

Caring for pregnant women who have a recreational opioid use disorder is a common clinical challenge in modern obstetric care. These are an elusive population who often have multiple social issues that complicate their pregnancy management. Comprehensive and supportive maternal care can motivate these mothers to change her lifestyle. Multidisciplinary non-judgemental approach with appropriate medication and management, can result in good pregnancy outcomes for mother and her baby.

Chronic exposure to methadone impairs memory, induces microgliosis, astrogliosis and neuroinflammation in the hippocampus of adult male rats

Methadone is a centrally-acting synthetic opioid analgesic widely used in methadone maintenance therapy (MMT) programs throughout the world. Given its neurotoxic effects, particularly on the hippocampus, this study aims to address the behavioral and histological alterations in the hippocampus associated with methadone administration. To do so, twenty-four adult male albino rats were randomized into two groups, methadone treatment and control. Methadone was administered subcutaneously (2.5-10 mg/kg) once a day for two consecutive weeks. A comparison was drawn with behavioral and structural changes recorded in the control group. The results showed that methadone administration interrupted spatial learning and memory function. Accordingly, treating rats with methadone not only induced cell death but also prompted the actuation of microgliosis, astrogliosis, and apoptotic biomarkers. Furthermore, the results demonstrated that treating rats with methadone decreased the complexity of astrocyte processes and the complexity of microglia processes. These findings suggest that methadone altered the special distribution of neurons. Also, a substantial increase was observed in the expression of TNF-α due to methadone. According to the findings, methadone administration exerts a neurodegenerative effect on the hippocampus via dysregulation of microgliosis, astrogliosis, apoptosis, and neuro-inflammation.

Effect of tramadol on apoptosis and synaptogenesis in hippocampal neurons: The possible role of µ-opioid receptor

Tramadol is a synthetic opioid with centrally acting analgesic activity that alleviates moderate to severe pain and treats withdrawal symptoms of the other opioids. Like other opioid drugs, tramadol abuse has adverse effects on central nervous system components. Chronic administration of tramadol induces maladaptive plasticity in brain structures responsible for cognitive function, such as the hippocampus. However, the mechanisms by which tramadol induces these alternations are not entirely understood. Here, we examine the effect of tramadol on apoptosis and synaptogenesis of hippocampal neuronal in vitro. First, the primary culture of hippocampal neurons from neonatal rats was established, and the purity of the neuronal cells was verified by immunofluorescent staining. To evaluate the effect of tramadol on neuronal cell viability MTT assay was carried out. The western blot analysis technique was performed for the assessment of apoptosis and synaptogenesis markers. Results show that chronic exposure to tramadol reduces cell viability of neuronal cells and naloxone reverses this effect. Also, the level of caspase-3 significantly increased in tramadol-exposed hippocampal neurons. Moreover, tramadol downregulates protein levels of synaptophysin and stathmin as synaptogenesis markers. Interestingly, the effects of tramadol were abrogated by naloxone treatment. These findings suggest that tramadol can induce neurotoxicity in hippocampal neuronal cells, and this effect was partly mediated through opioid receptors.

Frontal Lobe Functions, Demoralization, Depression and Craving as Prognostic Factors and Positive Outcomes of Patients with Heroin Use Disorder Receiving 6 Months of Methadone Maintenance Treatment

Methadone maintenance therapy (MMT) is a well-established and effective treatment for heroin use disorders. Whether frontal lobe function and demoralization serve as suitable prognostic and outcome assessment factors remains unknown. A quasi-experimental study was conducted with a single-group repeated-measures design at a medical center and mental hospital in Taiwan. We enrolled 70 participants (39 completed treatments and 31 dropped out). Frontal lobe function, demoralization, depression, and craving at three time points were analyzed. There were differences between patients who completed the treatment (n = 39) and those who did not (n = 31). Thirty-nine patients completed the treatment (average age, 45.5 years; 89.7% men; average duration of heroin use, 27.21 years; MMT, 38.18 mg/day). Post-MMT (6 months), frontal lobe function, demoralization, depression, and craving significantly improved. Dropouts had higher frontal lobe function, lower demoralization, higher craving, younger age, and earlier onset age than patients who completed the pretest treatment. Clinicians should be aware of the severity of demoralization. Clinicians may select suitable patients for MMT by assessing frontal lobe function, demoralization, craving, age, and onset age. A 6-month course of MMT improved demoralization, frontal lobe function, depression, and addiction. Six months of treatment was more effective than 3 months. Suitable patient identification and continuous treatment are important in MMT.

Therapy Dose Mediates the Relationship Between Buprenorphine/Naloxone and Opioid Treatment Outcomes in Youth Receiving Medication for Opioid Use Disorder Treatment

BACKGROUND

Evidence-based interventions for treating opioid use disorder (OUD) in youth are limited and little is known about specific and general mechanisms of OUD treatments and how they promote abstinence.

METHODS

The present study used data from the NIDA-CTN-0010 trial to evaluate the mediating effects of psychosocial treatment-related variables (therapy dose and therapeutic alliance) on end-of-treatment opioid abstinence in a sample of youth with OUD (n = 152, 40% female, mean age = 19.7 years) randomized to receive either 12-weeks of treatment with Bup/Nal ("Bup-Nal") or up to 2 weeks of Bup/Nal detoxification ("Detox") with both treatment arms receiving weekly individual and group drug counseling ± family therapy.

RESULTS

Participants in the Bup-Nal group attended more therapy sessions (16 vs 6 sessions), had increased therapeutic alliance at week-4, and had less opioid use by week-12 compared to those in the Detox group. In both treatment arms, youth who attended more therapy sessions were less likely to have a week-12 opioid positive urine. In a multiple mediator model, therapy dose mediated the association between treatment arm and opioid abstinence.

CONCLUSIONS

These findings provide preliminary support for a "dose-response" effect of addiction-focused therapy on abstinence in youth OUD. Further, the results identified a mediating effect of therapy dose on the relationship between treatment assignment and opioid treatment outcomes, suggesting that extended Bup-Nal treatment may enhance abstinence, in part, through a mechanism of therapy facilitation, by increasing therapy dose during treatment.

Clinical and Cognitive Effects of Computer Assisted Cognitive Remediation Method in Turkish Men with Opioid Use Disorder: A Randomized Controlled Trial

Objective: Substance use disorders are associated with significant cognitive impairments causing many individual or social problems besides poor treatment outcomes. The cognitive remediation method is effective in so many neuropsychiatric disorders. This study aimed to evaluate the effects of this method among individuals with opioid use disorder. Method:60 patients diagnosed with opioid use disorder under buprenorphine-naloxone treatment and who accepted the informed consent were included. Seven patients left the study initially. 53 male patients were randomly assigned to receive treatment in the usual control or cognitive remediation-intervention group. The intervention group completed 3 to 4 sessions a week, 8 different exercises in each session, for 4 weeks, a total of 12 sessions, individually. Addiction Profile Indeks, Barrat Impulsivity Scale-SF, CGI, and Delay Discounting scores were measured before and after the 1 month cognitive Remediation practices. Three months later, patients were contacted, and their remission status was evaluated. Results: In the intervention group; 17(89.5%) people had remission and 2(10.5%) people had relapse. In the control group, 7(31.8%) individuals had remission, and 15(68.2%) had relapsed at the end of the 3 months. It was determined that craving, addiction severity, and self-reported and behavioral impulsivity values decreased while the improvement in treatment response was higher in the intervention group. Conclusion: Our results showed that the computer-assisted cognitive remediation method, in addition to buprenorphine-naloxone treatment, improves treatment response, increases remission, and has positive clinical and cognitive effects on individuals with opioid use disorder. It suggests that cognitive remediation practices can be added to the treatment programs for addiction.

Underrepresentation of diverse populations and clinical characterization in opioid agonist treatment research: A systematic review of the neurocognitive effects of buprenorphine and methadone treatment

INTRODUCTION

The relative neurocognitive effects of the two most common opioid agonist treatments (OAT; buprenorphine and methadone) for opioid use disorder (OUD) are poorly understood. The aim of this systematic review is to examine the neurocognitive effects of OAT (buprenorphine and methadone) and the clinical and sociodemographic characteristics of study samples.

METHODS

The research team queried PubMed, PsycINFO and Cochrane Reviews for articles (01/1980-01/2020) with terms related to neurocognitive testing in adults (age ≥ 18) prescribed OAT. The team extracted neurocognitive data and grouped them by domain (e.g., executive functioning, learning/memory), and assessed study quality.

RESULTS

The search retrieved 2341 abstracts, the team reviewed 278 full articles, and 32 met inclusion criteria. Of these, 31 were observational designs and one was an experimental design. Healthy controls performed better across neurocognitive domains than OAT-treated persons (buprenorphine or methadone). Compared to those with active OUD, OAT-treated persons had better neurocognition in various domains. However, in seven studies comparing buprenorphine- and methadone-treated persons, buprenorphine was associated with better neurocognition than was methadone, with moderate to large effect sizes in executive functioning, attention/working memory, and learning/memory. Additionally, OAT research underreports clinical characteristics and underrepresents Black and Latinx adults, as well as women.

CONCLUSIONS

Findings suggest that compared to active opioid use, both buprenorphine and methadone treatment are associated with better neurocognitive functioning, but buprenorphine is associated with better executive functioning, attention/working memory, and learning/memory. These findings should be interpreted with caution given widespread methodological heterogeneity, and limited representation of ethnoracially diverse adults and women. Rigorous longitudinal comparisons with more diverse, better characterized samples will help to inform treatment and policy recommendations for persons with OUD.

Risk of motor vehicle collisions after methadone use

Methadone maintenance treatment (MMT) can alleviate opioid dependence. However, MMT possibly increases the risk of motor vehicle collisions. The current study investigated preliminary estimation of motor vehicle collision incidence rates. Furthermore, in this population-based retrospective cohort study with frequency-matched controls, opiate adults receiving MMT (cases) and those not receiving MMT (controls) were identified at a 1:2 ratio by linking data from several nationwide administrative registry databases. From 2009 to 2016, the crude incidence rate of motor vehicle collisions was the lowest in the general adult population, followed by that in opiate adults, and it was the highest in adults receiving MMT. The incidence rates of motor vehicle collisions were significantly higher in opiate users receiving MMT than in those not receiving MMT. Kaplan–Meier curves of the incidence of motor vehicle collisions differed significantly between groups, with a significant increased risk during the first 90 days of follow-up. In conclusion, drivers receiving MMT have higher motor vehicle collision risk than those not receiving MMT in opiate users, and it is worthy of noticing road safety in such drivers, particularly during the first 90 days of MMT.

In 2019, 58 million people were estimated to use opioids – a group of substances that include drugs like heroin and morphine. Dependence on opioids can be managed using a prescribed dose of an opioid called methadone, which is administered through a controlled treatment plan. This so-called methadone maintenance treatment manages withdrawal symptoms in opioid-dependent individuals and can reduce the occurrences of overdose, criminal activity and transmission of diseases such as HIV.

However, methadone acts on the same brain receptors as other opioids, and individuals receiving methadone may experience impaired motoric and cognitive functioning, including reduced driving ability. It is therefore important to know whether methadone maintenance treatment may increase an individual’s risk to cause road accidents.

To assess motor vehicle collision risk associated with individuals receiving methadone maintenance treatment, Yang et al. analysed data from the Taiwan National Health Insurance Research Database and six Taiwanese administrative registries, including the ministries of health and welfare, interior and justice, and registries in substitution maintenance therapy, road accidents and the National Police Agency.

Initial analyses found that individuals receiving treatment had a higher risk to be involved in car accidents than the general adult population or those without methadone maintenance treatment. Further tests showed that individuals receiving treatment were at three times higher risk of collisions than individuals not receiving treatment, particularly in the first 90 days.

These findings may help individuals undergoing methadone maintenance treatment manage their risk of motor vehicle collisions. Further investigation is needed to reveal the underlying mechanisms of methadone-related impairment of driving ability.

Impaired working memory performance in opioid-dependent patients is related to reduced insula gray matter volume: a voxel-based morphometric study

Opioid-dependent patients frequently show deficits in multiple cognitive domains that might impact on their everyday life performance and interfere with therapeutic efforts. To date, the neurobiological underpinnings of those deficits remain to be determined. We investigated working memory performance and gray matter volume (GMV) differences in 17 patients on opioid maintenance treatment (OMT) and 17 healthy individuals using magnetic resonance imaging and voxel-based morphometry. In addition, we explored associations between substance intake, gray matter volume, and working memory task performance. Patients on OMT committed more errors during the working memory task than healthy individuals and showed smaller insula and putamen GMV. The duration of heroin use prior to OMT was associated with working memory performance and insula GMV in patients. Neither the substitution agent (methadone and buprenorphine) nor concurrent abuse of illegal substances during the 3 months prior to the experiment was significantly associated with GMV. Results indicate that impaired working memory performance and structural deficits in the insula of opioid-dependent patients are related to the duration of heroin use. This suggests that early inclusion into OMT or abstinence-oriented therapies that shorten the period of heroin abuse may limit the impairments to GMV and cognitive performance of opioid-dependent individuals.

Baseline executive functions and receiving cognitive rehabilitation can predict treatment response in people with opioid use disorder

BACKGROUND

Impaired cognitive functions, particularly executive function, predicts poor treatment success in people with substance use disorders. The current study investigated the effect of receiving adjunct cognitive rehabilitation and baseline executive function (EF) measures on treatment response among people with opioid use disorder (OUD).

METHOD

The analysis sample consisted of 113 participants with OUD who were discharged from a compulsory court-mandated methadone maintenance treatment (MMT) and followed for 3 months. We used the Backward digit span/Auditory verbal learning, Stroop, and Trail making tests to assess the three measures of EF, including working memory, inhibition, and shifting, respectively. Treatment response was operationalized as (1) treatment retention and (2) the number of positive urine tests for morphine during 3-month follow-up periods. The study used Cox's proportional hazards model and linear mixed model to identify predictive factors.

RESULTS

Lower Stroop interference scores predicted increased length of stay in treatment (χ² = 33.15, P < 0.001). The linear mixed model showed that scores on auditory verbal learning test and group intervention predicted the number of positive urine tests during a 3-month follow-up.

CONCLUSION

Working memory and inhibitory control, as well as receiving cognitive rehabilitation, could be potentially considered as predictors of treatment response for newly MMT admitted patients with OUD. Assessment of EF before treatment initiation may inform treatment providers about patient's cognitive deficits that may interfere with therapeutic interventions.

Effects of extended abstinence on cognitive functions in tramadol-dependent patients: A cohort study

BACKGROUND

Some pieces of the literature report impaired cognitive functioning in tramadol dependence. Whether extended abstinence improves cognitive functioning or not is not well studied.

AIM

We aimed to measure the change in cognitive functioning following complete abstinence among individuals with tramadol dependence.

METHODS

Eighty-three male tramadol-dependent (TD) and 57 matched healthy controls participated in this study. Cognitive functions were assessed using: The Trail making test (TMT), Wechsler Memory Scale-Revised (WMS-R), and Wechsler Adult Intelligence Scale (WAIS). Patients were assessed in the first week immediately after the end of the in-patient treatment program (T1), and after six months of sustained abstinence (T2).

RESULTS

At T1, the TD group showed deficits on all tested cognitive parameters (visual attention, task switching, working memory, visual memory, verbal memory, verbal knowledge, Verbal IQ, Performance IQ, and Full-Scale IQ) in comparison to the control group. At T2, significant improvements had occurred in all the tested parameters except performance IQ. The cognitive performance of the abstinent individuals at T2 was comparable to the control group for the verbal subsets of WMS-R, Verbal IQ, Performance IQ, and Full-Scale IQ. Nevertheless, it was still worse than the control group in TMT, and all other WMS subsets.

CONCLUSION

tramadol dependence has negative effects on cognitive performance, which improves with extended abstinence.

Improvement in Cognitive Performance after One Year of Methadone Maintenance Treatment

Individuals with substance use disorders are known to suffer from stress, poor sleep, and cognitive impairment. We investigated whether individuals with opioid use disorder would improve cognitive performance following a year of methadone maintenance treatment (MMT). Perceived Stress Scale (PSS), the Pittsburgh Sleep Quality Index (PSQI), and a standardized computerized cognitive battery were administered at admission (T0) to 29 patients, and repeatedly following one year of MMT (T1) by 19 patients. Admission measures did not differ between those who studied once or twice. Patients who perceived very high stress levels (PSS ≥24) at T0 (11, 37.9%) had lower computerized global cognitive scores (67.6±16.2 vs. 90.9±12.5 p≤0.0005). At T1, PSS and PSQI scores improved significantly among 11 patients with no substance abuse, but worsened among 8 with substance abuse (PSS p(interaction)=0.009, p(groups)=0.005, PSQI p(interaction)=0.01, p(groups)=0.04). Global cognitive score improved at T1 for the entire sample (81.8±20.1 to 89.2±13.8, p=0.05). Differentiation by high stress at T0 or by substance abuse at T1 subgroups showed that improvement was observed by those with very low cognitive scores at T0. Patients with poor cognition may improve following one year of MMT, due to stress and substance abuse reduction. Interventions for stress reduction are recommended.

Cognitive profiles in persons with opioid use disorder enrolled in methadone treatment

Cognitive impairment is common in persons with opioid use disorder and associated with poor treatment outcomes, including elevated risk for relapse. Much less is known about the underlying structure of these deficits and the possible presence of cognitive phenotypes. A total of 177 adults (average 42.2 years of age, 52.0% male, 65.5% Caucasian) enrolled in a methadone maintenance treatment program completed the NIH Toolbox as part of a larger project. Cluster analyses revealed a 2-cluster solution-persons with intact cognitive function in all domains (n = 93; Intact) and those with impairments on tests of attention and executive function (n = 83; Impaired). Follow-up analyses revealed that the Impaired group was slightly older, more likely to self-identify as a racial/ethnic minority, and less likely to report consuming alcohol four or more times per week. These findings suggest the existence of distinct cognitive profiles in persons with opioid use disorder and encourage further examination, particularly studies to examine the possible benefits of routine screening for cognitive impairment as part of substance use treatment.

Altering Opioid Neuromodulation in the Songbird Basal Ganglia Modulates Vocalizations

Although the interplay between endogenous opioids and dopamine (DA) in the basal ganglia (BG) is known to underlie diverse motor functions, few studies exist on their role in modulating speech and vocalization. Vocal impairment is a common symptom of Parkinson’s disease (PD), wherein DA depletion affects striosomes rich in μ-opioid receptors (μ-ORs). Symptoms of opioid addiction also include deficiencies in verbal functions and speech. To understand the interplay between the opioid system and BG in vocalization, we used adult male songbirds wherein high levels of μ-ORs are expressed in Area X, a BG region which is part of a circuit similar to the mammalian thalamocortical-basal ganglia loop. Changes in DA, glutamate and GABA levels were analyzed during the infusion of different doses of the μ-OR antagonist naloxone (50 and 100 ng/ml) specifically in Area X. Blocking μ-ORs in Area X with 100 ng/ml naloxone led to increased levels of DA in this region without altering the number of songs directed toward females (FD). Interestingly, this manipulation also led to changes in the spectro-temporal properties of FD songs, suggesting that altered opioid modulation in the thalamocortical-basal ganglia circuit can affect vocalization. Our study suggests that songbirds are excellent model systems to explore how the interplay between μ-ORs and DA modulation in the BG affects speech/vocalization.

Intact responses to non-drug rewards in long-term opioid maintenance treatment

Disruption of non-drug reward processing in addiction could stem from long-term drug use, addiction-related psychosocial stress, or a combination of these. It remains unclear whether long-term opioid maintenance treatment (OMT) disrupts reward processing. Here, we measured subjective and objective reward responsiveness in 26 previously heroin-addicted mothers in >7 years stable OMT with minimal psychosocial stress and illicit drug use. The comparison group was 30 healthy age-matched mothers (COMP). Objective reward responsiveness was assessed in a two-alternative forced-choice task with skewed rewards. Results were also compared to performance from an additional 968 healthy volunteers (meta-analytic approach). We further compared subprocesses of reward-based decisions across groups using computational modelling with a Bayesian drift diffusion model of decision making. Self-reported responsiveness to non-drug rewards was high for both groups (means: OMT = 6.59, COMP = 6.67, p = 0.84, BF10 = 0.29), yielding moderate evidence against subjective anhedonia in this OMT group. Importantly, the mothers in OMT also displayed robust reward responsiveness in the behavioral task (t19 = 2.72, p = 0.013, BF10 = 3.98; d = 0.61). Monetary reward changed their task behavior to the same extent as the local comparison group (reward bias OMT = 0.12, COMP = 0.12, p = 0.96, BF10 = 0.18) and in line with data from 968 healthy controls previously tested. Computational modelling revealed that long-term OMT did not even change decision subprocesses underpinning reward behavior. We conclude that reduced sensitivity to rewards and anhedonia are not necessary consequences of prolonged opioid use.

Profiles of visuospatial memory dysfunction in opioid-exposed and dependent populations

BACKGROUND

Chronic opioid exposure is common world-wide, but behavioural performance remains under-investigated. This study aimed to investigate visuospatial memory performance in opioid-exposed and dependent clinical populations and its associations with measures of intelligence and cognitive impulsivity.

METHODS

We recruited 109 participants: (i) patients with a history of opioid dependence due to chronic heroin use (n = 24), (ii) heroin users stabilised on methadone maintenance treatment (n = 29), (iii) participants with a history of chronic pain and prescribed tramadol and codeine (n = 28) and (iv) healthy controls (n = 28). The neuropsychological tasks from the Cambridge Neuropsychological Test Automated Battery included the Delayed Matching to Sample (DMS), Pattern Recognition Memory, Spatial Recognition Memory, Paired Associate Learning, Spatial Span Task, Spatial Working Memory and Cambridge Gambling Task. Pre-morbid general intelligence was assessed using the National Adult Reading Test.

RESULTS

As hypothesised, this study identified the differential effects of chronic heroin and methadone exposures on neuropsychological measures of visuospatial memory (p &lt; 0.01) that were independent of injecting behaviour and dependence status. The study also identified an improvement in DMS performance (specifically at longer delays) when the methadone group was compared with the heroin group and also when the heroin group was stabilised onto methadone. Results identified differential effects of chronic heroin and methadone exposures on various neuropsychological measures of visuospatial memory independently from addiction severity measures, such as injecting behaviour and dependence status.

Interrelationship of Opioid Dependence, Impaired Impulse Control, and Depressive Symptoms: An Open-Label Cross-Sectional Study of Patients in Maintenance Therapy

OBJECTIVE

A growing number of studies indicate increased impulsivity in patients with opioid dependence (OD). However, few studies exclude concomitant drug use and consider depression as a comorbidity, both of which can bias results.

AIM

We aimed to compare impulsivity in patients with OD enrolled in maintenance therapy (ICD code F11.22) and well-matched healthy controls taking psychopathological impairments into account. Furthermore, we compared the result to risky behavioral patterns in patients.

METHODS

This cross-sectional study included 50 patients with OD enrolled in either methadone or buprenorphine maintenance therapy and 50 healthy controls matched for gender, age, education, marital status, and premorbid intelligence. Abstinence from benzodiazepines, amphetamines, and cocaine was verified by urine analysis. We used the Barratt Impulsiveness Scale 11 (BIS-11), Beck's Depression Inventory (BDI), the Symptom Checklist 90 Revised (SCL-90R), and the European version of the Addiction Severity Index (EuropASI).

RESULTS

Patients exhibited significantly worse impulse control than healthy individuals. We found no correlation between impulsiveness and reported risky behavior patterns but found a significant correlation between depressive symptoms and psychopathological impairment.

CONCLUSIONS

Patients with OD showed a higher impulsivity than healthy individuals. Impulsivity could be a cause or a consequence of a substance use disorder; further research is warranted to explain this relationship. Impulsivity was associated with depression, an important confounder; future research needs to take this into account.

Cognitive function is largely intact in methadone maintenance treatment patients

OBJECTIVES

To confirm our previous findings of less cognitive impairments (based on cognitive screening tools) among methadone maintenance treatment (MMT) patients who achieved take-home dose (THD) privileges.

METHODS

a random sample of 65 Israeli MMT patients were studied using computerised, age and education standardised, cognitive domains (attention, executive function, memory, motor skills), and non-computerised phonetic and semantic verbal fluency.

RESULTS

Cognitive scores were within ±1 standard deviation (SD) of average for most domains, including non-verbal IQ, attention and motor skills. Verbal fluency and memory were >1 SD below average (mean = 84; z = -1.1 for both). Females were younger than the males and had poorer motor skills (P = 0.005) but better verbal memory (P < 0.0005). Opiate usage duration correlated with reaction time (P = 0.05) and inversely with verbal memory (P = 0.01). Overall cognitive function was poorest among 25 (38.5%) current drug users, and 6 (9.2%) lifetime schizophrenia patients. Cognitive domains were comparable between THD privileges subgroups.

CONCLUSIONS

Despite heterogeneity in MMT duration, abuse duration, substance use and psychiatric comorbidity, all performed within ±1 SD of average for age and education in most cognitive domains. Our findings challenge the notion of MMT as being synonymous with compromised cognition and may lead to reduced bias regarding cognitive function of MMT patients.

Neuropsychological changes in patients with substance use disorder after completion of a one month intensive outpatient treatment program

BACKGROUND AND OBJECTIVES

Data suggest individuals with substance use disorders (SUD) exhibit high rates of executive functioning (EF) impairment, and that EF level can predict treatment retention. The primary aim of the present study was to investigate if patients who completed a 1 month intensive outpatient program (IOP) for SUD demonstrated recovered EF.

METHODS

Baseline and follow-up neurocognitive functioning was assessed by the Cambridge Neuropsychological Test Automated Battery (CANTAB) and the self-reported Behavior Rating Inventory of Executive Functioning (BRIEF-A) questionnaire.

RESULTS

The final sample included 15 patients who completed the one month IOP and for whom data were available (53% male, aged 36 years ± 13.4). Despite exhibiting general improvements in EF and significant improvements in organization, subjects continued to manifest significant executive dysfunction as evaluated by self-report and computerized assessment.

CONCLUSIONS AND SCIENTIFIC SIGNIFICANCE

Patients with SUD often manifest high levels of executive dysfunction upon entry into SUD treatment that, while improving minimally, appears to persist despite intensive outpatient treatment at 1 month. These persistent EF deficits may affect patient engagement and participation in treatment, thus necessitating SUD programs to assess and accommodate EF issues throughout treatment. (Am J Addict 2018;XX:1-7).

Acute effects of methadone on EEG power spectrum and event-related potentials among heroin dependents

Methadone as the most prevalent opioid substitution medication has been shown to influence the neurophysiological functions among heroin addicts. However, there is no firm conclusion on acute neuroelectrophysiological changes among methadone-treated subjects as well as the effectiveness of methadone in restoring brain electrical abnormalities among heroin addicts. This study aims to investigate the acute and short-term effects of methadone administration on the brain's electrophysiological properties before and after daily methadone intake over 10 weeks of treatment among heroin addicts. EEG spectral analysis and single-trial event-related potential (ERP) measurements were used to investigate possible alterations in the brain's electrical activities, as well as the cognitive attributes associated with MMN and P3. The results confirmed abnormal brain activities predominantly in the beta band and diminished information processing ability including lower amplitude and prolonged latency of cognitive responses among heroin addicts compared to healthy controls. In addition, the alteration of EEG activities in the frontal and central regions was found to be associated with the withdrawal symptoms of drug users. Certain brain regions were found to be influenced significantly by methadone intake; acute effects of methadone induction appeared to be associative to its dosage. The findings suggest that methadone administration affects cognitive performance and activates the cortical neuronal networks, resulting in cognitive responses enhancement which may be influential in reorganizing cognitive dysfunctions among heroin addicts. This study also supports the notion that the brain's oscillation powers and ERPs can be utilized as neurophysiological indices for assessing the addiction treatment traits.

Neuropsychological functioning in opioid use disorder: A research synthesis and meta-analysis

BACKGROUND

Research has demonstrated that patients with opioid use disorders (OUD; including both opioid abuse and/or dependence) have poorer neuropsychological functioning compared to healthy controls; however, the pattern and robustness of the findings remain unknown.

OBJECTIVES

This study meta-analyzed the results from previous research examining the neuropsychological deficits associated with opioids across 14 neurocognitive domains.

METHOD

Articles comparing patients with OUD to healthy controls were selected based on detailed inclusion/exclusion criteria and variables of interest were coded. In total, 61 studies were selected for the analyses. These consisted of 2580 patients with OUD and 2102 healthy control participants (15.9% female). Drug-related variables were analyzed as potential moderators.

RESULTS

The largest effect size difference in neuropsychological performance was observed in complex psychomotor ability. With the exception of the motor and processing speed domains, which showed no group differences, small-to-medium effect sizes were associated with all neurocognitive domains examined. Meta-regression revealed that increases in the length of abstinence were associated with decreases in effect sizes of the complex psychomotor domain. Additionally, attentional ability predicted effect size differences in executive functioning as well as verbal memory ability. Although the majority of meta-analyzed studies demonstrated significant differences between patients with OUD and controls, the average raw scores for patients with OUD in these studies typically fell within the normal range.

CONCLUSION

The pattern of neuropsychological performance among patients with OUD appears to reflect mild generalized cognitive dysfunction, with a large effect in complex psychomotor abilities.

Correlation of cytokines, BDNF levels, and memory function in patients with opioid use disorder undergoing methadone maintenance treatment

BACKGROUND

Patients with opioid use disorder (OUD) show memory deficiencies and impaired treatment outcomes. Emerging evidence suggests that opioid abuse activates proinflammatory processes by increasing cytokine production and impairing neuroprotection, which damages the memory function in OUD patients. Therefore, we investigated whether plasma-based inflammatory and neurotrophic markers correlate with memory function in OUD patients.

METHOD

OUD patients undergoing methadone maintenance therapy (MMT) were investigated and followed up for 12 weeks. Plasma tumor necrosis factor (TNF)-α, C-reactive protein (CRP), interleukin (IL)-6, transforming growth factor (TGF)-β1, brain-derived neurotrophic factor (BDNF) levels, and Wechsler Memory Scale-Revised (WMS-R) scores were assessed at baseline and after 12 weeks of MMT. Multiple linear regressions and generalized estimating equations (GEEs) were used to examine the correlation between cytokines and memory performance.

RESULTS

We enrolled 89 patients at baseline; 47 patients completed the end-of-study assessments. Although Pearson correlations showed that CRP and TGF-β1 levels were significantly, negatively associated with some memory indices, the results were not significant after correction. The GEE results, controlled for several confounding factors and multiple testing, showed that changes in TNF-α levels were negatively correlated with changes in the visual memory index (P = 0.01), and that changes in IL-6 levels were negatively correlated with changes in the verbal memory index (P = 0.009).

CONCLUSION

Memory performance, TNF-α, and IL-6 levels in OUD patients were negative correlated. Additional studies on regulating TNF-α and IL-6 expression to improve memory function in OUD patients might be warranted.

Delay-Dependent Impairments in Memory and Motor Functions After Acute Methadone Overdose in Rats

Methadone is used as a substitution drug for the treatment of opioid dependence and chronic pain. Despite its widespread use and availability, there is a serious concern with respect to the relative safety of methadone. The purpose of this study was to characterize how acute methadone overdose affects the cognitive and motor performance of naïve healthy rats. The methadone overdose was induced by administering an acute toxic dose of methadone (15 mg/kg; ip; the equivalent dose of 80% of LD50) to adolescent rats. Resuscitation using a ventilator pump along with a single dose of naloxone (2 mg/kg; ip) was administered following the occurrence of apnea. The animals which were successfully resuscitated divided randomly into three apnea groups that evaluated either on day 1, 5, or 10 post-resuscitation (M/N-Day 1, M/N-Day 5, and M/N-Day 10 groups) in the Y-maze and novel object memory recognition tasks as well as pole and rotarod tests. The data revealed that a single toxic dose of methadone had an adverse effect on spontaneous behavior. In addition, Recognition memory impairment was observed in the M/N-Day 1, 5, and 10 groups after methadone-induced apnea. Further, descending time in the M/N-Day 5 group increased significantly in comparison with its respective Saline control group. The overall results indicate that acute methadone-overdose-induced apnea produced delay-dependent cognitive and motor impairment. We suggest that methadone poisoning should be considered as a possible cause of delayed neurological disorders, which might be transient, in some types of memory or motor performance in naïve healthy rats.

A comparative study of the effectiveness of group-based cognitive behavioral therapy and dialectical behavioral therapy in reducing depressive symptoms in Iranian women substance abusers

Various therapeutic approaches have been used to improve depressive symptoms in substance abusers. In a quasi-experimental study with a pretest-posttest design and experimental and control groups, we examined and compared the effectiveness of two group-based treatment strategies-cognitive behavioral therapy (CBT) and dialectical behavioral therapy (DBT)-in reducing depressive symptoms among Iranian women substance abusers. The statistical population included all female addict patients who referred to addiction treatment centers of Birjand city in 2015. A sample of 30 subjects were selected through the available sampling method and randomly assigned into experimental (CBT and DBT) and control groups (each group, 10 patients). The data collection instrument was the Beck Depression Inventory (BDI) questionnaire. The patients in the experimental groups were given skills in eight sessions of 90 min. The data were analyzed by the SPSS-19 software by using mean, standard deviation, and percentages at the descriptive level and analysis of covariance (ANCOVA) test at the inferential level. The comparison of the mean depression score before intervention in all the groups showed no significant difference. However, after intervention, the findings showed that both CBT and DBT interventions could reduce the mean scores of depression in women substance abusers, 17.5 ± 3.0 vs 29.3 ± 4.1 (F[1,17] = 51.91, p value < 0.01) and 14.7 ± 1.8 vs 29.3 ± 4.1 (F[1,17] = 106.62, p value < 0.01), respectively, for CBT and DBT. Post-treatment effect sizes were large and did not differ statistically for CBT (ηp2, 0.75) and DBT (ηp2, 0.86). Therefore, this study highlights the importance of CBT and DBT skills training to substance abusers and provides initial evidence of their effectiveness.

Cognitive effects of labeled addictolytic medications

INTRODUCTION

Alcohol, tobacco, and illegal drug usage is pervasive throughout the world, and abuse of these substances is a major contributor to the global disease burden. Many pharmacotherapies have been developed over the last 50years to target addictive disorders. While the efficacy of these pharmacotherapies is largely recognized, their cognitive impact is less known. However, all substance abuse disorders are known to promote cognitive disorders like executive dysfunction and memory impairment. These impairments are critical for the maintenance of addictive behaviors and impede cognitive behavioral therapies that are regularly administered in association with pharmacotherapies. It is also unknown if addictolytic medications have an impact on preexisting cognitive disorders, and if this impact is modulated by the indication of prescription, i.e. abstinence, reduction or substitution, or by the specific action of the medication.

METHOD

We reviewed the cognitive effects of labeled medications for tobacco addiction (varenicline, bupropion, nicotine patch and nicotine gums), alcohol addiction (naltrexone, nalmefene, baclofen, disulfiram, sodium oxybate, acamprosate), and opioid addiction (methadone, buprenorphine) in human studies. Studies were selected following MOOSE guidelines for systematic reviews of observational studies, using the keywords [Cognition] and [Cognitive disorders] and [treatment] for each medication.

RESULTS

971 articles were screened and 77 studies met the inclusion criteria and were reported in this review (for alcohol abuse, n=21, for tobacco n=22, for opioid n=34. However, very few comparative clinical trials have explored the chronic effects of addictolytic medications on cognition in addictive behaviors, and there are no clinical trials on the cognitive impact of nalmefene in patients suffering from alcohol use disorders.

DISCUSSION

Although some medications seem to enhance cognition in patients suffering from cognitive disorders, others could promote cognitive impairments, and our work highlights a lack of literature on this subject. In conclusion, more comparative clinical trials are needed to better understand the cognitive impact of addictolytic medications.

Cognitive rehabilitation for individuals with opioid use disorder: A randomized controlled trial. Neuropsychol Rehabil 2017;29:1273-1289. [PMID: 29161998 DOI: 10.1080/09602011.2017.1391103]

Aim: To examine the efficacy of cognitive rehabilitation treatment (CRT) for people with opioid use disorder who were recruited into a methadone maintenance treatment (MMT) programme. Method: 120 male subjects were randomly assigned to (1) MMT plus CRT in two months or (2) MMT plus a control intervention. Subjects were assessed at the beginning, mid-point and post-intervention as well as at 1-, 3- and 6-month follow-up time points. Results: Analysis with repeated measure ANOVA showed that the CRT group performed significantly better in tests of learning, switching, processing speed, working memory and memory span. Moreover, the CRT group had significantly lower opiate use over the control group during 3-months follow-up. Analysis including only those with a history of methamphetamine use showed that the CRT group had significantly lower amphetamine use. No group differences were observed for treatment retention. Conclusions: Our findings provide evidence that adding CRT as an adjunct intervention to MMT can improve cognitive performance as well as abstinence from both opiates and stimulants.

Neuroscience-informed psychoeducation for addiction medicine: A neurocognitive perspective

Psychoeducation (PE) is defined as an intervention with systematic, structured, and didactic knowledge transfer for an illness and its treatment, integrating emotional and motivational aspects to enable patients to cope with the illness and to improve its treatment adherence and efficacy. PE is considered an important component of treatment in both medical and psychiatric disorders, especially for mental health disorders associated with lack of insight, such as alcohol and substance use disorders (ASUDs). New advancements in neuroscience have shed light on how various aspects of ASUDs may relate to neural processes. However, the actual impact of neuroscience in the real-life clinical practice of addiction medicine is minimal. In this chapter, we provide a perspective on how PE in addiction medicine can be informed by neuroscience in two dimensions: content (knowledge we transfer in PE) and structure (methods we use to deliver PE). The content of conventional PE targets knowledge about etiology of illness, treatment process, adverse effects of prescribed medications, coping strategies, family education, and life skill training. Adding neuroscience evidence to the content of PE could be helpful in communicating not only the impact of drug use but also the beneficial impact of various treatments (i.e., on brain function), thus enhancing motivation for compliance and further destigmatizing their symptoms. PE can also be optimized in its "structure" by implicitly and explicitly engaging different neurocognitive processes, including salience/attention, memory, and self-awareness. There are many interactions between these two dimensions, structure and content, in the delivery of neuroscience-informed psychoeducation (NIPE). We explore these interactions in the development of a cartoon-based NIPE to promote brain recovery during addiction treatment as a part of the brain awareness for addiction recovery initiative.

An Update of the Review of Neuropsychological Consequences of HIV and Substance Abuse: A Literature Review and Implications for Treatment and Future Research

Neuropyschological dysfunction, ranging from mild cerebral indicators to dementia has been a consistent part of the medical picture of HIV/AIDS. However, advances in medical supervision, particularly as a result of antiretroviral (ARV) treatment, have resulted in some mitigation of the neuropsychological effects of HIV and necessitate re-evaluation of the pattern and nature of HIV-related cognitive or mental deficits. The associated enhancements in morbidity and mortality that have occurred as a result of ARV medication have led to a need for interventions and programs that maintain behaviors that are healthy and stop the resurgence of the risk of HIV transmission. Risk factors such as mental illness and substance use that may have contributed to the initial infection with HIV still need consideration. These risk factors may also increase neuropsychological dysfunction and impact observance of prevention for treatment and recommendations. Explicitly, a better comprehension of the role of substance use on the progression of HIV-related mental decline can enlighten management and evaluation of persons living with HIV with concurrent disorders of substance use. This review provides a summary of the neurophyschology of substance use and HIV and the existing research that has looked at the effects of both substance use and HIV disease on neurophyscological function and suggestions for future research and treatment.

Visual and verbal learning deficits in Veterans with alcohol and substance use disorders

BACKGROUND

This study examined visual and verbal learning in the early phase of recovery for 48 Veterans with alcohol use (AUD) and substance use disorders (SUD, primarily cocaine and opiate abusers). Previous studies have demonstrated visual and verbal learning deficits in AUD, however little is known about the differences between AUD and SUD on these domains. Since the DSM-5 specifically identifies problems with learning in AUD and not in SUD, and problems with visual and verbal learning have been more prevalent in the literature for AUD than SUD, we predicted that people with AUD would be more impaired on measures of visual and verbal learning than people with SUD.

METHODS

Participants were enrolled in a comprehensive rehabilitation program and were assessed within the first 5 weeks of abstinence. Verbal learning was measured using the Hopkins Verbal Learning Test (HVLT) and visual learning was assessed using the Brief Visuospatial Memory Test (BVMT).

RESULTS

Results indicated significantly greater decline in verbal learning on the HVLT across the three learning trials for AUD participants but not for SUD participants (F=4.653, df=48, p=0.036). Visual learning was less impaired than verbal learning across learning trials for both diagnostic groups (F=0.197, df=48, p=0.674); there was no significant difference between groups on visual learning (F=0.401, df=14, p=0.538).

DISCUSSION

Older Veterans in the early phase of recovery from AUD may have difficulty learning new verbal information. Deficits in verbal learning may reduce the effectiveness of verbally-based interventions such as psycho-education.

Resting EEG and ERPs findings in methadone-substituted opiate users: a review

Methadone has been used to treat opiate dependence since the mid-1960s. Despite its clinical effectiveness there is evidence from neuropsychological studies demonstrating that its long-term use might have negative effects on cognition. Nevertheless, it remains uncertain whether the observed cognitive impairments in patients undertaking methadone maintenance treatment (MMT) are solely attributable to the pharmacological effects of methadone, as suggested by some researchers. Determining the effects of MMT on neuropsychological function using electroencephalography (EEG) combined with event-related potentials (ERP) has been used infrequently. However EEG and ERP provide a means of closely examining information processing to determine whether MMT induces any deficits. The purpose of this review was to investigate whether psychophysiological evidence supports cognitive impairment in association with MMT by focusing on research using EEG and ERPs. The findings of EEG studies to date appear not support the notion that cognitive impairments are attributable to the specific pharmacological effects of methadone suggested by some neuropsychological studies. However, due to the methodological deficits and limited number of the studies, any conclusion based on the findings of the existing EEG studies should be avoided.

A randomized controlled trial of the effects of working memory training in methadone maintenance patients

OBJECTIVE

Working memory impairment in individuals with chronic opioid dependence can play a major role in cognitive and treatment outcomes. Cognitive training targeting working memory shows promise for improved function in substance use disorders. To date, cognitive training has not been incorporated as an adjunctive treatment for opioid dependence.

METHODS

Methadone maintenance patients were randomly assigned to experimental (n=28) or active control (n=28) 25-session computerized training and run in parallel. Cognitive and drug use outcomes were assessed before and after training.

RESULTS

Participants in the experimental condition showed performance improvements on two of four working memory measures, and both groups improved on a third measure of working memory performance. Less frequent drug use was found in the experimental group than in the control group post-training. In contrast to previous findings with stimulant users, no significant effect of working memory training on delay discounting was found using either hypothetical or real rewards. There were no group differences on working memory outcome measures that were dissimilar from the training tasks, suggesting that another mechanism (e.g., increased distress tolerance) may have driven drug use results.

CONCLUSIONS

Working memory training improves performance on some measures of working memory in methadone maintenance patients, and may impact drug use outcomes. Working memory training shows promise in patients with substance use disorders; however, further research is needed to understand the mechanisms through which performance is improved and drug use outcomes are impacted.

NEuro COgnitive REhabilitation for Disease of Addiction (NECOREDA) Program: From Development to Trial

Despite extensive evidence for cognitive deficits associated with drug use and multiple publications supporting the efficacy of cognitive rehabilitation treatment (CRT) services for drug addictions, there are a few well-structured tools and organized programs to improve cognitive abilities in substance users. Most published studies on cognitive rehabilitation for drug dependent patients used rehabilitation tools, which have been previously designed for other types of brain injuries such as schizophrenia or traumatic brain injuries and not specifically designed for drug dependent patients. These studies also suffer from small sample size, lack of follow-up period assessments and or comprehensive treatment outcome measures. To address these limitations, we decided to develop and investigate the efficacy of a paper and pencil cognitive rehabilitation package called NECOREDA (Neurocognitive Rehabilitation for Disease of Addiction) to improve neurocognitive deficits associated with drug dependence particularly caused by stimulants (e.g. amphetamine type stimulants and cocaine) and opiates. To evaluate the feasibility of NECOREDA program, we conducted a pilot study with 10 opiate and methamphetamine dependent patients for 3 months in outpatient setting. NECOREDA was revised based on qualitative comments received from clients and treatment providers. Final version of NECOREDA is composed of brain training exercises called "Brain Gym" and psychoeducational modules called "Brain Treasures" which is implemented in 16 training sessions interleaved with 16 review and practice sessions. NECOREDA will be evaluated as an add-on intervention to methadone maintenance treatment in a randomized clinical trial among opiate dependent patients starting from August 2015. We discuss methodological features of NECOREDA development and evaluation in this article.

Auditory event-related potentials in methadone substituted opiate users

The effects of methadone maintenance treatment (MMT) on neurophysiological function are unclear. Using an auditory oddball paradigm, event-related potential (ERP) amplitudes and latencies were measured in 32 patients undertaking MMT, 17 opiate users who were addicted but not receiving substitution treatment and 25 healthy control subjects. Compared with healthy control subjects, the MMT and opiate user groups showed an increased P200 amplitude in response to target stimuli. The opiate user group also exhibited a decreased amplitude and an increased latency of N200, and a greater number of task-related errors than either healthy control subjects or patients undertaking MMT. There were no significant group differences in the P300 amplitude. However, it is noteworthy that the frontal P300 amplitude of the MMT group was greater than that of opiate users or healthy controls. Our findings suggest that altered sensory information processing associated with a history of opiate use remains in patients undertaking MMT. However, there are less marked ERP abnormalities in those receiving MMT than in active opiate users. The deficits in information processing associated with illicit opiate use are likely to be reduced during MMT.

Low-dose add-on memantine treatment may improve cognitive performance and self-reported health conditions in opioid-dependent patients undergoing methadone-maintenance-therapy

An important interaction between opioid and dopamine systems has been indicated, and using opioids may negatively affect cognitive functioning. Memantine, a medication for Alzheimer's disease, increasingly is being used for several disorders and maybe important for cognitive improvement. Opioid-dependent patients undergoing methadone-maintenance-therapy (MMT) and healthy controls (HCs) were recruited. Patients randomly assigned to the experimental (5 mg/day memantine (MMT+M) or placebo (MMT+P) group: 57 in MMT+M, 77 in MMT+P. Those completed the cognitive tasks at the baseline and after the 12-week treatment were analyzed. Thirty-seven age- and gender-matched HCs, and 42 MMT+P and 39 MMT+M patients were compared. The dropout rates were 49.4% in the MMT+P and 26.3% in the MMT+M. Both patient groups' cognitive performances were significantly worse than that of the HCs. After the treatment, both patient groups showed improved cognitive performance. We also found an interaction between the patient groups and time which indicated that the MMT+M group's post-treatment improvement was better than that of the MMT+P group. Memantine, previously reported as neuroprotective may attenuate chronic opioid-dependence-induced cognitive decline. Using such low dose of memantine as adjuvant treatment for improving cognitive performance in opioid dependents; the dose of memantine might be a worthy topic in future studies.

Methadone use in a male with the FMRI premutation and FXTAS

The fragile X-associated tremor ataxia syndrome (FXTAS) is caused by the premutation in FMR1 gene. Recent reports of environmental toxins appear to worsen the progression of FXTAS. Here we present a case of male adult with FXTAS and a long history of methadone use. The patient shows a faster progression in both symptoms of disease and MRI changes compared to what is typically seen in FXTAS. There has been no research regarding the role of narcotics in onset, progression, and severity of FXTAS symptoms. However, research has shown that narcotics can have a negative impact on several neurodegenerative diseases, and we hypothesize that in this particular case, methadone may have contributed to a faster progression of FXTAS as well as exacerbating white matter disease through RNA toxicity seen in premutation carriers.

Assessment of Cognitive Functions in Methadone Maintenance Patients

BACKGROUND

Methadone maintenance has received little scientific attention regarding neurocognitive effects. This study is aimed to assess the neuropsychological performance of methadone maintenance patients (MMP) compared to those healthy controls.

METHODS

Thirty-five MMP and 35 healthy controls, matched for age, gender, education and employment status, examined on a battery of tests aimed at assessing verbal fluency, executive functions, verbal memory, and working memory, using controlled oral word association test (COWAT), trial making test (TMT) Part A and B, Rey auditory verbal learning test (RAVLT), and backward digit span.

FINDINGS

MMP performed significantly poorly than controls in cognitive domains of verbal fluency, executive function, and verbal memory. MMP did not exhibit impairment in working memory, and TMT Part A compared to controls.

CONCLUSION

These results suggest that methadone consumption induces significant cognitive impairment that could compromise drug-treatment outcomes in MMP.

Stroop task among patients with obsessive-compulsive disorder (OCD) and pathological gambling (PG) in methadone maintenance treatment (MMT)

OBJECTIVES

To evaluate the impaired attention selection (Stroop interference effect) and general performance [reaction times (RTs)] on the Stroop task among methadone maintenance treatment (MMT) patients with obsessive compulsive disorder (OCD), pathological gambling (PG), both PG/OCD or none, and the influence if having ADHD.

METHODS

Eighty-six patients and 15 control subjects underwent the Stroop task, which measured RTs of condition-related words (color, obsessive compulsive disorder, pathological gambling, addiction) and neutral words.

RESULTS

MMT patients had longer RTs on the Stroop task compared with controls. RTs were longer among patients with OCD and in those who abused drugs on the study day. The combined PG/OCD group had the longest RTs, but they were also characterized as abusing more drugs, being older, and having worse cognitive status. Stroop color interference differed only among MMT patients with ADHD, and it was higher among those with OCD than those without OCD. The modified condition-related Stroop did not show any interference effect of OCD, addiction, or gambling words.

CONCLUSIONS

MMT patients had generally poorer performance, as indicated by longer RTs, that were related to clinical OCD, drug abuse, poor cognitive state, and older age. Patients with both clinical OCD and ADHD had a higher Stroop interference effect, which is a reflection of an attention deficit. In order to improve clinical approach and treatment of MMT patients, OCD and ADHD should be evaluated (and treated as needed).

Research gaps on methadone harms and comparative harms: findings from a review of the evidence for an American Pain Society and College on Problems of Drug Dependence clinical practice guideline

Methadone-associated overdose deaths have dramatically increased. In order to inform an evidence-based clinical practice guideline to improve safety of methadone prescribing, the American Pain Society commissioned a systematic review on various aspects related to methadone safety. We searched Ovid MEDLINE, Cochrane Library, and PsycINFO databases through July 2012 to identify studies that addressed 1 or more of 17 Key Questions related to methadone safety; an update search was performed in 2014 for new studies related to methadone-related overdose and risks related to cardiac arrhythmias. A total of 168 studies met inclusion criteria for the review. The purpose of this article is to highlight critical research gaps in the literature related to methadone safety. These include lack of evidence on risk factors associated with methadone-overdose deaths and adverse events, limited evidence to evaluate the comparative mortality of methadone versus other opioids, insufficient evidence to fully understand the harms associated with methadone use during pregnancy, and insufficient evidence to determine effects of risk mitigation strategies such as electrocardiogram monitoring, strategies for managing patients with prolonged QTc intervals on screening, urine drug testing, alternative dosing regimens for initiation and titration of therapy, and timing of follow-up. Therefore, most guideline recommendations are based on weak evidence. More research is needed to guide safe methadone prescribing practices and decrease the adverse events associated with methadone.

PERSPECTIVE

This article summarizes critical research gaps in the literature related to methadone safety, based on a systematic review commissioned by the American Pain Society. Critical research gaps were identified in a number of areas, highlighting the need for additional research to guide safer prescribing and risk mitigation strategies.

Changes in resting EEG following methadone treatment in opiate addicts

OBJECTIVE

This study investigated the electrophysiological activity associated with methadone maintenance treatment (MMT).

METHODS

The resting EEG spectrum of beta (14.5-30 Hz), alpha (8-13 Hz), theta (4-7.5 Hz) and delta (1.5-3.5 Hz) rhythm were measured in 32 patients undertaking chronic MMT, 17 opiate users and 25 healthy volunteers. Differences in the EEG components of each group were evaluated using a repeated measures Analyses of Variance (ANOVA). Post-hoc comparisons were Bonferroni corrected.

RESULTS

Our results show that either patients undertaking MMT or active opiate users exhibited a significant increase in the power of beta and theta bands relative to healthy control subjects. However, the spectral power of patients undertaking MMT fell between that of current opiate users and healthy control subjects on many regional EEG measures. There was an inverse correlation between the power of beta or theta bands and cognitive performance.

CONCLUSION

The abnormal neural electrical activity present in those still using illicit opiates might be reduced following MMT.

SIGNIFICANCE

The present findings provide further support for MMT of opiate dependence and demonstrates potentially positive effects of substitution treatment on brain function.

Neuropsychological performance of methadone-maintained opiate users

Methadone maintenance treatment (MMT) has been used to treat opiate dependence since the mid-1960s. Previous studies have investigated the effects of methadone on cognitive function however the findings have been inconsistent. Some report a complete absence of deficits while others report different types of cognitive impairment. Our research aimed to investigate the effects of MMT on cognitive function by comparing the performance of patients currently enrolled in MMT (n=32) with opiate-dependent subjects (n=17) and healthy control subjects (n=25) on a computerised neuropsychological test battery. Both the patients undertaking MMT and the opiate users showed less efficient interaction between visual searching and manually connecting digits and letters during the Switching of Attention Task than the healthy control subjects (F(2,64)=3.25, p=0.05), which indicates deficits in information processing. Nevertheless, the performance of the MMT group was similar to that of healthy control subjects in all other tasks, in contrast to the group of opiate users who performed poorly when compared to healthy control subjects during tests of attention (mean difference (MD)=2.8, 95% confidence interval (CI) (0.9-4.7), p=0.001) and executive function (MD=5.9, 95% CI (1.3-10.5), p=0.007). These findings suggest that cognitive function in patients undertaking MMT is improved compared to those dependent on illicit opiates.

Prospective memory impairment in long-term opiate users

RATIONALE

Opiate use is associated with a range of neurological and cognitive deficits. However, to date, no studies have assessed whether these cognitive deficits extend to the ability to perform intended actions in the future (i.e. prospective memory). Reduced ability in this area might be anticipated due to impaired executive functions and episodic memory associated with long-term opiate use.

OBJECTIVES

The main objectives of this study are to assess the performance of long-term opiate users on a laboratory measure of prospective memory which closely simulates the types of prospective memory tasks encountered in everyday life ('Virtual Week') and to investigate the extent to which prospective memory performance is related to executive functions and episodic memory ability.

METHODS

Twenty-six long-term heroin users enrolled in an opiate substitution program, and 30 controls with no previous history of drug use were tested on Virtual Week. Retrospective memory and executive functions were also assessed.

RESULTS

Long-term opiate users were significantly impaired on prospective memory performance compared with controls (p = 0.002, η(2) p = 0.17), and these deficits did not vary as a function of prospective memory task type (regular, irregular, event, time). The findings also suggest that retrospective memory difficulties contribute to the prospective memory difficulties seen in opiate users (r s  = 0.78, p < 0.001) but that executive dysfunction is less influential.

CONCLUSIONS

Prospective memory is sensitive to long-term opiate use. Importantly, opiate users suffer from generalised deficits in prospective memory, regardless of the task demands, which may have significant implications for day-to-day functioning. These results may therefore contribute to the development of clinical intervention strategies to reduce the negative impact of prospective memory failures in daily life.

Cognitive performance in methadone maintenance patients: effects of time relative to dosing and maintenance dose level

Given the long-term nature of methadone maintenance treatment, it is important to assess the extent of cognitive side effects. This study investigated cognitive and psychomotor performance in 51 methadone maintenance patients (MMP) as a function of time since last methadone dose and maintenance dose level. MMP maintained on doses ranging from 40 to 200 mg (mean = 97 mg) completed a battery of psychomotor and cognitive measures across 2 sessions, during peak and trough states, in a double-blind crossover design. Peak sessions were associated with worse performance on measures of sensory processing, psychomotor speed, divided attention, and working memory, compared with trough sessions. The effects of maintenance dose were mixed, with higher dose resulting in worse performance on aspects of attention and working memory, improved performance on executive function, and no effects on several measures. Longer treatment duration was associated with better performance on some measures, but was also associated with increased sensitivity to time since last dose (i.e., worse performance at peak vs. trough) on some measures. The results suggest that cognitive functioning can fluctuate as a function of time since last dose even in MMP who have been maintained on stable doses for an extended time (mean duration in treatment = 4 years), but worsened performance at peak is limited to a subset of functions and may not be clinically significant at these modest levels of behavioral effect. For patients on stable methadone maintenance doses, maintenance at higher doses may not significantly increase the risk of performance impairment.