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2010, Addictive Behaviors
Background-Methamphetamine (METH) is an increasing popular and highly addictive psychostimulant with a significant impact on public health. Chronic METH exposure has been associated with neurotoxic effects, profound neuropsychological deficits, and impaired quality of life, but few studies have examined the effect of the drug on the ability to carry out everyday activities. We assessed the effect of METH dependence on everyday functioning using the UCSD Performance-Based Skills Assessment (UPSA-2), a performance-based measure designed to evaluate real-life skills. Method-UPSA-2 performance was quantified in 15 currently abstinent individuals with a history of METH dependence and 15 drug-free comparison subjects. The Positive and Negative Syndrome Scale (PANSS) and Wisconsin Card Sorting Task (WCST) were administered to assess psychopathology and executive function. Results-METH-dependent participants exhibited significant impairment on the UPSA-2 total score and several UPSA-2 subscales, including comprehension, finance, transportation, communication, and medication management compared to drug-free comparison subjects. Lower UPSA-2 scores were associated with impaired performance on the WCST, higher PANSS scores, and drug use at an earlier age. dependence may be associated with decreased everyday functioning ability potentially mediated by frontal cortex dysfunction or the emergence of psychopathology related to chronic drug use.
Objective: The purpose of this work was to assess neu-ropsychological functioning of individuals in early abstinence from methamphetamine dependence and to test for cognitive change over the first month of abstinence. Method: Methamphetamine-dependent subjects in very early abstinence from methamphetamine (4-9 days; n = 27) were compared with healthy comparison subjects (n = 28) on a test battery that evaluated five cognitive domains (attention/processing speed, learning/memory, working memory, timed executive functioning, and untimed executive functioning). A subsample of the methamphetamine-dependent subjects (n =18), who maintained abstinence for 1 month, as well as a subsample of the comparison subjects (n = 21), were retested. Results: At the first assessment, the methamphetamine-dependent subjects showed significantly worse performance than the comparison group on a test of processing speed; they also performed 0.31 SDs worse than the control group on a global battery composite score (p < .05). After a month of abstinence, methamphetamine-dependent subjects demonstrated slightly more cognitive improvement than healthy control subjects on the entire cognitive battery, but this difference did not approach statistical significance (p = .33). Conclusions: Our findings suggest that methamphetamine-dependent subjects do not show considerable cogni-tive gains in the first month of abstinence. A greater length of abstinence may be needed for cognitive improvement. (J. Stud. Alcohol Drugs, 71,
Introduction: Several studies have conducted on impairments of executive functions in individuals with methamphetamine addiction; however, only a few have investigated the relationship between executive functions and duration of addiction or abstinence. This study was designed to assess the executive functions in methamphetamine-addicted individuals in relation to the duration of addiction or abstinence. Methods: A total of 161 subjects aged between 20 and 45 years were categorized into three subgroups: currently abusing (n=41), abstinent (n=60), and control healthy individuals (n=60). A battery of standardized executive function tasks, including Stroop test, Wisconsin Card Sorting test, and Tower of London task, were administered. Data were analyzed using Pearson correlation coefficient, analysis of variance, and post hoc Bonferroni test with SPSS16.0. Results: Methamphetamine-addicted and abstinent subjects performed worse than the controls. Methamphetamine-abstinent subjects performed better than the currently methamphetamine abusers in most executive functions. Duration of addiction and abstinence were correlated with executive dysfunctions. Conclusion: This study revealed that although executive functions may be improved by protracted abstinence, executive dysfunctions are not completely relieved, and specific attention to planning and implementation of intervention programs are necessary.
The prevailing view is that recreational methamphetamine use causes a broad range of severe cognitive deficits, despite the fact that concerns have been raised about interpretations drawn from the published literature. This article addresses an important gap in our knowledge by providing a critical review of findings from recent research investigating the impact of recreational methamphetamine use on human cognition. Included in the discussion are findings from studies that have assessed the acute and long-term effects of methamphetamine on several domains of cognition, including visuospatial perception, attention, inhibition, working memory, long-term memory, and learning. In addition, relevant neuroimaging data are reviewed in an effort to better understand neural mechanisms underlying methamphetamine-related effects on cognitive functioning. In general, the data on acute effects show that methamphetamine improves cognitive performance in selected domains, that is, visuospatial perception, attention, and inhibition. Regarding long-term effects on cognitive performance and brain-imaging measures, statistically significant differences between methamphetamine users and control participants have been observed on a minority of measures. More importantly, however, the clinical significance of these findings may be limited because cognitive functioning overwhelmingly falls within the normal range when compared against normative data. In spite of these observations, there seems to be a propensity to interpret any cognitive and/or brain difference(s) as a clinically significant abnormality. The implications of this situation are multiple, with consequences for scientific research, substance-abuse treatment, and public policy.
Drug and Alcohol Dependence, 2010
Mariana Cherner designed the study, including identifying the questions of interest, subject selection, and statistical analysis, and wrote the overall manuscript. Corinna Casey, conducted psychiatric and substance use interviews and analyzed data pertaining to these assessments. Robert Deiss provided a literature review for the discussion section. Paola Suarez, MA provided a literature review for the background section. Scott Letendre participated in the conceptual phase of the study, provided data regarding HIV and HCV infection status, and provided writing for the discussion section. Thomas Marcotte was instrumental in the design of the substance use history protocol employed in the study. Florin Vaida reviewed and commented on the study design and statistical analyses. J. Hampton Atkinson is a senior psychiatrist who conceptualized the neuropsychiatric and substance history protocols, as well as supervised the standardized training for collection of these data. He also provided substantive editing to the manuscript. Igor Grant is the Principal Investigator of the parent projects under which these data were collected. He conceptualized the overall scientific approach and hypotheses of interest from which the current analyses are derived. He also provided substantive editing to the manuscript. Robert K. Heaton is a senior neuropsychologist who designed the neuropsychological assessment battery and methods utilized in the current study. He worked closely with the first author to shape the analytic approach and contributed text to the discussion section.
Psychopharmacology, 2010
Background Methamphetamine (METH) is a widely abused psychostimulant that is associated with neurotoxicity and neurocognitive impairments in adults. However, the effects of METH use on neurocognitive performance of adolescents are unclear. Methods Fifty-four adolescent METH users and 74 agematched comparison subjects (ages 12 to 23 years) were evaluated with a battery of neuropsychological tests. The cognitive domains evaluated include psychomotor (Symbol Digit, Trail Making), executive function (Stroop Interference task, Wisconsin Card Sort task), fine-motor speed (Grooved Pegboard), memory (Digit span and Auditory Verbal Learning Task), as well as attention and working memory (California Computerized Assessment package). Results METH users were slower on the Stroop Interference task than the comparison subjects (F(1,114)=4.33, p= 0.03). METH subjects also performed worse than controls on the Wechsler Adult Intelligence Scale III/Wechsler Intelligence Scale for Children IV (WAIS/WISC) Matrices task (F(1,114)=4.37, p=0.04) and performed signif-icantly worse on the Peg Board task than the comparison subjects for both the dominant (F(1,114)=7.56, p=0.01) and non-dominant (F(1,114) = 6.75, p = 0.01). Lastly, length of abstinence was associated with improved performance on the Peg Board test with the dominant had (r=−0.34), as well as the WAIS/WISC Forward Digit Span task (r=0.38) Conclusions METH use is associated with impaired executive functions in adolescent users.
Drug and Alcohol Dependence, 2009
Although some individuals who abuse methamphetamine have considerable cognitive deficits, no prior studies have examined whether neurocognitive functioning is associated with outcome of treatment for methamphetamine dependence. In an outpatient clinical trial of bupropion combined with cognitive behavioral therapy and contingency management (Shoptaw et al., 2008), 60 methamphetamine-dependent adults completed three tests of reaction time and working memory at baseline. Other variables that were collected at baseline included measures of drug use, mood/ psychiatric functioning, employment, social context, legal status, and medical status. We evaluated the relative predictive value of all baseline measures for treatment outcome using Classification and Regression Trees (CART; Breiman, 1984), a nonparametric statistical technique that produces easily interpretable decision rules for classifying subjects that are particularly useful in clinical settings. Outcome measures were whether or not a participant completed the trial and whether or not most urine tests showed abstinence from methamphetamine abuse. Urine-verified methamphetamine abuse at the beginning of the study was the strongest predictor of treatment outcome; two psychosocial measures (e.g., nicotine dependence and Global Assessment of Functioning) also offered some predictive value. A few reaction time and working memory variables were related to treatment outcome, but these cognitive measures did not significantly aid prediction after adjusting for methamphetamine usage at the beginning of the study. On the basis of these findings, we recommend that research groups seeking to identify new predictors of treatment outcome compare the predictors to methamphetamine usage variables to assure that unique predictive power is attained.
Methamphetamine is a neurotoxic agent. Its chronic abuse may result in cognitive impair-ment with negative consequences for patientsreatment and rehabilitation. The aim of the study was to compare Continuous Performance Test (CPT) profiles of subjects dependent on methamphetamine with healthy individuals. Forty-five hospitalized patients including twenty-nine men at the average age of 25.3±5.4years dependent on methamphetamine for 6.0±3.3 years were assessed by the Continuous Performance Test. We used the same neurocognitive test for the comparison group of healthy controls (controls N=118, men N=50, average age of 28.1±7.2 years). We applied the Chi-Square Test, Two-Sample T Test, Mann-Whitney U Test and Kolmogorov-Smirnov Test to compare methamphetamine dependent patients with healthy volunteers. In the Continuous Performance Test, general T scores of commissions were significantly higher (p=0.02; Mann-Whitney U Test), but general T scores of hit reaction time (p<0.001; Mann-Wh...
Neuropsychopharmacology, 2018
Individuals with cognitive problems may be predisposed to develop substance use disorders; therefore, differences in cognitive function between methamphetamine users and control participants may be attributable to premorbid factors rather than methamphetamine use. The goal of this study was to clarify the extent to which this is the case. Childhood academic transcripts were obtained for 37 methamphetamine-dependent adults and 41 control participants of similar educational level and premorbid IQ. Each participant completed a comprehensive cognitive battery and received a structural magnetic resonance imaging scan. Data from control participants and linear regression were used to develop a normative model to describe the relationship between childhood academic performance and scores on the cognitive battery. Using this model, cognitive performance of methamphetamine users was predicted from their premorbid academic scores. Results indicated that methamphetamine users' childhood grade point average was significantly lower than that of the control group (p < 0.05). Further, methamphetamine users' overall cognitive performance was lower than was predicted from their grade point average prior to methamphetamine use (p = 0.001), with specific deficits in attention/concentration and memory (ps < 0.01). Memory deficits were associated with lower wholebrain cortical thickness (p < 0.05). Thus, in addition to having an apparent premorbid weakness in cognition, methamphetamine users exhibit subsequent cognitive function that is significantly lower than premorbid estimates would predict. The results support the view that chronic methamphetamine use causes a decline in cognition and/or a failure to develop normative cognitive abilities, although aside from methamphetamine use per se, other drug use and unidentified factors likely contribute to the observed effects.
Iranian Journal of Psychiatry, 2018
Objective: Attention-deficit hyperactivity disorder (ADHD) is common in adulthood, and it is associated with different high- risk behaviors, particularly substance use. Evidence suggests a high prevalence of ADHD in adults who take methamphetamine (METH). This study aimed at comparing functional level, quality of life, and psychiatric comorbidities in METH users with and without adult ADHD (A-ADHD). Method : In this cross-sectional study, 134 patients who had a history of METH use (at least once in lifetime) were selected from among inpatient and outpatient referrals to a psychiatric hospital. DIVA was performed for those who were positive on the Conners' Adult ADHD Rating Scales–Self-Report-Screening Version (CAARS-SR-SV). The Global Assessment of Functioning (GAF) and World Health Organization Quality of Life Scale-Brief (WHOQoL-BREF) were used to assess the participants’ level of functioning and quality of life, respectively. Psychiatric comorbidities including substance use ...
Journal of Substance Abuse Treatment, 2021
Background: Research has yet to empirically evaluate methamphetamine (MA) use outcome measures commonly used to indicate treatment success. Clinically meaningful outcomes must be associated with long-term functioning in important life domains. This study evaluated the association between different MA use outcomes and long-term life-functioning. Method: The data that this study used in its secondary analyses were pooled from two treatment trials for MA use disorders (n = 237). The study conducted multiple regression analyses (with multiple imputation for missing data) to determine the association of six within-treatment MA use outcome measures with problem severity in seven life domains and a proxy measure for overall functioning, measured with the Addiction Severity Index (ASI) and assessed at an 8-month followup. Results: The longest duration of abstinence (LDA) outcome achieved the most consistent performance, being associated with better scores in five of eight ASI outcomes (β ranging from −.203 to −.291; p<.01). The complete abstinence during treatment demonstrated the poorest performance and was not significantly associated with any of the ASI outcomes. All other MA use outcome measures were significantly (p<0.01) associated with at least one ASI outcome.
Trials
Introduction Cognitive deficit is a common syndrome of methamphetamine (MA) dependence. It is related to decision-making, control ability, and social functioning. High-intensity interval training (HIIT) is a training technique that requires people to work out at full intensity during a short period. Many studies have already shown the potential effects of HIIT on cognitive functions. The purpose of this trial is to evaluate the cognitive effects of HIIT on individuals with MA dependence. Methods and analysis A total of 240 individuals with MA dependence will be randomly assigned to the HIIT group, moderate-intensity continuous training (MICT) group and control (CON) group. HIIT will consist of a 24-min HIIT exercise on a treadmill. MICT will consist of a 1-h body–mind exercise. CON will be their traditional intervention. The experimental period will be 12 months with 3 interventions weekly for the first 6 months and follow-up for the next 6 months. All subjects will be given cogniti...
Addictive Behaviors Reports, 2021
Highlights • Used an apathy composite T-score approach validated in methamphetamine-dependence.• Apathy, above other factors, associated with poorer drug abstinence self-efficacy.• Methamphetamine use characteristics unrelated to drug abstinence self-efficacy.• Social peer pressure was riskiest situation for potential methamphetamine relapse.
Work, 2019
BACKGROUND: Young people recovering from drug addiction often face challenges in returning to the job market and in maintaining their jobs. Many of them feel they have no choice but to do entry-level work, and they are often unsure about their work ability and vocational choice. OBJECTIVE: In collaboration with a youth outreach service, this study aims to provide a package of vocational assessment, guidance, and support for these clients. METHODS: Using a strength-based case management framework, we conducted a comprehensive vocational evaluation for each participant (N = 17), which covered self-perception of abilities, work and occupational interests, work readiness, work-related self-efficacy, and work aptitudes. We presented assessment results to each client and provided guidance on their education, training, or vocational choice. The results of aptitude tests indicate that most participants can cope with an entry-level job. Many participants are strong in jobs that require quick decision-making, sorting, assembly, and clerical tasks, but many are weak in fine manual dexterity and eye-hand-foot coordination. Many participants preferred jobs that are creative, indefinite, and autonomous in nature. CONCLUSION: Longer-term vocational counseling and coaching is needed to help clients make vocational choices and extend their job tenure. Many clients will also need training in job seeking and job maintenance skills.
Neuropsychopharmacology, 2012
Methamphetamine (MA) is one of the most commonly abused illicit substances worldwide. Among other problems, abuse of the drug has been associated with reduced cognitive function across several domains. However, much of the literature has not attempted to differentiate cognitive difficulties caused by MA abuse from preexisting cognitive difficulties that are likely caused by other factors. Here, we address this question, evaluating evidence for a priori hypotheses pertaining to six lines of research: (a) animal studies; (b) crosssectional human studies; (c) a twin study; (d) studies of changes in cognition with abstinence from MA; (e) studies of changes in brain structure and function with abstinence from MA; and (f) studies of the relationship between the severity of MA abuse and the extent of cognitive deficits observed. Overall the findings were mixed, with some support for a causal relationship between MA abuse and cognitive decline, and other findings suggesting that there is no relationship. The preponderance of the data, however, does support the possibility that MA abuse causes cognitive decline, of unknown duration, in at least some users of the drug. When averaged across individuals, this decline is likely to be mild in early-to-middle adulthood. However, moderator variables are likely to contribute to the presence and/or severity of cognitive decline exhibited by a given individual.
The American Journal on Addictions, 2011
Inconsistencies in reports on methamphetamine (METH) associated cognitive dysfunction may be attributed, at least in part, to the diversity of study sample features (egg, clinical and demographic characteristics). The current study assessed cognitive function in a METH-dependent population from rural South Carolina, and the impact of demographic and clinical characteristics on performance. Seventy-one male (28.2%) and female (71.8%) METH-dependent subjects were administered a battery of neurocognitive tests including the Test of Memory Malingering (TOMM), Shipley Institute of Living Scale, Paced Auditory Serial Addition Test (PASAT), Symbol Digit Modalities Test (SDMT), Grooved Pegboard Test, California Verbal Learning Test (CVLT), and Wisconsin Card Sorting Test (WCST). Demographic and clinical characteristics (egg, gender, frequency of METH use) were examined as predictors of performance. Subjects scored significantly lower than expected on one test of attention and one of fine motor function, but performed adequately on all other tests. There were no predictors of performance on attention; however, more frequent METH use was associated with better performance for males and worse for females on fine motor skills. The METH-dependent individuals in this population exhibit very limited cognitive impairment. The marked differences in education, Intellectual Quotient (IQ), and gender in our sample when compared to the published literature may contribute to these findings. Characterization of the impact of clinical and/or demographic features on cognitive deficits could be important in guiding the development of treatment interventions.
Addictive Behaviors, 2013
Aims-Attention-Deficit/Hyperactivity Disorder (ADHD) is widely regarded as a common comorbidity of methamphetamine (MA) dependence, but the frequency, persistence, and realworld impact of ADHD among MA users is not known. Methods-Four hundred individuals with MA use disorders within 18 months of evaluation and 355 non-MA using comparison subjects completed a comprehensive neuropsychiatric research battery, including self-report measures of everyday functioning. Results-In logistic regression models adjusting for potential confounds, lifetime diagnoses of ADHD as determined by a structured clinical interview were significantly more prevalent among the MA participants (21%) versus comparison subjects (6%), particularly the hyperactive and combined subtypes. MA use was also associated with an increased persistence of combined subtype of ADHD into adulthood. Among the MA users, lifetime ADHD diagnoses were uniquely associated with greater concurrent risk of declines in instrumental activities of daily living, elevated cognitive symptoms in day-today life, and unemployment. Conclusions-Findings indicate that ADHD is prevalent among chronic MA users, who are at increased risk for persistence of childhood diagnoses of ADHD into their adult years. ADHD also
Progress in Neuro-Psychopharmacology and Biological Psychiatry, 2011
Abstinent methamphetamine (Meth) dependent individuals demonstrate poorer performance on tests sensitive to attention/information processing speed, learning and memory, and working memory when compared to non-Meth dependent individuals. The poorer performance on these tests may contribute to the morbidity associated with Meth-dependence. In light of this, we sought to determine the effects of acute, low-dose Meth administration on attention, working memory, and verbal learning and memory in 19 non-treatment seeking, Meth-dependent individuals. Participants were predominantly male (89%), Caucasian (63%), and cigarette smokers (63%). Following a four day, drug-free washout period, participants were given a single-blind intravenous infusion of saline, followed the next day by 30 mg of Meth. A battery of neurocognitive tasks was administered before and after each infusion, and performance on measures of accuracy and reaction time were compared between conditions. While acute Meth exposure did not affect test performance for the entire sample, participants who demonstrated relatively poor performance on these tests at baseline, identified using a median split on each test, showed significant improvement on measures of attention/information processing speed and working memory when administered Meth. Improved performance was seen on the following measures of working memory: choice reaction time task (p≤0.04), a 1-back task (p≤0.01), and a 2-back task (p≤0.04). In addition, those participants demonstrating high neurocognitive performance at baseline experienced similar or decreased performance following Meth exposure. These findings suggest that acute administration of Meth may temporarily improve Meth-associated neurocognitive performance in those individuals experiencing lower cognitive performance at baseline. As a result, stimulants may serve as a successful treatment for improving cognitive functioning in those Meth-dependent individuals experiencing neurocognitive impairment.
Drug and Alcohol Dependence, 2012
Background: We sought to test the hypothesis that methamphetamine use interferes with both the quantity and quality of one's education, such that the years of education obtained by methamphetamine dependent individuals serves to underestimate general cognitive functioning and overestimate the quality of academic learning. Methods: Thirty-six methamphetamine-dependent participants and 42 healthy comparison subjects completed cognitive tests and self-report measures in Los Angeles, California. An overall cognitive battery score was used to assess general cognition, and vocabulary knowledge was used as a proxy for the quality of academic learning. Linear regression procedures were used for analyses. Results: Supporting the hypothesis that methamphetamine use interferes with the quantity of education, we found that (a) earlier onset of methamphetamine use was associated with fewer years of education (p < .01); (b) using a normative model developed in healthy participants, methamphetamine-dependent participants had lower educational attainment than predicted from their demographics and performance on the cognitive battery score (p < .01); and (c) greater differences between methamphetaminedependent participants' predicted and actual educational attainment were associated with an earlier onset of MA use (p ≤ .01). Supporting the hypothesis that methamphetamine use interferes with the quality of education, years of education received prior to the onset of methamphetamine use was a better predictor of a proxy for academic learning, vocabulary knowledge, than was the total years of education obtained. Conclusion: Results support the hypothesis that methamphetamine use interferes with the quantity and quality of educational exposure, leading to under-and overestimation of cognitive function and academic learning, respectively.
Addictive Disorders & Their Treatment, 2016
Objectives-Compared with non-addicted controls (CTLs), adults in remission from methamphetamine addiction (MA-REM) evidence impairments on objective measures of executive functioning and impulsivity. Methods-To evaluate the impact of these impairments in MA-REM adults, demographically matched groups (MA-REM, n=30; CTLs, n=24) completed objective and self-report measures of executive functioning and impulsivity. Results-MA-REM adults demonstrated significantly (p < 0.050) greater objective and subjective problems with executive functioning and impulsivity. Conclusions-These results suggest that adults in MA-REM are aware of their deficits and that these deficits have significant impact in everyday life.
Frontiers in Psychiatry, 2022
ObjectiveIn considering the cognitive harms of methamphetamine (MA) use, there is currently a limited appreciation of the profile of pre-existing, comorbid, or modifiable risk factors for cognitive impairment in individuals with MA-polydrug use who present to clinical services. This is in contrast to the well-recognized evidence in alcohol use groups. The aim of this study was to investigate the biopsychosocial and neuropsychological profiles of MA-polysubstance using individuals reporting cognitive impairment in comparison to an alcohol-using group.MethodsA retrospective file audit was undertaken of individuals who presented for assessment to a specialist addiction neuropsychology service and reported either more than 1 year of heavy MA use as part of a polydrug use history (n = 40) or having only used alcohol (n = 27). Clinical histories including demographic, medical, mental health, substance use, and neuropsychological assessment results were extracted from medical records. Betw...
American Journal on Addictions, 2000
D espite the recent resurgence in methamphetamine (MA) use, there is little evidence concerning whether MA affects the cognitive processes of MA users. Although there are extensive anecdotal reports about MA detrimentally affecting the memory of users, there has been little systematic study of MA on cognition or memory. Since at this time cognitive behavioral interventions are used for MA treatment, 1 it is particularly important for providers of these types of treatment to know the cognitive capabilities of the population coming to them for treatment.
Journal of Substance Abuse Treatment, 2009
Chronic methamphetamine (MA) abuse is associated with disruption of frontostriatal function as well as deficits in cognitive control. To examine the relationship between drug use patterns and cognitive deficits, we pooled previously published behavioral data with new data collected using the Stroop Attention Test. Subject groups are composed of 38 MA-abusing individuals who recently initiated abstinence (36.1 ± 8.8 years of age), 27 MA-abusing individuals who had initiated abstinence more than 1 year prior to study (38.7 ± 7.7 years of age), and 33 non-substance-abusing controls (33.9 ± 8.5 years of age). The recently abstinent MA-abusing individuals exhibited greater Stroop reaction time (RT) interference compared with both the control group (p = .001) and the long-term abstinent MA-abusing individuals (p = .01). No difference was seen between long-term abstinent MA-abusing individuals and controls (p = .87). Stroop RT interference correlated positively with both duration of drug use (p = .003) and drug abstinence (p = .05). The data in the current study provide evidence that cognitive function may improve with protracted drug abstinence.
Neuropsychopharmacology, 2012
Methamphetamine (MA) is one of the most commonly abused illicit substances worldwide. Among other problems, abuse of the drug has been associated with reduced cognitive function across several domains. However, much of the literature has not attempted to differentiate cognitive difficulties caused by MA abuse from preexisting cognitive difficulties that are likely caused by other factors. Here, we address this question, evaluating evidence for a priori hypotheses pertaining to six lines of research: (a) animal studies; (b) crosssectional human studies; (c) a twin study; (d) studies of changes in cognition with abstinence from MA; (e) studies of changes in brain structure and function with abstinence from MA; and (f) studies of the relationship between the severity of MA abuse and the extent of cognitive deficits observed. Overall the findings were mixed, with some support for a causal relationship between MA abuse and cognitive decline, and other findings suggesting that there is no relationship. The preponderance of the data, however, does support the possibility that MA abuse causes cognitive decline, of unknown duration, in at least some users of the drug. When averaged across individuals, this decline is likely to be mild in early-to-middle adulthood. However, moderator variables are likely to contribute to the presence and/or severity of cognitive decline exhibited by a given individual.
Journal of Clinical and Experimental Neuropsychology, 2021
Objective: To evaluate whether cognitive performance in adults with active methamphetamine use (MA-ACT) differs from cognitive performance in adults in remission from MA use disorder (MA-REM) and adults without a history of substance use disorder (CTLs). Method: MA-ACT (n = 36), MA-REM (n = 48), and CTLs (n = 62) completed the Neuropsychological Assessment Battery (NAB). Results: The MA-ACT group did not perform significantly worse than CTLs on any NAB Index. The MA-REM group performed significantly (p < 0.050) worse than CTLs on the NAB Memory Index. The MA-ACT group performed significantly better than CTLs and the MA-REM group on the Executive Functions Index.
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