Declarative and procedural memory functioning in abstinent cocaine abusers

Comparing the validity of self-reported recent drug use between adult and juvenile arrestees

A large body of literature has explored the validity of self-reported drug use among criminal populations. These works have typically revealed strong underreporting of recent illicit drug use. To date, however, no studies have compared the validity of self-reported drug-using behaviors between adult and juvenile offenders. The authors overcome this limitation by assessing the validity of self-reported recent drug use with data collected from 1,425 adult and 551 juvenile Los Angeles arrestees surveyed through the Arrestee Drug Abuse Monitoring (ADAM) Program in 1997. Kappa statistics were computed and tests for specificity and sensitivity were conducted utilizing urinalysis as the reference standard. Results suggest that adult arrestees are more inclined to underreport their recent use of illicit drugs. Implications for drug use research are assessed in light of the current findings.

Cognitive efficiency in stimulant abusers with and without alcohol dependence

BACKGROUND

Although previous studies have found stimulant (i.e., cocaine, methamphetamine) abusers and alcoholics to have neuropsychological deficits, research examining which cognitive abilities are most affected by concurrent exposure to these substances is lacking. To address this issue, detoxified men and women who met criteria for dependence of (a) alcohol only (ALC) (n = 15); (b) stimulants only (STIM) (n = 15); and (c) both alcohol and stimulants (A/STIM) (n = 15) were compared with age- and education-matched community controls (n = 15).

METHODS

Tasks that measured visual spatial skills, problem-solving and abstraction, short-term memory, cognitive flexibility, and gross motor speed were administered to participants. For each test, both speed and accuracy were assessed and an efficiency ratio (accuracy/time) was derived. Based on an average of these efficiency ratios, an overall performance index of cognitive efficiency was obtained.

RESULTS

Overall, controls performed more efficiently than all other groups. However, they were statistically significantly better only in relation to the A/STIM and STIM groups (p < 0.01). Individual comparisons revealed that the ALC group performed significantly better than the STIM group, although the ALC group did not differ from either the control or A/STIM groups (p </= 0.05). This pattern of results was relatively consistent across the individual subtests of problem-solving/abstraction, short-term memory, and cognitive flexibility.

CONCLUSIONS

As expected, substance abuse was associated with cognitive inefficiency. More importantly, these findings suggest that the cognitive effects of chronic stimulant abuse are not additive with those of alcohol abuse. That is, singly addicted stimulant abusers demonstrated similar or greater neurocognitive impairments than individuals who abuse alcohol and stimulants concurrently. The reason for this pattern is speculative but may be attributed to alcohol's opposing actions on cerebrovascular effects brought on by stimulant abuse.

Substance abuse treatment outcomes for cognitively impaired and intact outpatients

The purpose of this research was to examine the effects of cognitive impairment on the efficacy of substance abuse treatment outcome. Alcohol, drug, medical, legal, psychological, employment, and family functioning related treatment outcomes were examined for 26 cognitively impaired and 68 cognitively intact abusing outpatients. Subjects were enrolled in an intensive, 3-week, outpatient program for the treatment of their substance abuse. Subjects were administered a battery of neuropsychological tests prior to treatment onset, and outcome data were obtained at 1, 3, 6, and 12 months posttreatment entry. No significant between-group differences were found on any of the outcome measures, and significant treatment gains were observed across all problem domains in both groups. Subjects' largest improvements were made in the first month of treatment for alcohol, drug, legal, family, and psychological problems. Improvements for employment and medical problems were not observed until 6 months posttreatment. Success across domains was maintained through 12 months follow-up, with the exception of psychological problems; 12-month data indicated a return to thelevel observed at 30 days posttreatment for psychological problems, a level that reflected significant improvement from baseline functioning. A greater proportion of treatment dropouts (i.e., no follow-up data obtained after 30 days) were cognitively impaired as compared to treatment completers. These results suggest that this method of intensive substance abuse outpatient treatment is effective for cognitively impaired patients, an important finding given that research evaluating the efficacy of interventions for such patients is limited. Additionally, neuropsychological evaluation may be important in reducing treatment dropouts, as the present findings indicated that greater cognitive impairment was related to an increased likelihood of treatment dropout.

Factors affecting cognitive functioning in a sample of human immunodeficiency virus-positive injection drug users

Injection drug users represent a major vector of human immunodeficiency virus (HIV) infection in the nation's inner cities, and are an important population for harm reduction treatment interventions to target. However, there has been relatively little research examining the specific contribution of the multiple factors contributing to cognitive functioning among injection drug users that may affect engagement in, and response to, addiction and HIV-related interventions. The current study examined the independent contributions to neuropsychological (NP) test performance of premorbid educational attainment, medical and psychiatric history, long- and short-term drug use, assessed by laboratory, observation, and self-report measures, and HIV disease, assessed by plasma HIV-1 RNA viral load and CD4+ count, in a sample of 90 HIV-positive injection drug users dually addicted to heroin and cocaine. Fully 88% of the sample showed evidence of impairment (>1 standard deviation below the population mean) on an NP test battery selected to assess processes associated with successful engagement in the treatment of substance abuse and HIV, such as learning and memory of verbal information, capacity to solve new problems and deal with more than one stimulus at a time, visual-motor coordination, and visual tracking and cognitive flexibility. In addition to drug use, independent predictors of NP test performance were HIV viral load, educational attainment, and premorbid medical and psychiatric problems. Findings underscore the multiplicity of factors that contribute to cognitive impairment in HIV-positive drug-abusing individuals in addition to drug use. Clinical implications are discussed.

Recovery from psychosis in schizophrenia and schizoaffective disorder: symptoms and neurocognitive rate-limiters for the development of social behavior skills

Neurocognitive deficits are believed to be important predictors of functional outcome in chronic psychotic disorders, but few supporting studies have utilized prospective designs and adequate control. The aim of this study was to estimate the relative influence of symptoms and neurocognitive deficits on the development of social behavior skills in a cohort of individuals with schizophrenia or schizoaffective disorder recovering from acute symptom exacerbations. Forty-six individuals were recruited upon discharge from an inpatient unit and completed assessments of symptoms, neurocognitive function, and social behavior at 3-month intervals for 1 year. Correlational analyses and random regression models were used to model social behavioral capacities longitudinally. Social behavior improved modestly (10% improvements in ratings) over the follow-up period for the group as a whole. Disorganized and negative symptoms, as well as neurocognitive deficits in short-term and working memory predicted changes in social behavior over time. Individuals with better working memory function showed significantly greater abilities to recover social behavior skills, whereas those with working memory deficits showed no functional improvement over time. Both symptoms and neurocognitive deficits are important determinants of functional outcome in schizophrenia. It is proposed that clinicians should consider neurocognitive thresholds for treatment response when developing rehabilitation plans.

Neuropsychological performance of individuals dependent on crack-cocaine, or crack-cocaine and alcohol, at 6 weeks and 6 months of abstinence

BACKGROUND

Little data exist on the neuropsychological effects of crack-cocaine dependence or crack-cocaine and alcohol dependence. This study examined cognitive function in abstinent crack dependent and crack and alcohol dependent individuals at 6 weeks and 6 months abstinence.

METHODS

a comprehensive neuropsychological battery, including the MicroCog computerized assessment, was administered to 20 abstinent crack dependent subjects, 37 abstinent crack and alcohol dependent subjects, and 29 normal controls. Depression was examined as a covariate, and the association between substance use variables and neuropsychological performance was examined.

RESULTS

the two substance dependent groups had similar neuropsychological profiles at 6 weeks abstinent, with both groups exhibiting significant cognitive impairment in a wide range of functions compared to controls. The substance dependent groups were still impaired significantly at 6 months of abstinence. Only mild effects of depression on neuropsychological performance were observed.

CONCLUSIONS

crack dependence and crack and alcohol dependence may lead to severe and persistent neuropsychological deficits over a wide range of domains. The strongest predictor of brain damage associated with substance dependence in this sample was dose (particularly quantity and duration of peak dose).

A Longitudinal Analysis of Drug Use Reporting among Houston Arrestees

Previous studies have indicated that certain illegal drugs are self-reported more readily than others. Respondents are typically more willing to report less serious drugs of abuse, such as marijuana, than they are “hard” drugs of abuse, such as cocaine. To date, however, no comprehensive analyses have examined whether the willingness to self-report illegal drugs fluctuates temporally. In the current study, we examine marijuana-, cocaine-, and heroin-positive Houston arrestees surveyed through the Arrestee Drug Abuse Monitoring (ADAM) Program between 1990 and 1997. Using Kappa statistics, we explore the temporal variation of self-reported drug use. Little variation is Identified. Policy Implications are assessed in light of the current findings.

Neuropsychological predictors of the attainment of treatment objectives in substance abuse patients

This study examined the contribution of neuropsychological functioning to the attainment of treatment objectives in substance abuse patients. Subjects were 85 patients enrolled in comprehensive, inpatient and outpatient substance abuse treatment at a VA Medical Center. Most subjects were diagnosed with Alcohol Dependence or Abuse, and nearly half were seeking treatment for Cocaine Dependence or Abuse. After acute detoxification, but before beginning individualized treatment, subjects were administered a neuropsychological screening battery to assess cognitive functioning and affective status. They then attended a variety of daily group therapies. Each therapy group had its own set of specific treatment objectives; on each treatment day, group therapists rated each patient's attainment of the specific objectives for their group. Groups included Assertiveness Training (Levels I and II), Stress Management (Levels I and II), Social Skills Training, Job Skills, Relapse Prevention (Levels I and II), Leisure Planning, Leisure Skills, Occupational Therapy, and 12-Step Study. Stepwise multiple regression indicated that the best predictors of overall objective attainment were better attention (WMS-R Digits Backwards) and less depressive symptomatology (Beck Depression Inventory). These results suggest that attention and mood have a modest yet significant impact on the success of treatment interventions for substance abuse patients. Thus, evaluation of cognitive as well as affective factors in substance abuse patients might be helpful in designing and implementing specialized interventions to maximize the likelihood of treatment success.

Neurobehavioural consequences of substance abuse and HIV infection

Although our understanding of how human immunodeficiency virus (HIV)-related neurobehavioural deficits develop is nascent and preliminary, some clues have emerged which may clarify lingering uncertainties. In particular, HIV seems to yield brain dysfunction by mediating pathological changes upon neuronal function. HIV also compromises immunological integrity, thereby resulting in secondary infections that may further increase brain dysfunction. Notably, many individuals with HIV tend to be current or past abusers of drugs, and, in some cases, their drug use may have actually presented a pathway for initial HIV infection. Similar to HIV, many drugs tend to yield pathological changes upon neuronal function. Further paralleling HIV, some drugs seem to compromise immune function, which in turn may yield secondary detrimental effects upon the brain. Yet, despite the relatively high comorbidity rates of HIV infection and substance abuse, few investigations have addressed the potential interaction between these two factors upon neurobehavioural status. Towards this end, the present paper reviews the existing literature concerning neuropsychological effects of HIV and substance use, and suggests potential mechanisms whereby substance use may potentiate and exacerbate the onset and severity of neurobehavioural abnormalities in HIV infection.

Quantitative medial temporal lobe brain morphology and hypothalamic-pituitary-adrenal axis function in cocaine dependence: a preliminary report

Preclinical and clinical studies have shown that cocaine increases plasma adrenocorticotropin hormone (ACTH) and cortisol. Chronic elevation of plasma cortisol exerts direct toxic effects upon hippocampal neurons and exacerbates hippocampal damage resulting from ischemia and seizures. The authors tested for evidence of hippocampal damage in patients with chronic cocaine dependence. Medial temporal lobe and total brain volumes were quantified using magnetic resonance imaging (MRI) in 27 patients with cocaine dependence and 16 healthy subjects. Basal and ovine corticotropin releasing hormone (oCRH) stimulated ACTH and cortisol levels were also examined in a subset of 8 healthy and 9 cocaine dependent subjects after 21 days of abstinence. No evidence for decreased hippocampal or total brain volume in cocaine dependence was observed. Similarly, basal and oCRH stimulated ACTH and cortisol levels in cocaine dependent patients did not differ from those in healthy subjects.

Differential effects of cocaine and cocaine alcohol on neurocognitive performance

OBJECTIVE

To investigate the dose-related effects of cocaine with or without alcohol use on the CNS by measuring performance on neurobehavioral tests.

BACKGROUND

Chronic use of cocaine is associated with persistent decrements in cognitive function that are most pronounced in heavy users. Specific neurobehavioral deficits in areas such as executive function and impulsivity would make it difficult for the cocaine abuser to discontinue using drugs. Because alcohol is often used in conjunction with cocaine, the CNS effects of alcohol when taken with cocaine deserve further investigation.

METHOD

The authors evaluated the dose-related effects of cocaine and alcohol use on performance in a variety of neuropsychological tests after 1 to 3 days of abstinence and again after 4 weeks of abstinence. Fifty-six chronic cocaine abusers who had used cocaine during the past 24 to 48 hours volunteered to perform a battery of neuropsychological tests on two separate occasions during a period of enforced abstinence. In addition to using cocaine, most of the volunteers consumed alcohol. Approximately half of the participants consumed more than 10 alcohol-containing drinks per week.

RESULTS

After controlling for the effects of age, sex, and intelligence on performance, the authors found dose-related associations between neurobehavioral performance and cocaine dose and alcohol dose. When the influences of cocaine and alcohol on neurobehavioral performance were taken separately, cocaine and alcohol each selectively affected performance on different neurobehavioral tests after 1 to 3 days of abstinence, with these effects persisting after 4 weeks of abstinence.

CONCLUSION

The concomitant use of cocaine and alcohol may have additive negative effects on the brain as compared to the use of only one of these two substances.

Mood state and recent cocaine use are not associated with levels of cocaine cue reactivity

Eighty-one cocaine-dependent outpatients were assessed for their reactions to cocaine-related cues in a laboratory setting. All subjects contributed a urine sample prior to the session. Compared with non-drug control cues, the cocaine stimuli produced increases in physiological arousal, self-reports of high, craving, and withdrawal, and self-reports of negative mood. Subjects who tested cocaine-positive on the day of testing differed only in skin resistance responding from those who tested cocaine-negative. Changes in cue-induced physiological and self-report measures were also not associated with between-subject variations in mood as measured by the Profile of Mood States (POMS) questionnaire administered prior to cue assessment. Thus, variations in baseline mood and recent cocaine use history do not introduce an additional source of variability in cue reactivity measurements. However, negative mood states at the start of a session were associated with higher levels of self-reported craving, high, and withdrawal both before and after cue exposure.

Learning and memory impairment in cocaine-dependent and comorbid schizophrenic patients

Impairments in verbal learning and memory functioning have been found to be cardinal features among individuals with schizophrenia as well as among non-schizophrenic cocaine abusers. Cognitive deficits in these areas, moreover, have been associated with poor treatment response and short-term outcome. Little is known, however, about the acute effects of cocaine abuse on schizophrenic patients' learning and memory functioning. Consequently, a potentially reversible and treatable source of cognitive impairment has been virtually ignored. The present study examined the extent of verbal learning and memory impairment in a group of cocaine-dependent schizophrenic patients (n=42) and a group of non-schizophrenic cocaine-dependent patients (n=21) within 72 h of the last cocaine use using the California Verbal Learning Test (CVLT). Schizophrenic patients (n=34) without any substance-use disorders were also tested in an identical time frame and served as a comparison group. Results revealed that all groups demonstrated significant learning and memory impairment relative to CVLT published age and gender corrected norms. Both cocaine-dependent and non-substance abusing schizophrenic groups presented a very similar pattern of impaired learning and recall performance across all CVLT task domains. Comorbid patients, in contrast, presented with marked deficits in their ability to learn and recall verbal information relative to either schizophrenic or cocaine-only groups. Moreover, the cocaine-abusing schizophrenic patients showed significant forgetfulness of the information that they did acquire during delayed recall conditions. The performance deficits exhibited by cocaine-abusing schizophrenic patients differed not only in relative severity of impairment, but also qualitatively in their increased rates of forgetfulness of acquired information. These results are interpreted in terms of the neurobiological substrates of learning and memory and the neurobiological impact of cocaine on schizophrenic patients' cognition during the early phase of inpatient hospitalization. These results suggest that comorbid patients should be targeted for specialized remediation efforts at the beginning phases of inpatient treatment.

Self-report and objective measures of cognitive deficit in patients entering substance abuse treatment

The relationship between self-reported cognitive deficits and objectively measured cognitive performance was examined in 86 patients entering substance abuse treatment. Self-ratings of cognitive impairment were strongly correlated with indices of depression and vulnerability to stress, but not with objective cognitive performance. Confirming the lack of relationship between self-report and objective cognitive measures, cognitive performance did not differ between patients at the extremes of the cognitive-complaint distribution; and cognitively impaired patients did not differ from cognitively intact patients in their self-ratings of impairment.