Prevalence of psychiatric disorder in a methadone maintenance population

OBJECTIVE

The objective of this study was to examine the prevalence of psychiatric disorders in a group of patients who had recently entered a methadone maintenance programme.

METHOD

A total of 62 patients were interviewed using the Composite International Diagnostic Interview (CIDI) within 6 months of commencing methadone maintenance. The CIDI was used to establish symptoms of psychiatric illness at interview and in the 12 months prior.

RESULTS

In the 12 months prior to interview, 76% of the sample fulfilled ICD-10 criteria for a psychiatric disorder other than substance-use disorder. Over half of the group interviewed fulfilled ICD-10 criteria for an affective disorder, two-thirds fulfilled criteria for an anxiety disorder and just under half fulfilled diagnostic criteria for both an affective disorder and an anxiety disorder in the 12 months prior to interview. At the time of interview, 19% fulfilled ICD-10 diagnostic criteria for a moderate or severe affective disorder. Seventy per cent of males and 89% of females interviewed had a comorbid psychiatric illness. In 71% of the group who had a comorbid psychiatric illness, the onset of psychiatric symptomatology was reported to predate the use of heroin.

CONCLUSION

The prevalence of psychiatric disorder is up to 10 times higher in the population on methadone maintenance than in the general population and is two to three times higher than that found in community surveys of those with a substance-use disorder. These results are consistent with earlier findings and have implications for service planning.

Factorial invariance for combined Wechsler Adult Intelligence Scale-Revised and Wechsler Memory Scale-Revised scores in a sample of clients with alcohol dependency

This study examined the joint factor structure of the WAIS-R and WMS-R in a sample of 289 participants (mostly males) with alcohol dependency. In a confirmatory phase we contrasted a range of factor models derived from previous analyses of the Wechsler scales. The best fitting model incorporated five factors representing Verbal Comprehension, Perceptual Organization, Attention-Concentration, Verbal Memory, and Visual Memory, with reassignment of factor loadings for two subtests. The invariance of the measurement model was then examined comparing data from a large sample of healthy participants (J. R. Carstairs & E. A. Shores, 1999). The results indicated that the number of factors was invariant across samples, and four of the factors satisfied the criterion of partial measurement invariance.

Working memory impairments in alcohol-dependent participants without clinical amnesia

BACKGROUND

The delayed alternation (DA) task is highly sensitive to the deficits of nonhuman animals with alcohol-related brain damage. DA is thought to measure working memory which serves as a temporary store for processing of information. However, performance on this type of task has only been investigated in alcohol-dependent humans with severe cognitive deficits. The aim of the current study was to explore the validity of DA as a test sensitive to alcohol-related brain damage by manipulating storage and processing components in three versions of the task. It was hypothesized that alcohol-dependent people would perform worse than control participants and that their deficits would be more pronounced in DA versions with maximal working memory demands.

METHODS

A sample of 12 alcohol-dependent participants without Wernicke-Korsakoff syndrome was compared with a sample of 12 nonalcohol-dependent controls on three versions of DA. These versions, in order of increasing working memory demand, were single alternation (LR), double alternation (LLRR), and asymmetric alternation (LRRR). DA was administered on a personal computer and performance measured by the number of trials taken to reach criterion.

RESULTS

Alcohol-dependent participants, compared with the control participants, took more trials to reach learning criterion on DA on all versions when analyzed together (p = 0.002). Performance on DA was also found to deteriorate with increased working memory demands in both groups of participants (p < 0.001). However, the deficits of alcohol-dependent participants were most pronounced on the DA task with moderate (LLRR) as opposed to extreme (LRRR) working memory demands.

CONCLUSIONS

The results indicate that both storage and processing demands are necessary for task performance and demonstrate sensitivity of DA to alcohol-related brain injury.

Thiamin treatment and working memory function of alcohol-dependent people: preliminary findings

BACKGROUND

Wernicke-Korsakoff syndrome (WKS) is most often seen in people who are alcohol dependent. Treatment with thiamin may rapidly resolve acute symptoms. However, much evidence suggests that identification of WKS on clinical examination is relatively insensitive when compared with diagnosis at postmortem. No study has investigated the therapeutic effect of thiamin in a sample of alcohol-dependent people without the clinical triad of acute WKS.

METHODS

We conducted a randomized, double-blind, multidose study of thiamin treatment in 107 subjects who were detoxifying from alcohol. Five groups of subjects were assessed with the Mini-Mental State Examination and were examined for the presence of neurological signs. Subjects were given different doses of intramuscular thiamin for two consecutive days. The posttreatment performance of these groups then was examined on a test of working memory derived from comparative neuropsychology, namely, the delayed alternation task. This test has been established as sensitive to the neuropathology of WKS.

RESULTS

Pretreatment measures of mental status and neurological signs were equivalent across groups. Groups were equated with respect to the background variables of age, education, typical daily alcohol consumption, and years of drinking. On the posttreatment measure, a superior performance was found in the group that received the highest dose of thiamin, compared with the other four treatment groups.

CONCLUSIONS

A therapeutic relationship between dose and working memory performance was indicated. These results have important implications for the management and prevention of WKS, but further investigations are needed to substantiate the nature of the therapeutic relationship.

Anaesthesia of the common marmoset (Callithrix jacchus) using continuous intravenous infusion of alphaxalone/alphadalone

A safe means of anaesthetizing common marmosets (Callithrix jacchus) for a study using magnetic resonance imaging (MRI) to investigate cerebral ischaemia was required. Continuous infusion of alphaxalone/alphadalone was used to anaesthetize 37 marmosets for non-recovery and recovery experiments. This was found to give safe, reliable anaesthesia when coupled with pulse oximetry and electrocardiographic (ECG) monitoring.

Confirmatory factor analysis of the Wechsler Memory Scale-Revised in a sample of clients with alcohol dependency

Previous analyses of the Wechsler Memory Scale-Revised (WMS-R; Wechsler, 1987) have reported one-, two-, and three-factor solutions and raised questions about the validity of the visual memory subtests. These various findings may stem in part from different methods of analysis, and from the study of different participant samples. To address these issues, we analysed data from the WMS-R and a spatial maze test administered to 154 participants with a history of alcohol dependence. Results from confirmatory factor analysis supported the interpretation of three factors underlying the WMS-R subtests and the spatial maze score in this sample, namely, attention-concentration, immediate memory, and delayed recall. This result held despite the inclusion of the maze score which is a well-validated measure of visuo-spatial memory.

Comparison of alcohol consumption patterns and social problems between women and men drink-drivers

OBJECTIVE

To compare the sociodemographic characteristics, patterns of alcohol consumption and driving histories of women and men drink-drivers.

DESIGN

Cross-sectional descriptive study.

SETTING AND SUBJECTS

All 156 women who attended the Drink-Drive Program at St Vincent's Hospital, Melbourne, between January 1990 and December 1993, and an age-matched sample of 298 men attending in the same period. All had been disqualified from driving after a conviction for driving under the influence of alcohol.

OUTCOME MEASURES

Self-reported weekly alcohol consumption and expenditure on alcohol at apprehension and during the program; blood alcohol level (BAL) at apprehension; demographic characteristics; number of previous drink-drive and other traffic convictions; and score on the Michigan Alcoholism Screening Test (MAST).

RESULTS

Women had a higher educational level than men, and were more likely to be managers or professionals and to live in areas of high socioeconomic status. Women reported lower levels of weekly alcohol consumption at both apprehension (women: 15.2 standard drinks; men: 31.6 standard drinks) and during the program (women: 7.1 standard drinks; men: 12.0 standard drinks) but had similar BALs to men at apprehension (mean, 0.12% [26 mmol/L]). Sixty percent of women drank wine, or wine, beer and spirits, while 75% of men drank beer. Women had lower MAST scores than men (mean [standard deviation]: women, 5.8 [5.2]; men, 8.9 [8.2]). Women were less likely than men to have prior convictions for drink-driving or other traffic offences.

CONCLUSION

Although women presented with similar blood alcohol levels to men, their drinking patterns and sociodemographic characteristics differ greatly. Health education for women drink-drivers needs to have a different strategy to that for men.

Multimedia benchmarking analysis for three risk assessment models: RESRAD, MMSOILS, and MEPAS

This paper is one in a series that describes results of a benchmarking analysis initiated by the Department of Energy (DOE) and the United States Environmental Protection Agency (EPA). An overview of the study is provided in a companion paper by Laniak et al. presented in this journal issue. The three models used in the study--RESRAD (DOE), MMSOILS (EPA), and MEPAS (DOE)--represent analytically-based tools that are used by the respective agencies for performing human exposure and health risk assessments. Both single media and multimedia benchmarking scenarios were developed and executed. In this paper, the multimedia scenario is examined. That scenario consists of a hypothetical landfill that initially contained uranium-238 and methylene chloride. The multimedia models predict the fate of these contaminants, plus the progeny of uranium-238, through the unsaturated zone, saturated zone, surface water, and atmosphere. Carcinogenic risks are calculated from exposure to the contaminants via multiple pathways. Results of the tests show that differences in model endpoint estimates arise from both differences in the models' mathematical formulations and assumptions related to the implementation of the scenarios.

An overview of a multimedia benchmarking analysis for three risk assessment models: RESRAD, MMSOILS, and MEPAS

Multimedia modelers from the United States Environmental Protection Agency (EPA) and the United States Department of Energy (DOE) collaborated to conduct a detailed and quantitative benchmarking analysis of three multimedia models. The three models--RESRAD (DOE), MMSOILS (EPA), and MEPAS (DOE)--represent analytically-based tools that are used by the respective agencies for performing human exposure and health risk assessments. The study is performed by individuals who participate directly in the ongoing design, development, and application of the models. Model form and function are compared by applying the models to a series of hypothetical problems, first isolating individual modules (e.g., atmospheric, surface water, groundwater) and then simulating multimedia-based risk resulting from contaminant release from a single source to multiple environmental media. Study results show that the models differ with respect to environmental processes included (i.e., model features) and the mathematical formulation and assumptions related to the implementation of solutions. Depending on the application, numerical estimates resulting from the models may vary over several orders-of-magnitude. On the other hand, two or more differences may offset each other such that model predictions are virtually equal. The conclusion from these results is that multimedia models are complex due to the integration of the many components of a risk assessment and this complexity must be fully appreciated during each step of the modeling process (i.e., model selection, problem conceptualization, model application, and interpretation of results).

Induction of anaesthesia with halothane and isoflurane in the rabbit: a comparison of the use of a face-mask or an anaesthetic chamber

The effects of induction of anaesthesia with halothane or isoflurane were studied in rabbits. The anaesthetic agents were delivered either via a face-mask, or the animals were placed in an anaesthetic induction chamber. All rabbits had periods of apnoea during induction, lasting 30-120 s, resulting in moderate hypercapnia and acidosis. Periods of apnoea were associated with a marked bradycardia. The combination of bradycardia and hypercapnia during induction may represent an increased risk of anaesthetic associated mortality. Animals in all groups tried to avoid inhaling anaesthetic vapour, and this behaviour, together with the occurrence of breath-holding suggests that induction was aversive.

Alcohol-related health problems in the elderly

Alcohol misuse is common in the elderly, and the problem may be compounded by the body's reduced ability to metabolise ethanol and interactions with over-the-counter and prescription drugs. Older heavy drinkers are likely to present with mental health problems--anxiety, depression, dementia, confusion and sleep disturbance--or physical problems--gait disturbance, falls and liver disease. Alcohol use must be accurately assessed, and physical, neurological and mental state examinations performed. Treatment should be individualised, with the patient's needs being matched to the treatment options available.

Anaesthesia of laboratory rabbits using etorphine/methotrimeprazine and midazolam

The use of etorphine (a potent mu-opioid), methotrimeprazine (a phenothiazine tranquilizer) and midazolam (a benzodiazepine) in laboratory rabbits is described. The central ear artery was cannulated under local anaesthesia using lignocaine/prilocaine cream, enabling cardiovascular monitoring in conscious animals. Anaesthesia was characterized by respiratory arrest, profound analgesia and a stable cardiovascular system (after commencing intermittent positive pressure ventilation). Reversal of anaesthesia with buprenorphine (a partial mu agonist) did not reduce the degree of post-operative respiratory depression, but shortened the period of unconsciousness considerably. This anesthetic regimen can only be recommended for rabbits that are free of respiratory disease and if facilities for IPPV are available.

The use of etorphine/methotrimeprazine and midazolam as an anaesthetic technique in laboratory rats and mice

The results of a preliminary evaluation of etorphine/methotrimeprazine ('Small Animal Immobilon') and midazolam in rats and mice are reported, and this regimen is compared to fentanyl/fluanisone/midazolam in mice. In rats, a surgical plane of anaesthesia with good muscle relaxation was produced, but blood gas analysis showed the presence of severe hypoxia, hypercapnia and acidosis. In mice etorphine/methotrimeprazine/midazolam and fentanyl/fluanisone/midazolam produced adequate anaesthesia, but blood gas analysis showed severe respiratory depression with both regimens. Since etorphine/methotrimeprazine/midazolam produced severe respiratory depression in rats and mice it is suggested that this regimen is used with caution. Administration of supplemental oxygen would seem advisable when using either etorphine/methotrimeprazine/midazolam or fentanyl/fluanisone/midazolam in rats and mice.

The assessment of depth of anaesthesia in animals and man

The assessment of the depth of anaesthesia in man has received much attention in recent years, following a number of reports of people being aware during surgery. A range of different measures have been suggested for determining the adequacy of anaesthesia in man, but such a critical assessment is rarely applied to laboratory animals. This article describes the methods used to assess anaesthetic depth in both man and animals, and compares the relative states of knowledge about anaesthetic depth in animals and man.

Oesophageal propulsive force and its relation to manometric pressure

A fixed volume capsule incorporating a force transducer and a side hole for manometric measurements was constructed and calibrated. Simultaneous measurements of the propulsive (aboral) force and the manometric pressure (intraluminal pressure) were made at 5, 10, and 15 cm above the lower oesophageal sphincter and in response to dry and wet (5, 10, and 15 ml) swallows. The propulsive force and manometric pressure waves had a simultaneous onset and were of similar duration. Peak values of propulsive force for wet swallows increased significantly as measurements were made progressively more distally within the oesophagus and were greatest in the distal oesophagus. The association between manometric pressure and propulsive force is not strong (r = 0.61) suggesting that intraluminal pressure is a poor predictor of propulsive force and hence an unreliable measure of oesophageal 'function'.

Biological markers of alcoholism

The roles of two categories of biological markers--those relating to alcohol consumption and those relating to the risk of developing alcohol related problems--are reviewed. Platelet Mono-amino oxidase levels are low in individuals with a strong inheritance of their drinking problem (Cloninger Type II alcoholics). Elevated gamma-glutamyl transpeptidase (GGT) levels identify regular heavy drinkers with a sensitivity between 40-60%. Mean corpuscular volume (MCV) has a high specificity (95%) and is useful in detecting regular heavy drinkers in the ambulatory care population if other causes of an elevated MCV can be included.

Does a blood alcohol level of 0.15 or more identify accurately problem drinkers in a drink-driver population?

OBJECTIVE

To determine whether a blood alcohol concentration (BAC) of 0.15 or more identifies accurately problem drinking in an apprehended drinking driver.

DESIGN

Cross-sectional analytic study of 86 drink drivers ("diagnostic test study").

SETTING

St Vincent's Hospital, Melbourne, drink-driver education programme.

SUBJECTS

Men aged between 18-25 years, applying for relicensing after disqualification, who were participants at 10 consecutive drink-driver education courses conducted in early 1987.

OUTCOME MEASURES

Self-reports of the amount of alcohol consumed and the amount of money spent on alcohol per week, the standard Michigan Alcoholism Screening Test (MAST) score and the blood alcohol level at apprehension. The first three measures were used as reference standards for alcohol-related problems, against which the blood alcohol level was compared.

MAJOR RESULTS

Scatter plots of BAC against amount consumed, amount spent and the MAST scores showed that a large proportion of the heaviest drinkers were not identified by the BAC. Log-transformed correlation coefficients were: for amount spent v. amount consumed, r = 0.73; for MAST score v. amount consumed, r = 0.52, and for MAST score v. amount spent r = 0.53. Correlating the BAC with the log of the MAST score gave r = 0.21, BAC with log of the amount consumed, r = 0.20, and BAC with log of the amount spent, r = 0.15. Comparing a BAC of 0.15 or more with a MAST score of greater than or equal to 5, we obtained a sensitivity of 0.36, a specificity of 0.76, a positive predictive value of 0.86, and a negative predictive value of 0.23. The prevalence of heavy drinking as measured by the MAST score was 0.80.

CONCLUSION

A blood alcohol concentration of 0.15 or more identifies only a third of the problem drinkers in this sample of drink drivers. Although it selected a group of drinkers with alcohol-related problems, it missed most of the problem drinkers and did not reliably identify the heaviest drinkers.