Reward drive and rash impulsiveness as dimensions of impulsivity: Implications for substance misuse

One of the primary personality dimensions or traits that has consistently been linked to substance abuse is impulsivity. However, impulsivity is not a homogenous construct and although many of the measures of impulsivity are correlated, the most recent review of published factor analytic studies has proposed two independent dimensions of impulsivity: reward sensitivity, reflecting one of the primary dimension of J. A. Gray's personality theory, and rash impulsiveness. These two facets of impulsivity derived from the field of personality research parallel recent developments in the neurosciences where changes in the incentive value of rewarding substances has been linked to alterations in neural substrates involved in reward seeking and with a diminished capacity to inhibit behavior due to chronic drug exposure. In this paper, we propose a model that integrates the findings from research into individual differences with recent models of neural substrates implicated in the development of substance misuse. (C) 2004 Elsevier Ltd. All rights reserved.

Expression of the iron regulatory peptide hepcidin is reduced in patients with chronic liver disease

Disturbances in iron metabolism often accompany liver disease in humans and hepatic iron deposition is a frequent finding. Since the peptide hepcidin, a major regulator of body iron homeostasis, is synthesised in the liver, alterations in hepcidin expression could be responsible for these effects. To investigate this possibility, we studied hepcidin expression in liver biopsies from patients with hepatitis C virus (HCV) infection, non-alcoholic fatty liver disease (NAFLD) and hemochromatosis (HC). Total RNA was extracted from the liver tissue of 24 HCV, 17 NASH and 5 HC patients, and 17 liver transplant donors (controls). The levels of mRNA for hepcidin and several other molecules involved in iron metabolism (DMT1, Dcytb, hephaestin, ferroportin, TfR1, TfR2, HFE and HJV) were examined by ribonuclease protection assay and expressed relative to the housekeeping gene GAPDH. The expression of hepcidin was significantly decreased in HCV and NASH patients relative to control liver (109±16 and 200±44 versus 325±26 respectively; P=0.008 and 0.02). We have previously reported similar findings in patients with HC, and this was confirmed in the current analysis (176±21; P=0.003). In both HCV and NAFLD patients the expression of the iron reductase Dcytb and the transferrin binding regulatory molecule TfR2 was also decreased, while the cellular iron exporter ferroportin showed a significant increase. Levels of the mRNA for the iron oxidase hephaestin were lower in HCV patients alone, while expression of the major transferrin binding molecule TfR1 was decreased only in NAFLD patients. Of particular interest was the finding that the expression of HJV (which is mutated in patients with juvenile HC) was significantly increased in NAFLD patients. No changes were seen in the expression of the iron importer DMT1 or the regulatory molecule HFE. Decreased expression of hepcidin in patients with HCV and NAFLD provides an explanation why iron homeostasis could be perturbed in these disorders. Reduced hepcidin levels would increase intestinal iron absorption and iron release from macrophages, which could contribute to hepatic iron accumulation. This in turn could lead to alterations in the expression of various proteins involved in iron transport and its regulation. Indeed most of the changes in the expression of such molecules observed in this study are consistent with this. However, the mechanisms leading to changes in the expression of hepcidin in these diseases remain to be elucidated.

Mucociliary clearance in patients with chronic asthma: Effects of beta(2) agonists

Chronic asthma is characterized by airway inflammation, mucus hypersecretion and impaired mucociliary clearance (MCC). We investigated baseline MCC and the acute effect of terbutaline in chronic asthmatics with sputum production while on long-term treatment with salmeterol in combination with inhaled corticosteroids (ICS). MCC was measured at baseline and in response to 1 mg terbutaline (or placebo) on three visits over 80 min in 16 asthmatics (52 +/- 13 years of age). Subjects who had greater than 10% absolute increase in MCC above baseline and placebo, after terbutaline, were categorized in group A and subjects who had less than 10% in group B. In group A subjects (n = 6), MCC increased from 23.7 +/- 4.0% at baseline to 43.7 +/- 4.9% with terbutaline (P < 0.0001) and to 34.4 +/- 5.7% with placebo (P < 0.01). In group B subjects (n = 10), MCC remained similar: 11.3 +/- 3.2% at initial baseline, 12.0 +/- 3.2% with terbutaline and 7.3 +/- 3.0% with placebo (P > 0.05). Group B subjects withdrew from all beta(2) agonists for a week and MCC was remeasured. After withdrawal, baseline MCC (7.0 +/- 1.8%) was similar to the initial baseline value (P > 0.1) and MCC with terbutaline (15.8 +/- 4.9%) was greater than baseline (P < 0.005) but remained abnormal in most subjects. Baseline percentage predicted FEV1 and FEF25-75% were 77.3 +/- 7.2 and 41.7 +/- 5.6 in group A and 59.9 +/- 8.1 and 29.5 +/- 8.4 in group B subjects, respectively. MCC was impaired in most of these asthmatics with persistent airway obstruction and sputum production, despite regular treatment with ICS and salmeterol. In addition, there was little or no stimulation of MCC acutely after terbutaline in most of these asthmatics.

Methadone maintenance therapy for opioid dependence - A guide to appropriate use

Opioid dependence is a chronic, relapsing condition that is associated with significant morbidity and mortality. Methadone maintenance therapy involves the provision of a controlled supply of an orally administered opioid, thereby stabilising the opioid-dependent patient. Research studies have shown that methadone maintenance reduces illicit opioid use, opioid-related crime, premature mortality and the risk of HIV infection. It is most effective when prescribed at an adequate dosage (usually 60 to 100 mg/day) and when long term maintenance on methadone is the goal of treatment rather than detoxification from all drugs including methadone. Successful long term methadone maintenance is more likely when it takes place within the context of a well established therapeutic relationship and when the medical, social and psychological needs of patients are met either through direct assistance or referral.

Dietary trends: Estimates from food supply and survey data

Objective: To illustrate methodological issues involved in estimating dietary trends in populations using data obtained from various sources in Australia in the 1980s and 1990s. Methods: Estimates of absolute and relative change in consumption of selected food items were calculated using national data published annually on the national food supply for 1982-83 to 1992-93 and responses to food frequency questions in two population based risk factor surveys in 1983 and 1994 in the Hunter Region of New South Wales, Australia. The validity of estimated food quantities obtained from these inexpensive sources at the beginning of the period was assessed by comparison with data from a national dietary survey conducted in 1983 using 24 h recall. Results: Trend estimates from the food supply data and risk factor survey data were in good agreement for increases in consumption of fresh fruit, vegetables and breakfast food and decreases in butter, margarine, sugar and alcohol. Estimates for trends in milk, eggs and bread consumption, however, were inconsistent. Conclusions: Both data sources can be used for monitoring progress towards national nutrition goals based on selected food items provided that some limitations are recognized. While data collection methods should be consistent over time they also need to allow for changes in the food supply (for example the introduction of new varieties such as low-fat dairy products). From time to time the trends derived from these inexpensive data sources should be compared with data derived from more detailed and quantitative estimates of dietary intake.

The alcohol withdrawal syndrome

The alcohol withdrawal syndrome (AWS) is a set of signs and symptoms that typically develops in alcohol-dependent people within 6–24 h of their last drink. It may occur unintentionally if abstinence is enforced by illness or injury, or deliberately if the person voluntarily stops drinking because of an alcohol-related illness, or as a prelude to becoming and remaining abstinent. The signs and symptoms of the syndrome (panel) are largely, but not exclusively, those of autonomic hyperactivity, the reverse of the effects of alcohol intoxication. They represent a homoeostatic readjustment of the central nervous system (CNS) to the neuroadaptation that occurs with prolonged alcohol intoxication.1 RC Turner, PR Lichstein and JG Peden et al., Alcohol withdrawal syndromes: a review of pathophysiology, clinical presentation and treatment, J Gen Intern Med 4 (1989), pp. 432–444. Full Text via CrossRef | View Record in Scopus | Cited By in Scopus (39)1 They vary in severity from mild to severe.1

Ocular abnormalities in chronic schizophrenia: clinical implications

Objective: As part of a randomised double-blind study of a new atypical antipsychotic we sought to determine both the levels of visual acuity and the occurrence of toxic side-effects in a group of patients treated for many years on a variety of antipsychotics. Method: Twenty-three inpatients with a DSM-III-R diagnosis of chronic schizophrenia from two separate hospital locations who met the criteria for the double-blind trial were examined for ocular abnormalities at both baseline and at trial completion. Results: At baseline a high prevalence of abnormalities was identified: 19 patients (82.6%) were found to have one or more ocular abnormalities, including lens opacities/cataracts and corneal pigmentation; three patients, with delusions related to the sun, were noted to have solar burns; a high proportion (almost 70%) of patients had untreated visual acuity problems. No further changes were observed at the follow-up examinations. Conclusions: The possible causes of ocular disturbance in schizophrenia and the reasons for the relatively high ocular morbidity in this group are thought to result from both illness-related factors and the effects of antipsychotic medication. Causality is confounded by a number of issues such as the high prevalence of smoking, poor general health and the variety of antipsychotic medications used in the treatment of psychosis as well as substance abuse. The clinical implications are considered in this paper in relation to the move towards community-based psychiatric services.

Models of alcohol use by young adults: An examination of various attitude-behavior theories

Objective: The aim of this study was to test the effectiveness of various attitude-behavior theories in explaining alcohol use among young adults. The theory of reasoned action (TRA), the theory of planned behavior and an extension of the TRA that incorporates past behavior were compared by the method of maximum-likelihood estimation, as implemented in LISREL for Windows 8.12. Method: Respondents consisted of 122 university students (82 female) who were questioned about their attitudes, subjective norms, perceived behavioral control, past behavior and intentions relating to drinking behavior. Students received course credit for their participation in the research. Results: Overall, the results suggest that the extension of the theory of reasoned action which incorporates past behavior provides the best fit to the data. For these young adults, their intentions to drink alcohol were predicted by their past behavior as well as their perceptions of what important others think they should do (subjective norm). Conclusions: The main conclusions drawn from the research concern the importance of focusing on normative influences and past behavior in explaining young adult alcohol use. Issues regarding the relative merit of various alternative models and the need for greater clarity in the measure of attitudes are also discussed.

The role of legal coercion in the treatment of offenders with alcohol and heroin problems

This article discusses the ethical justification for and reviews the American evidence on the effectiveness of; treatment for alcohol and heroin dependence that is provided under legal coercion to offenders whose alcohol and drug dependence has contributed to the commission of the offence with which they have been charged or convicted. The article focuses on legally coerced treatment for drink-driving offenders and heroin-dependent property offenders. it outlines the various arguments that have been made for providing such treatment under legal coercion, namely. the over-representation of alcohol and drug dependent persons in prison populations; the contributory causal role of alcohol and other drug problems in the offences that lead to their imprisonment; the high rates of relapse to drug use and criminal involvement after incarceration; the desirability of keeping injecting heroin users out of prisons as a way of reducing the transmission of infectious diseases such as HIV and hepatitis; and the putatively greater cost-effectiveness of treatment compared with incarceration. The ethical objections to legally coerced drug treatment are briefly discussed before the evidence on the effectiveness of legally coerced treatment for alcohol and other drug dependence is reviewed. The evidence, which is primarily from the USA, gives qualified support for some forms of legally coerced drug treatment provided that these programs are well resourced, carefully implemented, and their performance is monitored to ensure that they provide a humane and effective alternative to imprisonment. Expectations about what these programs can achieve also need to be realistic.

The personal constructs of coping with chronic low back pain: is coping a necessary evil?

The construct of coping is explored in this paper utilising repertory grid technique with a small group of non-patients with chronic pain. Nineteen volunteers with low back pain completed a repertory grid with eight given elements signifying various self and illness-related roles. Two constructs were given and the remainder elicited using the triad method. The 19 participants rated themselves as being in less pain than those they typified as ill or disabled and considered themselves to be coping with their pain. The constructs elicited emphasised authenticity, the limitations of being a coper, mastery, active stoicism, cheerfulness, acceptance and maintaining acceptable social interactions and appearances. Copers were considered to not be in constant pain. Self, ideal-self and social-self constructs were closely related, The participants rated themselves more like copers than ill, pain-suffering, invalid or hypochondriacal persons. Being a coper, however, was less desirable than being pain free, In essence, these volunteers with low back pain see coping as a necessary evil. This ambivalent and ambiguous construing of coping needs to be further explored in community and patient groups if we are to improve the collaboration between patients and therapists in achieving good pain management. (C) 1997 International Association for the Study of Pain. Published by Elsevier Science B.V.