Alex Baldacchino

Dissociable deficits in the decision-making cognition of chronic amphetamine abusers, opiate abusers, patients with focal damage to prefrontal cortex, and tryptophan-depleted normal volunteers: evidence for monoaminergic mechanisms.

We used a novel computerized decision-making task to compare the decision-making behavior of chronic amphetamine abusers, chronic opiate abusers, and patients with focal lesions of orbital prefrontal cortex (PFC) or dorsolateral/medial PFC. We also assessed the effects of reducing central 5-hydroxytryptamine (5-HT) activity using a tryptophan-depleting amino acid drink in normal volunteers. Chronic amphetamine abusers showed sub-optimal decisions (correlated with years of abuse), and deliberated for significantly longer before making their choices. The opiate abusers exhibited only the second of these behavioral changes. Importantly, both sub-optimal choices and increased deliberation times were evident in the patients with damage to orbitofrontal PFC but not other sectors of PFC. Qualitatively, the performance of the subjects with lowered plasma tryptophan was similar to that associated with amphetamine abuse, consistent with recent reports of depleted 5-HT in the orbital regions of PFC of methamphetamine abusers. Overall, these data suggest that chronic amphetamine abusers show similar decision-making deficits to those seen after focal damage to orbitofrontal PFC. These deficits may reflect altered neuromodulation of the orbitofrontal PFC and interconnected limbic-striatal systems by both the ascending 5-HT and mesocortical dopamine (DA) projections.

Profiles of cognitive dysfunction in chronic amphetamine and heroin abusers

Groups of subjects whose primary drug of abuse was amphetamine or heroin were compared, together with age- and IQ-matched control subjects. The study consisted of a neuropsychological test battery which included both conventional tests and also computerised tests of recognition memory, spatial working memory, planning, sequence generation, visual discrimination learning, and attentional set-shifting. Many of these tests have previously been shown to be sensitive to cortical damage (including selective lesions of the temporal or frontal lobes) and to cognitive deficits in dementia, basal ganglia disease, and neuropsychiatric disorder. Qualitative differences, as well as some commonalities, were found in the profile of cognitive impairment between the two groups. The chronic amphetamine abusers were significantly impaired in performance on the extra-dimensional shift task (a core component of the Wisconsin Card Sort Test) whereas in contrast, the heroin abusers were impaired in learning the normally easier intra-dimensional shift component. Both groups were impaired in some of tests of spatial working memory. However, the amphetamine group, unlike the heroin group, were not deficient in an index of strategic performance on this test. The heroin group failed to show significant improvement between two blocks of a sequence generation task after training and additionally exhibited more perseverative behavior on this task. The two groups were profoundly, but equivalently impaired on a test of pattern recognition memory sensitive to temporal lobe dysfunction. These results indicate that chronic drug use may lead to distinct patterns of cognitive impairment that may be associated with dysfunction of different components of cortico-striatal circuitry.

Staff regard towards working with substance users: a European multi-centre study

AIMS To compare regard for working with different patient groups (including substance users) among different professional groups in different health-care settings in eight European countries. DESIGN A multi-centre, cross-sectional comparative study. SETTING Primary care, general psychiatry and specialist addiction services in Bulgaria, Greece, Italy, Poland, Scotland, Slovakia, Slovenia and Spain. PARTICIPANTS A multi-disciplinary convenience sample of 866 professionals (physicians, psychiatrists, psychologists, nurses and social workers) from 253 services. MEASUREMENTS The Medical Condition Regard Scale measured regard for working with different patient groups. Multi-factor between-subjects analysis of variance determined the factors associated with regard for each condition by country and all countries. FINDINGS Regard for working with alcohol (mean score alcohol: 45.35, 95% CI 44.76, 45.95) and drug users (mean score drugs: 43.67, 95% CI 42.98, 44.36) was consistently lower than for other patient groups (mean score diabetes: 50.19, 95% CI 49.71, 50.66; mean score depression: 51.34, 95% CI 50.89, 51.79) across all countries participating in the study, particularly among staff from primary care compared to general psychiatry or specialist addiction services (P<0.001). After controlling for sex of staff, profession and duration of time working in profession, treatment entry point and country remained the only statistically significant variables associated with regard for working with alcohol and drug users. CONCLUSIONS Health professionals appear to ascribe lower status to working with substance users than helping other patient groups, particularly in primary care; the effect is larger in some countries than others.

Internet pharmacies and online prescription drug sales: a cross-sectional study

Psychonaut2002 is a European Union, multi-site research project to investigate the developing relationship between the Internet and drugs with abuse potential. This paper describes the findings of the Scotland research site, which investigated the online availability of prescription drugs. The project used a cross-sectional study to investigate 275 English-language websites, found by searching Google.com and AltaVista.com for ‘prescription drugs’. We found that online pharmacies selling prescription drugs can be classified into four types: (1) legitimate pharmacies; (2) subscription pharmacies; (3) lifestyle pharmacies; and (4) no-prescription pharmacies. The paper considers these findings in relation to what is already known about Internet access. We specifically consider the issues of literacy, Internet access, and credit-card ownership in relation to online pharmacies. We suggest that those from higher socioeconomic groups would be most able to access online pharmacies. However, drug abuse within this population may not be so readily recognized. Efforts to bridge the digital divide may increase access to Internet-sourced drugs amongst those in lower socioeconomic groups. We conclude that stereotypical notions of drug abuse being limited to lower socioeconomic groups may need to change. Increased Internet access may increase the role of the Internet in drug abuse.

Social exclusion in clients with comorbid mental health and substance misuse problems.

Abstract.Background:The concept of comorbid mental health problems and substance misuse has gained prominence in the last two decades, due in part to the closure of large psychiatric hospitals and to the increasing prevalence of drug use in the community. This client group has a dual requirement for both medical and social care needs and is at risk for social exclusion.Methods:A retrospective matched case-control study to examine aspects of social exclusion between service users who have comorbid diagnoses and those with a single diagnosis. Samples were drawn from the service users of a mental health Trust in the South-East of England, from both Adult Mental Health (n = 400) and Drug and Alcohol services (n = 190). Data were collected from Care Programme Approach assessment forms and medical records. McNemar’s χ2 and odds ratios via a conditional logit regression model are used to test for differences in the social exclusion indicators.Results:There were significant differences in social exclusion between the comorbid and singly diagnosed clients of the Adult Mental Health service, but differences were less pronounced between the comorbid and singly diagnosed clients of the specialist Drug and Alcohol service.Conclusions:Recent Government policy advocates treating comorbid clients within mainstream mental health services. Health care workers need to recognise the likelihood of high levels of social exclusion among clients with comorbid problems.

Treating an opiate-dependent inpatient population: a one-year follow-up study of treatment completers and noncompleters.

INTRODUCTION The aim of this study was to compare the characteristics of patients who completed (completers) inpatient treatment of drug dependence with those who failed to complete this programme (noncompleters). METHOD Participants were assessed at admission using the Substance Abuse Assessment Questionnaire (SAAQ) to obtain information about the sociodemographic background, history of drug and alcohol use, physical health, mental health, offending behaviour, and interpersonal relationships. Follow-up interviews were carried out 3, 6, 9, and 12 months after discharge using the SAAQ-Follow-up. To form the three comparison groups, participants were divided on the basis of completion of detoxification and receipt of aftercare. RESULTS AND CONCLUSIONS Significantly better treatment outcome was observed amongst those who completed detoxification and went on to spend at least 6 weeks in a recovery and/or residential rehabilitation unit. In contrast, there were no significant differences between noncompleters and completers who had no aftercare on the majority of measures of drug use during follow-up.

Substance misuse of gabapentin.

Neuropathic pain affects up to 8% of the population,1 causing significant distress and morbidity. Good evidence-based treatment is available,2 so early diagnosis is important. Recent publicity and guidelines, and increasing prevalences of age-related causes of neuropathic pain (including postherpetic neuralgia and diabetic neuropathy), have led to increasing rates of diagnosis and treatment in primary care. Gabapentin is one of the recommended mainstays of evidence-based treatment.3 Unfortunately, our clinical experience suggests that gabapentin is now prevalent as a drug of abuse. The drug’s effects vary with the user, dosage, …

Association between depression and non-fatal overdoses among drug users: A systematic review and meta-analysis

BACKGROUND Assessing factors associated with non-fatal overdose is important as these could be useful to identify individuals with substance use disorders at high risk of adverse outcomes and consequences. Depression may play an important role in terms of overdose risk. We aimed to test if drug users suffering from a depressive disorder might have significantly higher risk of non-fatal overdose as compared with drug users without depression. METHODS We conducted a systematic review and meta-analysis. PubMed, Embase and Web of Knowledge were searched. The pooled analyses were based on prevalence rates, risk difference (RD) and odds ratio (OR), reporting 95% confidence intervals (CIs). The combined estimates were obtained weighting each study according to random effects model for meta-analysis. RESULTS Seven articles, involving 12,019 individuals, and run in the US, Canada, Sweden, Norway, and Australia, were included. Pooled analyses comparing depressed with not depressed individuals highlighted a RD (95% CIs) for non-fatal overdose of 7.3% (4.8-9.7%) and an OR (95% CIs) of 1.45 (1.17-1.79). The subgroups analyses based on specific characteristics of included studies confirmed the association between depression and overdose. CONCLUSIONS Depressive disorders seem to be important factors associated to the risk of non-fatal overdose. Longitudinal studies might appropriately clarify causal inference issues. Future research should address the role of depressive disorders as predictors of subsequent non-fatal overdoses.

Abnormal Brain Activity During a Reward and Loss Task in Opiate-Dependent Patients Receiving Methadone Maintenance Therapy

A core feature of human drug dependency is persistence in seeking and using drugs at the expense of other life goals. It has been hypothesized that addiction is associated with overvaluation of drug-related rewards and undervaluation of natural, nondrug-related rewards. Humans additionally tend to persist in using drugs despite adverse consequences. This suggests that the processing of both rewarding and aversive information may be abnormal in addictions. We used fMRI to examine neural responses to reward and loss events in opiate-dependent patients receiving methadone maintenance treatment (MMT, n=30) and healthy controls (n=23) using nondrug-related stimuli. Half of the patients were scanned after/before daily methadone intake (ADM/BDM patient groups). During reward trials, patients as a whole exhibited decreased neural discrimination between rewarding and nonrewarding outcomes in the dorsal caudate. Patients also showed reduced neural discrimination in the ventral striatum with regard to aversive and nonaversive outcomes and failed to encode successful loss avoidance as a reward signal in the ventral striatum. Patients also showed decreased insula activation during the anticipation/decision phase of loss events. ADM patients exhibited increased loss signals in the midbrain/parahippocampal gyrus, possibly related to a disinhibition of dopamine neurons. This study suggests that patients with opiate dependency on MMT exhibit abnormal brain activations to nondrug-related rewarding and loss events. Our findings add support to proposals that treatments for opiate addiction should aim to increase the reward value of nondrug-related rewarding events and highlight the importance of potential abnormalities in aversive information processing.

Poly-substance use and related harms: a systematic review of harm reduction strategies implemented in recreational settings.

The growing trends of poly-substance use and associated health and public concerns have been reported in various studies with particular focus on young adults patronising popular recreational settings. Harm reduction interventions targeting this population have been reported for a number of settings, however only limited data is available on the current strategies employed. A systematic review of peer-reviewed journals was conducted to determine interventions published since 1998 which targeted 17-24 year olds within recreational settings: defined as clubs, pubs, discos, festivals or raves. The identified studies were examined for similarities in design, implementation and outcome measures. The findings and their limitations are discussed alongside implications for future research needed to fill a void in the current knowledge base.