Modifying the risk associated with an impulsive temperament: a prospective study of drug dependence treatment

The evidence linking the personality trait of impulsivity and substance misuse is well established. Importantly, impulsivity not only predicts substance misuse problems but has an association with duration in treatment, likelihood of completing treatment and time to relapse. Treatment that focuses on increasing awareness and acceptance of thoughts and emotions may potentially address impulsive behaviour and in this respect improve treatment outcomes for substance misuse. The current paper investigated the relationship between the facet of impulsivity that taps into poor inhibitory control and treatment outcome. In addition, there was a specific focus on ascertaining the impact of an increase in awareness and attentional control measured in 144 adult substance users receiving treatment in a residential therapeutic community. Impulsivity predicted poorer treatment outcome (measured as drug use severity). Increases in awareness and acceptance of emotions and thoughts during treatment were related to better outcome although this was not associated with baseline levels of impulsivity. Clinical and theoretical implications are discussed.

Genetic polymorphisms in glutathione-S-transferases are associated with anxiety and mood disorders in nicotine dependence

Nicotine dependence is associated with an increased risk of mood and anxiety disorders and suicide. The primary hypothesis of this study was to identify whether the polymorphisms of two glutathione-S-transferase enzymes (GSTM1 and GSTT1 genes) predict an increased risk of mood and anxiety disorders in smokers with nicotine dependence.

A comparison of olanzapine with haloperidol in cannabis-induced psychotic disorder: a double-blind randomized controlled trial

Little controlled data exist on the treatment of substance induced psychotic disorders. In this study, 30 patients meeting DSM-IV criteria for cannabis induced psychotic disorder were randomly allocated to receive either olanzapine or haloperidol in a 4-week double-blind clinical trial. There were no significant outcome differences between the two groups on any of the primary outcome measures, the Brief Psychiatric Rating Scale (haloperidol 25.7; olanzapine 27.1; P = 0.70); Clinical Global Impression (CGI) severity scale (haloperidol 1.8, olanzapine 2.3; P = 0.21) or the CGI improvement scale (haloperidol 1.3, olanzapine 1.7; P = 0.16). The haloperidol group however, developed significantly more extrapyramidal side-effects as measured by the Simpson Angus Scale (haloperidol 11.4, olanzapine 2.5; P = 0.014). Significantly (P = 0.027) more biperidin was used for extrapyramidal side-effects in the haloperidol (7.143 mg) than in the olanzapine (0.357 mg) group. Olanzapine appears to be as effective as haloperidol in the treatment of cannabis induced psychotic disorder, but is associated with a lower rate of extrapyramidal side-effects.

Bioprocessing of hemp hurd (Cannabis sativa) for biofuel production

 This project is based on production of biofuel from lignocellulosic waste. Hemp hurds were used for the production of ethanol. This was achieved by treating hemp at high temperature followed by enzymatic reaction and fermentation. Different techniques were used to detect the changes occurred on hemp structure and product quantification.

Impact of cannabis use on long-term remission in bipolar I and schizoaffective disorder

OBJECTIVE: To investigate the impact of regular cannabis use on long-term remission of mood symptoms in bipolar spectrum disorders. METHODS: The 24-month prospective observational study included patients (n=239) with bipolar I disorder and schizoaffective disorder, bipolar type. Participants were classified as regular cannabis users (three times or more per week) or non-users. The primary outcome measure was the achievement of remission on the evaluations during the 24 months. RESULTS: Of the 234 participants for whom data was available, 25 (10.7%) were regular cannabis users, and the group comprised significantly more males than females. In the total population, cannabis use was significantly associated with decreased likelihood of remission during the 24-month follow-up period. Subgroup analyses showed that cannabis use was significantly associated with lower remission rates on the Hamilton Depression Rating Scale in females (n=139) and patients prescribed mood stabilizers alone (n=151), whereas in males (n=95) and patients prescribed olanzapine and/or a mood stabilizer (n=83), cannabis use was significantly associated with lower remission rates on the Young Mania Rating Scale. Remission rates were lowest in the concurrent cannabis and tobacco smoking group (n=22) followed by the tobacco smoking only group (n=97), and the non-smoker group (n=116). The post-hoc analysis revealed that all remission rates were significantly lower in the concurrent cannabis and the tobacco smoking group compared to the non-smoker group. CONCLUSION: Cannabis use negatively affects the long-term clinical outcome in patients with bipolar spectrum disorders. A comprehensive assessment and integrated management of cannabis use are required to achieve better treatment outcomes for bipolar spectrum disorders.

Adolescent substance use and educational attainment: an integrative data analysis comparing cannabis and alcohol from three Australasian cohorts

BACKGROUND: The relative contributions of cannabis and alcohol use to educational outcomes are unclear. We examined the extent to which adolescent cannabis or alcohol use predicts educational attainment in emerging adulthood. METHODS: Participant-level data were integrated from three longitudinal studies from Australia and New Zealand (Australian Temperament Project, Christchurch Health and Development Study, and Victorian Adolescent Health Cohort Study). The number of participants varied by analysis (N=2179-3678) and were assessed on multiple occasions between ages 13 and 25. We described the association between frequency of cannabis or alcohol use prior to age 17 and high school non-completion, university non-enrolment, and degree non-attainment by age 25. Two other measures of alcohol use in adolescence were also examined. RESULTS: After covariate adjustment using a propensity score approach, adolescent cannabis use (weekly+) was associated with 1½ to two-fold increases in the odds of high school non-completion (OR=1.60, 95% CI=1.09-2.35), university non-enrolment (OR=1.51, 95% CI=1.06-2.13), and degree non-attainment (OR=1.96, 95% CI=1.36-2.81). In contrast, adjusted associations for all measures of adolescent alcohol use were inconsistent and weaker. Attributable risk estimates indicated adolescent cannabis use accounted for a greater proportion of the overall rate of non-progression with formal education than adolescent alcohol use. CONCLUSIONS: Findings are important to the debate about the relative harms of cannabis and alcohol use. Adolescent cannabis use is a better marker of lower educational attainment than adolescent alcohol use and identifies an important target population for preventive intervention.

Temperature and grain orientation dependence of mechanical twinning in a high manganese TWIP steel

 This thesis contains fundamental studies of the deformation mechanisms of the third generation steel at different deformation temperatures. To analyse the microstructure of the steel a unique characterisation technique was implemented for the first time. These analyses provided with vital parameters for modelling the stress-strain behaviour of the steel at different deformation temperatures.

Brain substrates of social decision-making in dual diagnosis: cocaine dependence and personality disorders

Cocaine dependence frequently co-occurs with personality disorders, leading to increased interpersonal problems and greater burden of disease. Personality disorders are characterised by patterns of thinking and feeling that divert from social expectations. However, the comorbidity between cocaine dependence and personality disorders has not been substantiated by measures of brain activation during social decision-making. We applied functional magnetic resonance imaging to compare brain activations evoked by a social decision-making task-the Ultimatum Game-in 24 cocaine dependents with personality disorders (CDPD), 19 cocaine dependents without comorbidities and 19 healthy controls. In the Ultimatum Game participants had to accept or reject bids made by another player to split monetary stakes. Offers varied in fairness (in fair offers the proposer shares ~50 percent of the money; in unfair offers the proposer shares <30 percent of the money), and participants were told that if they accept both players get the money, and if they reject both players lose it. We contrasted brain activations during unfair versus fair offers and accept versus reject choices. During evaluation of unfair offers CDPD displayed lower activation in the insula and the anterior cingulate cortex and higher activation in the lateral orbitofrontal cortex and superior frontal and temporal gyri. Frontal activations negatively correlated with emotion recognition. During rejection of offers CDPD displayed lower activation in the anterior cingulate cortex, striatum and midbrain. Dual diagnosis is linked to hypo-activation of the insula and anterior cingulate cortex and hyper-activation of frontal-temporal regions during social decision-making, which associates with poorer emotion recognition.

Prevalence of psychiatric co-morbidity in treatment-seeking problem gamblers: A systematic review and meta-analysis

OBJECTIVE: The aim of this paper was to systematically review and meta-analyse the prevalence of co-morbid psychiatric disorders (DSM-IV Axis I disorders) among treatment-seeking problem gamblers. METHODS: A systematic search was conducted for peer-reviewed studies that provided prevalence estimates of Axis I psychiatric disorders in individuals seeking psychological or pharmacological treatment for problem gambling (including pathological gambling). Meta-analytic techniques were performed to estimate the weighted mean effect size and heterogeneity across studies. RESULTS: Results from 36 studies identified high rates of co-morbid current (74.8%, 95% CI 36.5-93.9) and lifetime (75.5%, 95% CI 46.5-91.8) Axis I disorders. There were high rates of current mood disorders (23.1%, 95% CI 14.9-34.0), alcohol use disorders (21.2%, 95% CI 15.6-28.1), anxiety disorders (17.6%, 95% CI 10.8-27.3) and substance (non-alcohol) use disorders (7.0%, 95% CI 1.7-24.9). Specifically, the highest mean prevalence of current psychiatric disorders was for nicotine dependence (56.4%, 95% CI 35.7-75.2) and major depressive disorder (29.9%, 95% CI 20.5-41.3), with smaller estimates for alcohol abuse (18.2%, 95% CI 13.4-24.2), alcohol dependence (15.2%, 95% CI 10.2-22.0), social phobia (14.9%, 95% CI 2.0-59.8), generalised anxiety disorder (14.4%, 95% CI 3.9-40.8), panic disorder (13.7%, 95% CI 6.7-26.0), post-traumatic stress disorder (12.3%, 95% CI 3.4-35.7), cannabis use disorder (11.5%, 95% CI 4.8-25.0), attention-deficit hyperactivity disorder (9.3%, 95% CI 4.1-19.6), adjustment disorder (9.2%, 95% CI 4.8-17.2), bipolar disorder (8.8%, 95% CI 4.4-17.1) and obsessive-compulsive disorder (8.2%, 95% CI 3.4-18.6). There were no consistent patterns according to gambling problem severity, type of treatment facility and study jurisdiction. Although these estimates were robust to the inclusion of studies with non-representative sampling biases, they should be interpreted with caution as they were highly variable across studies. CONCLUSIONS: The findings highlight the need for gambling treatment services to undertake routine screening and assessment of psychiatric co-morbidity and provide treatment approaches that adequately manage these co-morbid disorders. Further research is required to explore the reasons for the variability observed in the prevalence estimates.