Psychotic symptom and cannabis relapse in recent-onset psychosis - Prospective study

Background: Cannabis use appears to exacerbate psychotic symptoms and increase risk of psychotic relapse. However, the relative contribution of cannabis use compared with other risk factors is unclear. The influence of psychotic symptoms on cannabis use has received little attention. Aims: To examine the influence of cannabis use on psychotic symptom relapse and the influence of psychotic symptom severity on relapse in cannabis use in the 6 months following hospital admission. Method: At baseline, 84 participants with recent-onset psychosis were assessed and 81 were followed up weekly for 6 months, using telephone and face-to-face interviews. Results: A higher frequency of cannabis use was predictive of psychotic relapse, after controlling for medication adherence, other substance use and duration of untreated psychosis. An increase in psychotic symptoms was predictive of relapse to cannabis use, and medication adherence reduced cannabis relapse risk. Conclusions: The relationship between cannabis use and psychosis may be bidirectional, highlighting the need for early intervention programmes to target cannabis use and psychotic symptom severity in this population. Declaration of interest: None. Funding detailed in Acknowledgements.

The mental health risks of adolescent cannabis use

Since the early 1970s, when cannabis first began to be widely used [1], the proportion of young people who have used cannabis has steeply increased and the age of first use has declined [2, 3]. Most cannabis users now start in the mid-to-late teens [1], an important period of psychosocial transition when misadventures can have large adverse effects on a young person's life chances.

Effect of Mn deficiency and legume inoculation on rhizosphere pH in highly alkaline soils

Although plant growth is often limited at high pH, little is known about root-induced changes in the rhizospheres of plants growing in alkaline soils. The effect of Mn deficiency in Rhodes grass (Chloris gayana cv. Pioneer) and of legume inoculation in lucerne (Medicago sativa L. cv. Hunter River), on the rhizosphere pH of plants grown in highly alkaline bauxite residue was investigated. Rhizosphere pH was measured quantitatively, with a micro pH electrode, and qualitatively, with an agar/pH indicator solution. Manganese deficiency in Rhodes grass increased root-induced acidification of the rhizosphere in a soil profile in which N was supplied entirely as NO3-. Rhizosphere pH in the Mn deficient plants was up to 1.22 pH units lower than that of the bulk soil, while only 0.90 to 0.62 pH units lower in plants supplied with adequate Mn. When soil N was supplied entirely as NO3-, rhizosphere acidification was more efficient in inoculated lucerne (1.75 pH unit decrease) than in non-inoculated lucerne (1.16 pH unit decrease). This difference in capacity to lower rhizosphere pH is attributable to the ability of the inoculated lucerne to fix atmospheric N2 rather than relying on the soil N (NO3 ) reserves as the non-inoculated plants. Rhizosphere acidification in both Rhodes grass and lucerne was greatest in the meristematic root zone and least in the maturation root zone.

A review of the use of the basic cation saturation ratio and the "ideal" soil

The use of 'balanced' Ca, Mg, and K ratios, as prescribed by the basic cation saturation ratio (BCSR) concept, is still used by some private soil-testing laboratories for the interpretation of soil analytical data. This review aims to examine the suitability of the BCSR concept as a method for the interpretation of soil analytical data. According to the BCSR concept, maximum plant growth will be achieved only when the soil’s exchangeable Ca, Mg, and K concentrations are approximately 65 % Ca, 10 % Mg, and 5 % K (termed the ‘ideal soil’). This ‘ideal soil’ was originally proposed by Firman Bear and co-workers in New Jersey (USA) during the 1940s as a method of reducing luxury K uptake by alfalfa (Medicago sativa L.). At about the same time, William Albrecht, working in Missouri (USA), concluded through his own investigations that plants require a soil with a high Ca saturation for optimal growth. Whilst it now appears that several of Albrecht’s experiments were fundamentally flawed, the BCSR (‘balanced soil’) concept has been widely promoted, suggesting that the prescribed cationic ratios provide optimum chemical, physical, and biological soil properties. Our examination of data from numerous studies (particularly those of Albrecht and Bear, themselves) would suggest that, within the ranges commonly found in soils, the chemical, physical, and biological fertility of a soil is generally not influenced by the ratios of Ca, Mg, and K. The data do not support the claims of the BCSR, and continued promotion of the BCSR will result in the inefficient use of resources in agriculture and horticulture.

Jobless - Unemployment and young people's health

Morrell, Taylor and Kerr, from the University of Sydney's Department of Public Health, review the evidence of an association between unemployment and psychological and physical ill-health in young people aged 15-24 years. Aggregate data show youth unemployment and youth suicide to be strongly associated Youth unemployment is also associated with psychological symptoms, such as depression and loss of confidence. Effects on physical health have been less extensively studied; however, there is some evidence for an association with raised blood pressure. Finally, the prevalence of lifestyle risk factors (cannabis use and, less consistently tobacco and alcohol consumption) is higher in unemployed compared with employed young people.

Methadone maintenance and drug-related crime

Using data from an evaluation of methadone maintenance treatment, this study investigated factors associated with continued involvement irt crime during treatment, and in particular whether there appeared to be differences in effectiveness of treatment between different methadone clinics. The methodology was an observational study, in which 304 patients attending three low-intervention, private methadone clinics in Sydney were interviewed on three occasions over a twelve month period. Outcome measures were self-reported criminal activity and police department records of convictions. By self-report, crime dropped, promptly and substantially on entry to treatment, to a level of acquisitive crime about one-eighth that reported during the last addiction period. Analysis of official records indicated that rates of acquisitive convictions were significantly lower in the in-treatment period compared to prior to entry to treatment, corroborating the changes suggested by self-report. Persisting involvement in crime in treatment was predicted by two factors: the cost of persisting use of illicit drugs, particularly cannabis, and ASPD symptom count. Treatment factors also were independently predictive of continued involvement in crime. By both self-report and official records, and adjusting for subject factors, treatment at one clinic teas associated with greater involvement in crime. This clinic operated in a chaotic and poorly organized way. it is concluded that crime during methadone treatment is substantially lower than during street addiction, although the extent of reduction depends on the quality of treatment being delivered.