Determinants of high rates of smoking among people with psychosis living in a socially disadvantaged region in South Australia

Objective: This study aimed to identify factors associated with the high rates of smoking amongst people with psychosis living in a disadvantaged region in Adelaide, South Australia. Methods: Data were collected from 402 people with psychosis, aged 18–64 years, who lived in the northern suburbs of Adelaide. This area is disadvantaged on many measures of socioeconomic well-being and people living in this region have higher rates of smoking compared to the general Australian population. We hypothesised that whilst tobacco use by people with psychosis living in this region was primarily associated with mental illness, factors related to social disadvantage also contributed to the high rates of smoking. Results: Approximately 74% of men and 71% of women with psychotic disorders living in the northern suburbs of Adelaide were current smokers. Factors such as unemployment, lower levels of education and receiving government welfare, factors known to be associated with smoking in the general population, were more prevalent in the northern region. Smokers with psychosis were less likely to participate in recreational programs and physical activity, and more likely to use illicit substances and be a victim of crime. They had poorer health and financial outcomes than non-smokers. There were some gender differences: for men with psychosis, employment and having a post-school qualification decreased the risk of smoking while cannabis use increased the risk; for women with psychosis, a diagnosis of alcohol abuse/dependence, using cannabis and being sedentary were risk factors for smoking, while attending recreational programs reduced this risk. Conclusion: Smoking rates were strikingly high in both men and women, and particularly high in women when compared with previous research. Our study shows that the risk of smoking is increased by factors related to the social disadvantage of living in the northern Adelaide region. Smoking cessation interventions for people with mental illness should take into account the social context, and also address relevant comorbidities such as drug and alcohol disorders.Lisa Hahn, Ashlee Rigby and Cherrie Galletl

Effects of acute memantine administration on MATRICS Consensus Cognitive Battery performance in psychosis: Testing an experimental medicine strategy

RATIONALE: Pro-cognitive agents for chronic psychotic disorders (CPDs) might be detected via experimental medicine models, in which neural targets engaged by the drug predict sensitivity to the drug’s pro-cognitive effects. OBJECTIVE: This study aims to use an experimental medicine model to test the hypothesis that “target engagement” predicts pro-cognitive effects of the NMDA antagonist, memantine (MEM), in CPDs. METHODS: MATRICS Consensus Cognitive Battery (MCCB) performance was assessed in CPD (n = 41) and healthy subjects (HS; n = 41) in a double-blind, randomized cross-over design of acute (single dose) MEM (placebo vs. 10 or 20 mg p.o.). Measures of prepulse inhibition (PPI) and mismatch negativity previously reported from this cohort substantiated target engagement. Biomarkers predicting MEM neurocognitive sensitivity were assessed. RESULTS: Testing confirmed MCCB deficits associated with CPD diagnosis, age, and anticholinergic exposure. MEM (20 mg p.o.) reduced MCCB performance in HS. To control for significant test order effects, an “order-corrected MEM effect” (OCME) was calculated. In CPD subjects, greater age, positive MEM effects on PPI, and SNP rs1337697 (within the ionotropic NMDA receptor gene, GRIN3A) predicted greater positive OCME with 20 mg MEM. CONCLUSIONS: An experimental medicine model to assess acute pro-cognitive drug effects in CPD subjects is feasible but not without challenges. A single MEM 20 mg dose had a negative impact on neurocognition among HS. In CPD patients, age, MEM effects on PPI, and rs1337697 predicted sensitivity to the neurocognitive effects of MEM. Any potential clinical utility of these predictive markers for pro-cognitive effects of MEM in subgroups of CPD patients cannot be inferred without a validating clinical trial