Acute and chronic tonsillitis are frequently treated with antibiotics. This study aimed to understand the presence of pathogenic micro-organisms on the surface and core of chronically infected tonsils among Tanzanian children.

The study enrolled children undergoing adenotonsillectomy. Surface and core tonsillar swabs were taken. Quantitative polymerase chain reaction was performed for Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, Staphylococcus aureus, Neisseria meningitidis and Pseudomonas aeruginosa.

Surface and core combined, isolated N meningitidis (86.1 per cent) was found the most, followed by H influenzae (74.9 per cent), S pneumoniae (42.6 per cent) and S aureus (28.7 per cent). M catarrhalis and P aeruginosa were only found in a few patients, 5.6 per cent and 0.8 per cent respectively.

Colonisation of the tonsillar surface and core has been found. Potentially pathogenic micro-organisms are likely to be missed based on a throat swab. Hence, the practice of surface tonsillar swabbing may be misleading or insufficient.

Little is known about the effect of ethnicity on the response to antipsychotic medication in patients with schizophrenia.

To determine whether ethnicity moderates the response to antipsychotic medication in patients with schizophrenia, and whether this moderation is independent of confounders.

We analysed 18 short-term, placebo-controlled registration trials of atypical antipsychotic medications in patients with schizophrenia (N = 3880). A two-step, random-effects, individual patient data meta-analysis was applied to establish the moderating effect of ethnicity (White versus Black) on symptom improvement according to the Brief Psychiatric Rating Scale (BPRS) and on response, defined as >30% BPRS reduction. These analyses were corrected for baseline severity, baseline negative symptoms, age and gender. A conventional meta-analysis was performed to determine the effect size of antipsychotic treatment for each ethnic group separately.

In the complete data-set, 61% of patients were White, 25.6% of patients were Black and 13.4% of patients were of other ethnicities. Ethnicity did not moderate the efficacy of antipsychotic treatment: pooled β-coefficient for the interaction between treatment and ethnic group was −0.582 (95% CI −2.567 to 1.412) for mean BPRS change, with an odds ratio of 0.875 (95% CI 0.510–1.499) for response. These results were not modified by confounders.

Atypical antipsychotic medication is equally effective in both Black and White patients with schizophrenia. In registration trials, White and Black patients were overrepresented relative to other ethnic groups, limiting the generalisability of our findings.

Structural variation in subcortical brain regions has been linked to substance use, including the most commonly used substances nicotine and alcohol. Pre-existing differences in subcortical brain volume may affect smoking and alcohol use, but there is also evidence that smoking and alcohol use can lead to structural changes.

We assess the causal nature of the complex relationship of subcortical brain volume with smoking and alcohol use, using bi-directional Mendelian randomisation.

Mendelian randomisation uses genetic variants predictive of a certain ‘exposure’ as instrumental variables to test causal effects on an ‘outcome’. Because of random assortment at meiosis, genetic variants should not be associated with confounders, allowing less biased causal inference. We used summary-level data of genome-wide association studies of subcortical brain volumes (nucleus accumbens, amygdala, caudate, hippocampus, pallidum, putamen and thalamus; n = 50 290) and smoking and alcohol use (smoking initiation, n = 848 460; cigarettes per day, n = 216 590; smoking cessation, n = 378 249; alcoholic drinks per week, n = 630 154; alcohol dependence, n = 46 568). The main analysis, inverse-variance weighted regression, was verified by a wide range of sensitivity methods.

There was strong evidence that liability to alcohol dependence decreased amygdala and hippocampal volume, and smoking more cigarettes per day decreased hippocampal volume. From subcortical brain volumes to substance use, there was no or weak evidence for causal effects.

Our findings suggest that heavy alcohol use and smoking can causally reduce subcortical brain volume. This adds to accumulating evidence that alcohol and smoking affect the brain, and likely mental health, warranting more recognition in public health efforts.

Obsessive-compulsive disorder (OCD) is a highly disabling condition, with frequent early onset. Adult/adolescent OCD has been extensively investigated, but little is known about prevalence and clinical characterization of geriatric patients with OCD (G-OCD = 65 years). The present study aimed to assess prevalence of G-OCD and associated socio-demographic and clinical correlates in a large international sample.

Data from 416 outpatients, participating in the ICOCS network, were assessed and categorized into 2 groups, age < vs = 65 years, and then divided on the basis of the median age of the sample (age < vs = 42 years). Socio-demographic and clinical variables were compared between groups (Pearson Chi-squared and t tests).

G-OCD compared with younger patients represented a significant minority of the sample (6% vs 94%, P < .001), showing a significantly later age at onset (29.4 ± 15.1 vs 18.7 ± 9.2 years, P < .001), a more frequent adult onset (75% vs 41.1%, P < .001) and a less frequent use of cognitive-behavioural therapy (CBT) (20.8% vs 41.8%, P < .05). Female gender was more represented in G-OCD patients, though not at a statistically significant level (75% vs 56.4%, P = .07). When the whole sample was divided on the basis of the median age, previous results were confirmed for older patients, including a significantly higher presence of women (52.1% vs 63.1%, P < .05).

G-OCD compared with younger patients represented a small minority of the sample and showed later age at onset, more frequent adult onset and lower CBT use. Age at onset may influence course and overall management of OCD, with additional investigation needed.