Accurate diagnosis of bipolar disorder (BPD) is difficult in clinical practice, with an average delay between symptom onset and diagnosis of about 7 years. A depressive episode often precedes the first manic episode, making it difficult to distinguish BPD from unipolar major depressive disorder (MDD).

We use genome-wide association analyses (GWAS) to identify differential genetic factors and to develop predictors based on polygenic risk scores (PRS) that may aid early differential diagnosis.

Based on individual genotypes from case–control cohorts of BPD and MDD shared through the Psychiatric Genomics Consortium, we compile case–case–control cohorts, applying a careful quality control procedure. In a resulting cohort of 51 149 individuals (15 532 BPD patients, 12 920 MDD patients and 22 697 controls), we perform a variety of GWAS and PRS analyses.

Although our GWAS is not well powered to identify genome-wide significant loci, we find significant chip heritability and demonstrate the ability of the resulting PRS to distinguish BPD from MDD, including BPD cases with depressive onset (BPD-D). We replicate our PRS findings in an independent Danish cohort (iPSYCH 2015, N = 25 966). We observe strong genetic correlation between our case–case GWAS and that of case–control BPD.

We find that MDD and BPD, including BPD-D are genetically distinct. Our findings support that controls, MDD and BPD patients primarily lie on a continuum of genetic risk. Future studies with larger and richer samples will likely yield a better understanding of these findings and enable the development of better genetic predictors distinguishing BPD and, importantly, BPD-D from MDD.

Estimate the impact of 20 % flat-rate and tiered sugary drink tax structures on the consumption of sugary drinks, sugar-sweetened beverages and 100 % juice by age, sex and socio-economic position.

We modelled the impact of price changes – for each tax structure – on the demand for sugary drinks by applying own- and cross-price elasticities to self-report sugary drink consumption measured using single-day 24-h dietary recalls from the cross-sectional, nationally representative 2015 Canadian Community Health Survey-Nutrition. For both 20 % flat-rate and tiered sugary drink tax scenarios, we used linear regression to estimate differences in mean energy intake and proportion of energy intake from sugary drinks by age, sex, education, food security and income.

Canada.

19 742 respondents aged 2 and over.

In the 20 % flat-rate scenario, we estimated mean energy intake and proportion of daily energy intake from sugary drinks on a given day would be reduced by 29 kcal/d (95 % UI: 18, 41) and 1·3 % (95 % UI: 0·8, 1·8), respectively. Similarly, in the tiered tax scenario, additional small, but meaningful reductions were estimated in mean energy intake (40 kcal/d, 95 % UI: 24, 55) and proportion of daily energy intake (1·8 %, 95 % UI: 1·1, 2·5). Both tax structures reduced, but did not eliminate, inequities in mean energy intake from sugary drinks despite larger consumption reductions in children/adolescents, males and individuals with lower education, food security and income.

Sugary drink taxation, including the additional benefit of taxing 100 % juice, could reduce overall and inequities in mean energy intake from sugary drinks in Canada.

Peritonsillar abscess is a localised infection in the peritonsillar space. Pus from the abscess can contain anaerobes. Many clinicians prescribe metronidazole in addition to penicillin, but evidence to support this is limited. This review assessed the evidence of benefit of metronidazole for the treatment of peritonsillar abscess.

A systematic review was conducted of the literature and databases including Ovid Medline, Ovid Embase, PubMed and Cochrane library. Search terms included all variations of peritonsillar abscess, penicillin and metronidazole.

Three randomised, control trials were included. All studies assessed the clinical outcomes after treatment for peritonsillar abscess, including recurrence rate, length of hospital stay and symptom improvement. There was no evidence to suggest additional benefit with metronidazole, with studies suggesting increased side effects.

Evidence does not support the addition of metronidazole in first-line management of peritonsillar abscess. Further trials to establish optimum dose and duration schedules of oral phenoxymethylpenicillin would benefit clinical practice.

Although most people do not develop mental health disorders after exposure to traumatic events, they may experience subtle changes in cognitive functioning. We previously reported that 2–3 years after the Canterbury earthquake sequence, a group of trauma-exposed people, who identified as resilient, performed less well on tests of spatial memory, had increased accuracy identifying facial emotions and misclassified neutral facial expressions to threat-related emotions, compared with non-exposed controls.

The current study aimed to examine the long-term cognitive effects of exposure to the earthquakes in this resilient group, compared with a matched non-exposed control group.

At 8–9 years after the Canterbury earthquake sequence, 57 earthquake-exposed resilient (69% female, mean age 56.8 years) and 60 non-exposed individuals (63% female, mean age 55.7 years) completed a cognitive testing battery that assessed verbal and visuospatial learning and memory, executive functioning, psychomotor speed, sustained attention and social cognition.

With the exception of a measure of working memory (Digit Span Forward), no significant differences were found in performance between the earthquake-exposed resilient and non-exposed groups on the cognitive tasks. Examination of changes in cognitive functioning over time in a subset (55%) of the original earthquake-exposed resilient group found improvement in visuospatial performance and slowing of reaction times to negative emotions.

These findings offer preliminary evidence to suggest that changes in cognitive functioning and emotion processing in earthquake-exposed resilient people may be state-dependent and related to exposure to continued threat in the environment, which improves when the threat resolves.

Using physiological markers to detect patients at risk of deterioration is common. Deaths at music festivals in Australia prompted scrutiny of tools to identify critically unwell patients for transport to hospital. This study evaluated initial physiological parameters to identify patients selected for transport to hospital from a music festival.

A retrospective audit of 2045 presentations at music festivals in Victoria, Australia, was performed. Presentation heart rate, systolic blood pressure, respiratory rate, oxygen saturation, temperature, and Glasgow Coma Scale were assessed using area under the receiver operating characteristic curve (AUROC) analysis, with a prespecified threshold of 0.7.

The only measured variable to exceed the prespecified cutpoint was initial systolic blood pressure, with an AUROC of 0.72 and optimal cutpoint of 122 mmHg. Using commonly accepted cutpoints for variables did not improve detection performance to acceptable levels, nor did using combination systems of cutpoints.

Initial physiological variables are poor predictors of the decision to transport to hospital from music festivals. Systolic blood pressure was significant, but only at a clinically insignificant value. Decisions on which patients to transport from an event site should incorporate more information than initial physiology. Senior clinicians should lead decision-making about hospital transport from music festivals.

Studying phenotypic and genetic characteristics of age at onset (AAO) and polarity at onset (PAO) in bipolar disorder can provide new insights into disease pathology and facilitate the development of screening tools.

To examine the genetic architecture of AAO and PAO and their association with bipolar disorder disease characteristics.

Genome-wide association studies (GWASs) and polygenic score (PGS) analyses of AAO (n = 12 977) and PAO (n = 6773) were conducted in patients with bipolar disorder from 34 cohorts and a replication sample (n = 2237). The association of onset with disease characteristics was investigated in two of these cohorts.

Earlier AAO was associated with a higher probability of psychotic symptoms, suicidality, lower educational attainment, not living together and fewer episodes. Depressive onset correlated with suicidality and manic onset correlated with delusions and manic episodes. Systematic differences in AAO between cohorts and continents of origin were observed. This was also reflected in single-nucleotide variant-based heritability estimates, with higher heritabilities for stricter onset definitions. Increased PGS for autism spectrum disorder (β = −0.34 years, s.e. = 0.08), major depression (β = −0.34 years, s.e. = 0.08), schizophrenia (β = −0.39 years, s.e. = 0.08), and educational attainment (β = −0.31 years, s.e. = 0.08) were associated with an earlier AAO. The AAO GWAS identified one significant locus, but this finding did not replicate. Neither GWAS nor PGS analyses yielded significant associations with PAO.

AAO and PAO are associated with indicators of bipolar disorder severity. Individuals with an earlier onset show an increased polygenic liability for a broad spectrum of psychiatric traits. Systematic differences in AAO across cohorts, continents and phenotype definitions introduce significant heterogeneity, affecting analyses.

The degree to which suicide risk aggregates in US families is unknown. The authors aimed to determine the familial risk of suicide in Utah, and tested whether familial risk varies based on the characteristics of the suicides and their relatives.

A population-based sample of 12 160 suicides from 1904 to 2014 were identified from the Utah Population Database and matched 1:5 to controls based on sex and age using at-risk sampling. All first through third- and fifth-degree relatives of suicide probands and controls were identified (N = 13 480 122). The familial risk of suicide was estimated based on hazard ratios (HR) from an unsupervised Cox regression model in a unified framework. Moderation by sex of the proband or relative and age of the proband at time of suicide (<25 v. ⩾25 years) was examined.

Significantly elevated HRs were observed in first- (HR 3.45; 95% CI 3.12–3.82) through fifth-degree relatives (HR 1.07; 95% CI 1.02–1.12) of suicide probands. Among first-degree relatives of female suicide probands, the HR of suicide was 6.99 (95% CI 3.99–12.25) in mothers, 6.39 in sisters (95% CI 3.78–10.82), and 5.65 (95% CI 3.38–9.44) in daughters. The HR in first-degree relatives of suicide probands under 25 years at death was 4.29 (95% CI 3.49–5.26).

Elevated familial suicide risk in relatives of female and younger suicide probands suggests that there are unique risk groups to which prevention efforts should be directed – namely suicidal young adults and women with a strong family history of suicide.

Antidepressant use has risen x3-5 in Western countries since the early 1990s, outstripping changes in depression incidence or prevalence. This represents a major public health challenge.

Nationally-collected antidepressant data were used to assess the impact of "Doing Well", (DW) a novel depression care programme operating in Renfrewshire, Scotland. "Doing Well" implemented a model of “stepped collaborative care”, practitioner education and significant service redesign. Prescribing was compared for three groups: "DW" (76,000 population; clinical and educational intervention), "DW neighbours” (101,000 population; educational interventions only), and Scotland (no specific intervention).

A national rise in antidepressant prescriptions was stabilised for the "DW" group (graph). Antidepressant cost/item fell by 42% and 40% in both “DW” and “DW neighbours” groups but rose by 8% nationally.

Access to clinical interventions are required to reduce antidepressant prescriptions, but cost savings may be made with educational interventions alone.

Triage at mass gatherings in Australia is commonly performed by staff members with first aid training. There have been no evaluations of the performance of first aid staff with respect to diagnostic accuracy or identification of presentations requiring ambulance transport to hospital.

It was hypothesized that triage decisions by first aid staff would be considered correct in at least 61% of presentations.

A retrospective audit of 1,048 presentations to a single supplier of event health care services in Australia was conducted. The presentations were assessed based on the first measured set of physiological parameters, and the primary triage decision was classified as “expected” if the primary and secondary triage classifications were the same or “not expected” if they differed. The performance of the two triage systems was compared using area under the receiver operating characteristic curve (AUROC) analysis.

The expected decision was made by first aid staff in 674 (71%) of presentations. Under-triage occurred in 131 (14%) presentations and over-triage in 142 (15%) presentations. The primary triage strategy had an AUROC of 0.7644, while the secondary triage strategy had an AUROC of 0.6280, which was significantly different (P = .0199).

The results support the continued use of first aid trained staff members in triage roles at Australian mass gatherings. Triage tools should be simple, and the addition of physiological variables to improve the sensitivity of triage tools is not recommended because such an approach does not improve the discriminatory capacity of the tools.

Serotonin and sympathomimetic toxicity (SST) after ingestion of amphetamine-based drugs can lead to severe morbidity and death. There have been evaluations of the safety and efficacy of on-site treatment protocols for SST at music festivals.

The study aimed to examine the safety and efficacy of treating patients with SST on-site at a music festival using a protocol adapted from hospital-based treatment of SST.

The study is an audit of presentations with SST over a one-year period. The primary outcome was need for ambulance transport to hospital. The threshold for safety was prospectively defined as less than 10% of patients requiring ambulance transport to hospital.

The protocol suggested patients be treated with a combination of benzodiazepines; cold intravenous (IV) fluid; specific therapies (cyproheptadine, chlorpromazine, and clonidine); rapid sequence intubation; and cooling with ice, misted water, and convection techniques.

One patient of 13 (7.7%) patients with mild or moderate SST required ambulance transport to hospital. Two of seven further patients with severe SST required transport to hospital.

On-site treatment may be a safe, efficacious, and efficient alternative to urgent transport to hospital for patients with mild and moderate SST. The keys to success of the protocol tested included inclusive and clear education of staff at all levels of the organization, robust referral pathways to senior clinical staff, and the rapid delivery of therapies aimed at rapidly lowering body temperature. Further collaborative research is required to define the optimal approach to patients with SST at music festivals.