There is little investigation on the interaction effects of adverse childhood experiences (ACEs) and social support on non-suicidal self-injury (NSSI), suicidal ideation and suicide attempt in community adolescent populations, or gender differences in these effects.

To examine the individual and interaction effects of ACEs and social support on NSSI, suicidal ideation and suicide attempt in adolescents, and explore gender differences.

A school-based health survey was conducted in three provinces in China between 2013–2014. A total of 14 820 students aged 10–20 years completed standard questionnaires, to record details of ACEs, social support, NSSI, suicidal ideation and suicide attempt.

Of included participants, 89.4% reported one or more category of ACEs. The 12-month prevalence of NSSI, suicidal ideation and suicide attempt was 26.1%, 17.5% and 4.4%, respectively; all were significantly associated with increased ACEs and lower social support. The multiple adjusted odds ratio of NSSI in low versus high social support was 2.27 (95% CI 1.85–2.67) for girls and 1.81 (95% CI 1.53–2.14) for boys, and their ratio (Ratio of two odds ratios, ROR) was 1.25 (P = 0.037). Girls with high ACEs scores (5–6) and moderate or low social support also had a higher risk of suicide attempt than boys (RORs: 2.34, 1.84 and 2.02, respectively; all P < 0.05).

ACEs and low social support are associated with increased risk of NSSI and suicidality in Chinese adolescents. Strategies to improve social support, particularly among female adolescents with a high number of ACEs, should be an integral component of targeted mental health interventions.

None.

To assess the association of fish consumption with risk of dementia and its dose–response relationship, and investigate variations in the association among low-, middle- and high-income countries.

A new community-based cross-sectional study and a systematic literature review.

Urban and rural communities in China; population-based studies systematically searched from worldwide literature.

Chinese adults aged ≥60 years in six provinces (n 6981) took part in a household health survey of dementia prevalence and risk factors. In addition, 33 964 participants from eleven published and eligible studies were included in the systematic review and meta-analysis.

In the new study in China, 326 participants were diagnosed with dementia (4·7 %); those who consumed any amount of fish in the past two years v. those who consumed no fish had reduced risk of dementia (adjusted OR=0·73, 95 % CI 0·64, 0·99), but the dose–response relationship was not statistically significant. The meta-analysis of available data from the literature and the new study showed relative risk (RR) of dementia of 0·80 (95 % CI 0·74, 0·87) for people with fish consumption; the impact was similar among countries with different levels of income. Pooled dose–response data revealed RR (95 % CI) of 0·84 (0·72, 0·98), 0·78 (0·68, 0·90) and 0·77 (0·61, 0·98) in people with low, middle and high consumption of fish, respectively. Corresponding figures for Alzheimer’s disease were 0·88 (0·74, 1·04), 0·79 (0·65, 0·96) and 0·67 (0·58, 0·78), respectively.

Greater consumption of fish is associated with a lower risk of dementia. Increasing fish consumption may help prevent dementia worldwide regardless of income level.

People from lower socioeconomic groups have a higher risk of mortality. The impact of low socioeconomic status on survival among older adults with dementia and depression remains unclear.

To investigate the association between socioeconomic status and mortality in people with dementia and late-life depression in China.

Using Geriatric Mental Status – Automated Geriatric Examination for Computer Assisted Taxonomy (GMS-AGECAT) we interviewed 2978 people aged ⩾60 years in Anhui, China. We characterised baseline socioeconomic status and risk factors and diagnosed 223 people with dementia and 128 with depression. All-cause mortality was followed up over 5.6 years.

Individuals with dementia living in rural areas had a three times greater risk of mortality (multivariate adjusted hazard ratio (HR) = 2.96, 95% CI 1.45–6.04) than those in urban areas, and for those with depression the HR was 4.15 (95% CI 1.59–10.83). There were similar mortality rates when comparing people with dementia with low v. high levels of education, occupation and income, but individuals with depression with low v. high levels had non-significant increases in mortality of 11%, 50% and 55% respectively.

Older adults with dementia and depression living in rural China had a significantly higher risk of mortality than urban counterparts. Interventions should be implemented in rural areas to tackle survival inequality in dementia and depression.

Determinants for undetected dementia and late-life depression have been not well studied.

To investigate risk factors for undetected dementia and depression in older communities.

Using the method of the 10/66 algorithm, we interviewed a random sample of 7072 participants aged ⩽60 years in six provinces of China during 2007–2011. We documented doctor-diagnosed dementia and depression in the interview. Using the validated 10/66 algorithm we diagnosed dementia (n = 359) and depression (n = 328).

We found that 93.1% of dementia and 92.5% of depression was undetected. Both undetected dementia and depression were significantly associated with low levels of education and occupation, and living in a rural area. The risk of undetected dementia was also associated with ‘help available when needed‘, and inversely, with a family history of mental illness and having functional impairment. Undetected depression was significantly related to female gender, low income, having more children and inversely with having heart disease.

Older adults in China have high levels of undetected dementia and depression. General socioeconomic improvement, associated with mental health education, targeting high-risk populations are likely to increase detection of dementia and depression in older adults, providing a backdrop for culturally acceptable service development.

Depression and dementia often exist concurrently. The associations of depressive syndromes and severity of depression with incident dementia have been little studied.

To determine the effects of depressive syndromes and cases of depression on the risk of incident dementia.

Participants in China and the UK aged ⩾565 years without dementia were interviewed using the Geriatric Mental State interview and re-interviewed 1 year later in 1254 Chinese, and 2 and 4 years later in 3341 and 2157 British participants respectively (Ageing in Liverpool Project Health Aspects: part of the Medical Research Council – Cognitive Function and Ageing study).

Incident dementia was associated with only the most severe depressive syndromes in both Chinese and British participants. The risk of dementia increased, not in the less severe cases of depression but in the most severe cases. The multiple adjusted hazard ratio (HR)=5.44 (95% CI 1.67–17.8) for Chinese participants at 1-year follow-up, and HR=2.47 (95% CI 1.25–4.89) and HR=2.62 (95% CI 1.18–5.80) for British participants at 2- and 4-year follow-up respectively. The effect was greater in younger participants.

Only the most severe syndromes and cases of depression are a risk factor for dementia.

Risk factors of depression in later life, particularly for sub-cases and for psychotic and neurotic types of depression, are unclear.

To identify such risk factors.

Over 5200 older people ($65 years), randomly selected from Liverpool, were interviewed using the Geriatric Mental State (GMS)and the Minimum Data Set (MDS). The computer-assisted diagnosis AGECAT identified 483 cases and 575 sub-cases of depression and 2451 with no mental problems. Logistic regression was employed to examine factors relevant to caseness.

In multiple logistical regression, odds ratios (ORs) were significantly high for being female (2.04, 95% CI 1.56–2.69), widowed (2.00, 1.18–3.39), having alcohol problems (4.37, 1.40–2.94), physical disablement (2.03, 1.40–2.94), physical illness (1.98,.1.25–3.15), taking medications to calm down (10.04, 6.41 −15.71), and dissatisfaction with life (moderate 4.54, 3.50–5.90; more severe 29.00, 16.00–52.59). Good social networks reduced the ORs. If sub-cases were included as controls, the statistical significance was reduced.

Age was not associated with depression in later life whereas gender, physical disablement and dissatisfaction with life were. The sub-cases shared many risk factors with cases, suggesting that prevention may need to be attempted at an early stage.