Around the world, people living in objectively difficult circumstances who experience symptoms of generalized anxiety disorder (GAD) do not qualify for a diagnosis because their worry is not ‘excessive’ relative to the context. We carried out the first large-scale, cross-national study to explore the implications of removing this excessiveness requirement.

Data come from the World Health Organization World Mental Health Survey Initiative. A total of 133 614 adults from 12 surveys in Low- or Middle-Income Countries (LMICs) and 16 surveys in High-Income Countries (HICs) were assessed with the Composite International Diagnostic Interview. Non-excessive worriers meeting all other DSM-5 criteria for GAD were compared to respondents meeting all criteria for GAD, and to respondents without GAD, on clinically-relevant correlates.

Removing the excessiveness requirement increases the global lifetime prevalence of GAD from 2.6% to 4.0%, with larger increases in LMICs than HICs. Non-excessive and excessive GAD cases worry about many of the same things, although non-excessive cases worry more about health/welfare of loved ones, and less about personal or non-specific concerns, than excessive cases. Non-excessive cases closely resemble excessive cases in socio-demographic characteristics, family history of GAD, and risk of temporally secondary comorbidity and suicidality. Although non-excessive cases are less severe on average, they report impairment comparable to excessive cases and often seek treatment for GAD symptoms.

Individuals with non-excessive worry who meet all other DSM-5 criteria for GAD are clinically significant cases. Eliminating the excessiveness requirement would lead to a more defensible GAD diagnosis.

Major depressive disorder (MDD) is characterised by a recurrent course and high comorbidity rates. A lifespan perspective may therefore provide important information regarding health outcomes. The aim of the present study is to examine mental disorders that preceded 12-month MDD diagnosis and the impact of these disorders on depression outcomes.

Data came from 29 cross-sectional community epidemiological surveys of adults in 27 countries (n = 80 190). The Composite International Diagnostic Interview (CIDI) was used to assess 12-month MDD and lifetime DSM-IV disorders with onset prior to the respondent's age at interview. Disorders were grouped into depressive distress disorders, non-depressivedistress disorders, fear disorders and externalising disorders. Depression outcomes included 12-month suicidality, days out of role and impairment in role functioning.

Among respondents with 12-month MDD, 94.9% (s.e. = 0.4) had at least one prior disorder (including previous MDD), and 64.6% (s.e. = 0.9) had at least one prior, non-MDD disorder. Previous non-depressive distress, fear and externalising disorders, but not depressive distress disorders, predicted higher impairment (OR = 1.4–1.6) and suicidality (OR = 1.5–2.5), after adjustment for sociodemographic variables. Further adjustment for MDD characteristics weakened, but did not eliminate, these associations. Associations were largely driven by current comorbidities, but both remitted and current externalising disorders predicted suicidality among respondents with 12-month MDD.

These results illustrate the importance of careful psychiatric history taking regarding current anxiety disorders and lifetime externalising disorders in individuals with MDD.

Depressive and anxiety disorders are highly comorbid, which has been theorized to be due to an underlying internalizing vulnerability. We aimed to identify groups of participants with differing vulnerabilities by examining the course of internalizing psychopathology up to age 45.

We used data from 24158 participants (aged 45+) in 23 population-based cross-sectional World Mental Health Surveys. Internalizing disorders were assessed with the Composite International Diagnostic Interview (CIDI). We applied latent class growth analysis (LCGA) and investigated the characteristics of identified classes using logistic or linear regression.

The best-fitting LCGA solution identified eight classes: a healthy class (81.9%), three childhood-onset classes with mild (3.7%), moderate (2.0%), or severe (1.1%) internalizing comorbidity, two puberty-onset classes with mild (4.0%) or moderate (1.4%) comorbidity, and two adult-onset classes with mild comorbidity (2.7% and 3.2%). The childhood-onset severe class had particularly unfavorable sociodemographic outcomes compared to the healthy class, with increased risks of being never or previously married (OR = 2.2 and 2.0, p < 0.001), not being employed (OR = 3.5, p < 0.001), and having a low/low-average income (OR = 2.2, p < 0.001). Moderate or severe (v. mild) comorbidity was associated with 12-month internalizing disorders (OR = 1.9 and 4.8, p < 0.001), disability (B = 1.1–2.3, p < 0.001), and suicidal ideation (OR = 4.2, p < 0.001 for severe comorbidity only). Adult (v. childhood) onset was associated with lower rates of 12-month internalizing disorders (OR = 0.2, p < 0.001).

We identified eight transdiagnostic trajectories of internalizing psychopathology. Unfavorable outcomes were concentrated in the 1% of participants with childhood onset and severe comorbidity. Early identification of this group may offer opportunities for preventive interventions.

The present study explored associations between food choice motives, attitudes towards and intention to adopt personalised nutrition, to inform communication strategies based on consumer priorities and concerns.

A survey was administered online which included the Food Choice Questionnaire (FCQ) and items assessing attitudes towards and intention to adopt personalised nutrition.

Nationally representative samples were recruited in nine EU countries (n 9381).

Structural equation modelling indicated that the food choice motives ‘weight control’, ‘mood’, ‘health’ and ‘ethical concern’ had a positive association and ‘price’ had a negative association with attitude towards, and intention to adopt, personalised nutrition. ‘Health’ was positively associated and ‘familiarity’ negatively associated with attitude towards personalised nutrition. The effects of ‘weight control’, ‘ethical concern’, ‘mood’ and ‘price’ on intention to adopt personalised nutrition were partially mediated by attitude. The effects of ‘health’ and ‘familiarity’ were fully mediated by attitude. ‘Sensory appeal’ was negatively and directly associated with intention to adopt personalised nutrition.

Personalised nutrition providers may benefit from taking into consideration the importance of underlying determinants of food choice in potential users, particularly weight control, mood and price, when promoting services and in tailoring communications that are motivationally relevant.

The patterns of comorbidity among mental disorders have led researchers to model the underlying structure of psychopathology. While studies have suggested a structure including internalizing and externalizing disorders, less is known with regard to the cross-national stability of this model. Moreover, little data are available on the placement of eating disorders, bipolar disorder and psychotic experiences (PEs) in this structure.

We evaluated the structure of mental disorders with data from the World Health Organization Composite International Diagnostic Interview, including 15 lifetime mental disorders and six PEs. Respondents (n = 5478–15 499) were included from 10 high-, middle- and lower middle-income countries across the world aged 18 years or older. Confirmatory factor analyses (CFAs) were used to evaluate and compare the fit of different factor structures to the lifetime disorder data. Measurement invariance was evaluated with multigroup CFA (MG-CFA).

A second-order model with internalizing and externalizing factors and fear and distress subfactors best described the structure of common mental disorders. MG-CFA showed that this model was stable across countries. Of the uncommon disorders, bipolar disorder and eating disorder were best grouped with the internalizing factor, and PEs with a separate factor.

These results indicate that cross-national patterns of lifetime common mental-disorder comorbidity can be explained with a second-order underlying structure that is stable across countries and can be extended to also cover less common mental disorders.

Major depressive disorder (MDD) is a leading cause of disability worldwide.

To examine the: (a) 12-month prevalence of DSM-IV MDD; (b) proportion aware that they have a problem needing treatment and who want care; (c) proportion of the latter receiving treatment; and (d) proportion of such treatment meeting minimal standards.

Representative community household surveys from 21 countries as part of the World Health Organization World Mental Health Surveys.

Of 51 547 respondents, 4.6% met 12-month criteria for DSM-IV MDD and of these 56.7% reported needing treatment. Among those who recognised their need for treatment, most (71.1%) made at least one visit to a service provider. Among those who received treatment, only 41.0% received treatment that met minimal standards. This resulted in only 16.5% of all individuals with 12-month MDD receiving minimally adequate treatment.

Only a minority of participants with MDD received minimally adequate treatment: 1 in 5 people in high-income and 1 in 27 in low-/lower-middle-income countries. Scaling up care for MDD requires fundamental transformations in community education and outreach, supply of treatment and quality of services.

Previous research suggests that many people receiving mental health treatment do not meet criteria for a mental disorder but are rather ‘the worried well’.

To examine the association of past-year mental health treatment with DSM-IV disorders.

The World Health Organization's World Mental Health (WMH) Surveys interviewed community samples of adults in 23 countries(n = 62 305) about DSM-IV disorders and treatment in the past 12 months for problems with emotions, alcohol or drugs.

Roughly half (52%) of people who received treatment met criteria for a past-year DSM-IV disorder, an additional 18% for a lifetime disorder and an additional 13% for other indicators of need (multiple subthreshold disorders, recent stressors or suicidal behaviours). Dose–response associations were found between number of indicators of need and treatment.

The vast majority of treatment in the WMH countries goes to patients with mental disorders or other problems expected to benefit from treatment.

Previous community surveys of the drop out from mental health treatment have been carried out only in the USA and Canada.

To explore mental health treatment drop out in the World Health Organization World Mental Health Surveys.

Representative face-to-face household surveys were conducted among adults in 24 countries. People who reported mental health treatment in the 12 months before interview (n = 8482) were asked about drop out, defined as stopping treatment before the provider wanted.

Overall, drop out was 31.7%: 26.3% in high-income countries, 45.1% in upper-middle-income countries, and 37.6% in low/ lower/middle-income countries. Drop out from psychiatrists was 21.3% overall and similar across country income groups (high 20.3%, upper-middle 23.6%, low/lower-middle 23.8%) but the pattern of drop out across other sectors differed by country income group. Drop out was more likely early in treatment, particularly after the second visit.

Drop out needs to be reduced to ensure effective treatment.

Mental and physical disorders are associated with total disability, but their effects on days with partial disability (i.e. the ability to perform some, but not full-role, functioning in daily life) are not well understood.

To estimate individual (i.e. the consequences for an individual with a disorder) and societal effects (i.e. the avoidable partial disability in the society due to disorders) of mental and physical disorders on days with partial disability around the world.

Respondents from 26 nationally representative samples (n = 61 259, age 18+) were interviewed regarding mental and physical disorders, and day-to-day functioning. The Composite International Diagnostic Interview, version 3.0 (CIDI 3.0) was used to assess mental disorders; partial disability (expressed in full day equivalents) was assessed with the World Health Organization Disability Assessment Schedule in the CIDI 3.0.

Respondents with disorders reported about 1.58 additional disability days per month compared with respondents without disorders. At the individual level, mental disorders (especially post-traumatic stress disorder, depression and bipolar disorder) yielded a higher number of days with disability than physical disorders. At the societal level, the population attributable risk proportion due to physical and mental disorders was 49% and 15% respectively.

Mental and physical disorders have a considerable impact on partial disability, at both the individual and at the societal level. Physical disorders yielded higher effects on partial disability than mental disorders.