DASH gives insights into the diversity of contemporary urban life for young people in London. Eighty-six countries of birth, ~100 languages and ~50 religions were reported. 51 % spoke a language other than English at home. While 63 % of ethnic minorities were UK-born, 87 % had at least one foreign-born parent. Religious affiliation was high in all ethnic minority groups. Christianity was the dominant religion for White British (39 %), Black Caribbeans (78 %) and Black Africans (73 %), Hinduism for Indians (59 %), and Islam for Pakistanis/Bangladeshis (96 %). 21 % of Black Africans were Muslims.
Table 1 shows ethnic distributions of measures of structural adversity, psychosocial support and key health behaviours in adolescence. Ethnic minority adolescents remained generally more exposed to structural adversity than White British, including more racism and, apart from Indians, more socio-economic disadvantage. Black Caribbeans and Black Africans were more likely to be in a lone parent household and South Asians least likely. Ethnic minorities also reported more attendance to a place of worship, higher parental control and less parental care , and significantly more engagement in family activities (data not shown) . Ethnic diversity in friendships was common across all groups . In relation to health behaviours, ethnic minorities were generally less likely to report tobacco smoking or alcohol consumption, but this increased with age. Questionnaire responses for smoking were validated with salivary cotinine . Overweight and skipping breakfast (a correlate of childhood obesity), however, were more common among some groups, notably Black Caribbean and Black African girls .
Findings from the pilot follow-up at 21–23 years suggest a shift towards socio-economic parity across ethnic groups in relation to higher education. Forty percent of White British had completed a degree, compared with 57 % Indians and Black Africans, 49 % Pakistanis/Bangladeshis, and 34 % Black Caribbeans. Ethnic differences remained, however, in perceived racism , parental control, and attendance to a place of worship. Twenty percent of White British, 52 % of Black Africans and 38 % of Indians reported racism. Higher proportions of ethnic minority groups reported high parental control, ranging from 33 % of Black Africans to 7 % of White British. Similarly, attendance at a place of worship at least once a week remained more common for ethnic minorities (Whites 2 %, Indians 23 %, Pakistani/Bangladeshis 39 %, Black Africans 47 %, Black Caribbeans 23 %).
Better mental health despite structural adversity in adolescence
Figure 1 illustrates the ethnic patterning of mean TDS. Ethnic minority boys and girls in DASH generally reported better psychological well-being than White British throughout adolescence. Lowest TDS was consistently observed for Black African boys and Indian girls [24, 28, 29, 33]. These patterns remained after adjustment for whether born in the UK or abroad, individual SEC, psychosocial support, and neighbourhood (based on Carstairs index ) and school (e.g. percentage eligible for free school meals) SEC. We also examined ‘probable clinical cases’ using a cut-off of TDS >17 (http://www.sdqinfo.org/py/doc/c0.py) by gender and ethnicity, adjusted for potential modifying factors. The pattern by ethnicity was similar to that seen for mean TDS.
In contrast to boys, girls born abroad had better psychological well-being compared with UK-born girls (mean difference in TDS −0.50, 95 % confidence interval −0.95 to −0.05). This effect did not differ by ethnicity. Unlike other measures of adversity, perceived racism was consistently associated with poorer psychological well-being across gender, ethnicity and age. For example, mean difference in TDS between boys who experienced racism and those who did not at age 12 years was −1.88 (−1.75 to −2.01) and at 16 years was −1.19 (−1.07 to −1.31) . Regardless of ethnicity, girls reporting low family affluence had worse psychological well-being which remained significant on adjustment for psychosocial influences (+1.16, 0.21 to 2.10). Living in deprived neighbourhoods was associated with poorer psychological well-being only for White British and Black Caribbeans.
Parenting, religion, and mental health
Other recent studies report a similar ethnic minority advantage in mental health [36, 37], but it remains unclear what accounts for this apparent resilience. In DASH, regardless of ethnicity, measures of parental care, family connectedness, cultural integration (measured by ethnic diversity of friendships ), and frequency of attendance at a place of worship were consistently associated with a protective effect on mental health even after adjustment for SEC [24, 28, 29]. Figures 2 and 3 illustrate this for parenting and place of worship attendance. Increasing parental care, decreasing parental control, and increasing frequency of attendance were independent correlates of better psychological well-being. Religious affiliation itself was not associated with mental health. We also examined the influence of potential psychosocial support from ethnic density and diversity in schools and communities . High own group ethnic density has been hypothesised to be protective of mental health as a result of common social norms and access to support networks . In contrast to studies with adults , DASH showed little evidence of an effect of own group ethnic density or diversity on psychological well-being .
The interpretation of these findings is complex. The consistency of TDS patterns across ethnic groups argues against any substantial reporting bias by ethnicity. However, cultural influences on family life appear to play an important role. We previously reported that the pattern of relatively better mental health compared with White British was observed among those who reported least autonomy (high parental control) in low SEC as well as two-parent families . Social ecological approaches recognise interactions between individual, social and environmental factors in fostering resilience, including cultural patterns of family life and access to opportunities and resources . The parenting experiences of ethnic minorities are consistent with an ‘authoritative’ parenting style combining warmth and support with a disciplinary framework, considered optimal for child development [42, 43] and academic achievement . Specific goal-directed parenting practices, such as helping with homework or engaging children in family social functions, may also be beneficial .
DASH findings are partially consistent with evidence for a protective effect from religious involvement on mental health in adolescence [46, 47]. Religion is thought to influence mental health through social support, social regulation, a sense of meaning and coherence, and positive coping . Regardless of religious affiliation, attendance to a place of worship provides wider family support from a community with shared norms and values . For example, if greater parental control is considered normative in a community, religious involvement may reinforce this parenting style, the children may not perceive the relative lack of autonomy to be unfair, and its influence on mental health may be less negative than for White British children. The qualitative interviews (reported below) gave insight into such intersections between religion, culture and family life.
Cardio-respiratory health and psychological well-being in adolescence
While mental health resilience among ethnic minorities has been a feature throughout adolescence in DASH, a less positive picture emerged for physical health. In summary, DASH has shown systematic differences in cardio-respiratory health risks in adolescence. For example, at age 12 years, many ethnic minority groups had lower systolic blood pressure (BP) than White British, but greater age-related increases by 16 years. By age 16 years, African boys had significantly higher BP than White British, after accounting for differences in body size . Lower lung function for most minority groups compared with White British persisted after taking into account anthropometric differences , and there was more asthma in Black Caribbean boys. As reported above, there were also significant ethnic differences in overweight , with skipping breakfast, maternal overweight and maternal smoking key correlates across all groups [51, 52].
Psychosocial support mattered for some of these outcomes. Table 2 shows that attendance at a place of worship less than once per week and low parental care were both independently related to current tobacco smoking, alcohol use, and skipping breakfast. Ethnic patterns of generally less smoking or alcohol use were maintained after adjusting for SEC, parenting and religious involvement. In contrast to TDS, religious affiliation was independently associated with some behaviours. For example, Hindu girls and Muslim boys and girls were less likely to smoke or drink alcohol, regardless of frequency of attendance to a temple or mosque. There was also some evidence of the varying relationship between ethnicity, religion and place of worship attendance. For example, the lower likelihood of drinking alcohol with increasing frequency of attendance appeared to be more distinct for Pakistani/Bangladeshi or Muslim boys than for White British or Christian boys. Psychological well-being was also associated with some of these outcomes although reverse causality is possible. Adjusted for SEC, poorer psychological well-being was associated with lower lung function , and a higher likelihood of asthma . Figure 4 illustrates a similar pattern with increasing mean TDS associated with a greater likelihood of smoking, alcohol consumption, and skipping breakfast.
Tracking of resilience at 21–23 years in the pilot follow-up sample?
A key question is whether the relative mental health advantage found in ethnic minority adolescents will erode with age and whether positive psychosocial influences in childhood will continue to have a favourable effect in adulthood. While interpretation of the findings from the pilot follow-up at 21–23 years should be viewed with caution because of the small sample size (N = 665), the pattern of GHQ-12 scores among ethnic minority groups indicates potential continuation of the mental health advantage into early adulthood. Adjusted for gender, SEC and psychosocial support, and compared to White British (GHQ mean 12.4), there was a pattern of lower GHQ scores in Black Caribbeans (−1.22, 95 % confidence interval −3.23 to 0.80), Black Africans (−2.56, −4.65 to −0.46), Indians (−3.19, −5.86 to −0.52), and Pakistanis/Bangladeshis (−0.37, −3.03 to 2.29). GHQ scores were higher for females (+2.27, 1.14 to 3.41) than males (GHQ mean 10.2), among those who reported low maternal care (+2.85, 1.33 to 4.36) than high care (GHQ 9.7), and among those who reported high maternal control (+1.90, 0.28 to 3.53) than low control (GHQ 10.5). In contrast to what was observed in adolescence, religion or place of worship attendance did not appear to be associated with mental health. Small sample sizes prevent reliable inferences, but the continuity and discontinuity of these patterns in adulthood raise intriguing questions as to why parenting, but not attendance to a place of worship, remained significant. Arguably whilst the experience of parenting may have remained similar for participants in their 20s, what it means to attend a place of worship may have changed.
Perceptions of childhood experiences and transition to adulthood
Qualitative interviews at 21–23 years enhanced the interpretation of quantitative findings on mental health in adolescence and young adulthood. In a separate paper, we report on the cultural appropriateness of the GHQ comparing data from questionnaire responses and qualitative interviews. In brief, the GHQ-12 appears to be conceptually congruent regardless of ethnicity; however, known sensitivity to temporal effects may have had some effect on mean scores. High mean scores in the pilot study sample may be a consequence of acute stresses related to life-stage transitions particularly study, financial difficulties or finding work. One participant who scored 7 on the GHQ bimodal score (indicating poor psychological well-being) stated: “Lately it’s because like I haven’t been able to find a job. So I feel like, ‘Oh my God, I don’t have any money, how am I going to live?’ Stuff like that. That’s what’s really straining me right now” (Participant 25, Female, Bangladeshi, degree, one parent).
Key themes emerged in the qualitative analysis around the influence of family life and religion on well-being through a variety of intersecting, mutually reinforcing effects including: group membership and cultural identity, social and instrumental support, moral guidance, aspirations and sense of purpose, and coping strategies (Box 1). These map onto factors which have been identified as fostering resilience from childhood into early adult life including identity formation, social support, ‘planfulness’ (future motivation) and coping skills .
Continued commitment to family life and values from childhood into adulthood was a recurring theme regardless of family type. Several participants described the absence of a father from the household due to separation, divorce or migration, however, access to networks of support through extended and transnational family ties was common. Most participants were living in the family home at 21–23 years facilitating the continuation of close family ties and access to social and instrumental support during study or insecure, low-paid employment. Higher reported parental control among ethnic minorities may reflect cultural and religious influences on parenting styles with “strict”, “traditional” or “authoritative” parenting based on respect for elders and those in authority linked to perceived “Asian”, “Caribbean” or “African” cultural values, as well as Christian or Islamic teaching.
Many described such parenting as shaping aspirations in adult life. In participants’ accounts parental discipline was often combined with encouragement to “work hard” and “do your best”. Ethnic minority participants expressed high educational and career goals nurtured by parents’ aspirations and an awareness of opportunities for social mobility resulting from parents’ migration and hard work, often in low-paid, low-status jobs such as cleaners, security guards and taxi drivers. The ethnic parity in higher education status at 21–23 years in DASH is comparable to that reported for 16–24 years olds in the 2011 census and a striking contrast to ethnic differences in education status for their parents’ generation . Selection factors might also have played a role. As migrants, their parents are likely to have experienced downward mobility on migration and fewer opportunities for upward mobility . In contrast, the White British population may have lived in deprived London areas for several generations and partly represent a residual population from which the more aspiring have left. Though aspirations generally appeared to enhance well-being among DASH participants, for some they were experienced as stressful, placing them under “pressure” to achieve.
Religious practice and the instillation of religious values were an important part of family life and cultural identity in childhood for many ethnic minority participants. For Muslim and Hindu participants, this included explicit prohibition on the use of drugs and alcohol but family and cultural values of self-discipline, forbearance and altruism were described across religious and ethnic groups. Places of worship or religious societies were reported to provide social and instrumental support, for example providing friendship networks when moving to university outside London or help finding work. Religious practices and values were described as “our culture” forming an important part of processes of cultural socialisation and solidarity. This was supported by shared religious orientations with friends and peers as well as family. Religion was discussed as providing a sense of meaning and purpose in life in the face of adversity, including experiences of discrimination and racism. Though religious practice was discontinued by some in adulthood, for African Christian and Pakistani/Bangladeshi Muslim participants in particular, religion remained an important influence on identity, lifestyle, aspirations and values, as well as providing coping strategies for life challenges such as praying for guidance, retaining a sense of self-worth, and keeping in mind “the bigger picture”.
Potential for follow-up
Around 80 % of the cohort has been located, now aged 21–23 years, and 665 participants (90 % of those invited) took part in the feasibility study. Flexibility in interview locations and appointment times boosted participation rates, with one-third seen at weekends or in the evening. Interview locations offered included General Practitioner surgeries and community pharmacies within 2 km of residential postcodes. Overall, regardless of ethnicity or interview location, response rates to all measures and quality of data collected were high (less than 10 % missing data in any interview setting). For all ethnicities, consent rates ranged between 85 and 90 % for new biomedical measures and linkage of health and administrative records. There is strong potential for a three-generation study with consent for parents of the cohort to be contacted and about 300 babies born to participants. Feasibility study findings will be reported fully in subsequent papers.
Strengths and limitations of DASH
In 2002/2003, empirical studies of ethnicity and health on such a large scale were unprecedented in the UK. The cohort is well characterised in relation to socio-economic, psychosocial, physical and mental health measures. The qualitative study at 21–23 years has provided nuanced exploration of contextual influences on health and well-being. Attrition has been kept low by regular contact with cohort members and their communities, consultation with a participant advisory group, and use of social media and electronic tracing. Multidisciplinary input from social and biomedical scientists provides a platform for general population health studies and for specialist sub-studies. Lessons learnt about successful methods of engaging populations conventionally thought ‘hard to reach’ have been valuable to the science of maintaining representativeness of cohorts.
DASH findings have also informed follow-on studies including intervention studies using participatory approaches to optimise sustainability of behaviour change, including PROmoting Wellbeing, Equality, and Support in breast cancer Survivorship (PROWESS) (http://controlled-trials.com/isrctn/pf/14016157), the Size and Lung function in Children (SLIC) study , and the DiEt and Active Living (DEAL) study . Key measures of exposures and outcomes in DASH are harmonised with those in other cohorts giving scope for comparative studies. Planned linkage of primary and secondary health records will capture some early life exposures (such as birth details for those born in the UK), and also pregnancies, births and later health (e.g. admissions to hospital, cancer or death registrations). Cohort members are based in London which is unique in the extent of social and cultural diversity. Nonetheless, increasing globalisation and migration mean that the effects of urban context, deprivation, culture and ethnicity on health and well-being carry implications for other urban settings in the UK and abroad.
In summary, the DASH study focuses on a generation of ethnically diverse children who were born in the 1990s and have grown up in London. It provides a unique opportunity to examine how biology, behaviours and socio-economic and psychosocial environments in childhood shape health and well-being in adulthood. There are no other contemporary British-based cohorts that can be used to examine the role of childhood circumstances in ethnic-gender transitions to adulthood in times of economic precariousness. As expected from national statistics , young adults in DASH faced stressful transitions to adulthood with low-paid, often part-time, insecure employment. Although there appeared to be parity by educational level across ethnic groups, increases in racism  may frustrate aspirations.
DASH points to the importance of adherence to traditions of family life and religion, and of cultural adaptability, such as living with diversity, in nurturing mental health and well-being . In contrast, greater cardiovascular risks in ethnic minority adolescents indicate a continuation of the biological legacy of earlier generations. A key question is whether culturally based psychosocial experiences in childhood that appear to have fostered psychological resilience will also mitigate biological ‘wear and tear’ and reduce the high cardiovascular disease risks of their parents’ generation. The successful pilot follow-up opens up unique opportunities to track the health and well-being of young Londoners. Researchers can access information about the DASH study and scientific publications through the study website, dash.sphsu.mrc.ac.uk, where data information, data sharing policies and application forms for data access are available, and also via https://www.datagateway.mrc.ac.uk/search/site/DASH.