Tim Croudace

Outcomes of conduct problems in adolescence: 40 year follow-up of national cohort

Objective To describe long term outcomes associated with externalising behaviour in adolescence, defined in this study as conduct problems reported by a teacher, in a population based sample. Design Longitudinal study from age 13-53. Setting The Medical Research Council National Survey of Health and Development (the British 1946 birth cohort). Participants 3652 survey members assessed by their teachers for symptoms of externalising behaviour at age 13 and 15. Main outcome measures Mental disorder, alcohol abuse, relationship difficulties, highest level of education, social class, unemployment, and financial difficulties at ages 36-53. Results 348 adolescents were identified with severe externalising behaviour, 1051 with mild externalising behaviour, and 2253 with no externalising behaviour. All negative outcomes measured in adulthood were more common in those with severe or mild externalising behaviour in adolescence, as rated by teachers, compared with those with no externalising behaviour. Adolescents with severe externalising behaviour were more likely to leave school without any qualifications (65.2%; adjusted odds ratio 4.0, 95% confidence interval 2.9 to 5.5), as were those with mild externalising behaviour (52.2%; 2.3, 1.9 to 2.8), compared with those with no externalising behaviour (30.8%). On a composite measure of global adversity throughout adulthood that included mental health, family life and relationships, and educational and economic problems, those with severe externalising behaviour scored significantly higher (40.1% in top quarter), as did those with mild externalising behaviour (28.3%), compared with those with no externalising behaviour (17.0%). Conclusions Adolescents who exhibit externalising behaviour experience multiple social and health impairments that adversely affect them, their families, and society throughout adult life.

Incidence of Schizophrenia and Other Psychoses in England, 1950–2009: A Systematic Review and Meta-Analyses

Background We conducted a systematic review of incidence rates in England over a sixty-year period to determine the extent to which rates varied along accepted (age, sex) and less-accepted epidemiological gradients (ethnicity, migration and place of birth and upbringing, time). Objectives To determine variation in incidence of several psychotic disorders as above. Data Sources Published and grey literature searches (MEDLINE, PSycINFO, EMBASE, CINAHL, ASSIA, HMIC), and identification of unpublished data through bibliographic searches and author communication. Study Eligibility Criteria Published 1950–2009; conducted wholly or partially in England; original data on incidence of non-organic adult-onset psychosis or one or more factor(s) pertaining to incidence. Participants People, 16–64 years, with first -onset psychosis, including non-affective psychoses, schizophrenia, bipolar disorder, psychotic depression and substance-induced psychosis. Study Appraisal and Synthesis Methods Title, abstract and full-text review by two independent raters to identify suitable citations. Data were extracted to a standardized extraction form. Descriptive appraisals of variation in rates, including tables and forest plots, and where suitable, random-effects meta-analyses and meta-regressions to test specific hypotheses; rate heterogeneity was assessed by the I2-statistic. Results 83 citations met inclusion. Pooled incidence of all psychoses (N = 9) was 31.7 per 100,000 person-years (95%CI: 24.6–40.9), 23.2 (95%CI: 18.3–29.5) for non-affective psychoses (N = 8), 15.2 (95%CI: 11.9–19.5) for schizophrenia (N = 15) and 12.4 (95%CI: 9.0–17.1) for affective psychoses (N = 7). This masked rate heterogeneity (I2: 0.54–0.97), possibly explained by socio-environmental factors; our review confirmed (via meta-regression) the typical age-sex interaction in psychosis risk, including secondary peak onset in women after 45 years. Rates of most disorders were elevated in several ethnic minority groups compared with the white (British) population. For example, for schizophrenia: black Caribbean (pooled RR: 5.6; 95%CI: 3.4–9.2; N = 5), black African (pooled RR: 4.7; 95%CI: 3.3–6.8; N = 5) and South Asian groups in England (pooled RR: 2.4; 95%CI: 1.3–4.5; N = 3). We found no evidence to support an overall change in the incidence of psychotic disorder over time, though diagnostic shifts (away from schizophrenia) were reported. Limitations Incidence studies were predominantly cross-sectional, limiting causal inference. Heterogeneity, while evidencing important variation, suggested pooled estimates require interpretation alongside our descriptive systematic results. Conclusions and Implications of Key Findings Incidence of psychotic disorders varied markedly by age, sex, place and migration status/ethnicity. Stable incidence over time, together with a robust socio-environmental epidemiology, provides a platform for developing prediction models for health service planning.

Early developmental milestones in adult schizophrenia and other psychoses. A 31-year follow-up of the Northern Finland 1966 Birth Cohort.

Delayed childhood development may precede adult psychoses. We tested this hypothesis in a large, general population birth cohort (n=12058) followed to age 31 years. The ages at which individuals learned to stand, walk, speak, and became potty-trained (bowel control) and dry (bladder control), were recorded at a 1-year examination. Psychiatric outcome was ascertained through linkage to a national hospital discharge register. Cumulative incidence of DSM-III-R schizophrenia, other psychoses and non-psychotic disorders were stratified according to the timing of milestones and compared within the cohort using internal standardization. 100 cases of DSM-III-R schizophrenia, 55 other psychoses, and 315 non-psychotic disorders were identified. The ages at learning to stand, walk and become potty-trained were each related to subsequent incidence of schizophrenia and other psychoses. Compared with the whole cohort, earlier milestones reduced, and later milestones increased, the risk in a linear manner. These developmental effects were not seen for non-psychotic outcomes. The findings support hypotheses regarding psychosis as having a developmental dimension with precursors apparent in early life.

Psychometric evaluation and predictive validity of Ryff's psychological well-being items in a UK birth cohort sample of women.

BackgroundInvestigations of the structure of psychological well-being items are useful for advancing knowledge of what dimensions define psychological well-being in practice. Ryff has proposed a multidimensional model of psychological well-being and her questionnaire items are widely used but their latent structure and factorial validity remains contentious.MethodsWe applied latent variable models for factor analysis of ordinal/categorical data to a 42-item version of Ryffs psychological well-being scales administered to women aged 52 in a UK birth cohort study (n = 1,179). Construct (predictive) validity was examined against a measure of mental health recorded one year later.ResultsInter-factor correlations among four of the first-order psychological well-being constructs were sufficiently high (> 0.80) to warrant a parsimonious representation as a second-order general well-being dimension. Method factors for questions reflecting positive and negative item content, orthogonal to the construct factors and assumed independent of each other, improved model fit by removing nuisance variance. Predictive validity correlations between psychological well-being and a multidimensional measure of psychological distress were dominated by the contribution of environmental mastery, in keeping with earlier findings from cross-sectional studies that have correlated well-being and severity of depression.ConclusionOur preferred model included a single second-order factor, loaded by four of the six first-order factors, two method factors, and two more distinct first-order factors. Psychological well-being is negatively associated with dimensions of mental health. Further investigation of precision of measurement across the health continuum is required.

A Longitudinal Typology of Symptoms of Depression and Anxiety Over the Life Course

BACKGROUND Little is known about long-term profiles of depressive and anxious symptomatology over the life course and about the developmental determinants of different trajectories. The objective of this study was to identify a novel typology of symptoms of depression and anxiety over the life course and examine its neurodevelopmental antecedents in an epidemiological sample. METHODS A longitudinal latent variable analysis was conducted on measures of anxious and depressive symptoms at ages 13, 15, 36, 43, and 53 years among 4627 members of the Medical Research Council National Survey of Health & Development (the British 1946 birth cohort). Early life predictors of class membership were studied with ordinal logistic regression. RESULTS We identified six distinct profiles up to age 53: absence of symptoms (44.8% of sample); repeated moderate symptoms (33.6%); adult-onset moderate symptoms (11.3%); adolescent symptoms with good adult outcome (5.8%); adult-onset severe symptoms (2.9%); and repeated severe symptoms over the life course (1.7%). Heavier babies had lower likelihood of depressive and anxious symptoms (odds ratio [OR] = .92; 95% confidence interval [CI] .85-.99), whereas delay in first standing (OR = 1.19; 95% CI 1.11-1.28) and walking (OR = 1.22; 95% CI 1.14-1.31) was associated with subsequent higher likelihood of symptoms, controlling for social circumstances and stressful life events during childhood. CONCLUSIONS There was evidence of distinct profiles of depressive and anxious symptomatology over the life course and associations with markers of neurodevelopment. This suggests very early factors are associated with long-term experience of symptoms of depression and anxiety.

Non-linear relationship between an index of social deprivation, psychiatric admission prevalence and the incidence of psychosis

BACKGROUND Indicators of population socio-economic disadvantage expressed as weighted deprivation indices show strong relationships with mental health and underpin national funding of psychiatric services. A new index of social deprivation, the Mental Illness Needs Index, has been devised specifically to predict need for psychiatric services. Its validity has not been established outside the area in which it was developed. METHODS We explored the relationship between the Mental Illness Needs Index and two alternative indicators of need for mental health services: the prevalence of psychiatric admission for electoral wards in Nottingham (calculated from Hospital Episode Statistics for the years 1992 and 1993) and ward-based incidence rates for psychosis (ICD-10 F1X-F33). Relationships were explored graphically using local regression models, and estimated using Generalized Linear and Additive Models, and Poisson regression. RESULTS Social deprivation was strongly related to admission prevalence and psychosis incidence (Spearmans rho 0.63 and 0.44 respectively). Neither admission prevalence, nor the incidence of psychosis were linearly related to social deprivation. Areas with above average social deprivation had both more new cases of psychoses and a higher proportion of the population admitted than expected from a linear function. CONCLUSIONS Application of a linear function to funding gradients may underfund high and low need areas and overfund median need areas. Improving the precision of estimates of the relationship between social deprivation and need for services is crucial to more equitable resource allocation.

Mokken scale analysis of mental health and well-being questionnaire item responses: a non-parametric IRT method in empirical research for applied health researchers

BackgroundMokken scaling techniques are a useful tool for researchers who wish to construct unidimensional tests or use questionnaires that comprise multiple binary or polytomous items. The stochastic cumulative scaling model offered by this approach is ideally suited when the intention is to score an underlying latent trait by simple addition of the item response values. In our experience, the Mokken model appears to be less well-known than for example the (related) Rasch model, but is seeing increasing use in contemporary clinical research and public health. Mokkens method is a generalisation of Guttman scaling that can assist in the determination of the dimensionality of tests or scales, and enables consideration of reliability, without reliance on Cronbachs alpha. This paper provides a practical guide to the application and interpretation of this non-parametric item response theory method in empirical research with health and well-being questionnaires.MethodsScalability of data from 1) a cross-sectional health survey (the Scottish Health Education Population Survey) and 2) a general population birth cohort study (the National Child Development Study) illustrate the method and modeling steps for dichotomous and polytomous items respectively. The questionnaire data analyzed comprise responses to the 12 item General Health Questionnaire, under the binary recoding recommended for screening applications, and the ordinal/polytomous responses to the Warwick-Edinburgh Mental Well-being Scale.Results and conclusionsAfter an initial analysis example in which we select items by phrasing (six positive versus six negatively worded items) we show that all items from the 12-item General Health Questionnaire (GHQ-12) – when binary scored – were scalable according to the double monotonicity model, in two short scales comprising six items each (Bech’s “well-being” and “distress” clinical scales). An illustration of ordinal item analysis confirmed that all 14 positively worded items of the Warwick-Edinburgh Mental Well-being Scale (WEMWBS) met criteria for the monotone homogeneity model but four items violated double monotonicity with respect to a single underlying dimension.Software availability and commands used to specify unidimensionality and reliability analysis and graphical displays for diagnosing monotone homogeneity and double monotonicity are discussed, with an emphasis on current implementations in freeware.

Cognitive behaviour therapy for improving social recovery in psychosis: a report from the ISREP MRC Trial Platform study (Improving Social Recovery in Early Psychosis)

BACKGROUND This study reports on a preliminary evaluation of a cognitive behavioural intervention to improve social recovery among young people in the early stages of psychosis showing persistent signs of poor social functioning and unemployment. The study was a single-blind randomized controlled trial (RCT) with two arms, 35 participants receiving cognitive behaviour therapy (CBT) plus treatment as usual (TAU), and 42 participants receiving TAU alone. Participants were assessed at baseline and post-treatment. METHOD Seventy-seven participants were recruited from secondary mental health teams after presenting with a history of unemployment and poor social outcome. The cognitive behavioural intervention was delivered over a 9-month period with a mean of 12 sessions. The primary outcomes were weekly hours spent in constructive economic and structured activity. A range of secondary and tertiary outcomes were also assessed. RESULTS Intention-to-treat analysis on the combined affective and non-affective psychosis sample showed no significant impact of treatment on primary or secondary outcomes. However, analysis of interactions by diagnostic subgroup was significant for secondary symptomatic outcomes on the Positive and Negative Syndrome Scale (PANSS) [F(1, 69)=3.99, p=0.05]. Subsequent exploratory analyses within diagnostic subgroups revealed clinically important and significant improvements in weekly hours in constructive and structured activity and PANSS scores among people with non-affective psychosis. CONCLUSIONS The primary study comparison provided no clear evidence for the benefit of CBT in a combined sample of patients. However, planned analyses with diagnostic subgroups showed important benefits for CBT among people with non-affective psychosis who have social recovery problems. These promising results need to be independently replicated in a larger, multi-centre RCT.

Randomised trial of a parenting intervention during neonatal intensive care

Objective: To evaluate the influence of parenting intervention on maternal responsiveness and infant neurobehavioural development following a very premature birth. Design: Cluster-randomised controlled trial, with a crossover design and three-month washout period. Setting: Six neonatal intensive care units. Patients: Infants born <32 weeks’ gestation. Intervention: The Parent Baby Interaction Programme (PBIP) is a supportive, educational intervention delivered by research nurses in the neonatal intensive care unit, with optional home follow-up for up to six weeks after discharge. Main outcome measures: Parenting stress at 3 months adjusted age, as measured by the Parenting Stress Index (PSI). Other outcomes included the Neurobehavioural Assessment of the Preterm Infant (NAPI) and maternal interaction as assessed by the Nursing Child Assessment Teaching Scale (NCATS) and the responsivity subscale for Home Observation for Measurement of the Environment (HOME). Results: 112 infants were recruited in the intervention phases and 121 in the control phases. Mean standardised NAPI scores at 35 weeks did not differ between the PBIP and control groups. Both groups had low but similar NCATS caregiver scores before discharge (36.6 in the PBIP group and 37.4 in control, adjusted mean difference −0.7, 95% CI −2.7 to 1.4). At three months, adjusted age mean PSI scores for the PBIP group were 71.9 compared with 67.1 for controls (adjusted mean difference 3.8, 95% CI −4.7 to 12.4). NCATS scores and HOME responsivity scores were similarly distributed between the groups. Conclusion: This early, nurse-delivered, parent-focused interaction programme intervention had no measurable effects on short-term infant neurobehavioural function, mother–child interaction or parenting stresses.

Developmental Trajectories of Sex-Typed Behavior in Boys and Girls: A Longitudinal General Population Study of Children Aged 2.5–8 Years

The stability of sex-typed behavior from the preschool to the middle school years was examined. The Preschool Activities Inventory, a measure of within-sex variation in sex-typed behavior, was completed by the primary caregiver when the child was 2.5, 3.5, and 5 years, and a modified version, the Child Activities Inventory, was completed by the child at age 8. The investigation involved a general population sample of 2,726 boys and 2,775 girls. Sex-typed behavior increased through the preschool years, and those children who were the most sex typed at age 2.5 were still the most sex typed at age 5, with those children who showed the highest levels of sex-typed behavior during the preschool years continuing to do so at age 8.