The objective of this study was to derive a factor structure of the measures of the National Institutes of Health (NIH) Toolbox Cognition Battery (CB) that is representative of cognitive abilities in a large ethnically diverse cohort of 8-year-old children in Aotearoa New Zealand.

Our sample comprised of 4298 8-year-old children from the Growing Up in New Zealand study. We conducted exploratory and confirmatory factor analysis for the NIH Toolbox CB measures to discover the best-fitting factor structure in our sample. Measurement invariance of the identified model was tested across child’s gender, socio-economic status (SES), and ethnicity.

A three-dimensional factor structure was identified, with one factor of Crystallised Cognition (Reading and Vocabulary), and two distinguished factors of fluid cognition: Fluid Cognition I (Attention/Inhibitory Control, Processing Speed, and Cognitive Flexibility) and Fluid Cognition II (Working Memory, Episodic Memory). The results demonstrate excellent model fit, but reliability of the factors was low. Measurement invariance was confirmed for child’s gender. We found configural, but neither metric nor scalar, invariance across SES and the four major ethnic groups: European, Māori, Pacific Peoples, and Asian.

Our findings show that, at the age of 8 years, fluid abilities are more strongly associated with one another than with crystallised abilities and that fluid abilities need to be further differentiated. This dimensional structure allows for comparisons across child’s gender, but evaluations across SES and ethnicity within the Aotearoa New Zealand context must be conducted with caution. We recommend using raw scores of the individual NIH Toolbox CB measures in future research.

Traumatic experiences are associated with a higher risk of psychotic illnesses, but little is known about potentially modifiable mechanisms underlying this relationship. This study aims to examine whether post-traumatic stress disorder (PTSD) symptoms mediate the relationship between trauma and psychotic experiences (PEs).

We used data from the Avon Longitudinal Study of Parents and Children to examine whether: PTSD symptoms mediate the relationships between (a) childhood trauma and adolescent PEs (study of adolescent PEs; n = 2952), and (b) childhood/adolescent trauma and PEs in early adulthood (study of adult PEs; n = 2492). We examined associations between variables using logistic regression, and mediation using the parametric g-computation formula.

Exposure to trauma was associated with increased odds of PEs (adolescent PEs: ORadjusted 1.48, 95% CI 1.23–1.78; adult PEs: ORadjusted 1.57, 95% CI 1.25–1.98) and PTSD symptoms (adolescent PTSD: ORadjusted 1.59, 95% CI 1.31–1.93; adult PTSD: ORadjusted 1.50, 95% CI 1.36–1.65). The association between PTSD symptoms and PE was stronger in adolescence (ORadjusted 4.63, 95% CI 2.34–9.17) than in adulthood (ORadjusted 1.62, 95% CI 0.80–3.25). There was some evidence that PTSD symptoms mediated the relationship between childhood trauma and adolescent PEs (proportion mediated 14%), though evidence of mediation was weaker for adult PEs (proportion mediated 8%).

These findings are consistent with the hypothesis that PTSD symptoms partly mediate the association between trauma exposure and PEs. Targeting PTSD symptoms might help prevent the onset of psychotic outcomes.

Symptoms of attention deficit hyperactivity disorder (ADHD) and trait impulsivity have been associated with disordered eating but are seldom assessed in community studies, or longitudinally and little is known about the mediating mechanisms.

We tested associations between ADHD symptoms and disordered eating cross-sectionally and between trait impulsivity and disordered eating longitudinally. We utilised data from a normative cohort of young adults (642 participants: 65% female, Mage = 23 years). Participants were classified as high risk or low risk for disordered eating using the SCOFF instrument. In the first two steps of both cross-sectional and longitudinal hierarchical logistic regression models, demographics and covariates were entered. For the cross-sectional regression, Adult ADHD self-report scale (ASRS) scores, separated into inattentive and hyperactive/impulsive symptoms, were entered in the third step. In a separate longitudinal model, Barratt impulsivity scale subscales (attentional, motor and non-planning impulsivity) were entered in the third step. Depression, as assessed by the moods and feelings questionnaire (MFQ), was examined as a mediator.

Cross-sectionally, sex, MFQ score and inattentive symptoms predicted disordered eating risk (model R2 = 20%). Longitudinally, sex, MFQ score and attentional impulsivity predicted disordered eating risk (model R2 = 16%). The relationship between inattentive symptoms and the disordered eating risk was partially mediated by MFQ score, whereas the relationship between attentional impulsivity and the disordered eating risk was fully mediated by MFQ scores.

These data highlight (1) a specific role for inattentive symptoms of ADHD and (2) the importance of both depression and impulsivity in predicting eating disorder risk.

The Cognitive Battery of the National Institutes of Health Toolbox (NIH-TB) is a collection of assessments that have been adapted and normed for administration across the lifespan and is increasingly used in large-scale population-level research. However, despite increasing adoption in longitudinal investigations of neurocognitive development, and growing recommendations that the Toolbox be used in clinical applications, little is known about the long-term temporal stability of the NIH-TB, particularly in youth.

The present study examined the long-term temporal reliability of the NIH-TB in a large cohort of youth (9–15 years-old) recruited across two data collection sites. Participants were invited to complete testing annually for 3 years.

Reliability was generally low-to-moderate, with intraclass correlation coefficients ranging between 0.31 and 0.76 for the full sample. There were multiple significant differences between sites, with one site generally exhibiting stronger temporal stability than the other.

Reliability of the NIH-TB Cognitive Battery was lower than expected given early work examining shorter test-retest intervals. Moreover, there were very few instances of tests meeting stability requirements for use in research; none of the tests exhibited adequate reliability for use in clinical applications. Reliability is paramount to establishing the validity of the tool, thus the constructs assessed by the NIH-TB may vary over time in youth. We recommend further refinement of the NIH-TB Cognitive Battery and its norming procedures for children before further adoption as a neuropsychological assessment. We also urge researchers who have already employed the NIH-TB in their studies to interpret their results with caution.

Awareness of dementia is examined in different scientific fields as significant for assessment of diagnosis, and for treatment and adaptation to the disease. There are very few longitudinal studies of individual experiences of awareness among people with dementia, related to quality of life.

To examine how younger people (< 65 years) with dementia (YOD) express awareness of the dementia and how, over time, they seem to handle awareness as a strategy to preserve quality of life.

A longitudinal qualitative study with individuals with YOD was performed with interviews every six months over five years for a maximum of ten interviews. The interviews were analysed by modified grounded theory.

Awareness is a complex, multidimensional concept. Awareness of dementia is predisposed by personality, life history and established coping styles. The main coping styles – live in the moment, ignore the dementia, and make the best of it – seem to be rather consistent throughout the progression of the disease. Transitions in life situation, such as moving to a nursing home, may change the individual’s awareness of dementia.

Unawareness of dementia may have an important adaptive function to preserve quality of life. To increase awareness must be approached with reflexivity and the utmost sensitivity.

Bipolar disorder (BD) is a familial psychiatric disorder associated with frontotemporal and subcortical brain abnormalities. It is unclear whether such abnormalities are present in relatives without BD, and little is known about structural brain trajectories in those at risk.

Neuroimaging was conducted at baseline and at 2-year follow-up interval in 90 high-risk individuals with a first-degree BD relative (HR), and 56 participants with no family history of mental illness who could have non-BD diagnoses. All 146 subjects were aged 12–30 years at baseline. We examined longitudinal change in gray and white matter volume, cortical thickness, and surface area in the frontotemporal cortex and subcortical regions.

Compared to controls, HR participants showed accelerated cortical thinning and volume reduction in right lateralised frontal regions, including the inferior frontal gyrus, lateral orbitofrontal cortex, frontal pole and rostral middle frontal gyrus. Independent of time, the HR group had greater cortical thickness in the left caudal anterior cingulate cortex, larger volume in the right medial orbitofrontal cortex and greater area of right accumbens, compared to controls. This pattern was evident even in those without the new onset of psychopathology during the inter-scan interval.

This study suggests that differences previously observed in BD are developing prior to the onset of the disorder. The pattern of pathological acceleration of cortical thinning is likely consistent with a disturbance of molecular mechanisms responsible for normal cortical thinning. We also demonstrate that neuroanatomical differences in HR individuals may be progressive in some regions and stable in others.

Subjective cognitive difficulties are common in mental illness and have a negative impact on role functioning. Little is understood about subjective cognition and the longitudinal relationship with depression and anxiety symptoms in young people.

To examine the relationship between changes in levels of depression and anxiety and changes in subjective cognitive functioning over 3 months in help-seeking youth.

This was a cohort study of 656 youth aged 12–25 years attending Australian headspace primary mental health services. Subjective changes in cognitive functioning (rated as better, same, worse) reported after 3 months of treatment was assessed using the Neuropsychological Symptom Self-Report. Multivariate multinomial logistic regression analysis was conducted to evaluate the impact of baseline levels of and changes in depression (nine-item Patient Health Questionnaire; PHQ9) and anxiety symptoms (seven-item Generalised Anxiety Disorder scale; GAD7) on changes in subjective cognitive function at follow-up while controlling for covariates.

With a one-point reduction in PHQ9 at follow-up, there was an estimated 11–18% increase in ratings of better subjective cognitive functioning at follow-up, relative to stable cognitive functioning. A one-point increase in PHQ9 from baseline to follow-up was associated with 7–14% increase in ratings of worse subjective cognitive functioning over 3 months, relative to stable cognitive functioning. A similar attenuated pattern of findings was observed for the GAD7.

A clear association exists between subjective cognitive functioning outcomes and changes in self-reported severity of affective symptoms in young people over the first 3 months of treatment. Understanding the timing and mechanisms of these associations is needed to tailor treatment.

To test whether perception of insufficient milk (PIM) supply in the breast-feeding relationship of one child predicts how long mothers breast-feed subsequent children, and whether this association differs for first-time mothers v. mothers with previous children.

Secondary analysis of Infant Feeding Practices Study II (ordinary least squares regression) and Year 6 follow-up.

Mailed, self-report survey of US mother–infant dyads, 2005–2012.

Women pregnant with a singleton were recruited from a consumer opinion panel. Exclusion criteria included: mother age <18; infant born <5 lbs, born before 35 weeks or with extended NICU stay, and mother or infant diagnosed with condition that impacts feeding. A subsample with PIM data (n 1460) was analysed.

We found that women who weaned because of PIM with the index child stopped breast-feeding 5·7 weeks earlier than those who weaned due to other reasons (4·9 weeks earlier for multiparas, P < 0·001; 7·1 weeks earlier for primiparas, P < 0·001). Using Year 6 follow-up data (n 350), we found subsequent child 1 weaned 9·2 weeks earlier if the mother experiences PIM as a multipara (P = 0·020) and 10·6 weeks earlier if the mother experiences PIM as a primipara (P = 0·019). For subsequent child 2 (n 78), the magnitude of association was even larger, although insignificant due to low power.

These findings indicate that PIM may carry forward in the reproductive life course, especially for first-time mothers. Perceptions of breast milk insufficiency and contributors to actual inadequate milk supply with the first child should be targeted, rather than intervening later in the reproductive life course.

Large population-based cohort studies of neuropsychological factors that characterise or precede depressive symptoms are rare. Most studies use small case-control or cross-sectional designs, which may cause selection bias and cannot test temporality. In a large UK population-based cohort, we investigated cross-sectional and longitudinal associations between inhibitory control of positive and negative information and adolescent depressive symptoms.

Cohort study of 2328 UK adolescents who completed an affective go/no-go task at age 18. Depressive symptoms were assessed with the Clinical Interview Schedule Revised (CIS-R) and short Mood and Feeling Questionnaire (sMFQ) at age 18, and with the sMFQ 1 year later (age 19). Analyses were multilevel and traditional linear regressions, before and after adjusting for confounders.

Cross-sectionally, we found little evidence that adolescents with more depressive symptoms made more inhibitory control errors [after adjustments, errors increased by 0.04% per 1 s.d. increase in sMFQ score (95% confidence interval 0.02–0.06)], but this association was not observed for the CIS-R. There was no evidence for an influence of valence. Longitudinally, there was no evidence that reduced inhibitory control was associated with future depressive symptoms.

Inhibitory control of positive and negative information does not appear to be a marker of current or future depressive symptoms in adolescents and would not be a useful target in interventions to prevent adolescent depression. Our lack of convincing evidence for associations with depressive symptoms suggests that the affective go/no-go task is not a promising candidate for future neuroimaging studies of adolescent depression.

Affective symptoms are associated with cognition in mid-life and later life. However, the role of cardiometabolic risk in this association has not been previously examined.

To investigate how cardiometabolic risk contributes to associations between affective symptoms and mid-life cognition.

Data were used from the National Child Development Study (NCDS), a sample of people born in Britain during one week in 1958. Measures of immediate and delayed memory, verbal fluency and information processing speed and accuracy were available at age 50. Affective symptoms were assessed at ages 23, 33 and 42 years and a measure of accumulation was derived. A cardiometabolic risk score was calculated from nine cardiometabolic biomarkers at age 44. Path models were run to test these associations, adjusting for sex, education, socioeconomic position and affective symptoms at age 50.

After accounting for missing data using multiple imputation, path models indicated significant indirect associations between affective symptoms and mid-life immediate memory (β = −0.002, s.e. = 0.001, P = 0.009), delayed memory (β = −0.002, s.e. = 0.001, P = 0.02) and verbal fluency (β = −0.002, s.e. = 0.001, P = 0.045) through cardiometabolic risk.

These findings suggest that cardiometabolic risk may play an important role in the association between affective symptoms and cognitive function (memory and verbal fluency). Results contribute to understanding of biological mechanisms underlying associations between affective symptoms and cognitive ageing, which can have implications for early detection of, and intervention for, those at risk of poorer cognitive outcomes.

In an initial study (Study 1), we found that motivation predicted community integration (i.e. functional recovery) 12 months after receiving housing in formerly homeless Veterans with a psychotic disorder. The current study examined whether the same pattern would be found in a broader, more clinically diverse, homeless Veteran sample without psychosis.

We examined four categories of variables as potential predictors of community integration in non-psychotic Veterans: perception, non-social cognition, social cognition, and motivation at baseline (after participants were engaged in a permanent supported housing program but before receiving housing) and a 12-month follow-up. A total of 82 Veterans had a baseline assessment and 41 returned for testing after 12 months.

The strongest longitudinal association was between an interview-based measure of motivation (the motivation and pleasure subscale from the Clinical Assessment Interview for Negative Symptoms) at baseline and measures of social integration at 12 months. In addition, cross-lagged panel analyses were consistent with a causal influence of general psychiatric symptoms at baseline driving social integration at 12 months, and reduced expressiveness at baseline driving independent living at 12 months, but there were no significant causal associations with measures of motivation.

The findings from this study complement and reinforce those in Veterans with psychosis. Across these two studies, our findings suggest that motivational factors are associated at baseline and at 12 months and are particularly important for understanding and improving community integration in recently-housed Veterans across psychiatric diagnoses.

To examine the associations of changes in the local food environment, individual behaviours and perceptions with changes in dietary intake, following relocation from an established neighbourhood to a new residential development.

Spatial food environment exposure measures were generated relative to each participant’s home address using the locations of food outlets at baseline (before moving house) and follow-up (1–2 years after relocation). Self-reported data on socio-demographics, self-selection, usual dietary intake, individual behaviours and perceptions of the local food environment were sourced from the RESIDential Environments (RESIDE) Project. Changes in spatial exposure measures, individual behaviours and perceptions with changes in dietary outcomes were examined using mixed linear models.

Perth, Western Australia, 2003–2007.

Adults (n 1200) from the RESIDE Project.

Moving to a new residential development with more convenience stores and café restaurants around the home was significantly associated with an increase in unhealthy food intake (β = 0·049, 95 % CI 0·010, 0·089; β = 0·020, 95 % CI 0·007, 0·033) and was partially mediated by individual behaviours and perceptions. A greater percentage of healthy food outlets around the home following relocation was significantly associated with an increase in healthy food (β = 0·003, 95 % CI 0·001, 0·005) and fruit/vegetable intake (β = 0·002, 95 % CI 0·001, 0·004).

Policy and planning may influence dietary intakes by restricting the number of convenience stores and other unhealthy food outlets and increasing the relative percentage of healthy food outlets.