The Early Growth and Development Study (EGDS) is a prospective adoption study of birth parents, adoptive parents and adopted children (n = 561 adoptees). The original sample has been expanded to include siblings of the EGDS adoptees who were reared by the birth mother and assessed beginning at age 7 years (n = 217 biological children), and additional siblings in both the birth and adoptive family homes, recruited when the adoptees were 8–15 years old (n = 823). The overall study aims are to examine how family, peer and contextual processes affect child and adolescent adjustment, and to examine their interplay (mediation, moderation) with genetic influences. Adoptive and birth parents were originally recruited through adoption agencies located throughout the USA following the birth of a child. Assessments are ongoing and occurred in 9 month’s intervals until the adoptees turned 3 years of age, and in 1 to 2 year intervals thereafter through age 15. Data collection includes the following primary constructs: child temperament, behavior problems, mental health, peer relations, executive functioning, school performance and health; birth and adoptive parent personality characteristics, mental health, health, context, substance use, parenting and marital relations; and the prenatal environment. Findings highlight the power of the adoption design to detect environmental influences on child development and provide evidence of complex interactions and correlations between genetic, prenatal environmental and postnatal environmental influences on a range of child outcomes. The study sample, procedures and an overview of findings are summarized and ongoing assessment activities are described.

To support people with dementia to live at home, a key national and international policy driver is to create dementia-friendly communities which draws attention to the importance of a local neighbourhood and living well with dementia. However, there is a lack of evidence about how people with dementia define and interact with their neighbourhood. This longitudinal narrative research aimed to uncover the meaning, construction and place of neighbourhood in the lives of people with dementia and their care partners through a participatory approach. Five couples, where one partner had an early diagnosis of dementia and capacity to consent, participated in the (up to) one-year mixed qualitative method study. During this time-frame, 65 home visits were conducted, resulting in over 57 hours of interview data alongside the development of other artefacts, such as neighbourhood maps, photographs, diaries and field notes. Narrative analysis was applied within and across the data-sets. This led to the emergence of three themes to describe a connected neighbourhood. First, ‘connecting to people’ is about the couples’ connections with family members, friends and neighbours through a sense of belonging, group identification and responsibilities. Second, ‘connecting to places’ shares the couples’ emotional and biographical attachment to places. Third, ‘connecting to resources’ refers to the couples actively seeking support to live independently and to retain neighbourhood connections.

The Boston University Twin Project (BUTP) uses a multimethod, longitudinal approach to study the role of genetic and environmental factors on the development of child temperament and related behaviors in early childhood. There are two phases in this project. The first, described in the previous Twin Research and Human Genetics special issue on twin registries, focused on activity level and comprised over 300 twin pairs assessed in the home and laboratory at ages 2 and 3. In this article, we describe subject recruitment, sample characteristics, and study procedures and measures of the second phase of the BUTP. This recent study focuses more broadly on the development of multiple temperament dimensions and explores associations between temperament trajectories, parenting and child adjustment in a new cohort of approximately 300 twin pairs assessed at 3, 4 and 5 years of age.

The Children of the Twins Early Development Study (CoTEDS) is a new prospective children-of-twins study in the UK, designed to investigate intergenerational associations across child developmental stages. CoTEDS will enable research on genetic and environmental factors that underpin parent–child associations, with a focus on mental health and cognitive-related traits. Through CoTEDS, we will have a new lens to examine the roles that parents play in influencing child development, as well as the genetic and environmental factors that shape parenting behavior and experiences. Recruitment is ongoing from the sample of approximately 20,000 contactable adult twins who have been enrolled in the Twins Early Development Study (TEDS) since infancy. TEDS twins are invited to register all offspring to CoTEDS at birth, with 554 children registered as of May 2019. By recruiting the second generation of TEDS participants, CoTEDS will include information on adult twins and their offspring from infancy. Parent questionnaire-based data collection is now underway for 1- and 2-year-old CoTEDS infants, with further waves of data collection planned. Current data collection includes the following primary constructs: child mental health, temperament, language and cognitive development; parent mental health and social relationships; parenting behaviors and feelings; and other socioecological factors. Measurement tools have been selected with reference to existing genetically informative cohort studies to ensure overlap in phenotypes measured at corresponding stages of development. This built-in study overlap is intended to enable replication and triangulation of future analyses across samples and research designs. Here, we summarize study protocols and measurement procedures and describe future plans.

Treatment-resistant schizophrenia, affecting approximately 20–30% of patients with schizophrenia, has a high burden both for patients and healthcare services. There is a need to identify treatment resistance earlier in the course of the illness, in order that effective treatment, such as clozapine, can be offered promptly. We conducted a systemic literature review of prospective longitudinal studies with the aim of identifying predictors of treatment-resistant schizophrenia from the first episode. From the 545 results screened, we identified 12 published studies where data at the first episode was used to predict treatment resistance. Younger age of onset was the most consistent predictor of treatment resistance. We discuss the gaps in the literature and how future prediction models can identify predictors of treatment response more robustly.

The Wisconsin Twin Project comprises multiple longitudinal studies that span infancy to early adulthood. We summarize recent papers that show how twin designs with deep phenotyping, including biological measures, can inform questions about phenotypic structure, etiology, comorbidity, heterogeneity, and gene–environment interplay of temperamental constructs and mental and physical health conditions of children and adolescents. The general framework for investigations begins with rich characterization of early temperament and follows with study of experiences and exposures across childhood and adolescence. Many studies incorporate neuroimaging and hormone assays.

The older Finnish Twin Cohort (FTC) was established in 1974. The baseline survey was in 1975, with two follow-up health surveys in 1981 and 1990. The fourth wave of assessments was done in three parts, with a questionnaire study of twins born during 1945–1957 in 2011–2012, while older twins were interviewed and screened for dementia in two time periods, between 1999 and 2007 for twins born before 1938 and between 2013 and 2017 for twins born in 1938–1944. The content of these wave 4 assessments is described and some initial results are described. In addition, we have invited twin-pairs, based on response to the cohortwide surveys, to participate in detailed in-person studies; these are described briefly together with key results. We also review other projects based on the older FTC and provide information on the biobanking of biosamples and related phenotypes.

This article reviews the Southern Illinois Twins/Triplets and Siblings Study (SITSS) and describes some of the findings related to recent projects that were completed using this sample. At this time, the SITSS has enrolled 375 twin pairs, 12 triplet families, 1 family of quadruplets, 98 nontwin sibling pairs and 287 singletons. Testing begins for twins and triplets as young as age 1 and then occurs yearly on their birthdays until 5 years of age. Through age 20, various follow-up studies have been conducted on the SITSS sample to examine their social, emotional, and cognitive development across childhood and adolescence from a behavioral genetic perspective. A variety of methodologies have been used to investigate gene–environment correlations (rGE) and gene–environment interactions (GxE). Advanced statistical procedures (e.g., genetic likelihood indices and multilevel modeling) have been utilized to further investigate genetic underpinnings of behavior. Recent results have indicated genetic influences on the aggressiveness of preschoolers’ media preferences, increased problem behaviors related to young children’s overestimation of self-competence, and the influence of early life temperament and internalizing problems on adolescent health behaviors. Additionally, the SITSS has provided evidence for evocative rGE for various behaviors (aggression, prosocial and play), as well as findings supporting interactions between the dopamine receptor D4 gene (DRD4) and the environment (peer victimization, prenatal birth complications and parental sensitivity). Together, by use of multitrait and multimethodological investigations, this behavior genetic data set assists in furthering our understanding of biological and environmental influences on children’s development.

Extra-care housing (ECH) has been hailed as a potential solution to some of the problems associated with traditional forms of social care, since it allows older people to live independently, while also having access to care and support if required. However, little longitudinal research has focused on the experiences of residents living in ECH, particularly in recent years. This paper reports on a longitudinal study of four ECH schemes in the United Kingdom. Older residents living in ECH were interviewed four times over a two-year period to examine how changes in their care needs were encountered and negotiated by care workers, managers and residents themselves. This paper focuses on how residents managed their own changing care needs within the context of ECH. Drawing upon theories of the third and fourth age, the paper makes two arguments. First, that transitions across the boundary between the third and fourth age are not always straightforward or irreversible and, moreover, can sometimes be resisted, planned-for and managed by older people. Second, that operational practices within ECH schemes can function to facilitate or impede residents’ attempts to manage this boundary.

While child self-regulation is shaped by the environment (e.g., the parents’ caregiving behaviors), children also play an active role in influencing the care they receive, indicating that children's individual differences should be integrated in models relating early care to children's development. We assessed 409 children's observed temperamental behavioral inhibition (BI), effortful control (EC), and the primary caregiver's parenting at child ages 3 and 5. Parents reported on child behavior problems at child ages 3, 5, and 8. Mediation analyses were conducted to examine relations between child temperament and parenting in predicting child problems. BI at age 3 was positively associated with structured parenting at age 5, which was negatively related to child internalizing and attention-academic problems at age 8. In contrast, parenting at child age 3 did not predict child BI or EC at age 5, nor did age 3 EC predict parenting at age 5. Findings indicate that child behavior may shape the development of caregiving and, in turn, long-term child adjustment, suggesting that studies of caregiving and child outcomes should consider the role of child temperament toward developing more informative models of child–environment interplay.

Institutionally deprived young children often display distinctive patterns of attachment, classified as insecure/other (INS/OTH), with their adoptive parents. The associations between INS/OTH and developmental trajectories of mental health and neurodevelopmental symptoms were examined. Age 4 attachment status was determined for 97 Romanian adoptees exposed to up to 24 months of deprivation in Romanian orphanages and 49 nondeprived UK adoptees. Autism, inattention/overactivity and disinhibited-social-engagement symptoms, emotional problems, and IQ were measured at 4, 6, 11, and 15 years and in young adulthood. Romanian adoptees with over 6 months deprivation (Rom>6) were more often classified as INS/OTH than UK and Romanian adoptees with less than 6 months deprivation combined. INS/OTH was associated with cognitive impairment at age 4 years. The interaction between deprivation, attachment status, and age for autism spectrum disorder assessment was significant, with greater symptom persistence in Rom>6 INS/OTH(+) than other groups. This effect was reduced when IQ at age 4 was controlled for. Age 4 INS/OTH in Rom>6 was associated with worse autism spectrum disorder outcomes up to two decades later. Its association with cognitive impairment at age 4 is consistent with INS/OTH being an early marker of this negative developmental trajectory, rather than its cause.

The aim of the 25 and Up (25Up) study was to assess a wide range of psychological and behavioral risk factors behind mental illness in a large cohort of Australian twins and their non-twin siblings. Participants had already been studied longitudinally from the age of 12 and most recently in the 19Up study (mean age = 26.1 years, SD = 4.1, range = 20–39). This subsequent wave follows up these twins several years later in life (mean age = 29.7 years, SD = 2.2, range =  22–44). The resulting data set enables additional detailed investigations of genetic pathways underlying psychiatric illnesses in the Brisbane Longitudinal Twin Study (BLTS). Data were collected between 2016 and 2018 from 2540 twins and their non-twin siblings (59% female, including 341 monozygotic complete twin-pairs, 415 dizygotic complete pairs and 1028 non-twin siblings and singletons). Participants were from South-East Queensland, Australia, and the sample was of predominantly European ancestry. The 25Up study collected information on 20 different mental disorders, including depression, anxiety, substance use, psychosis, bipolar and attention-deficit hyper-activity disorder, as well as general demographic information such as occupation, education level, number of children, self-perceived IQ and household environment. In this article, we describe the prevalence, comorbidities and age of onset for all 20 examined disorders. The 25Up study also assessed general and physical health, including physical activity, sleep patterns, eating behaviors, baldness, acne, migraines and allergies, as well as psychosocial items such as suicidality, perceived stress, loneliness, aggression, sleep–wake cycle, sexual identity and preferences, technology and internet use, traumatic life events, gambling and cyberbullying. In addition, 25Up assessed female health traits such as morning sickness, breastfeeding and endometriosis. Furthermore, given that the 25Up study is an extension of previous BLTS studies, 86% of participants have already been genotyped. This rich resource will enable the assessment of epidemiological risk factors, as well as the heritability and genetic correlations of mental conditions.

Research showing that risk for schizophrenia, bipolar disorder with psychosis, and other psychosis-spectrum diagnoses in adulthood is multidetermined has underscored the necessity of studying the additive and interactive factors in childhood that precede and predict future disorders. In this study, risk for the development of psychosis-spectrum disorders was examined in a 2-generation, 30-year prospective longitudinal study of 3,905 urban families against a sociocultural backdrop of changing economic and social conditions. Peer nominations of aggression, withdrawal, and likeability and national census information on neighborhood-level socioeconomic disadvantage in childhood, as well as changes in neighborhood socioeconomic conditions over the lifespan, were examined as predictors of diagnoses of schizophrenia, bipolar disorder, and other psychosis-spectrum disorders in adulthood relative to developing only nonpsychotic disorders or no psychiatric disorders. Individuals who were both highly aggressive and highly withdrawn were at greater risk for other psychosis-spectrum diagnoses when they experienced greater neighborhood disadvantage in childhood or worsening neighborhood conditions over maturation. Males who were highly aggressive but low on withdrawal were at greater risk for schizophrenia diagnoses. Childhood neighborhood disadvantage predicted both schizophrenia and bipolar diagnoses, regardless of childhood social behavior. Results provided strong support for multiple-domain models of psychopathology, and suggest that universal preventive interventions and social policies aimed at improving neighborhood conditions may be particularly important for decreasing the prevalence of psychosis-spectrum diagnoses in the future.