While several risk factors for schizophrenia have been identified, their individual impacts are rather small. The relative independent and cumulative impacts of multiple risk factors on disease risk and age of onset warrant further investigation.

We conducted a register-based case–control study including all individuals receiving a schizophrenia spectrum disorder in Denmark from 1973 to 2018 (N = 29,142), and a healthy control sample matched 5:1 on age, sex, and parental socioeconomic status (N = 136,387). Register data included parental history of psychiatric illness, birth weight, gestational age, season of birth, population density of birthplace, immigration, paternal age, and Apgar scores. Data were analysed using logistic regression and machine learning.

Parental history of psychiatric illness (OR = 2.32 [95%CI 2.21–2.43]), high paternal age (OR = 1.30 [1.16–1.45]), and low birth weight (OR = 1.28 [1.16–1.41]) increased the odds of belonging to the patient group. In contrast, being a second-generation immigrant (OR = 0.65 [0.61–0.69]) and high population density of the birthplace (OR = 0.92 [0.89–0.96]) decreased the odds. The findings were supported by a decision tree analysis where parental history, paternal age, and birth weight contributed most to diagnostic classification (ACCtest = 0.69, AUCtest = 0.59, p < 0.001). Twenty percent of patients were child-onset cases. Here, female sex (OR = 1.82 [1.69–1.97]) and parental psychiatric illness (OR = 1.62 [1.49–1.77]) increased the odds of receiving the diagnosis <18 years.

Multiple early factors contribute independently to a higher psychosis risk, suggesting cumulative effects leading to symptom onset. Routine assessments of the most influential risk factors could be incorporated into clinical practise. Being female increased the risk of diagnosis during childhood, suggesting sex differences in the developmental trajectories of the disorder.

The aim of this study was to examine the structural change in the hippocampal subfields in early-onset (EO) mild cognitive impairment (MCI) patients associated with the APOE ε4 carrier state.

This study had 50 subjects aged 55-63 years, all of whom were diagnosed with amnestic MCI at baseline via the Korean version of the Consortium to Establish a Registry for Alzheimer’s Disease Assessment Packet (CERAD-K). The EO-MCI patients were divided into the MCI continued (MCIcont) and Alzheimer’s disease (AD) converted (ADconv) groups 2 years later. The volumes of hippocampal subfields were measured for all the subjects. The calculations were based on the change of the volumes between the 2-year-interval brain Magnetic resonance image (MRI) scans between MCIcont and ADconv groups according to the Apolipoprotein ε4 (APOE ε4) carrier state.

There was a significant correlation between APOE ε4 allele and structural changes in several hippocampal subfields. The volume reduction in cornus ammonis 1 (CA1) field and subiculum, especially in the APOE ε4 carriers. The significance was more prominent in ADconv group.

These results suggest that the possession of APOE ε4 allele may lead to significantly greater predilection for the structural changes in hippocampal subfields, showing significant changes, especially in the ADconv patients compared with MCIcont patients.

While adolescent-onset schizophrenia (ADO-SCZ) and adolescent-onset bipolar disorder with psychosis (psychotic ADO-BPD) present a more severe clinical course than their adult forms, their pathophysiology is poorly understood. Here, we study potentially state- and trait-related white matter diffusion-weighted magnetic resonance imaging (dMRI) abnormalities along the adolescent-onset psychosis continuum to address this need.

Forty-eight individuals with ADO-SCZ (20 female/28 male), 15 individuals with psychotic ADO-BPD (7 female/8 male), and 35 healthy controls (HCs, 18 female/17 male) underwent dMRI and clinical assessments. Maps of extracellular free-water (FW) and fractional anisotropy of cellular tissue (FAT) were compared between individuals with psychosis and HCs using tract-based spatial statistics and FSL's Randomise. FAT and FW values were extracted, averaged across all voxels that demonstrated group differences, and then utilized to test for the influence of age, medication, age of onset, duration of illness, symptom severity, and intelligence.

Individuals with adolescent-onset psychosis exhibited pronounced FW and FAT abnormalities compared to HCs. FAT reductions were spatially more widespread in ADO-SCZ. FW increases, however, were only present in psychotic ADO-BPD. In HCs, but not in individuals with adolescent-onset psychosis, FAT was positively related to age.

We observe evidence for cellular (FAT) and extracellular (FW) white matter abnormalities in adolescent-onset psychosis. Although cellular white matter abnormalities were more prominent in ADO-SCZ, such alterations may reflect a shared trait, i.e. neurodevelopmental pathology, present across the psychosis spectrum. Extracellular abnormalities were evident in psychotic ADO-BPD, potentially indicating a more dynamic, state-dependent brain reaction to psychosis.

Our study examined whether the early-onset depression phenotype among young adults (probands) is associated with the metabolic syndrome (MetS) and its components, and if MetS characterizes unaffected but high-risk siblings of probands.

We studied three groups of young adults (Mage = 25 years, s.d. = 3.84 years): probands with histories of childhood onset depression – i.e. early-onset phenotype – (n = 293), their unaffected siblings (high-risk siblings, n = 273), and healthy controls (n = 171). Participants completed a full psychiatric interview, physical and laboratory assessments, and self-rating scales. MetS was defined using the criteria of the Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (2001).

Early-onset depression phenotype and being a high-risk sibling were associated with higher MetS composite scores relative to that of controls, but did not differ from one another. With regard to MetS components: Probands and siblings had similarly larger waist circumference and lower HDL than did controls, while siblings and controls had lower triglyceride levels than did probands but did not differ from one another. Groups did not differ on glucose levels and SBP.

Our study extends the literature on the association between MetS and depression and underscores the importance of depression phenotypes: failure to account for the clinical heterogeneity of depression may partly underlie the inconsistent findings regarding its relation to MetS. The results also suggest that, in depression-prone populations, MetS may predate and possibly function as a risk factor for eventual depression.

Young-onset dementia (YOD) is defined as the onset of dementia symptoms before the age of 65 years and accounts for 2–8% of dementia. YOD patients and their caregivers face unique challenges in diagnosis and management. We aimed to compare the characteristics of rural YOD and late-onset dementia (LOD) patients at a rural and remote memory clinic in Western Canada.

A total of 333 consecutive patients (YOD = 61, LOD = 272) at a rural and remote memory clinic between March 2004 and July 2016 were included in this study. Each patient had neuropsychological assessment. Health, mood, function, behaviour and social factors were also measured. Both groups were compared using χ2 tests and independent sample tests.

YOD patients were more likely to be married, employed, current smokers and highly educated. They reported fewer cognitive symptoms, but had more depressive symptoms. YOD patients were less likely to live alone and use homecare services. YOD caregivers were also more likely to be a spouse and had higher levels of distress than LOD caregivers. Both YOD and LOD patient groups were equally likely to have a driver’s licence.

Our findings indicate YOD and LOD patients have distinct characteristics and services must be modified to better meet YOD patient needs. In particular, the use of homecare services and caregiver support may alleviate the higher levels of distress found in YOD patients and their caregivers. Additional research should be directed to addressing YOD patient depression, caregiver distress and barriers to services.

Prior studies have suggested that major depressive disorder (MDD) with pre-adult onset represents a distinct subtype with greater symptom severity and higher rates of suicidal ideation. Whether these patients have poorer response to various types of antidepressant treatment than those with adult-onset MDD is unclear.

A total of 665 psychiatric and primary care out-patients (aged 18–75 years) with non-psychotic chronic or recurrent MDD participated in a single-blind, randomized trial that compared the efficacy of escitalopram plus placebo, bupropion sustained-release plus escitalopram, or venlafaxine extended-release plus mirtazapine. We compared participants who self-reported MDD onset (before age 18) to those with a later onset (adult onset) with respect to baseline characteristics and treatment/outcome variables at 12 and 28 weeks.

Early-onset chronic/recurrent MDD was associated with a distinct set of sociodemographic (female, younger age) and clinical correlates (longer duration of illness, greater number of prior episodes, greater likelihood of atypical features, higher rates of suicidality and psychiatric co-morbidity, fewer medical problems, poorer quality of life, greater history of child abuse/neglect). However, results from unadjusted and adjusted analyses showed no significant differences in response, remission, tolerability of medications, quality of life, or retention at 12 or 28 weeks.

Although early-onset chronic/recurrent MDD is associated with a more severe clinical picture, it does not seem to be useful for predicting differential treatment response to antidepressant medication. Clinicians should remain alert to an increased risk of suicidality in this population.