Assessment of risks of illnesses has been an important part of medicine for decades. We now have hundreds of ‘risk calculators’ for illnesses, including brain disorders, and these calculators are continually improving as more diverse measures are collected on larger samples.

We first replicated an existing psychosis risk calculator and then used our own sample to develop a similar calculator for use in recruiting ‘psychosis risk’ enriched community samples. We assessed 632 participants age 8–21 (52% female; 48% Black) from a community sample with longitudinal data on neurocognitive, clinical, medical, and environmental variables. We used this information to predict psychosis spectrum (PS) status in the future. We selected variables based on lasso, random forest, and statistical inference relief; and predicted future PS using ridge regression, random forest, and support vector machines.

Cross-validated prediction diagnostics were obtained by building and testing models in randomly selected sub-samples of the data, resulting in a distribution of the diagnostics; we report the mean. The strongest predictors of later PS status were the Children's Global Assessment Scale; delusions of predicting the future or having one's thoughts/actions controlled; and the percent married in one's neighborhood. Random forest followed by ridge regression was most accurate, with a cross-validated area under the curve (AUC) of 0.67. Adjustment of the model including only six variables reached an AUC of 0.70.

Results support the potential application of risk calculators for screening and identification of at-risk community youth in prospective investigations of developmental trajectories of the PS.

There is a high rate of psychiatric comorbidity in patients with epilepsy. However, the impact of surgical treatment of refractory epilepsy on psychopathology remains under investigation. We aimed to examine the impact of epilepsy surgery on psychopathology and quality of life at 1-year post-surgery in a population of patients with epilepsy refractory to medication.

This study initially assessed 48 patients with refractory epilepsy using the Structured Clinical Interview for DSM-IV Axis I Disorders (SCID-I), the Hospital Anxiety and Depression Scale (HADS) and the Quality of Life in Epilepsy Inventory 89 (QOLIE-89) on admission to an Epilepsy Monitoring Unit (EMU) as part of their pre-surgical assessment. These patients were again assessed using the SCID-I, QOLIE-89 and HADS at 1-year follow-up post-surgery.

There was a significant reduction in psychopathology, particularly psychosis, following surgery at 1-year follow-up (p < 0.021). There were no new cases of de novo psychosis and surgery was also associated with a significant improvement in the quality of life scores (p < 0.001).

This study demonstrates the impact of epilepsy surgery on psychopathology and quality of life in a patient population with refractory surgery. The presence of a psychiatric illness should not be a barrier to access surgical treatment.

Abnormal body mass index (BMI) has been associated with development of psychopathology. This association in children is well documented, for both overweight and underweight children. However, the association between change in BMI and the development of psychopathology has been less investigated.

To investigate the association between change in BMI between childhood and adolescence and psychopathology in adolescence.

Data from the Growing Up in Ireland cohort were used. We investigated the ’98 cohort (also known as the child cohort) at age 9/13. BMI, defined using internationally recognised definitions as underweight, healthy or overweight, was used as the exposure, and abnormal Strength and Difficulties Questionnaire scores were used as the outcome. Logistic regression was undertaken for the analysis. All analyses were adjusted for confounders.

A change to overweight from healthy BMI was significantly associated with increased risk of psychopathology (adjusted OR 1.66; 95% CI 1.19–2.32). Both change from underweight to healthy (adjusted OR 0.12; 95% CI 0.03–0.43) or from overweight to healthy (adjusted OR 0.47; 95% CI 0.79–0.8) was associated with a significantly reduced risk of developing psychopathology.

As a child’s BMI returns to within the healthy range, their risk of adolescent psychopathology is reduced. Interventions to restore healthy BMI, in both underweight and overweight, children may reduce their risk of adolescent psychopathology.

Often referred to as psychotic experiences, unusual perceptual experiences, thoughts and beliefs (UPTBs) are not uncommon in youth populations. Phenomenological studies of these experiences are lacking. This study aimed to (1) describe the phenomenological characteristics of UPTBs in a sample of young adolescents and (2) explore how young people made sense of those experiences.

Participants were 53 young people aged 11–13 years from a population-based study of mental health. All met criteria for UPTBs following clinical interviews as part of the study. Documentary data on UPTBs in the form of transcribed notes, recorded during clinical interviews, were analysed using content analysis. Data on UPTBs were coded, organised into categorical themes and quantified using descriptive statistics. Qualitative themes on how participants made sense of their experiences were identified.

Participants reported UPTBs across four domains: auditory verbal, auditory non-verbal, non-auditory perceptual experiences and unusual thoughts and beliefs. UPTBs were phenomenologically rich and diverse. Young people sought to make sense of their experiences in multiple ways: normalising them, externalising them by attributing them to paranormal entities and distancing them from psychiatric explanations. Uncertainty about the source of UPTBs was identified as a superordinate theme.

Findings from this study offer new insights into the phenomenological qualities and characteristics of UPTBs in young adolescents. They also reveal that early adolescents may not make sense of their experiences within a psychiatric framework. These findings highlight the need to develop a more phenomenologically sensitive and nuanced approach to studying UPTBs in young people.

To identify and synthesise the literature on the cost of mental disorders.

Systematic literature searches were conducted in the databases PubMed, EMBASE, Web of Science, EconLit, NHS York Database and PsychInfo using key terms for cost and mental disorders. Searches were restricted to January 1980–May 2019. The inclusion criteria were: (1) cost-of-illness studies or cost-analyses; (2) diagnosis of at least one mental disorder; (3) study population based on the general population; (4) outcome in monetary units. The systematic review was preregistered on PROSPERO (ID: CRD42019127783).

In total, 13 579 potential titles and abstracts were screened and 439 full-text articles were evaluated by two independent reviewers. Of these, 112 articles were included from the systematic searches and 31 additional articles from snowball searching, resulting in 143 included articles. Data were available from 48 countries and categorised according to nine mental disorder groups. The quality of the studies varied widely and there was a lack of studies from low- and middle-income countries and for certain types of mental disorders (e.g. intellectual disabilities and eating disorders). Our study showed that certain groups of mental disorders are more costly than others and that these rankings are relatively stable between countries. An interactive data visualisation site can be found here: https://nbepi.com/econ.

This is the first study to provide a comprehensive overview of the cost of mental disorders worldwide.

Migrant youths endure many challenges. Such challenges can be stressful and lead to psychological difficulties. We investigated the relationship between migration, psychopathology and stressful events in children and adolescents. We hypothesised that migrant youths would show higher levels of psychopathology and more stressful life events than non-migrant youths.

Using the Child cohort (Cohort ‘98) of the ‘Growing up in Ireland’ study we investigated psychopathology, as measured by the Strengths and Difficulties questionnaire (SDQ) at age 9 and 13 and stressful life events in migrant and non-migrant youths.

There was no significant difference between the proportion of migrant and non-migrant youths reporting psychopathology in childhood (p>0.05) or adolescence (p>0.05). Analysis of the SDQ subscales revealed that a significantly greater proportion of migrant youths had hyperactivity problems in childhood (p = 0.04) but a greater proportion of non-migrant youths had emotional problems in early adolescence (p = 0.04). We found that migrant youths experienced significantly more stressful life events than their non-migrant counterparts (p<0.01), however, once ‘Moving house/country‘ was removed as a stressor, there was no difference between the groups (p>0.27).

Contrary to our hypothesis, we observed that there were few differences between migrant and non-migrant youths in the levels of psychopathology. Migrant youths experienced a greater number of stressful life events, however, this was attributable to stressors relating to moving. An increased understanding of the factors promoting resilience, as demonstrated by the migrant youths, could aid health professionals and policy makers to effectively tailor interventions for mental health promotion.

Our understanding of the complex relationship between schizophrenia symptomatology and etiological factors can be improved by studying brain-based correlates of schizophrenia. Research showed that impairments in value processing and executive functioning, which have been associated with prefrontal brain areas [particularly the medial orbitofrontal cortex (MOFC)], are linked to negative symptoms. Here we tested the hypothesis that MOFC thickness is associated with negative symptom severity.

This study included 1985 individuals with schizophrenia from 17 research groups around the world contributing to the ENIGMA Schizophrenia Working Group. Cortical thickness values were obtained from T1-weighted structural brain scans using FreeSurfer. A meta-analysis across sites was conducted over effect sizes from a model predicting cortical thickness by negative symptom score (harmonized Scale for the Assessment of Negative Symptoms or Positive and Negative Syndrome Scale scores).

Meta-analytical results showed that left, but not right, MOFC thickness was significantly associated with negative symptom severity (β std = −0.075; p = 0.019) after accounting for age, gender, and site. This effect remained significant (p = 0.036) in a model including overall illness severity. Covarying for duration of illness, age of onset, antipsychotic medication or handedness weakened the association of negative symptoms with left MOFC thickness. As part of a secondary analysis including 10 other prefrontal regions further associations in the left lateral orbitofrontal gyrus and pars opercularis emerged.

Using an unusually large cohort and a meta-analytical approach, our findings point towards a link between prefrontal thinning and negative symptom severity in schizophrenia. This finding provides further insight into the relationship between structural brain abnormalities and negative symptoms in schizophrenia.

Although repeatedly associated with white matter microstructural alterations, bipolar disorder (BD) has been relatively unexplored using complex network analysis. This method combines structural and diffusion magnetic resonance imaging (MRI) to model the brain as a network and evaluate its topological properties. A group of highly interconnected high-density structures, termed the ‘rich-club’, represents an important network for integration of brain functioning. This study aimed to assess structural and rich-club connectivity properties in BD through graph theory analyses.

We obtained structural and diffusion MRI scans from 42 euthymic patients with BD type I and 43 age- and gender-matched healthy volunteers. Weighted fractional anisotropy connections mapped between cortical and subcortical structures defined the neuroanatomical networks. Next, we examined between-group differences in features of graph properties and sub-networks.

Patients exhibited significantly reduced clustering coefficient and global efficiency, compared with controls globally and regionally in frontal and occipital regions. Additionally, patients displayed weaker sub-network connectivity in distributed regions. Rich-club analysis revealed subtly reduced density in patients, which did not withstand multiple comparison correction. However, hub identification in most participants indicated differentially affected rich-club membership in the BD group, with two hubs absent when compared with controls, namely the superior frontal gyrus and thalamus.

This graph theory analysis presents a thorough investigation of topological features of connectivity in euthymic BD. Abnormalities of global and local measures and network components provide further neuroanatomically specific evidence for distributed dysconnectivity as a trait feature of BD.

Impulsivity is associated with bipolar disorder as a clinical feature during and between manic episodes and is considered a potential endophenotype for the disorder. Schizophrenia and major depressive disorder share substantial genetic overlap with bipolar disorder, and these two disorders have also been associated with elevations in impulsivity. However, little is known about the degree of overlap among these disorders in discrete subfacets of impulsivity and whether any overlap is purely phenotypic or due to shared genetic diathesis.

We focused on five subfacets of impulsivity: self-reported attentional, motor, and non-planning impulsivity, self-reported sensation seeking, and a behavioral measure of motor inhibition (stop signal reaction time; SSRT). We examined these facets within and across disorder proband and co-twin groups, modeled heritability, and tested for endophenotypic patterning in a sample of twin pairs recruited from the Swedish Twin Registry (N = 420).

We found evidence of moderate to high levels of heritability for all five subfacets. All three proband groups and their unaffected co-twins showed elevations on attentional, motor, and non-planning impulsivity. Schizophrenia probands (but not their co-twins) showed significantly lower sensation seeking, and schizophrenia and bipolar disorder probands (but not in their co-twins) had significantly longer SSRTs, compared with healthy controls and the other groups.

Attentional, motor, and non-planning impulsivity emerged as potential shared endophenotypes for the three disorders, whereas sensation seeking and SSRT were associated with phenotypic affection but not genetic loading for these disorders.

A series of research reports has indicated that the use of substances such as cannabis, alcohol and tobacco are higher in youth at clinical high risk (CHR) of developing psychosis than in controls. Little is known about the longitudinal trajectory of substance use, and findings on the relationship between substance use and later transition to psychosis in CHR individuals are mixed.

At baseline and 6- and 12-month follow-ups, 735 CHR and 278 control participants completed the Alcohol and Drug Use Scale and a cannabis use questionnaire. The longitudinal trajectory of substance use was evaluated with linear mixed models.

CHR participants endorsed significantly higher cannabis and tobacco use severity, and lower alcohol use severity, at baseline and over a 1-year period compared with controls. CHR youth had higher lifetime prevalence and frequency of cannabis, and were significantly younger upon first use, and were more likely to use alone and during the day. Baseline substance use did not differentiate participants who later transitioned to psychosis (n = 90) from those who did not transition (n = 272). Controls had lower tobacco use than CHR participants with a prodromal progression clinical outcome and lower cannabis use than those with a psychotic clinical outcome at the 2-year assessment.

In CHR individuals cannabis and tobacco use is higher than in controls and this pattern persists across 1 year. Evaluation of clinical outcome may provide additional information on the longitudinal impact of substance use that cannot be detected through evaluation of transition/non-transition to psychosis alone.

Increasing rates of young people not in education, employment or training (NEETs) are a cause of concern both in Ireland and internationally, but little longitudinal research has examined the link between psychiatric disorder in young people and NEET status.

The Challenging Times (CT) Study is a longitudinal, population-based study of psychopathology among 212 young Irish people. Clinical interviews were performed at two time points: 12–15 years and 19–24 years.

NEET status in young adulthood was associated with a sevenfold increased risk of current suicidal ideation. This result was independent of prior adolescent mental disorder. NEET young people had a fourfold increased odds of being diagnosed with a mental disorder in childhood or early adolescence compared with their economically active peers. NEET young people were at an almost threefold increased risk of any mental health disorder a twofold increased risk of anxiety disorder and threefold increased odds of suicide attempts over their lifetime compared with economically active peers.

NEET young people are at increased risk for mental disorder and suicidal ideation. The association is bidirectional, as prior mental disorder in adolescence appeared to account for much of the association between NEET status and current mental health problems. However, economic inactivity conveys an increased risk for suicidal ideation over and above that due to prior disorder. Our findings provide a compelling economic and societal argument for early intervention and treatment of mental disorder and the importance of vocational interventions for reducing suicide risk in young adults.

There is a lack of epidemiological research on the mental health of young adults in Ireland.

To determine prevalence of psychiatric disorders in a cohort of young Irish adults.

The Challenging Times study was a landmark study of the prevalence of psychiatric disorders in adolescents in North Dublin, Ireland: 212 school children aged 12-15 years were recruited through schools and interviewed using the K-SADS semi-structured diagnostic instrument. This cohort was traced again at age 19-24 years (mean age 20.8 years) and interviewed using SCID I & II. Main outcome measures were current and lifetime Axis I and Axis II psychiatric disorders.

Follow-up rate was 80%. Using a weighted population prevalence analysis 19.8% of the cohort had a current mental disorder, 56.0% had a lifetime mental disorder of whom 28.4% had mood disorders, 27.1% had anxiety disorders, 22.7% had substance use disorders; 25.4% had lifetime multi-morbidity. Cluster A personality disorders were found in 2.3%. Lifetime prevalence of binge-drinking was 75.0%, cannabis use 65% and 17% of young adults had fulfilled criteria for an alcohol use disorder at sometime in their life. Lifetime prevalence of suicidal thoughts/behaviour was 21.1%.

Lifetime prevalence of psychiatric disorder and substance use were high in this sample of young Irish adults. Mental Health service provision for this age group is a priority. Larger studies of nationally representative samples are needed to inform service development.

White matter (WM) abnormalities are proposed as potential endophenotypic markers of bipolar disorder (BD). In a diffusion tensor imaging (DTI) voxel-based analysis (VBA) study of families multiply affected with BD, we previously reported that widespread abnormalities of fractional anisotropy (FA) are associated with both BD and genetic liability for illness. In the present study, we further investigated the endophenotypic potential of WM abnormalities by applying DTI tractography to specifically investigate tracts implicated in the pathophysiology of BD.

Diffusion magnetic resonance imaging (MRI) data were acquired from 19 patients with BD type I from multiply affected families, 21 of their unaffected first-degree relatives and 18 healthy volunteers. DTI tractography was used to identify the cingulum, uncinate fasciculus (UF), arcuate portion of the superior longitudinal fasciculus (SLF), inferior longitudinal fasciculus (ILF), corpus callosum, and the anterior limb of the internal capsule (ALIC). Regression analyses were conducted to investigate the effect of participant group and genetic liability on FA and radial diffusivity (RD) in each tract.

We detected a significant effect of group on both FA and RD in the cingulum, SLF, callosal splenium and ILF driven by reduced FA and increased RD in patients compared to controls and relatives. Increasing genetic liability was associated with decreased FA and increased RD in the UF, and decreased FA in the SLF, among patients.

WM microstructural abnormalities in limbic, temporal and callosal pathways represent microstructural abnormalities associated with BD whereas alterations in the SLF and UF may represent potential markers of endophenotypic risk.