There is evidence that the COVID-19 pandemic has negatively affected mental health, but most studies have been conducted in the general population.

To identify factors associated with mental health during the COVID-19 pandemic in individuals with pre-existing mental illness.

Participants (N = 2869, 78% women, ages 18–94 years) from a UK cohort (the National Centre for Mental Health) with a history of mental illness completed a cross-sectional online survey in June to August 2020. Mental health assessments were the GAD-7 (anxiety), PHQ-9 (depression) and WHO-5 (well-being) questionnaires, and a self-report question on whether their mental health had changed during the pandemic. Regressions examined associations between mental health outcomes and hypothesised risk factors. Secondary analyses examined associations between specific mental health diagnoses and mental health.

A total of 60% of participants reported that mental health had worsened during the pandemic. Younger age, difficulty accessing mental health services, low income, income affected by COVID-19, worry about COVID-19, reduced sleep and increased alcohol/drug use were associated with increased depression and anxiety symptoms and reduced well-being. Feeling socially supported by friends/family/services was associated with better mental health and well-being. Participants with a history of anxiety, depression, post-traumatic stress disorder or eating disorder were more likely to report that mental health had worsened during the pandemic than individuals without a history of these diagnoses.

We identified factors associated with worse mental health during the COVID-19 pandemic in individuals with pre-existing mental illness, in addition to specific groups potentially at elevated risk of poor mental health during the pandemic.

The utility of questionnaire based self-report measures for non-clinical psychotic symptoms is unclear and there are few reliable data about the nature and prevalence of these phenomena in children. The study aimed to investigate psychosis-like symptoms (PLIKS) in children utilizing both self-report measures and semi-structured observer rated assessments.

The study was cross-sectional; the setting being an assessment clinic for members of the ALSPAC birth cohort in Bristol, UK. 6455 respondents were assessed over 21 months, mean age 12.9 years. The main outcome measure was: 12 self-report screening questions for psychotic symptoms followed by semi-structured observer rated assessments by trained psychology graduates. The assessment instrument utilised stem questions, glossary definitions, and rating rules adapted from DISC-IV and SCAN items.

The 6-month period prevalence for one or more PLIKS rated by self-report questions was 38.9 % (95% CI = 37.7-40.1). Prevalence using observer rated assessments was 13.7% (95% CI = 12.8-14.5). Positive Predictive Values for the screen questions versus observer rated scores were low, except for auditory hallucinations (PPV=70%; 95% CI = 67.1-74.2). The most frequent observer rated symptom was auditory hallucinations (7.3%); in 18.8% of these cases symptoms occurred weekly or more. The prevalence of DSM-IV ‘core’ schizophrenia symptoms was 3.62%. Rates were significantly higher in children with low socio-economic status.

With the exception of auditory hallucinations, self-rated questionnaires are likely to substantially over-estimate the frequency of PLIKS in 12-year-old children. However, more reliable observer rated assessments reveal that PLIKS occur in a significant proportion of children.

Adverse effects of maternal substance use during pregnancy on fetal development may increase risk of psychopathology.

To examine whether maternal use of tobacco, cannabis or alcohol during pregnancy increases risk of offspring psychotic symptoms.

A longitudinal study of 6356 adolescents, age 12, who completed a semi-structured interview for psychotic symptoms in the Avon Longitudinal Study of Parents and Children (ALSPAC) birth cohort.

Frequency of maternal tobacco use during pregnancy was associated with increased risk of suspected or definite psychotic symptoms (adjusted odds ratio 1.20, 95% CI 1.05–1.37, P = 0.007). Maternal alcohol use showed a non-linear association with psychotic symptoms, with this effect almost exclusively in the offspring of women drinking >21 units weekly. Maternal cannabis use was not associated with psychotic symptoms. Results for paternal smoking during pregnancy and maternal smoking post-pregnancy lend some support for a causal effect of tobacco exposure in utero on development of psychotic experiences.

These findings indicate that risk factors for development of non-clinical psychotic experiences may operate during early development. Future studies of how in utero exposure to tobacco affects cerebral development and function may lead to increased understanding of the pathogenesis of psychotic phenomena.

Previous studies have suggested that impaired fetal and childhood growth are associated with an increased risk of schizophrenia, but the association of pre-adult growth with non-clinical psychotic symptoms (psychosis-like symptoms) in children is not known.

To explore the associations of body size at birth and age 7.5 years with childhood psychosis-like symptoms.

Prospective cohort of children followed up from birth to age 12: the ALSPAC cohort.

Data on 6000 singleton infants born after 37 weeks of gestation. A one standard deviation increase in birth weight was associated with an 18% reduction in the risk of definite psychosis-like symptoms after adjusting for age and gestation (Odds ratio (OR) = 0.82, 95% CI = 0.73–0.92, P = 0.001). This association was partly confounded by maternal anthropometry, smoking during pregnancy, socioeconomic status and IQ. A similar association was seen for birth length and psychosis-like symptoms, which disappeared after controlling for birth weight. There was little evidence for an association of 7-year height or adiposity with psychosis-like symptoms.

Measures of impaired fetal, but not childhood, growth are associated with an increased risk of psychosis-like symptoms in 12-year-olds.

Non-clinical psychosis-like symptoms (PLIKS) occur in about 15% of the population. It is not clear whether adverse events during early development alter the risk of developing PLIKS. We aimed to examine whether maternal infection, diabetes or pre-eclampsia during pregnancy, gestational age, perinatal cardiopulmonary resuscitation or 5-min Apgar score were associated with development of psychotic symptoms during early adolescence.

A longitudinal study of 6356 12-year-old adolescents who completed a semi-structured interview for psychotic symptoms in the Avon Longitudinal Study of Parents and Children (ALSPAC) birth cohort. Prenatal and perinatal data were obtained from obstetric records and maternal questionnaires completed during pregnancy.

The presence of definite psychotic symptoms was associated with maternal infection during pregnancy [adjusted odds ratio (OR) 1.44, 95% confidence interval (CI) 1.11–1.86, p=0.006], maternal diabetes (adjusted OR 3.43, 95% CI 1.14–10.36, p=0.029), need for resuscitation (adjusted OR 1.50, 95% CI 0.97–2.31, p=0.065) and 5-min Apgar score (adjusted OR per unit decrease 1.30, 95% CI 1.12–1.50, p<0.001). None of these associations were mediated by childhood IQ score. Most associations persisted, but were less strong, when including suspected symptoms as part of the outcome. There was no association between PLIKS and gestational age or pre-eclampsia.

Adverse events during early development may lead to an increased risk of developing PLIKS. Although the status of PLIKS in relation to clinical disorders such as schizophrenia is not clear, the similarity between these results and findings reported for schizophrenia indicates that future studies of PLIKS may help us to understand how psychotic experiences and clinical disorders develop throughout the life-course.

Non-clinical psychotic symptoms appear common in children, but it is possible that a proportion of reported symptoms result from misinterpretation. There is a well-established association between pre-morbid low IQ score and schizophrenia. Psychosis-like symptoms in children may also be a risk factor for psychotic disorder but their relationship with IQ is unclear.

To investigate the prevalence, nature and frequency of psychosis-like symptoms in 12-year-old children and study their relationship with IQ.

Longitudinal study using the Avon Longitudinal Study of Parents and Children (ALSPAC) birth cohort. A total of 6455 children completed screening questions for 12 psychotic symptoms followed by a semi-structured clinical assessment. IQ was assessed at 8 years of age using the Wechsler Intelligence Scale for Children (3rd UK edition).

The 6-month period prevalence for one or more symptoms was 13.7% (95% CI 12.8–14.5). After adjustment for confounding variables, there was a non-linear association between IQ score and psychosis-like symptoms, such that only those with below average IQ score had an increased risk of reporting such symptoms.

Non-clinical psychotic symptoms occur in a significant proportion of 12-year-olds. Symptoms are associated with low IQ and also less strongly with a high IQ score. The pattern of association with IQ differs from that observed in schizophrenia.

There is increasing interest in the proposition that residential environment can affect mental health.

To study the degree to which common mental disorder clusters according to postcode units and households. To investigate whether contextual measures of residential environment quality and geographical accessibility are associated with symptoms of common mental disorder.

A total of 1058 individuals aged 16–75 years (response rate 66%) participated in a cross-sectional survey The 12-item General Health Questionnaire measured symptoms of common mental disorder.

Only 2% (95% CI 0–6) of the unexplained variation in symptoms existed at postcode unit level, whereas 37% (95% CI 27–49) existed at household-level, but the postcode unit variation was reduced to zero after adjustments. There was little evidence to suggest that residential quality or accessibility were associated with symptoms.

There was substantial unexplained variation at the household level but we could find no evidence of postcode unit variation and no association with residential environmental quality or geographical accessibility. It is likely that the psychosocial environment is more important than the physical environment in relation to common mental disorder.

Veterans of the Persian Gulf War of 1991 have reported symptoms attributed to their military service.

To review all studies comparing the prevalence of psychiatric disorders in Gulf War veterans and in a comparison group of service personnel not deployed to the Gulf War.

Studies of military personnel deployed to the Gulf published between 1990 and 2001 were identified from electronic databases. Reference lists and websites were searched and key researchers were contacted for information. Atotal of 2296 abstracts and 409 complete articles were reviewed and data were extracted independently by two members of the research team.

The prevalence of psychiatric disorder in 20 studies of Gulf War veterans was compared with the prevalence in the comparison group. Prevalence of post-traumatic stress disorder (PTSD) and common mental disorder were higher in the Gulf War veterans. Heterogeneity between studies was significant, but all reported this increased prevalence.

Veterans of the Persian Gulf War reported an increased prevalence of PTSD and common mental disorder compared with other active service personnel not deployed to the Gulf. These findings are attributable to the increase in psychologically traumatic events in wartime.

Previous research has found an association between obstetric complications and schizophrenia, but in many studies the sample size was limited, and no assessment of specific exposures was possible.

To assess the role of different complications, and in particular to distinguish between disordered foetal development and hypoxia at birth.

From the Stockholm County In-Patient Register and community registers, we identified 524 cases of schizophrenia and 1043 controls, matched for age, gender, hospital and parish of birth. Data on obstetric complications were obtained from birth records.

There was a strong association between signs of asphyxia at birth and schizophrenia (OR 4.4; 95% C11.9–10.3) after adjustment for other obstetric complications, maternal history of psychotic illness and social class.

Signs of asphyxia at birth are associated with an increased risk of schizophrenia in adults.

Obstetric complications have been studied frequently as possible risk factors for schizophrenia.

To test the hypotheses that individual obstetric complications are most strongly associated with an increased risk of schizophrenia in males, in patients with an early age at first diagnosis and in subjects with a maternal history of psychosis.

Cases of schizophrenia diagnosed between January 1971 and June 1994 were identified in the Stockholm County In-Patient Register. Controls were matched on age, gender, hospital of birth and parish of birth. Obstetric data were recorded blind to case–control status for 524 cases and 1043 controls.

This study did not find any large or consistent effect of gender, age at diagnosis or maternal history of psychosis on the risk of schizophrenia associated with individual complications.

Future studies should examine these effects using a much larger sample that includes patients with schizophrenia and control subjects whose genetic risk of schizophrenia has been assessed accurately.