The children of mothers who experience perinatal depression are more likely to report psychotic experiences at the age of 18, a UK prospective cohort study has found.¹

The Avon Longitudinal Study of Parents and Children recruited 14,541 women during pregnancy in 1991-92. Perinatal depression symptoms were measured with the Edinburgh Postnatal Depression Scale (EPDS) at 18 and 32 weeks antenatally, and at 8 weeks and 8 months postnatally. At age 18 their children were assessed with the semi-structured Psychosis-Like Symptom Interview (PLIKSi). This elicits key psychotic experiences occurring since the age of 12, i.e. hallucinations, delusions and thought interference.² Depression was measured with the computerised Clinical Interview Schedule-Revised (CIS-R).

Overall, 3,067 children for whom there were complete data on maternal perinatal depression and a completed PLIKSi were included in the analysis. There was a high degree of correlation between mean antenatal and postnatal EPDS scores (r = 0.66). The primary outcome measure was the association between the continuous mean antenatal EPDS scores and suspected/definite presence of offspring psychotic experiences at the age of 18. After adjustment for potential confounders, the odds ratio for a 5-point increase in the EPDS score was 1.26 (95% CI: 1.06-1.49).

A joint analysis found an association between maternal antenatal depression symptoms and both offspring psychotic experiences at age 18 (n = 2,830), OR for a 5-point increase in EPDS score 1.32 (95% CI: 1.16-1.51) and offspring depression at the age of 18, OR for a 5-point increase in EPDS score 1.18 (95% CI: 1.03-1.34). The correlation between offspring psychotic experiences and offspring depression was very weak (r = 0.16).

Attrition is a major problem with longitudinal studies. The participants in this study represented only 21% of the original cohort and this may have biased the association estimates. To compensate for this the authors performed imputation-based analyses and these yielded comparable results. There is also the possibility of residual confounding e.g. no adjustment was made for maternal alcohol consumption.

Psychotic symptoms are surprisingly common in adolescents: among the 4,720 participants from the Avon cohort who completed a PLIKSi at the age of 18, 7.9% had psychotic experiences (suspected or definite).² Reassuringly, most of those with psychotic symptoms will not go on to develop psychosis or schizophrenia: a Swedish study found that just 0.54% of adolescents had been treated for psychosis between the ages of 13 and 19.³  However, the majority who do not go on to develop mental health problems are still at increased risk of low educational and occupational achievement, social impairment, harmful drinking and substance misuse.²

Children of mothers with perinatal depression are at raised risk of developmental delay,⁴ impaired social competence, anxiety disorders and adolescent depression.⁵ This list now includes adolescent psychotic symptoms, although the absolute risk increase for a psychotic disorder will be very small. The authors conclude that their study ‘adds weight to the importance of identifying and treating maternal mental health problems during pregnancy and the postnatal period.’

Social isolation and lack of professional support are risk factors for antenatal and postnatal depression.^6,7

Hence it is likely that the incidence of perinatal depression will have increased as a result of the Covid-19 pandemic, and this may have adverse consequences for children’s mental health and wellbeing over the next 20 years. To mitigate the situation, it is essential that GPs should liaise closely with midwives and heath visitors to ensure continued provision of effective proactive follow-up, screening and support throughout pregnancy and the extended postpartum period.