This study aimed to investigate mother–infant interaction and infant development in women at-risk of postpartum psychosis (PP), with and without a postpartum relapse.

103 women (and their offspring) were included, 43 at-risk-of-PP because of a diagnosis of bipolar disorder, schizoaffective disorder or previous PP, and 60 with no current/previous mental illness or family history of PP. Of the at-risk women, 18 developed a psychiatric relapse within 4 weeks after delivery (AR-unwell), while 25 remained symptom-free (AR-well). Mother–infant interaction was assessed using the CARE-Index at 8 weeks' and 12 months' postpartum and infant development using the Bayley-III at 12 months' postpartum.

Women at-risk-of-PP as a group, regardless of whether they developed a psychiatric relapse within 4 weeks after delivery, had less synchronous mother–infant interactions and had infants with less optimal cognitive, language, motor and socio-emotional development than healthy controls. In particular, boys of at-risk women had the lowest scores in cognitive, language and motor development and in mother–infant interaction, while girls of the at-risk women had the lowest scores in socio-emotional development. The synchrony in the dyad predicted infant cognitive and language development. There was no evidence for a difference in mother–infant interaction nor in infant development between the AR-unwell and AR-well groups.

These results suggest that, while there is a lack of evidence that an early postpartum relapse in women at-risk-of-PP could represent a risk for the infant per se, maternal risk for PP may be associated with less optimal mother–infant interaction and infant development.

Although COVID-19 is known to have cardiac effects in children, seen primarily in severe disease, more information is needed about the cardiac effects following COVID-19 in non-hospitalised children and adolescents during recovery. This study aims to compare echocardiographic markers of cardiac size and function of children following acute COVID-19 with those of healthy controls.

This single-centre retrospective case–control study compared 71 cases seen in cardiology clinic following acute COVID-19 with 33 healthy controls. Apical left ventricle, apical right ventricle, and parasternal short axis at the level of the papillary muscles were analysed to measure ventricular size and systolic function. Strain was analysed on vendor-independent software. Statistical analysis was performed using t-test, chi-square, Wilcoxon rank sum, and regression modelling as appropriate (p < 0.05 significant).

Compared to controls, COVID-19 cases had slightly higher left ventricular volumes and lower left ventricular ejection fraction and right ventricular fractional area change that remained within normal range. There were no differences in right or left ventricular longitudinal strain between the two groups. Neither initial severity nor persistence of symptoms after diagnosis predicted these differences.

Echocardiographic findings in children and adolescents 6 weeks to 3 months following acute COVID-19 not requiring hospitalisation were overall reassuring. Compared to healthy controls, the COVID-19 group demonstrated mildly larger left ventricular size and lower conventional measures of biventricular systolic function that remained within the normal range, with no differences in biventricular longitudinal strain. Future studies focusing on longitudinal echocardiographic assessment of patients following acute COVID-19 are needed to better understand these subtle differences in ventricular size and function.

Despite emerging evidence suggesting the efficacy of psilocybin in the treatment of mood disorders such as depression, the exact mechanisms by which psilocybin is able to elicit these antidepressant effects remains unknown.

As the use of psilocybin as a treatment modality for depression has garnered increasing interest, this study aims to summarize the existing evidence of the mechanism of action with which psilocybin alleviates depressive symptoms, focusing specifically on the neurobiological effects of psilocybin in human subjects.

Four databases (Ovid MEDLINE, EMBASE, psychINFO, and Web of Science) were searched using a combination of MeSH terms and free text keywords in September 2021. The original search included both human and animal studies and must have included testing of the mechanism of action of psilocybin. Only antidepressant effects were considered, with no other mood disorders or psychiatric diagnoses included. Two independent researchers screened at every stage of the review, with a third researcher resolving any conflicts. Though a full systematic review outlining the current literature on the complete mechanisms of action of psilocybin on depression was conducted, this abstract will focus specifically on the nine papers that included human subjects, disregarding the five animal models. PROSPERO registration number: 282710.

After removing duplicates, the search identified 2193 papers and forty-nine were selected for full text review. Out of nine papers outlining the mechanisms of action of psilocybin use in human subjects, three papers investigated psilocybin’s effect on serotonin or glutamate receptor activity, two found an increase in synaptogenesis in regions such as the medial frontal cortex and hippocampus. Four found variation in blood flow to the amygdala, two found altered blood flow to the prefrontal cortex, and one found a reduction in delta power during sleep. Four papers found changes in functional connectivity or neurotransmission, most commonly in the hippocampus or prefrontal cortex.

Overall, the exact mechanism of psilocybin’s potential antidepressant effect remains unclear. Multiple pathways may be involved, including alterations in serotonin and glutamate receptor activity, as well as shifts in amygdala activity, neurogenesis, and functional connectivity in various brain regions. The relative lack of studies, and the variety of neurobiological modalities and endpoints used challenged the consolidation of data into consensus findings. Further studies are needed to better characterize psilocybin’s mechanism of action and to better understand the clinical effects of the use of psilocybin in the treatment of depression.

None Declared