Vitamin D concentration and psychotic disorder: associations with disease status, clinical variables and urbanicity

An epidemiological study of season of birth, mental health, and neuroimaging in the UK Biobank

Environmental exposures during the perinatal period are known to have a long-term effect on adult physical and mental health. One such influential environmental exposure is the time of year of birth which affects the amount of daylight, nutrients, and viral load that an individual is exposed to within this key developmental period. Here, we investigate associations between season of birth (seasonality), four mental health traits (n = 137,588) and multi-modal neuroimaging measures (n = 33,212) within the UK Biobank. Summer births were associated with probable recurrent Major Depressive Disorder (β = 0.026, pcorr = 0.028) and greater mean cortical thickness in temporal and occipital lobes (β = 0.013 to 0.014, pcorr<0.05). Winter births were associated with greater white matter integrity globally, in the association fibers, thalamic radiations, and six individual tracts (β = -0.013 to -0.022, pcorr<0.05). Results of sensitivity analyses adjusting for birth weight were similar, with an additional association between winter birth and white matter microstructure in the forceps minor and between summer births, greater cingulate thickness and amygdala volume. Further analyses revealed associations between probable depressive phenotypes and a range of neuroimaging measures but a paucity of interactions with seasonality. Our results suggest that seasonality of birth may affect later-life brain structure and play a role in lifetime recurrent Major Depressive Disorder. Due to the small effect sizes observed, and the lack of associations with other mental health traits, further research is required to validate birth season effects in the context of different latitudes, and by co-examining genetic and epigenetic measures to reveal informative biological pathways.

Urbanization and psychosis: an update of recent evidence

PURPOSE OF REVIEW

Urbanization, a complex global phenomenon, has a significant bearing on schizophrenia/psychosis burden through various socioeconomic and environmental factors. This review focuses on recent evidence (2019-2023) linking urbanization, schizophrenia, and the role of green space.

RECENT FINDINGS

This review analyzed 43 articles that examined the correlation between urban birth or upbringing, urban living (urbanicity), and various schizophrenia/psychosis-related outcomes such as incidence, psychotic experiences, etc. The studies showed differing results across geographical locations. Socioeconomic factors like area deprivation, migrant status (ethnic density) and social fragmentation were independently associated with the risk of schizophrenia/psychosis irrespective of urbanicity. More recently, environmental factors such as green space reduction and air pollution have been explored in urban living conditions and were positively associated with an increased risk of schizophrenia/psychosis.

SUMMARY

There is a need for further investigation in low and middle-income countries. The impact of urbanization-related factors and green space on the risk of schizophrenia/psychosis calls for appropriate governmental commitments toward structured and healthy urban planning.

Diminished social motivation in early psychosis is associated with polygenic liability for low vitamin D

Insufficiency of vitamin D levels often occur in individuals with schizophrenia and first-episode psychosis (FEP). However, it is unknown whether this represents a biological predisposition, or it is essentially driven by illness-related alterations in lifestyle habits. Lower vitamin D has also been associated with adverse neurodevelopmental outcomes and predominant negative psychotic symptoms. This study aimed to investigate the contribution of polygenic risk score for circulating 25-hydroxyvitamin D concentration (PRS-vitD) to symptom presentation among individuals with FEP enrolled in the Athens First-Episode Psychosis Research Study (AthensFEP n = 205) and the Psychosis Incident Cohort Outcome Study (PICOS n = 123). The severity of psychopathology was evaluated using the Positive and Negative Syndrome Scale at baseline and follow-up assessments (AthensFEP: 4-weeks follow-up, PICOS: 1-year follow-up). Premorbid intelligence and adjustment domains were also examined as proxy measures of neurodevelopmental deviations. An inverse association between PRS-vitD and severity of negative symptoms, in particular lack of social motivation, was detected in the AthensFEP at baseline (adjusted R2 = 0.04, p < 0.001) and follow-up (adjusted R2 = 0.03, p < 0.01). The above observation was independently validated in PICOS at follow-up (adjusted R2 = 0.06, p < 0.01). No evidence emerged for a relationship between PRS-vitD and premorbid measures of intelligence and adjustment, likely not supporting an impact of lower PRS-vitD on developmental trajectories related to psychotic illness. These findings suggest that polygenic vulnerability to reduced vitamin D impairs motivation and social interaction in individuals with FEP, thereby interventions that encourage outdoor activities and social engagement in this patient group might attenuate enduring negative symptoms.

Severe Vitamin D Deficiency-A Possible Cause of Resistance to Treatment in Psychiatric Pathology

In the last few years, vitamin D functions have been studied progressively, and along with their main role in regulating calcium homeostasis, the potential function in the nervous system and the link between different psychiatric disorders and vitamin D deficiency have been revealed. The discovery of vitamin D receptors in multiple brain structures, like the hippocampus, led to the hypothesis that vitamin D deficiency could be responsible for treatment resistance in psychiatric diseases. The aim of this study was to analyze the current knowledge in the literature regarding vitamin D deficiency among individuals afflicted with psychiatric disorders and assess the potential therapeutic benefits of vitamin D supplementation. A systematic search was conducted on the PubMed database for articles published in the last five years (2016-2022) in English, focusing on human subjects. Results show that vitamin D deficiency has implications for numerous psychiatric disorders, affecting mood and behavior through its influence on neurotransmitter release, neurotrophic factors, and neuroprotection. It also plays a role in modulating inflammation, which is often elevated in psychiatric disorders. In conclusion, vitamin D deficiency is prevalent and has far-reaching implications for mental health. This review underscores the importance of exploring the therapeutic potential of vitamin D supplementation in individuals with psychiatric disorders and highlights the need for further research in this complex field.

The association between vitamin D and symptom domains in psychotic disorders: A systematic review

BACKGROUND

Vitamin D deficiency is prevalent among people with psychosis and may play a role in the aetiology of psychotic disorders. However, its impact on clinical symptom severity has not been independently reviewed.

METHODS

We conducted a systematic search of randomized trials and observational studies that assessed the relationship between vitamin D and symptom domains (positive and negative psychotic symptoms, total and general psychopathology, cognitive and depressive) in people with a psychotic disorder.

RESULTS

1040 articles were identified, of which 29 were eligible for inclusion: 26 observational studies and 3 randomized trials. Five studies included people with First-Episode Psychosis (FEP) and 24 included people with enduring psychosis. Most observational studies found that vitamin D was inversely associated with negative symptoms (57%; 13/23), positively associated with cognitive performance (63%; 5/8), and bore no association with positive symptoms (68%; 15/22), total psychopathology (64%; 7/11), general psychopathology (57%; 4/7) or depressive symptoms (64%; 9/14). Randomized controlled trials indicated that vitamin D supplementation improved cognitive performance (100%; 1/1) and, in some cases, reduced total psychopathology (50%; 1/2), general psychopathology (50%; 1/2) and negative symptoms (30%; 1/3), but had no effect on positive (100%; 3/3) or depressive (100%; 3/3) symptoms. Some positive associations were attenuated when controlled for potential confounders.

CONCLUSION

Low vitamin D was found to be inversely associated with more severe clinical symptoms in some, but not all symptom domains in people with psychosis. These preliminary findings warrant further exploration, particularly in regard to cognitive performance and negative symptoms.

Seasonality in schizophrenia-An analysis of a nationwide registry with 110,735 hospital admissions

Background.

Seasonal patterns in hospitalizations have been observed in various psychiatric disorders, however, it is unclear whether they also exist in schizophrenia. Previous studies found mixed results and those reporting the presence of seasonality differ regarding the characteristics of these patterns. Further, they are inconclusive whether sex is an influencing factor. The aim of this study was therefore to examine if seasonal patterns in hospitalizations can be found in schizophrenia, with special regard to a possible influence of sex, by using a large national dataset.

Methods.

Data on all hospital admissions within Austria due to schizophrenia (F20.0–F20.6) for the time period of 2003–2016 were included. Age standardized monthly variation of hospitalization for women and men was analyzed and the level of significance adjusted for multiple testing.

Results.

The database comprised of 110,735 admissions (59.6% men). Significant seasonal variations were found in the total sample with hospitalization peaks in January and June and a trough in December (p < 0.0001). No significant difference in these patterns was found between women and men with schizophrenia (p < 0.0001).

Conclusion.

Our study shows that schizophrenia-related hospitalizations follow a seasonal pattern in both men and women. The distribution of peaks might be influenced by photoperiod changes which trigger worsening of symptoms and lead to exacerbations in schizophrenia. Further research is necessary to identify underlying factors influencing seasonal patterns and to assess whether a subgroup of patients with schizophrenia is especially vulnerable to the impact of seasonal variations.