Posts by:
Gabriella True

This large population-based study in Sweden investigated the potential link between severe infections and obsessive-compulsive disorder (OCD) through a familial co-aggregation approach. By analyzing data from over 4.9 million individuals born between 1960 and 2008, researchers explored the risk of OCD among relatives of those with severe infections, spanning varying degrees of genetic relatedness. The study found that the risk of OCD increased with closer genetic ties, with monozygotic twins showing the highest correlation. A dose-response relationship between the number of infections and the odds of OCD was also identified. These findings remained robust even after adjusting for comorbid autoimmune disorders and infections in relatives. The results suggest that genetic factors play a significant role in the observed association, pointing to shared genetic susceptibilities between infections and OCD. This supports the idea that genetic pleiotropy—where the same genes influence multiple traits—may contribute to both infection susceptibility and OCD risk. The study highlights the importance of considering both genetic and environmental factors in understanding OCD development.

Leonardi L, Perna C, Bernabei I, Fiore M, Ma M, Frankovich J, Tarani L, Spalice A. Pediatric Acute-Onset Neuropsychiatric Syndrome (PANS) and Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections (PANDAS): Immunological Features Underpinning Controversial Entities. Children. 2024; 11(9):1043. https://doi.org/10.3390/children11091043

This study found that about a quarter of patients meeting strict PANS criteria who underwent lumbar punctures (LP) had cerebrospinal fluid (CSF) abnormalities, with the most common being elevated CSF protein and albumin quotient. These patients also exhibited signs of inflammation and autoimmunity, such as low complement levels, high immune complexes, non-specific autoantibodies, vasculopathy, and arthritis.

Interestingly, the “other psychiatric deterioration” group—those referred for PANS but not meeting strict criteria—had an even higher frequency (45%) of CSF abnormalities. Many of these patients also showed systemic inflammation, with conditions like thyroiditis and arthritis, and had symptoms overlapping with PANS, including obsessive-compulsive behaviors and food restrictions.

Both groups demonstrated a notable prevalence of arthritis, emphasizing systemic inflammation’s potential role, possibly affecting the blood-brain barrier (BBB). While the study was not designed to assess the significance of these differences, it suggests an overlap in psychiatric symptoms and inflammatory features across the groups, which may involve complement activation and vascular inflammation, similar to what’s seen in Long Covid.