Streptococcus Was Associated with 6 Mental Disorders, ADHD Linked to 8 Bacterial Infections
A nationwide longitudinal study from Taiwan recently investigated the association between severe bacterial infections and the risk of subsequent major mental disorders (MMDs) in children and adolescents. This research also examined the link between bacterial infections and exposure to psychotropic medications during the same developmental period. Between 1997 and 2012, a nationwide cohort of 14,024 children and adolescents with hospitalized bacterial infection and noninfected controls were enrolled in this innovative study. The authors investigated eleven pathogens, including Streptococcus, Staphylococcus, Pseudomonas, Klebsiella, Hemophilus, Mycoplasma, Tuberculosis, Meningococcus, Escherichia, Chlamydia, and Scrub typhus. Primary outcomes reviewed for this work were autism spectrum disorder (ASD), attention-deficit/hyperactivity disorder (ADHD), obsessive-compulsive disorder (OCD), tic disorder, schizophrenia, bipolar disorder, and depressive disorder. Secondary outcomes were recognized as the subsequent risk of exposure to psychotropic drugs. Results demonstrated that compared to controls, pooled bacterial infection was associated with increased risk of the following six MMDs: ASD (reported as hazard ratios with 95% confidence intervals: 13.80; 7.40-25.75), ADHD (6.93; 5.98-8.03), OCD (3.93; 1.76-8.76), tic disorder (6.19; 4.44-8.64), bipolar disorder (2.50; 1.28-4.86), and depressive disorder (1.93; 1.48-2.51). Exposure to four psychotropic medications was also associated with an increased risk of MMDs, including ADHD drugs (11.81; 9.72-14.35), antidepressants (2.96; 2.45-3.57), mood stabilizers (4.51; 2.83-7.19), and atypical antipsychotics (4.23; 3.00-5.96). The relationship between MMDs and specific pathogens varied. Streptococcus was linked to the most MMDs (six total), and ADHD was associated with eight bacterial pathogen infections. The authors suggest that inflammation and alteration of the immune system induced by infectious pathogens could influence the metabolism or activity of serotonin, noradrenaline, dopamine, glutamate, or other molecular mechanisms that are possible psychopathologies of mental disorders.
