Additional studies are needed to define the optimal dosage and composition of probiotic regimens as well as optimal treatment regimens. In addition, methods for documenting potency and shelf life of different commercially available preparations are needed. For these reasons, probiotic or previous preparations are not currently recommended for general use in the prevention or treatment of psychiatric disorders.
Antibiotics have been shown to increase the incidence of psychiatric disorders when administered in childhood, and the administration of antibiotics has been shown to be increased before hospital admission for a psychiatric disorder.10 These studies suggest that alterations in the microbiome might also have adverse effects and that the judicious use of antibiotics and the normalization of the microbiome following antibiotic use might be way to prevent some cases of psychiatric disorders.
The resurgence of interest in the role of infections and inflammation in serious psychiatric disorders provides exciting opportunities in terms of novel diagnostic methods and therapeutic interventions. Most of these innovations remain in the future, although there may be individual patients who can benefit from immunological evaluations and immune-based therapies. However, blanket recommendations concerning specific diagnostic tests cannot be made at this time but should be evaluated on a case-by-case basis. The number of patients who might respond to immune or infectious disease-based therapies is unknown.
To make further advances clinical research studies are needed. In the meantime, we need to focus on the development of additional methods for the detection of infection and inflammation in the brain, improved pharmacological control of brain infection and inflammation, and clinicians who are alert to the possible occurrence of infectious and inflammatory disorders in each patient.
Dr Yolken is Theodore and Vada Stanley Distinguished Professor of Neurovirology in Pediatrics, Johns Hopkins University, Baltimore, MD; Ms Shwartz is a Psychiatric-Mental Health Nurse Practitioner, Telecare Corporation, Alameda County, CA; and Dr Quanbeck is Associate Medical Director, Cordilleras Mental Health Rehabilitation Center, San Mateo County Health, Redwood City, CA.
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