Birthdates of patients affected by mental illness and solar activity: A study from Italy

Purpose

This epidemiologic study tested an hypothesized association between the year of birth of persons with major mental illnesses and solar activity over the past century.

Methods

We collected data on diagnoses and birthdates of psychiatric patients born between 1926 and 1975 (N = 1954) in south Italy for comparison to yearly solar activity as registered by the International Observatories.

Results

We found a strong inverse correlation between high solar activity (HSA) and incidence of schizophrenia and bipolar disorder in a 20-year period whereas the incidence of non-affective/non-psychotic disorders was moderately associated with HSA in the same period.

Conclusions

Interpretation of the observed correlations between HSA during years of birth and the incidence of mental illnesses remains unclear, but the findings encourage further study.     

Analysis of Commutated Networks Employing Feedback Circuits

A method of analysis has been developed for feedback systems employing commutated networks in the forward loop and linear transfer functions in the feedback loop. The method handles single-phase and polyphase commutated networks as well as coupled and uncoupled networks. Although commutated networks are linear from the superposition theory viewpoint, linear feedback theory is shown to be not applicable because of the harmonics present in the feedback loop. Techniques for simplifying the analysis of commutated networks by the use of equivalent block diagrams provide additional insights into commutated network operation.