Suicide-homicide temporal interrelationship, links with other fatalities, and environmental physical activity

Homicide and suicide are extremes in human behavior. The aim of this study is to investigate the connection by time between suicide and homicide, between them and other fatalities, and their links with the level of cosmophysical activity. Methods: Using the national database of Lithuania (1990-2002) we found that 547,875 deaths, 4,638 homicides (3,374 male) and 19,527 (16,019 male) suicides were registered in that period. Their temporal distribution over 156 months was compared with solar and cosmic-ray activity. Pearson correlation coefficients and their probabilities were established. Results: There was a correlation between monthly rates of homicide and male groups. Female suicide rates correlated with male and total homicide numbers. Both homicide and suicide rates were inversely correlated with solar and cosmic-ray activity. Suicide numbers, but not homicides, were inversely related to geomagnetic activity. Suicide rates were inversely correlated with total, cardiovascular, traffic accident, and sudden deaths; homicide with total, traffic accident, and sudden deaths. Conclusion: Temporal distribution of homicide and suicide is significantly interrelated. Both are linked to parameters of cosmophysical activity. The influence of cosmic rays deserves special attention.