Personal conflicts biggest cause of murders in U.S.

Guns are the most commonly used weapons in both murders and suicides, according to the analysis of data from 2007 released on Thursday by the U.S. Centers for Disease Control and Prevention.

"The pattern that stands out the most is we see a lot of intimate partner violence, mental health problems and substance abuse," said the CDC's Debra Karch, who led the study.

Some of the findings from the report:

* Firearms were used in more than 50 percent of suicides, with hanging or suffocation accounting for 23 percent and poisoning 18 percent.

* Firearms were used in 66 percent of homicides and 80 percent of murder-suicides.

* Suicide rates were higher among people aged 45 to 54 -- a shift from previous years when the highest rates of suicide were among those over 80.

* Murder rates were more than three times higher among males than females. One third of women who were murdered were killed by a current or former spouse or partner, compared to five percent of men killed by intimate partners.

* Blacks made up the majority of homicide deaths and had the highest rate of homicide of any racial or ethnic group.

* Military suicides were frequently linked to a physical health problem.