The incidence of suicide (and related-party homicide) in households with guns is significantly higher. Unless we believe that there's a correlation between gun ownership and suicidal tendencies, the answer seems to be, mostly no.

Having a highly-effective killing device in the home turns attempts into suicides - and a gun is an order of magnitude more effective than other common methods.

http://archive.sph.harvard.edu/press-releases/2007-releases/...

Americans would go bonkers if someone started selling a do-it-yourself euthanasia machine. But we're ok with lots of handgun sales, despite that being one of their most common uses - more common than self-defense.