It is of little question that the readily available means to commit the act is a significant risk factor. The decision to kill one's self or the obsession with the idea can certainly be influenced external factors, such as the availability of a gun. Also, the likelihood of success of using a gun, as well as the avoidance of pain, are certainly influential factors as well. For some people there may be some other readily available means, such as living next to a giant cliff, that provides the straw to break the camels back but there is no question that a gun in the house can also be the straw.