FL: Should a doctor discover a depressed patient doesn't it make sense to ask about guns in the house?
Certainly, a firearm attempt is approx. 85% successful, the others about 15% combined.
From pew's graph below, suicide by gun dropped 12.4% by total, from 1993 to ~2000, the same time period which pew, gss, & gallup have all shown firearm ownership rates dropping by ~25% or slightly more. There is a definite association, & an apparent correlation, between declining gundeath rates & declining gun ownership rates.
The declining 12.4% figure is somewhat lower than the suicide by gun RATE would be, when you account for population increases (which are not considered in the graph of totals). I think around 18% decline in suicide by gun RATES from ~1993 to 2000, a rough estimate I did using 1990 & 2000 census totals - 1993 ~260m, 2000 281m, 2010 308m. (1990 census 248m).
Similarly, even tho suicide totals have risen markedly from 2000 to 2010 in pew's graph (16,586 - 19,392) as gun ownership rates leveled off, the suicide by RATE only rose ~4% during that 10 yr period, while from 93 - 2000 it dropped ~18%. http://www.pewsocialtrends.org/2013/05/07/gun-homicide-rate-down-49-since-1993-peak-public-unaware/
This coincides with drops in firearm homicide rates from 1993 to 2000; so a double whammy that the significant 1993 - 2000 drop in gun ownership rates are tied in with significant drops in firearm homicide rates, firearm suicide rates, firearm related violent crime rates. Ok, triple whammy.

Note the 60% drop in firearm related aggravated assault rate as well as ~50% drop in FA related robbery rate, during the 93-2000 time period, when gun ownership rates fell ~25%:
