When using drugs, the slowest bodily response comes from eating/ingesting the substance whereas the fastest bodily response comes from snorting?

The slowest drug absorption/response is definitely oral/digestion route.

The fastest drug response time route would be intravenous, the drugs directly enter the blood so it can work instantly. Snorting/inhaling drug still need time to be absorbed to the blood vessel. It might be fast enough if used for local response (example: asthma). The mechanism probably by mucosa diffusion so its similar to rectal or sublingual route.

Major sources of stress, such as a death or divorce, problems in family relationships, job loss, school, and substance abuse, can trigger or aggravate some mental disorders in some people. but not everyone who goes through those things develops a mental illness