I appreciate your share.
I agree, approaching things like smoking and drugs can turn a person defensive. That is an example of a lifestyle choice and humans will vehemently defend their choices- no matter how unhealthy they are.
With that being said, with something such as loneliness, it can be approached without the other person even knowing.
For instance, just by being aware of the issue can lead you to spend more time with the individual. That will help and they never even have to know.