You should be honest with your siblings
Remy has a drinking problem which has led to depression and his sister keeps asking him what is wrong.
Remy wants his sister to drop the issue.
Remy tells his sister that he is just going through a tough time and isn't ready to talk about it.
Remy tells his sister that his depression is purely seasonal and will likely go away by itself.
Remy gets her to drop it without having to lie.
Remy feels guilty about having to lie to his sister.