No. If it didn't happen on the show, it isn't to be counted.
Well, if it didn't happen on the first series, it didn't happen. All we know is that Chris took Amy and Sabrina and left Collinssport.
Yes, but we witnessed his near suicide in ep #897. Chris left a suicide note for Carolyn (not Amy, who was already living at Collinwood) and had a gun in his hand when [spoiler]Crazy Jenny appeared to him and talked him out of dying by saying there's hope if he finds Quentin.[/spoiler]
Though he didn't succeed at killing himself, I don't think it's out of the realm of possibility for this character because we know that someone who has attempted suicide once can remain vulnerable to it, especially since Quentin, as it turned out, failed at helping Chris find a cure.
I don't see how Chris could decide that Amy would be better off wiithout him when she desperately needed him to take care of her. The last time she lost a brother, she suffered a breakdown and had to be sent to Wyndcliff. Who would take care or her with him gone? He knew she couldn't take care of herself.
He must've forgotton about what happened to her the last time she lost a brother. When Tom died, Amy suffered a breakdown and had to be sent to Wyndcliff.
By broaching this subject, I mean no disrespect to anyone here that has lost someone dear from suicide. But, sadly, a person in such despair that suicide seems the only option may not be thinking rationally; he or she may not be capable of considering the feelings of family and friends. For them, suicide is truly an act of desperation.