If you draw 2 cards, the cards are considered to be drawn simultaneously.
Previously Official Rulings
These TCG rulings were issued by Upper Deck Entertainment and have since been deemed unofficial by Konami. They were previously considered official and can still be correct, as long as they follow the official gameplay rules, or unless Konami has issued a ruling that says otherwise. References: 
If this card is discarded from your hand by the opponent's card effect, you draw both cards at the same time. If you had "Solemn Wishes" on the field, you would only gain 500 Life Points.
Dark World Rulings
Judge Program Forum Rulings
These Ruling(s) have not been confirmed as applicable to the TCG.[Notes 1]
If you discard from your hand because of the effect of a "General Raiho of the Ice Barrier" your opponent controls, then it is treated as you discarding from your hand by the effect of an opponent's card.
These TCG rulings were issued by Upper Deck Entertainment and have since been deemed unofficial by Konami. They were previously considered official, but may or may not necessarily hold true nowadays.
↑Konami Judge Program Rulings are considered unverified, as their source(s) are not publicly viewable. They are not confirmed as applicable to the TCG until they have been officially published by Konami.