How have courts treated the issue of voluntary intoxication?

At the outset, we conclude that appellant has not forfeited this issue by failing to request further instruction on voluntary intoxication, as respondent argues. It is true that a trial court has no duty to instruct sua sponte on the relevance of voluntary intoxication. (People v. Castillo (1997) 16 Cal.4th 1009, 1014.) Nevertheless, since the trial court did give some instruction on voluntary intoxication, it was obliged to do so correctly. (Id. at p. 1015.) Therefore, we must determine whether the trial court prejudicially erred.