Holy cow, absolutely. Have an attorney draw up an operating agreement between you and your brother that provides a number of explicit contingencies in the event that he has another meltdown. You need a bullet-proof firewall that protects your interest AND the business in case he tries to funnel all of the liquid, begins to damage your reputation, etc.
Maybe reposting to the legal section can direct you to the correct type of business attorney, but the direct answer to your question is YES!
If you are satisfied with the response, please hit "Accept." That is the only way I can receive credit for my answer. Thanks-