As someone who's experienced so easy mental illness himself in the past, my condolences go out to AK and his entire family. They are without doubt going through unspeakable grief right now, and will be for some time, and they all have my deepest sympathies.
I only wish for the entire family that his brother had been able to understand the grief that his family will be going through for years, the depths to which he was doubtlessly loved. But that's the thing with depression or many mental illnesses...they are unable to see that or understand it.
All my best to you, AK, and your family.