dnd 5e – Does Mind Blast work through barriers (eg walls)?

See the description of Mind Blank in the statistics of the Elder Brain (VGM, pp. 173-174):

The older brain magically emanates psychic energy. Creatures of the choice of the older brain within 60 feet (…)

The only conditions specified for the destination are:

  1. It has to be a creature.
  2. The older brain has to pick it, which means it has to be aware of the presence of the creature.
  3. It must be within 60 feet of the older brain.

Rules for the spellcasting target in the PHB state the following:

To be able to target something, you must have a clear path to it, so that it is not behind the total cover. If you place an effect area at a point that you can not see, and there is an obstacle such as a wall between you and that point, the point of origin arises on the near side of that obstacle.

How Mind blast is not necessarily a spell that I can not say with certainty that this rule applies.

This would amount to the dm's decision.

If the DM allows it, it creates a very interesting combination with the older brain creature spirit Feature. Allows your enemies to be removed from security as long as it is completely shielded.