The Deep by Nick Cutter

     Lucas has received a distress call from his brother Clayton, who had been living eight miles down in the ocean trying to find a cure for a disease that is devastating mankind called "The Gets". With this disease, people start by forgetting small things then forget how to chew, breathe, etc.
Lucas and Clayton have not been that close, but Lucas feels compelled to go down, as this is his brother and it is very strange that his brother would reach out to him with such a strong call.
Things happen almost immediately down in The Trieste. There was just too much going on too soon and over and over again. I thought it was a jumbled mess of occasions and incidents and could have been written better.

http://www.craigdavidson.net/nickcutter/index.html

Book by an author who uses a pseudonym - PopSugar Reading Challenge 2017