Is Jake Sick or Just Lazy?

Susan and Randy both describe their 27-year-old son, Jacob, as "incapacitated" and virtually unable to do anything for himself, including showering regularly, making doctor appointments, filling out job applications, cleaning his bedroom … and the list goes on! Susan and Randy say they fear they will have to put off their plans of retirement and selling their home to take care of Jacob for the rest of their lives! But, there's nothing physically wrong with Jacob! So why do his parents let him get away with living in their home in a filthy bedroom and jobless, with no plans to change anytime soon? Is Jacob lazy, or is there something seriously wrong?