I'm sure that depression is not uncommon after a life-altering event such as a stroke. It must be recognized that up to half of patients who have a stroke will develop some depression in the first two weeks to six months following the stroke. In many incidences the use of anti-depressants during that time is helpful in allowing the patient to engage in physical therapy. Additionally, stroke support groups such as Stroke Connection through the American Heart Association are extremely helpful for patients and caregivers. The extent of the deficit depends upon the size and location of the stroke.
Recovery varies but is always aided by speech therapy.
Clinical trials in the past have revealed that engaging in speech therapy even one to two years after a stroke can be beneficial in regaining speech function. Have friends and family scan in pictures and send them to him. That's a great place to start. From there, his world can continually grow in different directions. There are genetic disorders that are associated with stroke risk in young patients.