Why does this young patient keep crashing his car?

Sebastian, a 28-year-old chemistry PhD student, presents with a two-month history of insomnia.
Sebastian is in the process of final data analysis and writing up his thesis.
He initially attributed his difficulty falling asleep and racing thoughts to his heavy workload and stress.
He reports that his vision has been “not quite right” in the last few months but denies any headaches. He states his “head is feeling heavy all the time”.