Yeah, if you can't get a doctor to sign off on you being in a good state to drive, they take it. And the doctor can send in something at any time to say you shouldn't be allowed to drive even if they had previously signed off on you.

List of "Reportable conditions" include:
cerebral palsy
diabetes requiring insulin
epilepsy
Multiple Sclerosis
muscular dystrophy
irregular heart rhythm or heart condition
stroke
alcohol dependence or abuse
drug or substance abuse or dependence
loss of limb(s)
traumatic brain injury
bipolar disorder
schizophrenic disorders
panic attack disorder
impaired or loss of consciousness, blackout, or seizure
disorder which prevents a certain range of vision
parkinson's disease
dementia
sleep disorders (like narcolepsy or sleep apnea)
autism