While the doctor-patient confidentiality that Charlie is counting on is real enough, it has to be waived if a patient realistically threatens someone else. The doctor has to decide if the threat is real. If it is, they have to report it.
The episode won an Emmy Award for Outstanding Multi-Camera Picture Editing for a Series.
When Alan has his panic attack and says there's not enough time to read all these books, it's reminiscent of the classic 1959 Twilight Zone episode, "Time Enough At Last" (s1e8), starring Burgess Meredith.
Episode title spoken by Charlie, to Beth (Valerie Azlynn) and Amy (Stephanie Reibel).