Merci Docteur Rey

Merci Docteur Rey is a 2002 gay comedy film from Merchant Ivory, directed by Andrew Litvack, starring Dianne Wiest and Jane Birkin. Filmed in Paris.

Seeking help with a psychiatrist, the young man comes across an eccentric actress Jane Birkin, who has come totally unhinged by the death of that psychiatrist, the infamous Docteur Rey. At first mistaking her for the doctor, the young man embarks on a madcap mystery, reminiscent of an Agatha Christie novel, with Paris as the backdrop.

Source: Wikipedia