PooDoo said:
Last episode showed why Laurie left her family and joined the Guiltly Smokers.
She lost the baby and her patient's questions pushed her over the edge.
I still believe the GR and the departure is due to that one quiet unspoken thought we have about folks "I wish you were gone".
The show opened on a woman dealing with a crying baby while she was on the phone, then she wished it away. Laurie confirmed she was pregnant, then she wished it away. Kevin was cleaning up after an adultery session, and he wished her away realizing he loved his wife. Nora, iirc, was entertaining a job she was super excited about, but her husband had reservations because of the kids, she secretly thought "if I didnt have a family I could do this."
Laurie's arc is a question of her motherhood and guilt. From "another" child nearly dying (snapping her out of it) to devoting herself to her son.
Nora's arc has been about her self-hatred and restoration, and her rejection of restoration when Kevin asked to conceived.
Kevin's arc has been all about responsibility and the ability to control himself (and those demons in his head).