Dean could never stand to hear crying so when he heard it right outside, the car Zion was driving in the direction of the bunker, he rushed towards it, immediately knowing who was crying. Seeing that she was hysterical, he opened the car door where her head was laying on. Zion was holding a deer in headlights look in his eyes, it seemed that he had dealt with her emotions before but not of this sort.
As she nearly fell headfirst, Dean had caught her and was already picking her up, her body in his arms and her head falling on his chest, still sobbing. As he held her in his arms simultaneously walking to the bunker, he could hear Zion running up behind him. "She—" Zion started to say but Dean cut him off. "I know—" Dean needed no words for Bree's behavior; he'd been there before: it was depression.
She was in the beginning stages of it and now he and Sam would have to deal with it and help her out of it. It is best that way, he would kick anyone's ass if someone disrupted her (if she were to make any progress out of it). There was no way in Hell or Heaven it was gonna stop him from helping people and saving her life as well.
As he carried her in, Sam noted his tenderness with her but said nothing. He knew his brother had a soft spot for women in general—even while sleeping with them. He knew that he would treat them well in the mornings with breakfast and give them a kiss goodbye even if they never saw him again.
He placed her on the couch where she lay still crying but now less considerably so and went to the kitchen to get a glass of water. Castiel had beaten him to it and was giving her the water to drink. Dean slightly cursed Cas in his mind and Cas couldn't help but give a small smirk to himself.
He already knew what was happening to Dean even if Dean didn't want to admit it. Cas then moved away from her, letting her drink the water slowly. She put it down on the table next to the couch and laid back down facing away from the group, she was wiping her tears away. Dean had gotten two medicine capsules for her but was unsure of how to give it to her.
So there he stood, awkward in his stance as he was wondering how to care for a female well past beyond breakfast. That was when Dean heard Cas saying something in a hushed voice. "Give her the medicine, Dean." He said. Dean only responded after the second or third time he told him that and moved towards Bree.
As Bree's crying began to soften, Dean leaned over her and gently grabbed her arm. He picked her up in his arms and told her to take her medicine. Bree made a noise that sounded a lot like no. Dean crooned to her that she must. She grabbed the cup of water reluctantly from Cas's hand and drank from it after having her medicine.
Dean placed her down on the couch, as she laid there, she faced him and the group now, moving slowly as she did it. She didn't want to, but it was inevitable that soon they would all talk about her nervous breakdown. She'd rather they did it while she was awake but she was so tired. And so she fell asleep.
Amid her random startled awakenings, she could hear them talk but not hear exact words except for "Bree—", "—Zion", and "—Zero". She ignored their voices and fell promptly back asleep, when she next awoke, it was two a.m. and she was alone, except for Dean who sat opposite her on the other couch, his face illuminated by the tv.