Infinitely Polar Bear (2014 Maya Forbes & scr)

Mark Ruffalo must get offered a lot of parts; it's good that he continues to takes smaller and more offbeat things like this study of a man with manic depression trying to look after his kids Imogene Wolordarsky (the writer's daughter) and Ashley Aufderhide while mum Zoe Zaldana betters herself.

To answer my question, yes it is definitely most autobiographical as this fascinating quote from The New Yorker reveals:

"In 1996, when Maya Forbes was twenty-eight, an alumna of “The Larry Sanders Show” with a studio development deal, she introduced her future husband, Wally Wolodarsky [the film's producer], to her father, a descendant of two of the older and more prominent families in Boston. They were with Forbes’s sister, China—the singer of a band called Pink Martini—and China’s boyfriend at the time, the director Wes Anderson, who was working on “Rushmore.” The group picked up Maya and China’s dad, Cameron, at McLean, the psychiatric hospital outside Boston where he stayed during bipolar episodes, and took him to lunch. Cam ordered a mushroom omelette, mushroom toast, mixed mushrooms, and a giant mushroom that took up an entire plate. He was a heavy smoker. After lunch, they dropped him back off at McLean. He popped in to get something and emerged with two cigarettes in his mouth. Wolodarsky took a picture of him smoking both, an arm around each daughter. Anderson gave Bill Murray two cigarettes in “Rushmore” and told Maya she should forget about whatever movie she was working on and write the story of her father instead."