I’m going to assume you’ve already read my deep dive into the Neon Genesis Evangelion franchise. If you were still left with questions concerning its creator, Hideaki Anno, then I highly recommend this Polygon piece by Aaron Stewart-Ahn that explores Anno’s background, career, and the role his struggles and years-long depression played in Evangelion’s creation.
In episode 16, about halfway through production of the series, creatively blocked and unable to go further writing the story for the character of the ambiguous Rei, Anno asked a friend for a suggestion on some reading about mental illness in an attempt to better understand her. The book he picked up startled him. What he found within was a diagnosis of his own problems in life. It was revelatory. Anno had been struggling with depression all these years and hadn’t had the language or understanding for it, or even accepted that it could be a clinical diagnosis.
Evangelion changed after Anno recognized his own life’s struggle. The show became more tragic, and more apocalyptic. Several of the mysteries were given incredible twists that took Jungian concepts into a pure science-fiction landscape (in particular, the revealed origins of the Eva units might be the hybridized future of the Oedipus complex).
As the show crescendoed, hinting toward an catastrophic final battle, the final two episodes loomed on the horizon: 25 and 26. There are rumors, never confirmed, that although Evangelion was by this point an ever-growing success with a large audience, the ending had come up against Anno’s desire to make a series that was reactive and in flux — which led to an inability to commit to what that ending would be, along with massive budgetary issues.
Stewart-Anh did a bang-up job with this article, which contained several pieces of information that were new to me. I also loved the peek at Anno’s earliest days as well as his analysis of how Anno’s work both praises and critiques the otaku lifestyle.