Depression is not (yet) characterized by any physical cause. The only definition of clinical depression is a set of behavioral symptoms. If he didn't have those symptoms (even in retrospect), then he wasn't depressed. "The diagnosis of major depressive disorder is based on the patient's self-reported experiences, behavior reported by relatives or friends, and a mental status examination." https://en.wikipedia.org/wiki/Clinical_depression

Sure, but you will never find a clinician who would base their depression diagnosis based only on behavior reported by a significant other. Especially immediately following a suicide.

What evidence do you have that he was depressed, other than hearsay and guesswork?

Why is that more reliable than direct statements from someone who lived with him?

I don't have any evidence nor claimed he was depressed. I was commenting on the reliability of significant others' post suicide reports. If I cared to investigate, I would look at almost anything else than her report for reliable evidence. His writings, statements made during his lifetime from those close to him, etc. The sheer amount of things that could color her post (laying blame outside of Aaron, refusal to believe someone she loved and lived with was that unhappy, continuing his battle posthumously, etc.) make it hard to lay much persuasive value in her report.

What evidence would convince you that Aaron was depressed?

Taren is arguing he wasn't depressed, or at least that the prosecution was the main cause of his depression. I would mostly look for evidence that presented itself before the suicide, with a preference for self report.