Short answer: No, science-based sources (including Healthline and Floyd, if you read them carefully) don't claim that physical contact is necessary for survival. Most of the literature on touch deprivation is focused on the benefits of physical affection.
While social isolation is often confounded by physical constraints (as in solitary ...
On the subject of criticism and how psychohistory is viewed by academicians, you stated that
The wiki is rather silent on such discussions.
Yet, the Wikipedia article outlines the criticism with plenty of citations. The criticism in the article is laid out below, although I was not able to find url links for some of the journal articles referenced.
How untrained people should approach interactions with depressed people or any other mental health problem?
The main point to make is that you must not try to counsel them.
I believe you may have worked this out for yourself, and I don't want to sound patronising and "tell you how to suck eggs", but to be clear being untrained, you can cause more ...
Humans tend to evaluate things primarily based on similarity/proximity with thyself and their faiths both in terms of time, space. Their association tendency is directly proportional to the similarity and a feeling of self-worth.
Associative memory and availability heuristics are classical examples.
Ref: Thinking fast and slow - Daniel Khneman