Scarlet's Pit of Frippery

Hi!

I have a character in a sci-fi universe who ends up "shipwrecked" alone on a completely uninhabited planet for two years. The planet, and the specific environment he lands in, are perfectly habitable by humans (we are in soft scifi territory here, very Star Trek inspired) and he's able to survive with some effort. (The details of how are not really important to the story - I know at least that he's the kind of guy who'd be able to salvage some tech and emergency supplies from his wrecked ship, and I'm comfortable with brushing past the details of what exactly he brought with him - but if anyone's really interested in coming at it from that logistical angle, I won't stop you!)

What is more relevant to the story is how this experience would continue to affect him by the time he's back home safely. I think there are a bunch of possible avenues here and I'd love to see people's takes on how they would approach this or approach researching it. For example, here are some of my cursory thoughts:

• PTSD is certainly a likely long-term complication
• It's implied that his shipwrecking was not an accident/was engineered maliciously - I imagine this is something he has dwelt on heavily throughout the two years and will affect his ability to trust people (and to visit other uninhabited planets in the future!). Seems like it would be easy to get caught in delusional spirals in a situation like that.
• I know that prolonged isolation can cause hallucination/psychosis in some cases, especially in solitary confinement, sensory deprivation contexts, etc. Is that as much of a risk in this case? And if so, do you think he'd still be experiencing psychotic symptoms after the fact?
• One of his personality traits is that he's fairly attention-seeking - I think it's likely this incident will exacerbate that and make him more desperate for connection
• It'll probably alter how he approaches social situations in the future in general; that's something I'll definitely be thinking about
• Perhaps he got into the habit of talking to himself on the planet, and this never went away