This doesn’t make sense to me. Pretty much every purported treatment for depression involves either increasing the amount of sensory stimulation you’re getting or else becoming more attuned to sensory stimulation: exercise, acupuncture, aromatherapy, drugs, meditation, float tanks, social interaction, music, intensely flavored foods, cold therapy, saunas, electroshock therapy, etc.

Occam’s razor would suggest its more likely that lack of sensory stimulation causes some sort of brain damage, e.g. inflammataion or receptor density changes, and that it just takes a few weeks to reverse. I’m not seeing what evidence there is for this pereptual confidence model beyond what I’m proposing. I wouldn’t doubt if people do get more confident in some aspects of their sensory experience, but it would seem difficult to prove this as an explanatory model.