Excellent. Thank you for providing the community with this important topic.

From what I think one wouldn' want to become addicted to psychedelics when certain requirements are followed. Like you said when it is taken for the cause of understanding one's depression. The look into one's own realm of psyche or "soul" takes first courage and secondly the will to change life for it doesn't become such a burden for the self and for others. Which includes the view you offered: to not see a depression of something to get rid of but to take the winds force in order to sail the sea. To integrate depression rather exclude it.

Also I think that the relationship between the treating and the receiving person must be strong and good. I have to trust the one who treats me and accompanies me within the psychic experience.

An ideal figure to picture is that of a shaman. We all know the movies where a careful shaman gives all his knowledge, wisdom and body to help his patient. He doesn't have a schedule, he devotes his energy to the patient and has an unselfish goal/intention.

This symbolic role model speaks of a human need we all have.

... what we call normal is in fact a delusional optimism. This theory brilliantly turns the table and claims that healthy people delude themselves into thinking that everything is just fine and dandy.

Yes, that raises the question by whom and how "health" is defined. I am unable to define health when I reject sickness and make it look evil.

... can mental problems be cured at all? To what extent is a mental 'problem' a part of ones very personality? Is there a necessary amount of suffering?

I don't think so. There is no cure once and for all anyway. People are looking inwards and outwards. They relate their depressions to their own biology and personality as well as to life circumstances and events and the social groups.

My life is like riding on the ocean. Sometimes its calm and quiet sometimes its rough and dangerous. I can totally rely on the fact that changes will come and I have to navigate through them. I wouldn't want that without my fish swarm where I can rest and take some time out.