Johnny said: “Do hormonal changes affect consciousness, or the other way round, or both support each other?”
We can look at it this way: Can the body affect the mind and/or can the mind affect the body? It is both, but the power of the mind is much more dramatic.
The body can affect the mind in the sense if one does not take care of the body, one can get obese and face health problems. That will affect the mind, even for a person who is trying to make progress in the Path. So, we must exercise and eat well to stay healthy. Furthermore, the body (especially the brain) naturally degrades as one gets old, so one must strive on the Path before getting old.
When one makes progress on the Path, one starts realizing the above and will act appropriately. Learning Dhamma and contemplating on deeper concepts will help brain function too. Furthermore, when one attains magga phala, one’s brain will definitely undergo drastic changes. It would be interesting if there is an study on one’s brain (and body) as one go through higher stages of magga phala.
For example, an Arahant’s bones (at least some) will crystalised and become “dhatu”, that will last until the end of this Buddha Sasana. I discussed this briefly and have pictures of dhatu in the post: “Parinibbāna of Waharaka Thēro“. Furthermore, an Arahant is not afraid to die (fear of death is there because one has so many things in the world that one values). So, there will be dramatic changes in the hormonal system.
More information at, “Truine Brain: How the Mind Rewires the Brain via Meditation/Habits“.