To my knowledge, doctors do NOT recognise this as a treatment in Singapore, and do NOT prescribe this type of therapy.
It lies within the realms of "alternative therapy", i.e. a type of treatment that is as yet unproven and not accepted by the medical community.
There is some very weak evidence and small scale studies that show that negatively ionised air has limited beneficial effects for mood, respiratory function and asthma control.
However, larger scale reviews of these studies have shown that they have no/minimal beneficial outcomes.
Air ions and respiratory function outcomes: a comprehensive review
Air ions and mood outcomes: a review and meta-analysis
The effect of positive and negative air ions on bronchial asthma
In summary, the evidence is still extremely equivocal (not convincing or scientifically sound enough for doctors to tell patients to try this therapy).
It's not something that I'd tell my own friends and family to get for sure!
