@OldFan you seem to accept hot flushes are caused by peri and HRT is OK, but that 'related illnesses' (not sure what you mean) and depression should be treated using other medication.
The posts on here should make it clear that mood changes are a primary early symptom of peri. Hot flushes actually come much later for most.
I went to the GP with anxiety as my main symptom, but also to a lesser extent new PMT, insomnia, shorter periods, dry skin, no libido, migraines before my period etc etc. I'd had these symptoms from 39 or possibly earlier. Went to GP at 40. I was told it was just anxiety as I was too young to be perimenopausal and prescribed sertraline which was a shit show.
2 years later I was given HRT which alleviated the anxiety and every single one of my 'related illnesses'.
Separate treatment (anti depressants, migraine meds, moisturiser, sleeping tablets etc) work, if they work at all, on the symptoms not the cause and, for me and many perimenopausal women, are not a rational solution when HRT alone can be so effective.