Mindful,
My father was an early diagnosis of BP and was treated with lithium for more than 50 years.
He also drank heavily his entire life.
His BP stayed under control provided he took his meds.
I dont know the impact that drinking may have had, but there was no outward sign of mood swings as long as he took his medicine.
Just as info, everyone has their own experience and most folks dont take lithium anymore for other reasons.
Always like your posts.