My Mum is 93 and has been hypothyroid for decades and taking levothyroxine 100mcg until and doctor decided to reduce to 75mcg based on the TSH. My Mum has developed dementia. I noticed today that Mum was quite normal during the day, talking about things using long and short term memory, she wasn't confused and you wouldn't know she has dementia. We had a cup of green tea late afternoon and quite quickly Mums memory deteriorated and she got confused. I have noticed this happens at the same time every day and I was wondering if it was linked to a change in thyroid or TSH levels later in the day. I have read that TSH levels reduce later in the day and I am wondering if T3 drops late afternoon which results in slower thinking, brain fog and other issues. I give Mum zinc selenium B12 D3 K2 Bvits. Does anyone have any ideas please?