Why is thyroxin called the personality hormone?

Thyroxin, or T4, is often referred to as the "personality hormone" because of its significant role in regulating metabolism and energy levels, which can influence mood, behavior, and cognitive functions. Adequate levels of thyroxin are essential for maintaining emotional stability and a positive outlook, while imbalances can lead to mood disorders such as depression or anxiety. This connection between thyroid function and mental health contributes to its nickname, highlighting the hormone's impact on personality traits and overall emotional well-being.