Which neurotransmitter is associated with mood regulation?

Serotonin is the neurotransmitter most commonly associated with mood regulation. It plays a crucial role in stabilizing mood, feelings of well-being, and happiness. It is often referred to as the "feel-good" hormone because higher levels of serotonin are linked to improved mood and emotional state. Low levels of serotonin are often associated with mood disorders such as depression and anxiety, which highlights its importance in maintaining emotional balance.

While dopamine and noradrenaline do contribute to various aspects of emotional and psychological states, such as reward and arousal, respectively, they are not as directly associated with mood regulation specifically as serotonin. Histamine, on the other hand, primarily functions in the immune response and is also involved in regulating sleep and wakefulness, but it does not play a significant role in mood regulation.