Dopamine and Serotonin are two different and separate compounds however Dopamine and Serotonin are neurotransmitters which are basically chemicals that send messages that regulate our countless functions and processes in our bodies including sleep as well as metabolism.
The main difference between Serotonin and Dopamine is in the way they work in our bodies.
The other main difference between the two are that A Dopamine system dysfunction is linked to certain symptoms of depression, such as low motivation.
But the compound Serotonin is involved in how you process your emotions, which can affect your overall mood.
So you might have a low mood when your Serotonin levels are low and when your serotonin levels are normal then you usually feel much better and in a better mood and have more energy and feel less depressed.