Where wild minds come to rest
Maladaptive daydreamers enjoy daydreams to an extend that they can not resist the temptation of it,its like an addiction of drug.If you don't take the drug you get a nagging feeling,typical drug addicts flood their circuit with a neurotrasmitter called dopamine which is a neurotransmitter present in regions of the brain that regulate movement, emotion, cognition, motivation, and feelings of pleasure. The overstimulation of this system, which rewards our natural behaviors, produces the euphoric effects sought by people who use drugs and teaches them to repeat the behavior.But for daydreamers Serotonin (also a neurotransmitter) plays crucial role .Serotonin is popularly thought to be a contributor to feelings of well-being and happiness.Negative emotions (like sadness, stress, anger, etc.) causes your Serotonin production to be low; when your Serotonin level is low, you are more prone to getting Anxiety, Panic Attacks, Depression, etc.
So,when you daydream you actually flood your system with Serotonin and it gives you feeling of well being and it makes you happy.In other words it means you are not happy with your life,it doesnt mean that you are depressed etc. I may mean that your standards of happiness are much more than in normal person.So you tend to daydream to get the right feeling of being happy.Imagine the happiest moment of your life(other than when you are daydreaming),i bet you were not daydreaming when you were most happy because you did not need daydreaming you serotonin levels were elevated because of happiness and your body had produced the right amount you needed.
There is a drug generic named Serotonin re-uptake inhibitor i.e. SSRI,what it does is that it stops your body to uptake serotonin once it has been released in the system thus decreasing your need for serotonin and that in turns means decreased daydreaming.
I'm no psychologist or any expert on this topic but I just wanted to share what I was thinking so please don't judge. :)