Answer:
Lack of uplifting neurotransmitters such as dopamine, as well as the encouragement to take drugs that mimic these neurotransmitters in the brain.
Step-by-step explanation:
While drugs such as antidepressants help to balance the lack of neurotransmitters that make people happy, sometimes people get the idea to abuse these drugs as a sort of coping method, which sadly happens way too often these days. Hope that helps :)