title: My friend was told that her depression is partly due to a chemical imbalance. What does this mean?
mesh_terms: D003863:Depression / Q000209:etiology*; D005260:Female; D006801:Humans; D018377:Neurotransmitter Agents / Q000172:deficiency*; D009435:Synaptic Transmission / Q000502:physiology*
chemical_list: D018377:Neurotransmitter Agents