He or she actually decreases the rate of serotonin production in the brain and thus makes the problem worse. A temporary fix creates a large persistent problem. Many times illness makes for temporary deficiency of neurotransmitter in the brain secondary to the altered metabolism. Chemotheraputic agents often cause poor brain function during cancer treatment . Hypoxia from lung disease or artery disease makes for poor function in the frontal lobe.
Depression is common in the face of chronic disease.
Wherever it occurs, it needs to be treated. Some of us are not so fortunate as to have only positive affirming messages from both parents during childhood. In fact many of us have had to deal with many obtuse, critical destructive and abusive messages . These memories are always ready to replay at the slightest trigger. Many times when one is depressed, these messages play more or less constantly.