I don't know anyone who has traveled through life without being depressed over some difficult circumstance in their life. It's only human and normal to respond in this way to trying times. The main factor which distinguishes this type of depression from others is its transient nature. Rarely does circumstantial depression last more than two weeks.
In contrast, clinical depression can last for weeks, months or even years. For that reason, it is the most dibilitating form of this disease. Its intensity is great enough to disrupt a person's ability to function in most areas of everyday living.
The scientific community concurs that major clinical depression is linked to a chemical imbalance in the brain. Most generally, there is a shortage of the neurotransmitters serotonin, norepinephrine or dopamine in the brain. That's why this type of depression is beyond the control of the individual. A person may wait for circumstances to change or seek counseling or address spiritual issues, but none of that will help if the problem is primarily in the biochemistry of the brain.
The biological component is one of the things that I and others find most frustrating. It's not under our immediate control. We can't just "pull ourselves up by the boot straps." There are no straps. Even though there are many effective medications available to help, there is no guarantee that any of them will be adequate to treat the illness. Sometimes, it seems as though the proper blend of medications has been found, only for them to lose effectiveness over a period of time. Then you have to go back to searching for the "magic potion" that will effectively treat the depression.
The individual's response to a knowledge of the biological factor in major clinical depression is not predictable. People view things differently. In my case, there was an "aha" moment, when I was formally diagnosed with clinical depression. Finally, I could make sense of the years of life disruption that I had experienced. Now, I could understand why I felt and behaved as I did. There was good news. I might be able to find a remedy. Even the possibility was encouraging.
There are people, though, who view themselves as having a "defect." In their mind, there is something "wrong" with them. They would prefer to be able to attribute their depression to external factors. The truth is that you can "wish I may, wish I might" all you want to, and it will not change the biochemistry of your brain.
Every year there are advances made in the study and understanding of the workings of the brain. We are closer than ever before to remedies that may be able to treat formerly untreatable depressive illness. This hope is part of the reason that I keep plugging along, doing what I can to assist my medical professionals, and praying for God's help when everything seems to fail.
"The Lord is near. Do not be anxious about anything, but in everything, by prayer and petition, with thanksgiving, present your requests to God. And the peace of God, which transcends all understanding, will guard your hearts and your minds in Christ Jesus (Philippians 4:5f)."
["I'm so low I could do a ten minute freefall off the edge of a dime."]