Where do we begin?
Some etiologies are more important than others. That's what it is by the way, a beginning. An etiology is how something (usually complex) gets it's start.
Next time you sit down to breakfast, take a single cornflake or oat kernel from your cereal bowl. And if you don't like either of those, or you're having lunch, use any food at hand. Now consider all of the steps taken to get it from the farm—to your tummy. So many people, interconnected, worked together to bring you your breakfast. The farmer. The hired hands. The produce company that shipped the food to the warehouse. The shipping company that brought the food from there to the supermarket. The person who stocked the shelf from which you saw it and wanted it. The cashier who rang you up. All these people have families. Concerns, needs, issues and problems. They also have feelings, hopes and dreams. I don't mean to sound too saccharine here and lose sight of practicality. Hundreds, maybe thousands of people were involved in getting that bowl of cereal to you. On time. Think about them, pray for them. God knows and loves each and every one.
Now let's explore a little deeper: Can you explain to me in any sort of detail why you think the way you do? Do you recall the instances and events in your life that led you to become the person you are today with the opinions and viewpoints that are integral to your worldview and philosophy? Are you on autopilot? I'm talking about the things that may not be at the forefront of your mind all the time but are what cause you to interact with the world at large in the manner you normally do. Are you generally optimistic? Are you sarcastic or sardonic? Are you cynical or merely pessimistic? (I hope neither) I suppose what I'm asking is for everyone to perform a little self-psychoanalysis, dispassionately if at all possible. Take a step back from your own mind and feelings. Not so far that you become schizophrenic, mind you. And don't self-medicate; that's dangerous as well. What I would suggest, as a Christian, is to take a look at the topic of the mind through the lens of God's Word. One question you might have is whether or not the mind is epiphenomenal (in this case, secondary or unrelated) to the brain. If you can show the tiniest glimmer of belief that God is real and He loves you, then take Him at His word and consider what He has to say regarding the mind. I believe consciousness is more than a byproduct of the brain. I suppose that's a debate for another time, though.
And I am not above dispassionate inquiry.
Firstly, upon receiving Jesus as our Savior, the real work of "renewing our mind" (Romans 12:2) comes in to play. This is what I'm getting at. Proverbs 16:3 says: "Commit thy works unto the Lord, and thy thoughts shall be established." This is a good cure for depression—I know. Clear thinking is the product of an uncluttered mind. And if you're having trouble lining out your thoughts, then maybe some decluttering is in order? After my parents' divorce and the disintegration of my family, my mind was so full that I had no choice but to write for a living. Not for a paycheck, mind you. For survival. A verse from Isaiah (26:3) follows the verse from Proverbs. It says that "Thou wilt keep him in perfect peace, whose mind is stayed on Thee: because he trusteth in Thee." God's peace is more than just the right balance of neurochemicals. His peace is centered in your spirit and is not affected by circumstances provided we affix our attention on him. It's a great place to start. But where do we go from there?
"In the multitude of my thoughts within me Thy comforts delight my soul." (Psalm 94:19)
I know this is a bold statement but, all our thought patterns need to be partnered, in some way, with how God thinks. With love as a basis, our opinions and outlooks will naturally flow into a worldview that exemplifies the way that Jesus thought and acted—towards others, Himself and God. And not necessarily in that order.