Hugs, to the best of my knowledge there are no tests to tell if it is depression or lack of drive. I'm pretty sure they both come from the same area. Low Seratonin levels. A little known fact is that 95% of Seratonin is built, stored and used in the body. The other 5% is built in the brain. It can not cross the blood brain barrier so has to be built there. It is built from Tryptophan, one of the eight essential amino acids. Which unfortunately compete with it for absorption. And usually win because of how we eat. Not what we eat. The body needs Seratonin for every message so that dragged out not interested feeling could be either. SSRIs don't build Seratonin they prevent it's loss. You have to have it first. If you can run on your treadmill and feel coordinated with each step but just don't feel like doing it then you probably have enough in your body but not enough in your brain. A study on the internet said to reduce the competition so more tryptophan gets to your brain you have to have a carbohydrate with every tryptophan bearing protein. Insulin strips the carrier from the other seven amino acids but not from Tryptophan So tryptophan can reach the brain and get converted to Seratonin. Pasta is a better source of carbohydrate than sugar, bread better than both. Milk, high in tryptophan has a built in carbohydrate. Heating milk releases more tryptophan. Granny wasn't wrong about hot milk calming. By itself is good but with oats, say as cheerios it is better. Eggs have tryptophan as does cheese, but a cheese omelette is worthless without a piece of toast too. Seratonin also helps prevent obesity. Eating right makes it easier to use those amino acids for energy and harder to store. Another reason to feel depressed or have no interest. Exercise uses the other essential amino acids, allowing tryptophan to do it's job. My favourite salad, a chefs salad should have croutons or grapes added. Without them and with a calorie wise dressing you are actually asking your body to store it as fat. So don't blame the salad for not giving you energy. And don't blame bread for making you fat. It is what you eat with it.
Just like potatoes. Another food blamed for weight gain. Milk and potatoes contain all the amino acids, balanced too. Boiled and mashed with milk is better than baked with butter. The only thing wrong with a fully loaded potato is volume. Calories are still calories and too many are not good.
Most people who work in the bush carry a couple of Eat More bars. Peanuts a good source of protein and Tryptophan along with the molasses and sugars is a balance that works. Dextrose is a usable sugar for energy where sucrose is not.
Taking Tryptophan as a supplement doesn't work without a carbohydrate with it. Often it is not that you need glycogens to fuel the muscles but Seratonin so the messages can get to the muscles telling them to use the glycogens.
I guess I rambled on, but by watching what I'm eating to keep it balanced has given me back interest. I just don't have much body left I can use.
Davit.