I'm a bit of an expert on depression, since I've had this problem for many years. I think winter blues might actually be SAD (Seasonal Affective Disorder) where the lack of sunlight makes you feel tired and depressed. Special light boxes help with that, but sometimes a person with this problem still needs to take antidepressants.
Depression usually lasts much longer, isn't affected by seasons (although it can be made worse if you also have SAD), and affects all aspects of your life. I think perhaps you're actually asking how you can tell the difference between depression and just feeling blue for a few days. If you've been feeling depressed for more than a couple weeks, if getting out and doing fun things with your friends isn't helping, if you don't feel like doing fun things or if those fun things just don't do it for you anymore, if you are having trouble getting your work done or having trouble concentrating ... those might be signs of depression.
Everyone gets depressed from time to time. For me, the clue is that I didn't need an event (like someone dying) to be depressed. I could wake up on a bright, sunny day and feel like someone poured a gallon of black tar on my head.
Nothing made me feel happy for more than a couple seconds. I didn't feel like doing those things I used to love to do. Another facet is how it affects your interpersonal relationships.
Some depressed people get sad and quiet, while others get argumentative and irritable. For this, you'd need to ask someone close to you if you've been particularly sensitive or if you get angry easy. I didn't know this until recently, but apparently depression can also affect your digestion.
If you have frequent stomach problems, some of that might be from depression. The best thing to do is to talk to a counselor. They have these questionnaires you can fill out to determine if you have a serious case of depression or if it's something that might be treated with diet, exercise and counseling.My personal opinion is, though, if you think you're depressed, you have a reason to think that and should go somewhere to be evaluated.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.