Mental health is totally a (multidimensional) spectrum, and in mental health it switches from normal to a "problem" if it's affecting your life. There are a ton of medical conditions where we've drawn lines in where we think it goes from normal to a problem (blood pressure, blood glucose) and I don't think anyone is saying "oh, your blood glucose is just different than mine, you don't have it that bad". We even have the term "prediabetic" to indicate that they are getting to the bad end of the spectrum.
I think it's incredibly useful to realize that all of us experience symptoms of anxiety and depression, intruding thoughts and compulsions, but those who with the problems are just those further along the line. It's not diminishing the issue, it's humanizing the sufferer. They aren't "crazy", they are suffering from something we all can relate to, but just in a manner that's unmanageable.
Too often the "spectrum" theory is used to humble-brag about one's own success in the face of self-diagnosed shortcomings. Vocal patients with mild cases of a disease can then receive more support and treatment than less-vocal patients with more severe cases.
I think it's incredibly useful to realize that all of us experience symptoms of anxiety and depression, intruding thoughts and compulsions, but those who with the problems are just those further along the line. It's not diminishing the issue, it's humanizing the sufferer. They aren't "crazy", they are suffering from something we all can relate to, but just in a manner that's unmanageable.