A depression diagnosis usually marks a turning point in your experience of the illness. Up to that point, you may have downplayed the seriousness of mood problems, or you may have been less aware of feelings and focused instead on pain or insomnia or some other physical symptom.
When things get so bad that you can’t lead the life you’re used to, then you know you need help but may still have no idea what the cause is. So you head for the doctor’s office – whether it’s your primary care physician or a psychiatrist – and hope they’ll be able to tell you what’s wrong and do something about it.