No. It's not. It's a mental illness.
The first time I was hospitalised after a suicide attempt I was told there's no way I can get better on my own without medication, because in long lasting severe cases like mine, even if my living conditions improve, the chemical imbalance in my brain will prevent me from feeling better. And guess what. The meds they gave me had no effect, so I eventually stopped taking them. Years later I was having a really bad depressive episode, so I packed a suitcase and up and left the country to go on a working holiday. The moment my plane landed I felt fine. No anxiety, no depression. Even the nightmares stopped. Chemical imbalance my boot. :P