sometimes people simply feel low, lack energy and have a feeling of being hopeless or lost. It may be unattached to any events, and may be caused by hormonal, mineral, chemical or other imbalances. For some, it may be due to lack of sunlight, others lack of emotional security, and for many other causes.
You are right in that drugs simply mask the symptoms, much like most medications.
But Depression is not imagined nor untreatable. It is a very real whole health issue that must be addressed properly.
For some it may seem easier than for others, but when a person cannot even muster enough energy to get up, or feels like they're in a dark lonesome room, it is a monumental challenge and accomplishment to get started on a chosen treatment protocol.