Depression,no one understands?...?

Why is it that just because you laugh and smile every now and then,that everyone thinks youre better or "cured"? Im severly depressed,and myy depression has brought on an anxiety disorder (i think GAD). And evrytime im the least bit happy everyones like "Oh youre doin soo good,im proud of you" ,orr "Hey maybe ur finally getting over this"(referring to the depression/anxiety). Whyy do they always say this? its like they think that just because u smile, ur not depressed anymore... GRR its frusteratingg.