Does melancholic depression mean you never smile or laugh at a joke?

On the contrary. I have a best friend next to my heart who despite the state she is in, smiles and laugh when either on the phone, text and most of all cracks up when she is with me. Yes, when i give a lecture i give jokes before, during or ending my talk. She keeps hitting me even on the way out and even in the car. So, i let her drive.