How long could effects of MDMA (cut with something?) last for?

[debjud]

My 18 yr old DD took something at a festival almost 3 weeks ago - stuff she takes occasionally to help her stay up all night. Since then she's been depressed, getting panic attacks, not sleeping - she thinks it's still the effects from that. Does anyone know if that's possible? Have made dr appt for her for tomorrow. As she's expecting A level results tomorrow also, I put it down to that, but she phoned me in this panic, crying this morning and asking for dr appt.

It's normally a few hours. The drugs are unlikely to still be in her system, but it sounds like it's triggered some anxiety and panic symptoms. A trip to the docs is the best idea and might offer some reassurance. If the GP feels it needs further assessment they can arrange it.
A level results day may also be feeding this anxiety.
I'm a mental health practitioner (CAMHS) by the way.

Thanks Selks for replying so quickly. It's what I thought, but it's great to have a qualified person reply. I'm going to tell her this in case it helps.

Yes, do. I hope she feels better soon.

A friend bought some MDMA at a festival recently and was very unwell, said he felt awful and paranoid/ panicky for a couple of weeks. He showed it to someone and did some internet research and it looks like it might have been crystal meth. I think as a 30 year old professional this might have made him finally grow up a bit

Thanks for this. Yes - she had also thought it might have been crystal meth. The dr checked her over - I think she was checking for meningitis - she also says she's had a headache for about 2 weeks. But seems to be fine (also a lot more cheerful since getting good a level results!) . The good thing is that she says that this experience means that she's done with the drug which I'm v pleased about - though we'll see when she's actually in that situation. Am hoping that going to uni/starting a new part of her life will make her do a re-think.