@Zeroluck Those typical symptoms are what could potentially happen to very heavy users that are lacking the mystery LTC causing impuritie(s) in their mdma. Everyone's body will react differently to impurities, some may not even react at all. From what I've seen amongst users the LTC's with physical symptoms seemed to be caused by large doses and or mixed substance use. There is a terrific discussion in the 'what is wrong with the mdma today' thread on the possible causes of an LTC. The timeline when certain precursors to mdma became more controlled matches when manufacturers likely turned to more easy to obtain precursors, most notably PMK-glycidate. This seems to be mainly purchased from China which is known for having unpure products, especially by countries in Europe. Several other people on this website have picked up through researching the anecdotes of LTC victims that the mdma causing this seems to be dutch mdma. Though nobody is certain of the impurity causing this, the top three candidates are acrylamide, mercury, or glycidol. And unfortunately LTC's seem to be on the rise even in users of other drugs. I haven't come across anyones story getting any symptoms in a physical LTC from any drug other than mdma, it seems to be dp/dr, anxiety, cognitive difficulties, etc but that doesn't mean it's not possible. I feel like as stated by @G_chem some time back that the neurotoxicity of mdma(or possibly another drug) is increased when combined with the impuritie(s) thus leading to an LTC.
@2C-X I haven't used ssri's during my LTC. Many studies have shown that ssri usage will deplete serotonin with chronic or even short term use, if you'd like to read some of them just let me know. In short it's antidepressant effect is caused by a temporary increase in serotonin that will leave you with less and less over time. Think of it like getting drunk or high, for a time you feel good but after it wears off you're likely to have a 'low' period. This is particularly dangerous in a physical LTC since your symptoms are caused by at least a horrible deficiency in serotonin. I say at least since more is at play in an LTC than serotonin depletion, but for the intents of using any serotonergic drug it's an all around setback. 5-htp is a good, although I think you should give Sam-e a try since rather than depleting the catecholamines like 5-htp does, you can raise serotonin, dopamine, and norepinephrine all at once. It's a truly unique supplement.