Enlightenment, as it stands, will be easy to find, too easy. When "enlightened" people lose such basic parts of their psyche as a love of rock n' roll, it's going to tell anyone close to them that something's seriously up. If your loved one suddenly dropped their hobbies and interests, you'd likely try talking to them. Whatever the enlightened's response will be, it'll likely be concerning and prompt some calls to a counselor and/or psychologist.
So, how can the government hunt down enlightened? Easily-by making the above groups (counselors and psychologists) informants. Just tell them the government is investigating the matter, is looking for a cure, and is keeping things hush-hush to prevent a panic. Or simply have government agents pose as fellow members of the field (mental disorder specialists) investigating the possibility of some sort of mental disorder epidemic (if that's the right terminology).
As for having the enlightened quarantined, have some people show up and offer "treatment" for their loved one (ie. bring them to a mental hospital). Don't worry, it's not a lie! You'll just be giving a different treatment than most people will expect (the exception being crazy conspiracy people).
As for treatment, there have been many great suggestions, but I have to assert something I noted: the 25th frame effect can "program" someone to do something, but it doesn't change the brain structure. What I think is happening here is simple:
- The aliens can effectively transmit psionic energy, convert energy to matter, as well as combine energy. So, here's how it works:
A. In order to transmit psionic energy, the aliens must form a link, and to do that, the humans must be in a receptive state. The 25th frame effect does this covertly and efficiently.
B. The aliens use this link to infuse psionic energy into a human's brain. At this point, just one signal will cause the energy-infused matter to convert into hybrid brain matter.
Since the alien's bodies are matter, they convert the alien's energy into energy and infuse the victim's body with this energy. The alien's goal is likely to enlighten enough humans that they can send another signal, which will convert the enlightened's bodies into hybrid forms. At this point, they've either taken over Earth or can take over Earth with their enlightened army.
However, let's say something goes wrong in the process; a plot twist. When the psionic energy is converted into matter, creating a hybrid brain, the human and alien mind is destroyed and replaced with a new mind altogether; a new entity. This eliminates the dangerous weakness of having the enlightened lose their hobbies and interests, at the cost of having a completely new being form inside the human victim's body.
This enlightened will have the memories of both the human and alien who were destroyed to create it, psionic abilities (telepathy and telekinesis), and a strong desire to take over Earth. This last one is easily explained; humans have a tendency to desire power, and these aliens clearly already seek it. In fact, these enlightened will likely see themselves as superior, the future of the human race.
So, there won't be any curing this with a drug in this case, and fighting enlightened after they gain their superhuman hybrid forms (perhaps even before that, since they have telekinesis and insidious schemes to back them up) is going to be difficult, but hey! It's not impossible.