Yes, it is possible... various life changes (taking Ritalin for me made everyone go away and impossible to dissociate), and healing. When/if we ever truly learn safety then we won't need the tool of dissociation, and our alters can leave or become adults or merge their talents and skills with ours.... the human mind is so wondrous, we have no idea of its power, so the possibilities are endless. And all people dissociate to some degree... highway hypnosos, losing time reading a great book or lost in an art project, or we see some horror our brain cannot compute. Going to the dentist is a great time to still have that skill...
One day at time.