Unintentional Harm by Professionals
Aside from the industry and individual therapists perpetrating intentional harm on plurals, there's many things that are done in an effort to help us that are harmful in a variety of ways.
Highly Suggestible
According to science, dissociation highly correlates with hypnotizability. As a rule, persons with dissociative disorders are HIGHLY suggestible and thus it's easier for external pressure to worm its way into the belief system of many plurals. When that pressure comes in the form of earnest advice from trusted professionals, supposed experts in their subject of specialization it can change the entire course of therapy.
It's imperative that any professional working with plurals is aware, as well as informing the client& (i.e. the plural) system in question on this topic so that both can be aware of what the professional says and the impact it can have on the system. It's impossible to know every triggering or suggesting statement that might be said so the client& being knowledgable and being informed to watch out for this is a positive interaction between professional and client&, and returns power to the client& to monitor the professional, while leveling the playing field. Professionals make mistakes. Admitting it empowers the client& to advocate for themselves.
Our T's suggestion was relatively harmless (unintentionally inspiring one night of insomnia), but it's a reminder that some folk within the system can take things quite literally. An authority figure telling a system that "the only way they'll ever be healthy is to be one 'whole, integrated' person" especially if it's repeated in a variety of forms! can sabotage years of headwork and progress, causing the system to believe that they WON'T be healthy until integration (merging) is completed throwing the entire process out the window!!
If you ask us, the idea of merging shouldn't even be mentioned unless it's in a conversation of the pros/cons of functional multiplicity and whether to attempt merging at all in the first place, knowing full well it may not be permanent and may waste a lot of time. In both cases you have to get healthier in order to become a functional internal community and/or to start the process of merging.
According to ISST-D's treatment standards, the client& system shouldn't be guided to the merging process until the system has stabilized and is processing traumas. That means the client& system is already healthier than when it first came to the therapeutic relationship. The poorly worded doom-and-gloom prediction probably done "innocently" in alignment with the therapist's convictions, but patently false becomes a self-fulfilling prophesy, and the client now is mired in the belief that they are doomed to be dysfunctional until merging is completed, creating a prophecy-fulfilling level of anxiety or panic in the system that prevents stabilization and encourages more dissociation and amnesia. The therapist may wonder why the system is malingering, and be at a loss to help the system stabilize itself. Years pass before this problem becomes obvious. But it's the therapist who caused the system to be convinced they can't get better until the merging is completed which creates this panic-reaction and anxiety catch-22 and delays therapeutic progress.
Please remember you are a helping profession. You don't do the work, they do. You assist, inspire, inform, and role-model. Any suggestions must be done with full knowledge of what you're doing with them it's a tool to use mindfully and with the utmost ethical consideration only to help the system get out of its own way towards healing. If you don't know what that means, and if the system has not asked for help with those blockages, then you shouldn't be using suggestions at all; it's not ethical.