I have tried EMDR and it was initially helpful. My therapist was trained in EMDR, where he attended sessions from Francine Shaprio's institute (the inventor of EMDR). EMDR claims to rebalance the brain for sufferers who have experienced trauma, such as PTSD. According to EMDR theory, traumas get stuck in the brain, and EMDR aids in reprocessing the trauma, so it doesn't get stuck in the brain's cognition.
From my background, I felt traumatized about my past, based on bullying and social peer pressure from fitting in. My therapist helped me re-processs my interpretation of events with EMDR, and there was a significant drop in charge around that subject area related to my anxiety, but not in my overall way in how my body handles anxiety.
So I will say EMDR did initially help, however, I will also say it never cured my anxiety disorder, since I still experience anxiety attacks that need to be regulated with medication. EMDR gave me a better understanding of why I reacted to my past, in terms of reprocessing, however it never alleviated how my brain over reacts to stress.
EMDR links a lot to trauma, where a user may assume every emotional reaction is based on some past decision, usually stemming from our childhood, which causes us to be stuck in how we interpret things. From my experience, I can buy that our behavior was influenced by our past, however EMDR seems to say the root of all our psychological problems comes from processing those traumatic decisions.
So you may feel every time you have an emotional reaction, it's based on some past trauma, and you'll have to continue to heal it. For me, this caused endless self analysis of the past, and constant eye movements to reprocess emotions, and this may never end.
EMDR helps, but for someone with an anxiety disorder, I don't recommend it as a stand-alone therapy, Likewise, don't ever think this therapy will permanently cure you from the need for medication, as relief from your anxiety disorder.
I find fault in the EMDR premise that our negative reactions can only be cured by finding the childhood decisions that led to those faulty decisions. EMDR focuses too much in past reprocessing, and for me this is just endless self analysis, which is just as faulty as Freud's inept views that our behaviors are caused by our sexual feelings toward our parental figures such as our parents, and endless talk therapy sessions are the only way to fix it. Freud's everyday psychoanalysis of laying on a couch, while a therapist just listens, are no longer practiced, due to its flaws of constant self analysis, and I feel EMDR partially has the same underlying faulty, approach as Freud.
So where I'm getting at, I'm not fond of therapies, like EMDR, that constantly push this need to "reprocess our past." If you find yourself reprocessing your past after six months, you may need to accept you have more of a brain disorder, rather than an emotional disorder. Otherwise you may be spending countless sessions in therapy, with no end in sight, since you're always stuck in how your past formed your now.
And for me, brain disorders are best managed by medication, than alternative therapies like EMDR.
So I will say EMDR is partially helpful, for someone with an anxiety disorder, but if you start going past five months with EMDR, and continue to process your past, my recommendation is to stop the EMDR therapy, because the benefits of EMDR have been fully used.