I applied for PIP on the 14th June 2013, I had my medical on August the 16th 2013 and I am still waiting for a decision, I have phoned so many times now it feels farcical. I am told I am still being assessed. DWP have said they are appalled at how long I have been waiting, PIP said put a formal complaint in about Capita, and Capita just say were sorry but we did not estimate how many people would apply for PIP. I have a spinal injury, it is not going to get better, I will not heal, surgery has been ruled out and sadly my future prospects are more pain and lessening mobility as I get older. I don't know how much assessing is needed since my MRI's clearly show the nerve and spinal damage that affects every part of my life. How long is too long to wait ??
I'm afraid that there is a huge backlog of PIP claimants, your story is not uncommon. The only thing we can suggest is to contact your MP, sometimes it is possible for them to speed the process along a bit.