This happens to me if I'm having an off day or if it's really slow at work. I have a really hard time staying focused, engaged, etc....

Now when there's a crisis I am high functioning and can "get the job done". I function much better in that "crisis" or "survival" mode. How screwed up is that? LOL

I make myself lists @ work (of stuff I need to complete), create tasks in Outlook w/ reminders, take notes when someone (supervisor/co-worker) is asking a question or assigning a task to me. Once I'm done with my notes, I'll repeat back what I noted.

I'm still working on this part of myself, so I hope that is somewhat helpful.

Ok so basically I have PTSD and though I'm not stupid, sometimes I lose the plot when people ask me things or are explaining things and I feel like an idiot because I can't understand a simple sentence and it frustrates me.

I basically wondered if anyone else with PTSD, anxiety or depression experienced the same and how/if they have managed to make it better.

There are two possible explanations.

Your general level of anxiety may be high due to the PTSD and what you describe may be due to symptoms of anxiety, exacerbated by your reaction to the situation.

Or it could be that when you lose the plot you are having a flashback or the trauma memory is being activated in some way. If it's the latter then you may find this leaflet on coping with flashbacks helpful: http://www.getselfhelp.co.uk/docs/CopingwithFlashbacks.pdf
This leaflet gives an explanation of the processing block which occurs at the time of the trauma and keeps being re-activated during the flashback: http://www.getselfhelp.co.uk/docs/PTSDmetaphor.pdf

Either way, Cognitive behavioral therapy (CBT) has a good evidence base of effectiveness for treatment of PTSD and anxiety.

Do you sometimes verbally communicate sentences in a way that some people don't understand? Or maybe you sometimes know what you want to say but the words aren't coming out right, or you don't even notice that the words aren't coming out right? What you describe reminds me of aphasia, which can occur in PTSD where the individual also experienced a head or brain injury, but it usually comes with some level of verbalization issues as well. It may also occur with just PTSD absent a head injury, but that might be due to non-diagnosis of a concussion or it might be due to the lack of research. I don't know, but aphasia might be something to investigate.

At any rate, I don't have aphasia, but I do process things a little differently than some. I need folks to be short and direct, so I've gotten in the habit of directing the flow of an important conversation and repeating things a lot to make sure I'm understanding what the person is trying to convey. John Doe might stop in my office and go into detail about some issue and I'll stop him right away and ask what kind of problem he has, then I'll have him take it through me step by step and I'll interrupt as often as I need to repeat things. I'll say something like, "Ok, so you're telling me that Jim doesn't want to honor his contract." He'll tell me more and then I'll stop and say, "I see, Jim doesn't want to honor his contract because of XYZ." and so on. As we expand things and I repeat the key points, I know I'm getting it right and I'm keeping things slow to make sure I can process everything. Even when I'm chatting with my wife, I sometimes have to ask her to slow it down or I'll focus on her lips moving rather than trying to look her in the eyes when she's speaking. For some reason watching the lips helps me a ton. I hope that helps.