Possible depersonalisation characterised primarily by cognitive issues

Hi all,

27 year old male here, ten years of mental health issues of fluctuating severity. I briefly checked this forum out back in 2008 when my problems started, but had all-but-forgotten it until yesterday. Apologies in advance for the slightly lengthy post and for what might, at times, appear to be arrogance - I want to lay out my story as honestly as possible in the hope that I can get some clarity on the nature of my problems and benefit from the wealth of experience that exists on this forum...

Story so far

My background has been one of very high achievement. I went to one of the best schools (high schools, that is) in the country (I'm from the UK), where I was one of the best students.

Then, at the beginning of my final year of school (I even remember the date - October 22, 2008), me and a friend went to his house for the day to smoke weed. I had never tried it before, but I made sure to do it in a really safe environment with one of my best friends. I had a deal with my uncle not to smoke tobacco before 21, so the stuff was pure. After only a few puffs I experience an altered state of reality (I assumed - and still assume - that this was a standard high, but obviously don't have a frame of reference) and then a prolonged state of panic. A week or so later I was watching Sin City when I had a return of that intense sense of terror that had been prevalent during the high, although I hadn't smoked again since.

A few days later came the event which I think of as the beginning of my troubles. During a talk at assembly one morning I became acutely aware of grasping at the words as the speaker said them, rather than just processing them - almost as if I was translating them and desperately making sure to keep up with them, rather than just letting them wash over me as normally happens in conversation.

The next few months (I can't quite remember how long) were manic, as I occupied this weird space of cognitive dysfunction and all-consuming anxiety. Eventually I settled down into a predicament where my cognition was still shot to pieces, but I wasn't in this heightened state of being. I had come to think of this as my new norm - a state of ill-temper and depression as my self-worth plummeted.

This continued until October 2010, when I started university. The cognitive issues were still very much present during my degree and I would regularly spiral emotionally as a result, but there was a steady trajectory of improvement until, some time towards the end of my second year (mid-2012), I was largely symptom-less. I ended up doing really well in my finals, felt intellectually back to my best, and also thought of myself as psychologically much more resilient - I had fully subscribed to a diagnosis of General Anxiety Disorder, and had embraced the idea that all my cognitive issues were underpinned by anxiety which could only proliferate and take hold if I responded to symptoms by according them importance. By shrugging off any recurrent symptoms, I was able to remain high-functioning and was doing very well at my master's.

At some point around March 2014, my efforts to disregard increasingly persistent cognitive symptoms weren't having the desired effect. I endured a gradual decline until I eventually went to mental health services and began taking Sertraline (an SSRI inhibitor). I have been functional on this since then - I am on an excellent career path, have a great group of friends, have had a bunch of girlfriends etc. - but have been operating fairly reliably at about 75% capacity. I have occasional days where things are pretty much fine, days which are characterised by cognitive dysfunction which derail me emotionally, and then the majority of days where I function well but have two or three cognitive incidents which needle me but aren't sufficient to severely disrupt my life. Recently I've dived again - I should be at work now but am at home as I just couldn't face going in.

My symptoms

I've always had trouble fully accepting the various half-diagnoses I've received.

Originally I was told I was suffering from depersonalisation, and subsequently was told by a different specialist that I had GAD. The problem has always been that my issues are very specifically cognitive (I have myriad other symptoms that come and go, but if I could just get rid of the cognitive symptoms I wouldn't care about the occasional tight chest or closed throat; the low mood and related phenomena have always struck me as very much secondary, the result of my having cognitive issues that strike at the core of who I am and what I value about myself). This doesn't fit with a normal anxiety profile, nor with the many accounts of dissociation-from-self that feature in this forum.

Might be helpful if I give a slightly clearer indication of what I mean by 'cognitive problems'. There are a few different categories of issue. On the one hand, there's the stuff that is recognisably f*cked up, in the sense that it's an instance of my just being unable to do something that is utterly standard for a normal-functioning human (child or adult). Things like not being able to follow conversations, basic logical inferences, especially when they involved negative clauses (e.g. "are you sure I don't need to do that?"). I remember tutoring during my year out between school and university and having exchanges with pupils as young as 8 years old where I thought 'they are literally able to grasp patterns of thought more easily than I am - I am struggling to keep up'. Then there's the slightly different group of issues which are a little less obvious - general mental malaise and slowing down.

Thank you if you've taken the time to read my post. Any diagnostic / treatment-related thoughts very welcome.