[nemesis]

While flicking though articles on depression, anxiety and depersonalization, I have noticed that there may be a common thread between the three illnesses in the form of the limbic system. A couple of quotes from articles are posted below.

.. the limbic system in the brain instigates this whole response and is responsible too for our emotions and behaviour One of the body symptoms that people hate most is the one when you feel all foggy, surreal, whoosy or spacey. It is not completely understood what goes here but it is generally thought that the limbic system in the brain decides there is too much going on and goes into a self protection mode and shuts out excess stimuli. As the adrenaline levels decrease and you calm down it clears. This can be several hours days or weeks. You may either feel that you are not real or that the earth is not real and you?re a time warp away. These are often the hardest symptoms to understand and its very common to deduce that you must be going mad which makes you panic even more
Common Symptoms of Anxiety and Panic, No More Panic, London

Not only does the limbic system appear to have the ability to shut down the prefrontal cortex (thus lessoning the our ability to processes executive thought), but it is also heavily involved in the processing of emmotion and sensory input.

This part of the brain is involved in setting a person's emotional tone. When the deep limbic system is less active there is generally a positive, more hopeful state of mind. When it is heated up, or overactive, negativity can take over. This finding actually surprised us at first. We thought that excessive activity in the part of the brain that controlled emotion might correlate with enhanced feelings, not necessarily negative feelings. Yet, we noticed, again and again, when this area was overactive on SPECT it correlated with depression and negativity. It seems when the deep limbic system is inflamed, painful emotional shading results. New research on depression from other laboratories around the world has born this out. Due to this emotional shading, the deep limbic system provides the filter through which you interpret the events of the day. It tags or colors events depending on the emotional state of mind. When you are sad (with an overactive deep limbic system) you are likely to interpret neutral events through a negative lens. For example, if you have a neutral or even positive conversation with someone whose deep limbic structure is overactive or "negatively set" he or she is likely to interpret the conversation in a negative way. When this part of the brain is "cool" or functions properly, a neutral or positive interpretation of events is more likely to occur. Emotional tagging of events is critical to survival. The valence or charge we give to certain events in our lives drives us to action (such as approaching a desired mate) or causes avoidance behavior (withdrawing from someone who has hurt you in the past).

..

This part of the brain is intimately connected with the prefrontal cortex and seems to acts as a switching station between running on emotion (the deep limbic system) and rational thought and problem solving with our cortex. When the limbic system is turned on - emotions tend to take over. When it is cooled down, more activation is possible in the cortex. Current research on depression indicates increased deep limbic system activity and shut down in the prefrontal cortex, especially on the left side.
Brain Function And Physiology: The Limbic System, The Amen Clinics Inc

I'm by no means an expert in any field of science, but would it be a far call to hypothesize that the dysfunction of the limbic system could could be responsible for switching off the pre-frontal cortex and thus making it harder to think and concentrate ('brain-fog'). Shutting out sensory input so that we feel like we arent apart of our environemnt. And finally, dampening our emmotional responses so that we feel like we have lost the ability to feel things like love, pain and desire? These all seem to be core symptoms that a DP sufferer will complain of.

I'll be receiving the results of a recent SPECT scan on Friday and out of interest?s sake, will post back to the thread if any limbic sequale is noted.

 

[Guest]

Very interesting, thanks for posting. Looking forward to hear how your appointment went.

Good luck,
Nancy

 

[Guest]

I think this is really interesting and makes a lot of sense. I'd be interested to know how you got on. I suppose the questions still remain - if this is the case then how do we balance it out again? But having some explanation definitely gives more 'control' back to it all. I think part of the terror comes from explaining to healthcare professionals and them looking back at you rather confused :? I wonder how rec drugs can trigger this in some people or stressful events? I suspect that part of the recovery is to stop wanting to understand it all ... but frustrating when you have been educated scientifically to have answers for most biological inbalances. Complex creatures us humans .... :shock:

 

[Ben]

Rock on, Nemisis. Good post.

 

[Ben]

I'll make a link to a website as opposed to past the content here in case you want to read more, but here is an interesting article that is similar in nature to the one quoted earlier by Nemesis:

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?CMD=DisplayFiltered&DB=pubmed

I find it interesting that the article (in summary) concludes that areas of the brain responsible for immediate reactions (knee-jerk analysis or fear/fight/flight) may be dampened in subjects with depersonalization.

reciprocal inhibition of the anterior cingulate, leading to experiences of "mind emptiness" and "indifference to pain"

I looked it up - and the anterior cingulate (AC), appears to have a lot to do with immediate judgment of outcomes. If someone is doing a particular activity, this part of the brain judges the negative or positive state of the outcome in relation to us. Dampening the ability to make immediate outcome analysis would, in my opinion, result in a flat-line effect of our reaction to people's actions and other events/situations around us.

left-sided prefrontal mechanism would inhibit the amygdala resulting in dampened autonomic output, hypoemotionality, and lack of emotional coloring that would in turn, be reported as feelings of "unreality or detachment."

I also looked this up, and the Amygdala is the "fear analyzer/reactor" of the brain. If you are laying in bed and notice some odd sound in the living room outside your door, and it frightens you - you're getting a nudge from your amygdala. Apparently in studies where rats have had their amygdala damaged, they snuggle up to cats, etc.

Whether an active "choice" by our brains to dampen these areas or the result of chemical damage (drugs), it's interesting to note that these areas would have a lot do, in my opinion, with shielding us from anxieties and constant stress. Think of you as a thinker in the midst of all these sensory mechanisms - the system as a whole may turn down various input devices in the event of stress, but the thinker notices something bizarre here and freaks.

 

[nemesis]

Further presenting evidence on the possible depersonalization / anxiety / ocd / cingulate gyrus argument, a brainplace.com article entitled "Obsessive Compulsive Spectrum Disorders" addressing SPECT scan results in OCD states, states that "increased cingulate activity a person may have trouble with repetitive thoughts about his or her anxiety".

This is dramatically demonstrated by the SPECT scan image below which shows over activity in both the cingulate and temporal lobe activities in a sufferer of OCD.

The afformentioned article goes on to state that "The anterior cingulate gyrus, which is heavily innervated by serotonergic fibers, has been postulated as being involved with shifting attention and cognitive flexibility, deficient in all of these disorders.

Peicing together the evidence presented in both posts, we could deduce that over activity in the cingulate gyrus can resullt in:

• 
  Increased anxiety
  Difficulties in shifting thought
  Depersonalized states
  Executive centre shutdown (foggy brain)

All of which are symptoms which many suffers of DP/DR have experienced.

One might quite easily come to the conclusion that cingulate gyrus dysfunction may play a signifigant role in both anxiety and depersonalization states.

Just a personal opinion backed by poor science.[/list]

 

[ShyTiger]

Am curious how you got to have spect test in first place. Do doctors refer you?

 

[Guest]

I am a pharmacist. I did a SPECT test. It showed a diminution in regional blood flow in the temporal region (bilateraly, two sides of the brain).