Posted by linkadge on January 16, 2009, at 21:25:43
In reply to Re: Gene link: schizophrenia + Bipolar Disorder?, posted by Trans-Human on January 16, 2009, at 19:07:13
I do agree that severe stress can cause many forms of mental illness. In many people with schizophrenia however, doctors nor family can identify any significant form of environmental trigger. Because many forms of mental illness resemble normal responces to environmental stress, people sometimes have a hard time believing that there is anything infact a thing as mental illness.
When the brain is under severe stress it can release all sorts of chemicals that can produce behavioral states resembling schizohprenia. For instance, stress increases PKC which supresses prefrontal and higher cortex functioning and can lead to impulsivity and distractability. In addition, severe stress can release endogenious compounds that bind to the same receptors as phenycyclidine. PCP interacts with NDMA receptors in a way that can produce a state remarkably similar to disorganized schizophrenia. Severe stress can also dramatically increase conceptrations of PEA which is similar in action to the amphetamines. There are a number of other compounds released during stress such as isatin (decreases the binding of gaba to gaba receptors) as well as tryptamine (which binds to the same receptors as LSD).
There have been a number of recent studies, however, suggesting that there is a progressive loss of grey matter in schizohprenia. This is interesting because some of the genes associated with *certain forms* of schizophrenia are responsable for the production and maintainance of myelin.
If stress is not too severe or prolonged, it doesn't tend to induce structural changes to the brain. This is why, some people can have psychotic breaks and just go back to normal. The healthy brain has a capacity to repair itself after certain forms of neurological insult.
In genuine mental illness however, there could be a reduced capacity for the brain to repair itself after stressfull events. There could be an initial decreased cellular resiliance. There may be impairments in the brain's capacity to undergo normal maintainance too. This is like what happens in MS, where, for whatever reason, the brain just starts to loose its remyleinating capacity. Many cases of schizophrenia start out as other mood disorders like anxiety disorders or depression. This could be an early indicator of the types of brain changes that are occuring.
Some of the mood stabilizers like lithium and valproate may be working by enhancing cellular resiliance and boosting the level of cetain neurotrophic factors. Early studies suggest they may be preventing the atrophy associated with the disorders.
(Some studies indiciate that bipolar is associated with significant reductions in DHA content. DHA like valproate inhibits GSK-3b, PKC and induces the neuroprotective protein BCL-2. PKC expression modifies the way the brain utilizes and responces to calcium. DHA is also critical for the maintainance of grey matter. Perhaps divalproex is just ameleorating the signal transduction deficits that result from severe DHA deficiancy. Then again, there are genes that code for the conversion of short chain omega-3's to DHA. Some studies like alchoholism, for instance, with a gene that impairs this process. Not to go on a tangent.)
I guess what I am trying to say that even though we do not have solid conclusive results at this point, I don't doubt that some cases of mental illness are associated with real and significant brain changes.
Nobody would doubt that parkinsons is an actually a brain disesase. Some forms of Parkinsons have been conclusively linked to genes, other forms are associated with exposure to neurotoxins. Perhaps mood disorders are like parkionsons of the limbic system. There could be many causes, but to say that search for particulalr causes is futile may not be entirely acurate.
>including Jung, John Weir Perry, Loren Mosher & >others - who all had over 85% full recovery >rates;Yes and modern studies claim that prozac works in 85% of depressed patients. That doesn't mean I believe that either.
Linkadge
poster:linkadge
thread:874305
URL: http://www.dr-bob.org/babble/20090104/msgs/874429.html