Thursday, September 1, 2011
Thirty years ago, Dr Cameron related, a psychiatrist told him that schizophrenia was not a brain disorder. Rather, it was a psychosis (in the Freudian sense of the term) that could be treated with family therapy. Too bad no one got better.
The first indication that schizophrenia could in fact have something to do with the biology of the brain came more then three decades ago in the form of a breakthrough brain scan study by Johnstone and Crow. The scans, which compared the brains of those with schizophrenia to controls, revealed that those with schizophrenia possessed larger ventricles (open spaces) than the controls. Check out what looks like a butterfly silhouette in the two images below. Notice the decidedly more pronounced butterfly on the right.
Dr Carter recounted reading the Johnstone and Crow study back when it was first published in The Lancet in 1976. “Bollocks!” (a UK term of derision) someone had scribbled in his copy.
More sophisticated imaging studies over the years reveal losses in gray matter volume in different areas of the brain, but this is not the same as loss of brain cells as in Alzheimer's, Dr Carter was quick to point out. All the cells are there. What seems to be going on, among other things, is loss of connectivity (circuitry anomalies, especially in the dorsolateral prefrontal cortex) and neuronal oscillations (particularly in GABA cells). The different regions of the brain, in effect, are out of sync. Thinking gets disrupted.
Dr Carter gave the example of an American tourist in the UK having to negotiate crossing the street. Habitual responding won't do.
But cognitive challenges and psychosis are related, with the first anticipating the latter. Well before psychosis rears its head, it appears that first there are changes in the cortical areas. As these changes progress, this may lead to subcortical dopamine dysregulation and psychosis.
Then there is something called “psychosis risk syndrome.” Thirty to forty percent of those who experience attenuated psychosis features - ie not meeting DSM criteria - go on to develop schizophrenia or bipolar over two years.
So perhaps by improving function in the cortical areas prior to first psychosis, we can prevent psychosis.
This is one of the hot areas in schizophrenia right now. Dr Carter heads up the EDAPT program - Early Diagnosis and Preventive Treatment of Psychotic Illness - at UC Davis. Family involvement, Dr Carter, told us, is the most effective component. New developments include the likelihood of two or three new meds - not antipsychotics or dopamine blockers - that would target cortical areas to improve cognition. Also, cognitive training - pioneered by Sophia Vinogradov of UCSF - based on the “use it or lose it” principle is taking off. Another possibility is transcranial magnetic stimulation.
The brain science over the past five or six years has led to enormous advances in our understanding of schizophrenia. But will our knowledge lead to better treatments and possibly even prevention? Good question.