For the first time, scientists have pinned down a molecular process in the brain that helps to trigger schizophrenia. The researchers involved in the landmark study, which was published Wednesday in the journal Nature, say the discovery of this new genetic pathway probably reveals what goes wrong neurologically in a young person diagnosed with the devastating disorder.The synaptic pruning theory has been around for a long time, but why and how has been the question. This is believed to be why it hits in teens and 20d; it's a point where your brain stops growing, and the normal pruning process may get carried away.
The study marks a watershed moment, with the potential for early detection and new treatments that were unthinkable just a year ago, according to Steven Hyman, director of the Stanley Center for Psychiatric Research at the Broad Institute at MIT. Hyman, a former director of the National Institute of Mental Health, calls it "the most significant mechanistic study about schizophrenia ever."
"I’m a crusty, old, curmudgeonly skeptic," he said. "But I’m almost giddy about these findings."
The researchers, chiefly from the Broad Institute, Harvard Medical School and Boston Children's Hospital, found that a person's risk of schizophrenia is dramatically increased if they inherit variants of a gene important to "synaptic pruning" -- the healthy reduction during adolescence of brain cell connections that are no longer needed.
In patients with schizophrenia, a variation in a single position in the DNA sequence marks too many synapses for removal and that pruning goes out of control. The result is an abnormal loss of gray matter.If you don't why this matters not just to those who have families where this gene is a source of grief:
The genes involved coat the neurons with "eat-me signals," said study co-author Beth Stevens, a neuroscientist at Children's Hospital and Broad. "They are tagging too many synapses. And they're gobbled up."
The Institute's founding director, Eric Lander, believes the research represents an astonishing breakthrough. "It’s taking what has been a black box...and letting us peek inside for the first time. And that is amazingly consequential," he said.
From my book My Brother Ron (2014):
A 1991 estimate was that it costs the United States about $65 billion in direct and indirect costs,[i] declining to $62.5 billion by 2002.[ii] In spite of the enormous number of patients who are not actively treated, schizophrenia treatment consumes about 2.5 percent of all U.S. health care expenditures, or about $50 billion a year. Schizophrenia is also responsible for more than 10 percent of all disabilities — not just mental disabilities. Government disability payments to schizophrenics in 2005 totaled more than $8 billion.[iii]The $19 billion in direct costs includes the criminal justice system dealing with a few spectacular and terrifying crimes, and a myriad of infractions, arrests, and short periods of observation.[iv] A 1999 study found that 16.2 percent of state prison inmates, 7.4 percent of federal prison inmates, and 16.3 percent of jail inmates, were mentally ill.[v] As of 2002, about 26,000 inmates in state prisons across the United States who were convicted of murder were also mentally ill. A detailed examination of Indiana prison inmates convicted of murder found that 18 percent were diagnosed with “schizophrenia or other psychotic disorder, major depression, mania, or bipolar disorder.”[vi]
[i] R.
J. Wyatt, I. Henter, M. C. Leary and E. Taylor, “An economic evaluation of
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accessed August 16, 2006.
[ii]
J.P. McEvoy, “The Costs of Schizophrenia,” Journal
of Clinical Psychiatry, 68 Suppl. 14:4-7 (2007), abstract available at http://www.ncbi.nlm.nih.gov/pubmed/18284271,
last accessed June 9, 2012.
[iii]
National Quality Measures Clearinghouse, “Schizophrenia: percent of patients
with severe symptoms or side effects and no recent medication treatment change
to address these problems,” February 25, 2008, http://www.qualitymeasures.ahrq.gov/summary/summary.aspx?ss=1&doc_id=418,
last accessed February 29, 2008; U.S. Social Security Administration Office of
Policy, “Annual Statistical Supplement, 2006,” Table 5.A4, http://www.socialsecurity.gov/policy/docs/statcomps/supplement/2006/5a.html#table5.a4,
last accessed March 9, 2008; Samuel L. Baker, “U.S. national health spending,
2005,” August 26, 2007, http://hspm.sph.sc.edu/Courses/Econ/Classes/nhe00/
last accessed March 9, 2008.
[iv]
R. J. Wyatt, I. Henter, M. C.Leary and E. Taylor, “An economic evaluation of
schizophrenia-1991,” Social Psychiatry and Psychiatric Epidemiology 30:5
[September 1995], 196-205, abstract available at http://www.springerlink.com/content/wj15686263364413/,
accessed August 16, 2006.
[v]
Paula M. Ditton, Bureau of Justice Statistics, “Mental Health and Treatment of
Inmates and Probationers,” (Washington: U.S. Department of Justice, 1999), NCJ
174463.
[vi] Jason C. Matejkowski, Sara W. Cullen,
and Phyllis L. Solomon, “Characteristics of Persons With Severe Mental Illness
Who Have Been Incarcerated for Murder,” Journal of the American Academy of
Psychiatry and the Law 36:1[2008]74-86, http://www.jaapl.org/cgi/reprint/36/1/74,
last accessed May 14, 2011.
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