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August 03, 2010

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Brain activity may predict schizophrenia

Sept. 12, 2009
Courtesy Columbia University Medical Center
and World Science staff

Sci­en­tists have iden­ti­fied a small ar­ea of the brain they be­lieve is in­volved in the ear­li­est stages of schiz­o­phre­nia and re­lat­ed psy­chot­ic dis­or­ders.

Ac­ti­vity in this re­gion may help pre­dict the on­set of the dis­ease, of­fer­ing op­por­tun­i­ties for ear­li­er di­ag­no­sis and de­vel­op­ment of pre­ven­tive drugs, sci­en­tists said.

De­tails were pub­lished in the Sept. 7 is­sue of the re­search jour­nal Ar­chives of Gen­er­al Psy­chi­a­try.

Schiz­o­phre­nia is a rel­a­tively com­mon men­tal ill­ness that typ­ic­ally causes a marked loss of tou­ch with real­ity. It af­fects about 1 per­cent of the world popula­t­ion, ac­cord­ing to the U.S. Na­tional Men­tal Health As­socia­t­ion.

“It is cru­cial to be able to vis­u­al­ize the most af­fect­ed ar­ea of the brain and to pin­point the re­gion that is most vulnera­ble. This will give us clues in­to the caus­es,” said Scott A. Small of Co­lum­bia Un­ivers­ity in New York, lead in­ves­ti­ga­tor in the stu­dy. “Our find­ings could help us im­prove di­ag­no­sis in the pre­clin­i­cal stage,” when treat­ment can be most ef­fec­tive, he added.

Small and col­leagues scanned the brains of 18 peo­ple with known early warn­ing signs of schiz­o­phre­nia. For in­stance, such a sign might con­sist of a per­son feel­ing that they can hear their own name in the wind, where­as a full-blown schiz­o­phren­ic might in­stead hear voices out of the blue.

“Right now, the odds of know­ing who will go on to de­vel­op schiz­o­phre­nia from the pro­dro­mal [early-warn­ing] stage is only a lit­tle bet­ter than a coin toss,” said study co-author Scott A. Scho­bel, a clin­i­cal psy­chi­a­trist at Co­lum­bia and the New York State Psy­chi­at­ric In­sti­tute.

The sci­en­tists tracked the health of these se­lected peo­ple for two years. Of those those who went on to de­vel­op psy­chot­ic dis­or­ders such as schiz­o­phre­nia, 70 per­cent had un­usu­ally high ac­ti­vity in a spe­cif­ic, small re­gion of the brain, the re­search­ers said.

The re­gion is called the CA1 sub­field of the hip­po­cam­pus. The hip­po­cam­pus is a horseshoe-shaped struc­ture lo­cated deep with­in each side of the brain, and im­pli­cat­ed in emo­tion and mem­o­ry forma­t­ion. Pre­vi­ous stud­ies had iden­ti­fied a gen­er­al in­crease in ac­ti­vity in the hip­po­cam­pus in chron­ic schiz­o­phre­nia. The new study sought to bet­ter pin­point the ex­act re­gion and fo­cus on pre-schiz­o­phren­ics.

The re­search re­lied on the scan­ning tech­nique func­tion­al mag­net­ic res­o­nance im­ag­ing, which meas­ures brain me­tab­o­lism based on blood flow, in­di­cat­ing what parts of the brain are ac­tive at diff­er­ent times.

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Scientists have identified a small area of the brain they believe is involved in the earliest stages of schizophrenia and related psychotic disorders. Activity in this region may help predict the onset of the disease, offering opportunities for earlier diagnosis and development of schizophrenia prevention drugs, scientists said. Details were published in the Sept. 7 issue of the research journal Archives of General Psychiatry. Schizophrenia is a relatively common mental illness that typically causes a marked loss of touch with reality. It affects about 1% of the world population, according to the U.S. National Mental Health Association. “It is crucial to be able to visualize the most affected area of the brain and to pinpoint the region that is most vulnerable. This will give us clues into the causes,” said Scott A. Small of Columbia University in New York, lead investigator in the study. “Our findings could help us improve diagnosis in the preclinical stage,” when treatment can be most effective, he added. Small and colleagues scanned the brains of 18 high-risk people with known early warning signs of schizophrenia. For instance, such a sign might consist of a person feeling that they can hear their own name in the wind; a full-blown schizophrenic might instead hear voices out of the blue. “Right now, the odds of knowing who will go on to develop schizophrenia from the prodromal [early-warning] stage is only a little better than a coin toss,” said study co-author Scott A. Schobel, a clinical psychiatrist at Columbia and the New York State Psychiatric Institute. The scientists tracked the health of these selected people for two years. Of those those who went on to develop psychotic disorders such as schizophrenia, 70 percent had unusually high activity in a specific, small region of the brain, the researchers said. The region is called the CA1 subfield of the hippocampus. The hippocampus is a horseshoe-shaped structure in deep within the brain, on each side, implicated in emotion and memory formation. Previous studies had identified a general increase in activity in the hippocampus in chronic schizophrenia. The new study sought to better pinpoint the exact region and focus on pre-schizophrenics. The research relied on the scanning technique functional magnetic resonance imaging, which measures brain metabolism based on blood flow, indicating what parts of the brain are active during which activities.