Thomas Reuters: Brain Analysis Can Predict Psychosis

Background: The following discussion concerns a new method of treatment that can predict the condition of psychotic patients. According to the author, Thomas Reuters, scientists from King's College London's Institute of Psychiatry and University College London's computer science department found that using computer algorithms to analyze MRI brain scans can predict a patient’s outcome. The part of the discussion I am interested in occurs near the end of the article when the sample is conducted and the researchers relay the results.


Article:http://www.foxnews.com/health/2011/11/07/brain-analysis-can-help-predict-psychosis/#ixzz1eDmMaNMM

Analysis: Thomas Reuters claims that professionals have proven that MRI scans can predict psychosis; however, his statements contradict the scientists results from a small sample conducted. Approximately 24 million people worldwide show symptoms of psychosis. The sample contained 100 people experiencing their first psychotic episode in the experimental group, and the control group contained 91 healthy patients. Scientist correctly predicted seven out of the ten patients that were said to developed continuous psychosis.

Premise/Conclusion

Premise (1) - "Dazzan's team worked with 100 patients and took MRI brain scans when they came into health clinics with their first psychotic episode. The researchers scanned also the brains of 91 healthy people as a control group."

Premise (2)- "The patients were followed up around six years later and put into groups of those who had developed either continuous, episodic or intermediate psychosis, depending on whether their symptoms continued or faded away during this time."

Premise (3)- "The team then analyzed in detail the scans from 28 people who had continuous psychosis, 28 patients with an episodic course, and 28 healthy controls and used the data gained to "train" computer software based on pattern recognition to enable it to distinguish between different illness severities."

Premise (4)- "When the resulting algorithm was used on scans of patients who had had a first psychotic episode, it was able to pick out those who had gone on to develop continuous psychosis and those who went on to develop a more benign, episodic psychosis in seven out of 10 cases, the researchers said."

Conclusion- "MRI (magnetic resonance imaging) brain scans can predict a patient's outcome."

Let's formalize the argument:

(1) Dazzan's team tested 100 patients who experienced their first psychotic episode and 91 healthy patients, they could determine which patient would show continuous symptoms.

(2) The test matched up with seven out of the ten patients that were said to have continuous symptoms.

Therefore,

(3) MRI brain scans can predict the outcome of psychotic patients.

I think that there are a number ways analyze the fallacy committed here. Notice that the author conclusion contradicts the statements from the professionals that actually conducted the research. The author says," Brain analysis can predict psychosis", which implies that there is an accurate medical procedure to do so. The researchers say, "Although we have some way to go to improve the accuracy of these test and validate the results on independent large sample, we have shown that in principle to use brain scans to identify...patients who are likely to go on to have a continuous psychotic illness and those who will likely develop a less severe form." Professionals still need to do some testing on this method of treatment, so when the author said, “brain analysis can predict psychosis”, the word "can" sways the readers to assume that there are no flaws and further testing is needed.

This is a case of an argument from hasty generalization fallacy. There are approximately 24 million people worldwide living with psychotic symptoms. A sample of 200 people could not possibly show reliable results for such a large population of patients. Next, the testing did not distinguish the difference between types of psychotic patients that display symptoms in their testing, whether the symptoms were natural or drug induced. Also, from the title of the article the author concludes that scientist can predict psychosis, but the results showed they were only able to predict seven out of ten patients would remain with the psychotic symptoms after a period of six years, which is not guaranteed but probable results.
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11/19/11
by Eugene Smith
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