Blood Tests for Schizophrenia
Schizophrenia can be a complex disease to diagnose.
Diagnosis relies on the subjective self-report of someone who may be in crisis, and someone who may have their own feelings about the experiences they are having and whether to share them. Self-reported symptoms can be culturally specific. Sometimes the doctor making diagnosis must rely on corroborating information from families or friends.
The symptoms of schizophrenia can vary quite significantly; the contents of hallucinations or delusions described as “schizophrenic” can be remarkably diverse – perhaps as diverse as the human imagination itself. The DSM distinguishes between a number of psychotic illnesses that seem to share features or overlap. These may include schizophrenia, schizoaffective disorder, psychotic depression, and post-partum psychosis. And finally, it can be difficult for professionals to identify the pre-illness phase; the “pro-dromal” period, when early intervention may take place.
Wouldn’t it be easier if we could just do a blood test?
Well, efforts to identify “biomarkers” of schizophrenia in blood have gone on, without much luck, for many years.
Recently, a team of scientists at the Baylor College of Medicine have sought to create just such a blood test. You can read about their research here.
They have been focusing on what are called “epigenetic factors”. Epigenetics is the “study of how cells control gene activity without changing the DNA sequence”. This means looking at how certain proteins inside cells “turn on” or “turn off” aspects of the DNA sequence. Research suggests the epigenetic factors can play an important role in developing schizophrenia.
Essentially, the researchers have been looking for chemical traces of epigenetic molecules present in the blood of people with schizophrenia, and not present in the blood of people without schizophrenia. The molecule they are looking for is one of the “methyl” chemical group. These molecules may exist for a long time before the illness is expressed, meaning the test could conceivably help predict whether a person will develop the illness, and allow for early intervention. Testing the blood test on an independent dataset revealed that it can identify schizophrenia patients with 80% accuracy, however the process and results of studies like this one must be rigorously re-tested and measured.
There is also an understandable scepticism amongst professionals about claims like this. Some professionals may feel that schizophrenia is an illness best identified through the process of discussing symptoms between patient and doctor. However, if biological data can improve diagnostic accuracy alongside these discussions, then perhaps simple blood tests may become part of diagnosing illnesses such as schizophrenia in the future.
Dr. Richard Schweizer, Policy Officer at One Door Mental Health richard.schweizer@onedoor.org.au.
To receive new blogs from Dr. Richard Schweizer subscribe to our eNews.
Dr Richard Schweizer