Maggie Chenault
11/19/2014
English 202D-02
McAllister
Metacognitive Cover Note
I have written many college research papers before, but only for economics and
political science courses. Our class period with the reference librarian opened my eyes to
databases beyond JSTOR and EconLit. It also made me realize that even with academic
research papers, it can be helpful to start with popular news sources and work backwards.
This time, I began my research with ScienceDaily and found the first article about
my breakthrough there. This article included background information on depression and
references to the actual scientific study. I then consulted Google and found a few news
and magazine articles all about the same study. This was the only almost dead-end that I
reached. I was concerned that perhaps this was the only real experiment conducted so far
relating to my breakthrough.
In my best effort to be optimistic, after reading some different summaries and
interpretations, I went to Academic Search Complete and searched for that specific
scientific article. I widened the search by using search terms like blood tests for
depression, diagnosis of depression, adult depression, adolescent depression, and blood
analysis for mental illness. I began to find other papers relating first to blood tests for
depression in teens and then schizophrenia and bipolar disorder. I used an online medical
encyclopedia to supplement what I knew about these illnesses so I could better
understand the breakthrough.
My research proved to be relatively difficult because it is such a recent
development, but I have learned so much about a topic I knew very little about.
Mental Illnesses: In the Mind AND In the Blood?
Have you ever heard of that saying, “everyone knows someone?” It is a
commonly used phrase when advocating for awareness of cancer, epilepsy, eating
disorders, and many other diseases and illnesses. One instance where it is not used quite
as often is in referring to mental illness. Whether you know it or not, it is likely someone
you know is struggling with depression. According to the World Health Organization,
depressive disorders are the leading cause of disability in the world (Redei et al. 2014). In
the United States alone, 6.7% of the population is affected by major depressive disorder
(“First Blood Test to Diagnose Depression in Adults”). Depression is characterized by
feelings of sadness, indifference, change in weight, issues sleeping or oversleeping,
feelings of worthlessness, and thoughts of death that linger and interrupt patterns in
everyday life (A.D.A.M. Medical Encyclopedia). It is a serious widespread condition that
is only growing. As depression rates increase, medical professionals are researching
potential advancements in the field of treatment and diagnosis.
The current method of diagnosis for depression is subjective and based on vague
and generalized symptoms like mood, fatigue, and change in appetite (“First Blood Test
to Diagnose Depression in Adults”). Clinical interviews are an imperfect method of
diagnosis because depressed patients often underreport their symptoms. This can happen
when people are embarrassed or don’t clearly understand their own issues (“First Blood
Test to Diagnose Depression in Adults”). The way depression is diagnosed today is
similar to diagnostic methods used in medicine almost a century ago (Fawcett 2014).
In addition, overworked physicians might not have the training or time to properly
evaluate patients for major depressive disorder (Fawcett 2014). There is typically a 2-40
month delay in diagnosis and the longer people go undiagnosed, the most severe
untreated symptoms of mental illness become (“First Blood Test to Diagnose Depression
in Adults”).
Furthermore, researcher David Rosenham tested subjective diagnostic interviews
in an experiment where healthy subjects simulating hallucinations were admitted to
hospitals and ultimately diagnosed with mental illnesses (Tomasik et al. S82). This
experiment showed that interviews are not only unreliable, but can sometimes lead to
dangerously incorrect conclusions.
A stepping-stone breakthrough in mental illness diagnosis began with serotonin.
Serotonin transporter is a protein in cell membranes that enables the transport of
neurotransmitter serotonin and normalizes neural depression networks. Researchers at
MedUni in Vienna found that serotonin transporter in the blood works the same as it does
in the brain by regulating concentration of serotonin in blood plasma. There is a
relationship between the speed of the serotonin uptake and how depression functions in
the brain (“Depression is Detectable in the Blood” 2014). This revolutionary finding
suggested that something in the blood directly correlated to depressive disorder.
Dr. Eva Redei, professor of psychiatry and behavioral sciences at Northwestern
University, developed a test that can identify depression and predict who will benefit
from cognitive behavioral therapy by measuring levels of nine RNA blood markers
(“First Blood Test to Diagnose Depression in Adults”). These biomarkers include
antitrypsin, myeloperoxidase, soluble tumor necrosis factor receptor II, brain-derived
neurotropic factor, S100B, cortisol, epidermal growth factor, prolactin, and serum
acylation-stimulating protein (Kaplan 3). Researchers studied 32 participants from
Northwestern General Internal Medicine clinics over 18 years old that could speak
English and had a Hamilton Depression Rating less than 16 (Redei et al. 2014). The
Hamilton Depression Scale measures 21 mental illness symptoms (“Hamilton Rating
Scale for Depression”). Ten of the symptoms are answered on a scale of zero to four, nine
on a scale of zero to two, and two on a scale of zero to three (“Hamilton Rating Scale for
Depression”). Researchers then compared the depressed participants to 32 non-depressed
controls matched by age, race, and sex (Redei et al. 2014). Blood RNA was extracted
from the participants using PAXgene Blood RNA Kits and analyzed using NanoDrop
spectrometers (Redei et al. 2014). After the test, patients who had cognitive behavioral
therapy for a period of 18 weeks experienced biological changes in those markers (Main
2014). However, three of the nine RNA markers remained different in depressed patients
and non-depressed patients even after the depressed ones achieved remission through
therapy (Main 2014). These three markers in particular indicate a vulnerability to
depression regardless of whether or not a patient is currently experiencing symptoms.
Redei also developed a blood test that diagnosed depression in adolescents.
However, most of the markers studied in that test are different from ones in the adult
depression panel (“First Blood Test to Diagnose Depression in Adults”). Additional
markers must be analyzed in teens because they help to distinguish normal hormonal
changes from indicators of serious depression.
Early onset major depressive disorder is a type of depression that occurs only in
people under 25 years old (Pajer et al. 2012). 15% of women and 7% of men between
ages 13 and 18 have early onset depression (Welsh 2012). Early onset depression is
characterized by abnormal development, substance use, illness, social issues, and
suicidality (Pajer et al. 2012). Treatments do exist, but side effects of medication are
unpredictable and adolescents have less successful response rates than adults (Pajer et al.
2012).
Redei first worked out which genes are involved in the condition by comparing
gene expression in rats with depression to that in normal rats (Raffensperger 2012). Her
team analyzed 52 of these genes in blood samples from 28 teenagers ages 15-19, half of
who had depression (Raffensperger 2012). They discovered 11 blood markers that
differentiated between subjects with and without major depressive disorder (Pajer et al.
2012).
Additionally, they found 18 transcripts that distinguished between subjects
suffering from depression and anxiety from those without anxiety (Pajer et al. 2012).
Animal research from the Rudolf Magnus Institute of Neuroscience in the Netherlands
has linked anxiety to low levels of magnesium in the brain (Read My Blood 16).
Researchers suspect manipulating magnesium levels may address some symptoms of the
disorder (Read My Blood 16). The test Redei and her team developed can detect
depression in 90% of people and could be largely beneficial since only 25% of depressed
teens are currently being treated (Welsh 2012).
Overall, blood tests are generally accurate and affordable and safer than extracting
tissue samples (Read My Blood 16). Blood tests for mental illness are more objective
than currently used diagnostic interviews (Verma, Kaur, Davis 1612). They would be
especially beneficial in rural communities where mental health professionals are rare and
diagnoses are even more backed up (Verma, Kaur, Davis 1612).
Even though blood tests could be extremely useful and seem to be reliable,
doctors must consider other mood disorders when interpreting depression results because
many conditions share overlapping symptoms (Verma, Kaur, Davis 1612). “Be hopeful,
but be skeptical and patient,” says Stephen Glatt, psychiatrist at SUNY Upstate Medical
College (Read My Blood 16). Scientists have recently started developing targeted blood
tests for other mental illnesses in an attempt to reduce uncertainty about results. One of
the latest illnesses to be studied through blood analysis is Schizophrenia.
Schizophrenia is considered primarily a brain disorder, but is now also regarded
as a systemic disorder because markers of the illness have been found in cerebrospinal
fluid and liver and skin cells of patients (Tomasik et al. S80). Blood is a promising
investigative tool for this particular illness because it carries molecules that regulate both
central and peripheral functions (Tomasik et al. S80). The National Institute of Mental
Health estimates 2.4 million American adults suffer from schizophrenia and fewer than
half of those receive the antipsychotic medication or psychological help they need (“The
Latest News in Hematology” 34).
The term schizophrenia was introduced in 1911, but took the better part of a
century until it was officially classified as a disease in the Diagnostic and Statistical
Manual of Mental Disorders (Tomasik et al. S79). There are five subtypes of
Schizophrenia including paranoid, disorganized, catatonic, undifferentiated, and residual
(Tomasik et al. S79). The illness is characterized by hearing voices, paranoid thoughts,
nonsensical speech, and lack of ability to care for self (A.D.A.M. Medical Encyclopedia).
Schizophrenia has three main types of symptoms: psychotic, negative, and cognitive.
Psychotic symptoms like delusions and hallucinations distort thinking. Negative
symptoms make it difficult to show emotion and function normally. Cognitive symptoms
cause difficulty making decisions and paying attention (A.D.A.M. Medical
Encyclopedia).
Blood tests offer an accessible and efficient alternative to brain tissue samples or
interviews in diagnosing Schizophrenia. Researchers attempted to identify a
schizophrenia specific signature by comparing molecular profiles in serum from
schizophrenic patients with matched controls. They used a high immunoassay platform
targeting 181 blood molecules to develop classifiers that could discriminate
schizophrenic patients from controls with 83% accuracy (Tomasik et al. S81).
After this preliminary research, Professor Sabine Bahn, Director of Cambridge
Centre for Neuropsychiatric Research and Director of Psynova Neurotech Ltd.,
developed a test for the disorder called VeriPsych (Kaplan 1). It is the first blood based
diagnostic test to confirm recent onset schizophrenia (Kaplan 1). VeriPsych uses a blood
sample to identify 51 protein biomarkers and has a success rate of 85% (Kaplan 1). Most
physicians agree the test could help diagnose, but may not be worth the cost of $2,500
(Tomasik et al. S82). However, some insurance companies are already covering the test.
This could be in part because according to the Food and Drug Administration, biomarker
research will be one of the main factors driving psychiatric drug development in the next
50 years (Tomasik et al. S80).
Bipolar disorder has recently been studied as well, but to a lesser extent than other
mental illnesses. Bipolar disorder is characterized by unusual mood swings between
mania and depression (A.D.A.M. Medical Encyclopedia). Alexander Niculescu at the
Indiana University School of Medicine scanned genetic patterns in people with high
mood, low mood, and average mood (Motluk). He scored each gene to form a panel of
the ten strongest ones and created a blood test to discriminate between highs and lows in
people with bipolar disorder (Motluk). The test was able to predict emotions with 80%
accuracy (Motluk). At this point, Niculescu’s test simply communicates the stage of the
illness a patient is experiencing at a particular time.
“Part of the reason there’s a stigma for mental illness… is that people think it’s
only in their heads,” Redei says (Weil 2012). As long as there is no measurable sign of
sickness, some people may continue to be skeptical of the reality of depression, anxiety,
schizophrenia, and bipolar disorders. Blood tests could help to legitimize the seriousness
of these mental conditions. Along with providing a type of “biological evidence” to the
people on the outside looking in, Lonna Williams, C.E.O. of Ridge Diagnostics, says
blood tests will help patients themselves in understanding mental illnesses are not their
fault (Weil 2012).
Works Cited
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2014.
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12 Nov. 2014.
<http://www.sciencedaily.com/releases/2014/09/140917121229.htm>.
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2014.
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