Throughout my graduate program, I completed many courses dedicated to teaching students how to identify, diagnose, and treat various mental health concerns. This was the bulk of the program, which makes sense given that this curriculum is vital to becoming a counselor.
From these courses, I learned how to recognize symptoms of diagnostic categories. This knowledge guides my differential diagnosis, meaning, once I narrow down the symptoms to one category, I compare criterion from a few related disorders to figure out which diagnosis fits best at that particular time. I also learned about treatment modalities, how to implement them, and how to select effective treatments for specific problems and clients. And I learned about types of assessments, when to administer them, how to score them, and how to relate them to the client’s situation.
So, this all sounds relatively comprehensive, right? Well there was one big question that never got answered. What is mental illness?
We knew types of mental illness, and we understood how a mental illness influences a person's thoughts and behaviors, but we really didn't have a definition for what makes up the entire basis of our careers. And while that seems somewhat backwards, let me explain why.
A single definition of mental illness that most practitioners agree on is nearly impossible because it is not observed in the same way as other medical illnesses. The way we can identify cancer is conceptually simple. We run some tests, take a few scans, and usually evidence of the disease is visible. This notion also applies to genetic disorders, such as Down’s syndrome, which can be detected through ultrasound tests prior to birth. (I am not implying that the tests themselves are easy to run or read, but the idea of a definitive “yes, you have signs of this disease” or “no, the tests came back negative” is what I’m referring to.)
But mental illness isn't measured that way. Diagnosis relies on the sound judgment of qualified clinicians.
So how do counselors identify disorders that we can't “prove”?
There are two main models that we use to conceptualize mental illness: the psychosocial model and the medical model. Proponents of the first theory argue that mental illness is a form of communication and does not exist in the same way as medically observable diseases. In the other field of thought is the medical model, which contends that mental illness can be explained as a disease of the brain and should be considered as any other medical disease.
Thomas Szasz is a libertarian psychiatrist and strong supporter of the psychosocial model. In an interview, he once said, “there are no mental diseases, only behaviors of which psychiatrists disapprove and call them ‘mental illnesses’,” (Wyatt, 2004, p. 73). This belief essentially suggests that while symptoms may exist, we cannot call them a “disorder” simply because they don't fit our idea of “normal.”
One problem with this belief is that there is, in fact, neurobiological support for certain mental illnesses. For example, schizophrenia is gaining traction in neuroimaging research. Some studies have demonstrated structural and functional abnormalities in the brain, such as enlarged ventricles and loss of cortical tissue (Buckley, 2005). Similar neuroimaging evidence was established for Attention-Deficit/Hyperactivity Disorder, showing deviations in the dopamine system using molecular genetic studies (Krause, Dresel, Krause, la Fougere, & Ackenheil, 2003).
These studies, along with hundreds of others showing similar results, would point to Szasz's statement, “if mental illnesses are brain diseases, we ought to call them brain diseases” (Wyatt, 2004, p. 73). Well, some researchers do (see Buckley, 2005, p. 193).
On one hand, Szasz does make a valid point that we have to diagnose mental disorders based on symptoms that are either self-reported from our clients or shared with us from concerned friends and family of clients. If they tell us “I can’t sleep”, or “I binge eat when I’m stressed”, or “I get distracted when I’m trying to work”, these are all behaviors. Even cognitive symptoms (negative thoughts, trauma flashbacks, suicidal ideation) are associated with physical experiences like increased heart rate, shortness of breath, nausea, etc. But all of these things rely on what our clients bring to us. That means that what they don't tell us (or what someone else doesn't tell us about the client's behavior), we have no way of knowing for sure.
On the other hand, we can look at two separate brain scans and–with no other information–distinguish which patient likely experiences symptoms of schizophrenia, ADHD, PTSD, as well as other disorders. Scientific American published an article a few years ago describing how neurological changes related to mental illness can be observed through these scans. If you're interested in learning more, read the literature about twin studies and genetics of mental illness.
Here is just one example of differences in brain chemistry and structure:
However, there are several challenges with relying on brain scans to show evidence mental illness. First is the issue of comorbidity (that is, having multiple diagnoses). Many clients do not fall into a single category. For instance, Psychiatric Times cites that prevalence of depression and anxiety as dual-diagnoses can reach up to 60%.
Another limitation of brain scans is early detection. While these scans may be useful for the purposes of researching mental illness, at this point in time, scans can only show brain abnormalities after the changes have already been made. At least in regards to preventative care, our current technology is not equipped to detect signs of future mental illness or recent onset of symptoms.
A third issue, and more philosophical in nature, is accuracy. If we have defined depression as chronic low mood, little interest in activities, social withdrawal, and fluctuations in appetite (just to list a few symptoms), and we have established how these changes impact neurological pathways or levels of hormones (e.g., lower serotonin secretion or absorption), then sure, we might see some evidence in brain scans. But diagnostic criteria are man-made, quite literally. We have constructed what anxiety means, and what bipolar means, and what a personality disorder means, all of which can constitute their own separate discussions. Of course when we decide what to look for, we find it.
Aboraya et al. offers evidence to support the legitimacy of criteria through several different models of diagnostic validity, including Robins and Guze’s (1970) proposal of a 5-phase classification, as well as Spitzer's (1983) focus on long-term evaluation based on available data. A take-away message from all of these models is that they each have benefits and limitations, as with most measures. In other words, there is some degree of legitimacy to diagnostic criteria–100 people suffering from depression are likely to share a number of symptoms–but we cannot rely whole-heartedly on the criteria written as the only truth to mental illnesses. (Again, this warrants its own separate discussion that I will address in a later post.)
So which is it? Are mental illnesses just groupings of symptoms or are they biological diseases?
The fact is, we still don't know for sure. We can be 99.999% confident, but the reality is that ten clinicians can look at the same patient and come up with eleven different diagnoses (a little psychology humor, but still true). For the most part, a client presenting with nightmares/flashbacks, trauma history, and avoidance symptoms will likely receive a PTSD diagnosis by all ten clinicians. But for more difficult cases, such as clients who report auditory hallucinations, but no other symptoms apart from traditional anxiety or depression, we have to dig a little deeper to identify what is going on.
It is necessary to understand the diagnostic criteria with which we identify clients, but an absolutely finalized definition of mental illness will likely never satisfy everyone. Having multiple fields of thought is helpful for advancing research, so I encourage the continued debate so long as it produces knowledge and healthy dialogue.
I hope that after reading this, you are curious to learn more. Since there is no one “right” approach to mental health, it is our duty as counselors, social workers, teachers, psychologists, psychiatrists, family, friends, and civilians to keep reading, keep questioning, and keep doing the best we can to help others and ourselves.
Have a question, comment, or want to share your perspective? Get in touch!
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Buckley, P.F. (2005). Neuroimaging of schizophrenia: Structural abnormalities and pathophysiological implications. Neuropsychiatric Disease and Treatment, 1(3), 193-204.
Krause, K., Dresel, S.H., Krause, J., la Fougere, C., & Ackenheil, M. (2003). The dopamine transporter and neuroimaging in attention deficit hyperactivity disorder. Neuroscience & Biobehavoral Reviews, 27(7), 605-613.
Robins E. & Guze, S.B. (1970). Establishment of diagnostic validity in psychiatric illness: Its application to schizophrenia. American Journal of Psychiatry. 126(7), 983–7.
Wyatt, R. C. (2004). Thomas Szasz: Liberty and the practice of psychotherapy. Journal of Humanistic Psychology, 44, 71-85. doi: 10.1177/0022167803261611