The Meaning of Mental Illness and Disorder

Mental Disorder

A while back, I read an online essay by David B. Feldman, titled: “Is Mental Illness Real?” The subtitle reads: “Some psychologists argue calling emotional difficulties ‘illnesses’ is nonsense.” I have been thinking a lot about the concept of mental illness and wanted to engage this piece, as a way into debates about the meaning of mental illness and disorder. My primary focus here is the issue of mental health diagnosis: what does it really tell us? I am also choosing to focus on the more common mental illnesses – roughly, anxiety and depression – as I believe there are important differences between these, and other disorders that are perhaps more biologically defined (e.g. neurocognitive disorders, Schizophrenia, etc.).

Diagnosis: Causal Explanation vs. Description

There is no debate about whether psychological symptoms are real, or that people truly suffer, suggests Feldman. “The question is whether it makes sense to refer to these experiences as ‘illnesses’ in the same way we think about HIV, cancer, or even the flu.” Feldman describes how psychologists diagnose mental disorders, according to subjective symptoms, duration, impairment in functioning, and so on. He points out important differences between this, and diagnosis as it pertains to a physical illness or disease, typically defined by their causes (or, empirically objective and verifiable physiological criteria, it might be better to say, since the causes of many diseases are still unknown).

Feldman explains that because a mental illness diagnosis is primarily based on subjective symptoms (and behavioral signs observable to others), it can only offer a description, as opposed to a causal explanation for why this person may be exhibiting the symptoms they have.

“This doesn’t mean that mental illnesses have no causes – clearly both important environmental as well as genetic factors are often involved – but a diagnosis by itself doesn’t tell you what those causes are, which could differ from case to case.”

These are crucial points that are sometimes lost on the layperson, and even overlooked by some mental health professionals who are overly enthusiastic about an all-encompassing medicalized conceptualization of mental illness. Up to this point, I am largely in agreement with Feldman. However, some curious issues arise when he goes on to defend the necessity of DSM-style diagnostics.

DSM-style Diagnostics & the Heterogeneity of Mental Disorders

Feldman gives the following account of the history of clinical psychology and the development of a unified diagnostic system:

“When mental health professionals began diagnosing mental illness about a hundred years ago, it was on the basis of the causes or etiologies of those illnesses, just like for physical diseases. Given the state of the science at that time, however, there was a big problem: Nobody could agree what the causes of any particular disorder were. The field was splintered into different schools of thought. … As a result of all of this disagreement, diagnosis was unreliable. If you went to three mental health providers complaining of the exact same problem, you would likely receive three different diagnoses. To remedy this situation, with the publication of the third edition of the DSM in 1980, the American Psychiatric Association changed over to the current, much more reliable, symptom-based system.”

Feldman is correct to say that clinical psychology encompasses divergent and often conflicting conceptual communities. Each theoretical framework has its own internal logic and research base, offering a different explanatory (i.e. causal) account for mental illness, alongside a rationale for therapeutic intervention (Walsh et al., 2014). While true, it is perhaps misleading to say that the resulting situation was one where “nobody could agree what the causes of any particular disorder were.” Agreement certainly existed (and continues to exist) within a conceptual community; it is largely between disparate theoretical frameworks where disagreement largely occurs.

Although I agree with much of what Feldman says, his brief overview of the history of psychodiagnostics is a somewhat Whiggish interpretation, suggesting that these fractured disagreements could be avoided, or were on the road to being resolved, through the advent of current DSM-style diagnostics. Yet it is unclear how the DSM could ever hope to do so. Recall that the DSM is descriptive; it does not reference an objective physical entity or occurrent process (as is typically the case in medicine), nor does it offer a causal or explanatory account for why a given person presents with the symptoms they do. For this we need the assistance of a theoretical framework (Cognitive-Behavioral, Psychodynamic, Existential, etc.), which serves as an interpretive lens for understanding psychological phenomena. On its own, the DSM cannot offer the kind of causal explanation that would point toward specific interventions or treatments.

DSM Diagnoses and Clinical Utility

Clinical Diagnosis

Nevertheless, the hope was that we could use our descriptive DSM categories (based on behavioral signs and subjective symptoms), and conduct experimental research to determine which theoretical framework or treatments (e.g. SSRI medications, Cognitive Therapy, Behavioral Therapy) work for a given disorder (e.g., Major Depressive Disorder, Generalized Anxiety Disorder, etc.). Some argue that this approach is parallel to that seen in physical medicine, where diagnoses are sometimes made, and effective treatments developed, without knowing the cause of the illness. A medical diagnosis may thus lack a causal explanation, though the diagnostic label maintains some validity and has clinical utility.

Yet the parallels between physical medicine and psychiatry are far from analogous. Even if medical diagnoses lack a causal framework, objective physical criteria nearly always define an illness category. So, while it is true that Crohn’s disease has no known cause, it nonetheless references a clear physico-anatomical process (chronic inflammation of the intestines) that can be confirmed by empirically objective means (e.g. colonoscopy and biopsy). Indeed, the medical diagnosis seems to have at least a modest identity relationship with the physiological criteria, such that one might say that “Crohn’s disease is chronic inflammation of the intestines.” There is nothing comparable as it relates to the most common mental illnesses.

To summarize, a medical diagnosis may or may not involve visible signs and subjective symptoms, but it nearly always refers to, and is primarily defined by, some generalized physiological entity or process. Psychological diagnoses, in contrast, typically reference signs and subjective symptoms. And while we might argue that mental disorders are still, in a sense, ‘objective,’ it is of a different sort – an intersubjective objectivity, held together by social convention and consensus within specific professional groups (e.g. the DSM Task Force). Thus, mental illnesses qua DSM disorders, are not so much ‘discovered,’ as they are voted into existence by a select group of mental health professionals. So, while a medical diagnosis (e.g., Crohn’s disease), refers to third-person confirmation of a physiological entity or process (e.g. colonoscopy, inflamed intestines), a psychological diagnosis, such as Major Depressive Disorder, is confirmed when someone answers “yes” to 5 of 9 questions in a book called the DSM.

I should mention that while medical diagnoses nearly always refer to a physiological entity or process, there are rare exceptions: fibromyalgia, chronic fatigue, restless legs syndrome, and irritable bowel syndrome, all are medical conditions, without known causes or distinguishing physico-anatomical criteria. Despite this, treatments have been developed, tested, and experimentally validated. Is this evidence against the claim that there is no meaningful difference between medical diagnoses and mental disorders? I think what we have here are a handful of conditions, that do not represent paradigm cases, but are rather exceptions to the general rule of medical diagnostics. In defense of this interpretation is the fact that these diagnoses are primarily diagnoses of exclusion. In other words, these diagnoses are often given after ruling out diagnoses with known physiological criteria. Another possibility is that in *some* cases, these diagnoses are manifesting along a fuzzy continuum that borders on, and perhaps crosses into, the realm of mental illness (note that some of these conditions appear to benefit from psychotherapy; e.g., Abbass, Kisely, & Kroenke, 2009).

Competing Conceptual Frameworks

Feldman contends that descriptive DSM-style diagnostics will assist in directing research and treatment – helping us overcome disagreement between opposing theoretical camps. But this claim is undercut by the fact that many competing and even contradictory conceptual frameworks, have been ‘empirically-validated’ for treating the same DSM disorders (e.g. Ladouceur et al., 2000; Keefe, et al., 2014). This means that the psychological difficulties experienced by someone diagnosed with Generalized Anxiety Disorder (GAD), may be conceptualized, and treated quite differently, depending on the theoretical commitments of the therapist.

A traditional Cognitive-Behavioral Therapist (CBT), for example, presumes that psychological problems result from the person’s cognitive appraisal of a situation: how they mentally construe their experiences. From this model, personal experiences are interpreted within the framework of various cognitive schemas, which are usually implicit, and serve as the ground for specific ‘automatic thoughts’ that in turn produce complementary emotional and behavioral responses. The CBT therapist will focus on ‘negative’ automatic thoughts that are presumed to maintain the clients distressing symptoms. Cognitive introspection is an important part of CBT, and the therapist will often instruct the client to report on their thoughts without interpreting them. This is facilitated by assigned homework and the encouragement of note-taking and journaling. The therapist helps the client identify and challenge emotion-eliciting automatic thoughts and ‘cognitive distortions,’ such as tendencies toward catastrophizing, overgeneralizing, jumping to conclusions, and so on. The client learns to better monitor and control their dysfunctional (i.e. irrational) thinking, which can often settle distressing anxiety or feelings. As suggested, a great deal of research demonstrates that CBT is effective in reducing the severity of symptoms associated with DSM disorders such as GAD (e.g. Borkovec & Costello, 1993; Ladouceur et al., 2000).

Halifax Psychologist and Depressed ManThe same symptoms or DSM diagnosis would be conceptualized and treated quite differently, if the therapist were working from a model of Short-Term Dynamic Psychotherapy (STDP). In this case, psychological distress is often hypothesized to result from repressed emotions. Presumably, sometime in the client’s history, they sensed a bodily intuition that strong emotional experience(s) might exhaust their ability to cope; so, without being aware of it, the client began engaging in various ‘defense-mechanisms’ (e.g. denial, dissociation, projection, intellectualization, etc.) to avoid experiencing the threatening emotion. Although this process allowed them to cope at a time when it might have been necessary, it may have led to other psychological or interpersonal problems. Anxiety, which is the body’s ‘threat-detection’ mechanism, is usually interpreted by the therapist as a signal: identifying the proximity of a conflicted thought, feeling, or experience. In therapy, the psychologist asks questions about the client’s difficulties, noting and eventually challenging defenses that prevent the client from fully engaging with parts of their experience. The therapist encourages the client to notice their own avoidance patterns, while putting gentle pressure to stay with their experience, tolerating anxiety long enough to break through into the repressed feeling, which provides relief from the anxiety and crippling defenses; this is followed by a process of ‘working through’ relevant feelings and interpreting them within the context of the client’s life-narrative and significant experiences. As with CBT, STDP has been an ‘empirically validated’ treatment for those diagnosed with GAD and similar disorders (e.g. Keefe et al., 2014; Leichsenring, et al., 2014).

Feldman claimed that in the early history of psychological assessment and treatment, “nobody could agree what the causes of any particular disorder were.” But that statement is obviously still true today. Therapists continue to work from different theoretical frameworks. These frameworks arguably have equal or comparable empirical evidence, though proponents of such models disagree about what causes or maintains ‘mental illness,’ and about the best form of treatment.

For example, proponents of CBT will often point to the fact that their model has been the most heavily researched and has been subjected to a greater number of Randomized Controlled Trials (RCT’s), which many consider to be the ‘gold standard’ of psychotherapy research. Such therapists will often imply that by comparison, dynamic therapists operate more on intuition and subjective opinion, than empirical evidence. Conversely, a dynamic therapist may accuse the CBT therapist of conflating symptoms and cause, and of relying on generalized and heavily abstracted low-resolution data to justify an approach that does little more than help a client achieve relief through overreliance on defense mechanisms – particularly rationalization and intellectualization – to better manage surface symptoms. The point here, is to suggest that disagreement still exists, and that the mainstream diagnostic systems (e.g. DSM, ICD), and the research based on them, have done little to settle the matter.

Diagnostic Reliability and Utility

Feldman claims that the most unfortunate effect of the disagreement between the divergent conceptual communities, was that explanatory diagnoses were unreliable (when comparing across conceptual frameworks with divergent causal assumptions). The issue of reliability, he suggests, is one of the main reasons why we were correct to shift the focus from diagnosis based on causal explanations, to diagnosis based on descriptive symptoms. But does the shift away from explanation not then make the diagnosis less informative? Feldman does not think so.

“A diagnosis accomplishes two very important things. First, it helps direct the therapist toward what treatments work for that disorder. As a psychologist, if I know that my patient has the particular combination of symptoms that would allow me to diagnose Major Depression or Panic Disorder or Obsessive-Compulsive Disorder, I can turn to the empirical research about what techniques have helped others with that diagnosis in the past, rather than reinventing the wheel each time. Personally, if I were a patient, I’d want to know that what my therapist were doing was something that had been shown to work for others with problems similar to my own. As such, diagnostic labels facilitate an evidence-based approach to treatment.”

Earlier, Feldman agreed that DSM diagnostics cannot offer a causal account of a mental illness (only a description of subjective symptoms), yet he maintains that the diagnosis can help direct “what treatments work for that disorder [emphasis added],” based on the available research. As already explained, we cannot simply rely on the DSM diagnosis, then turn to the research to decide the best form of treatment, since there are still multiple ‘empirically validated’ treatments to choose from, each with different and sometimes contradictory causal assumptions.

Moreover, the argument once again presupposes the ontological validity of the DSM-style ‘disorder.’ For example, when Feldman says he is concerned about ‘what treatment works for that disorder,’ he assumes that the decontextualized and causally unexplained disorder should now be the target of treatment, as opposed to a more holistic account, involving the contextualized person. We should not forget that the ‘disorder’ is nothing more than a generalized and highly abstract designation based on clusters of symptoms. It is not the kind of entity that could be conceived independently of the first-person experiencer, embedded within a world of interpersonal relationships (being-with-others), familiar ways of feeling, and a sociohistorical and culturally-defined significance structure (worldhood); this is the situated context within which a person understands him or herself – we therapists should try to understand our patients within those same terms.

Paralleling medicine, DSM diagnostics also assume a kind of reductionism, where the disorder is presumed to reside primarily within the individual. Mental health professionals do not typically interview friends and family members, to better understand interpersonal dynamics that may partly explain a client’s presenting symptoms. We tend to ignore or overlook power imbalances within the various social structures that constitute the world of the patient. And because we are so often caught up in them ourselves, we are nearly blind to cultural maladies that could be bearing their weight upon the clients we try to help.

As the mainstream thinking goes, the psychotherapist is supposed to ask: “based on my client’s symptoms, what disorder do they have, and what treatment would work for that disorder?” These are the wrong questions, in my opinion. Instead, we should ask: “why is this particular person, at this particular time in their life, struggling with these particular problems?” Once we have some beginning understanding of the situated individual and have confirmation from the client that they indeed feel understood, we are in a better place to decide upon which conceptual framework (i.e. therapeutic ‘treatment’) best addresses the client’s difficulties.

Feldman says that if he were the patient, he’d want to know that his therapist was doing something that had been “shown to work for others with problems similar to my own.” Yet he seems to conflate the concept of ‘diagnosis’ with that of a ‘psychological problem.’ Unless one is in the business of mere symptom management, a problem should be conceptualized according to the client’s lived experience, and in the light of a possible explanation – something that a DSM-style diagnosis cannot provide. In other words, a ‘problem’ should not be understood as stand-alone symptoms, since two people with the same diagnosis may have very different problems, requiring two entirely different forms of treatment.

An example may illustrate the point. Suppose two different people come to therapy with a DSM diagnosis of GAD. The first, is a woman constantly on the edge of being overwhelmed by emotion and anxiety. Her thoughts are frequently racing; she cannot slow them down long enough to reflect on her experiences. She seems to have many caring supports, though friends and family cannot seem to talk her down when she gets worked up about any number of things. This person may not be ready, or, might be so dysregulated as to be unable to make use of an emotion-focused approach. Instead, she might benefit from a CBT-style approach, focusing first on practical exercises to de-escalate cycles of panic or emotion-dysregulation. This might be followed by a cognitive focus that will also help her ‘detach’ (i.e., intellectualize) a little bit from the raw phenomenal experience. It could help her build a capacity for putting words to her experience, notice the power of her own agency and thinking, and ultimately develop some top-down cognitive control that will help ground her.

The second person is a middle-aged man who also meets criteria for GAD. He spends a great deal of time in thought and regards the expression of vulnerable feelings (e.g. sadness, loneliness) as a senseless activity. He has friends, but he does not talk to them about matters that he considers ‘too personal.’ His anxiety apparently manifests suddenly and without explanation, but he can also discern patterns of thought where he is prone to irrational thinking, such as having overly perfectionistic ideals, or sometimes assuming something bad will happen without reason. Much of the time he experiences bouts of panic or anxiety without being able to identify a thought at all. The client appears emotionally flat and almost detached in most of the therapy sessions. Some preliminary inquiries into possible problems (e.g. recent death in the family), cause him to change the topic (avoidance) as well as experience mild tension and anxiety. The therapist suspects that he tends to think about his feelings, as opposed to feel them, and that this may be an important part of what maintains his anxiety. A cognitive approach would certainly play to this client’s strengths (i.e. abstract thinking) and area of comfort (avoidance of feelings or interpersonal intimacy), but it is unlikely to get to the root of his issues. In this case, an emotion-focused dynamic approach might prove more beneficial.

Based on the above, we can begin to see that the ‘disagreement’ between theoretical communities is less of an issue, when we focus on the contextualized person, as opposed to a generalized diagnosis. In such cases opposing theories may complement one another … offering different explanatory possibilities, depending on the person the therapist is working with, or perhaps even depending on the stage of the therapy. Therapeutic utility is thus less ‘disorder specific,’ than it is ‘person-situation specific.’

Reliability and Clinical Utility

I suspect that some people, like Feldman, emphasize diagnostic reliability (perhaps to the detriment of conceptual clarity?), because it would make it easier to generalize our concepts across a greater number of individuals, making it more amenable to certain kinds of research (e.g. Randomized Controlled Trials or RCT’s) that have the appearance of scientific credibility. However, advocating a DSM-style diagnostic system, for the sake of ‘reliability,’ may obscure our explanatory understanding, as well as our ability to help those who need it.

If I were the patient, I would prefer a therapist help me address whatever is the cause of, or identify what was maintaining my problems, as opposed to having my issues decontextualized and framed according to symptom clusters that fit the DSM-style diagnostics.[1] This approach might make sense if we could assume that the DSM categories were homogeneous, with a similar causal structure. But diagnostic categories are quite heterogeneous, possibly necessitating different forms of intervention (e.g. Fernandez, 2014; Malhi et al., 2005; Parker, 2006).

An accurate understanding of a single instance of mental illness, arguably necessitates attending to the situated or contextualized person. The sort of context I have in mind, is perhaps less relevant in medicine, where we are dealing with generalized biophysical causal laws. But psychological problems are arguably nothing like that – more than event-driven biophysical mechanisms, we are self-determining agents embedded within a sociocultural significance structure. Understanding this will go a long way to making sense of how mental illnesses are unlike physical illnesses, and in what sense we should consider them ‘real.’

I believe that part of the desire to refer to mental illnesses as ‘brain diseases,’ has to do with the worry that the alternative implies that they are not ‘real,’ which would add to the stigma surrounding mental illness. This concern is unwarranted, in my opinion, and likely based on dubious metaphysical assumptions (ontological and causal). We can consider mental illnesses real without naturalizing them; we needn’t claim that they can be reduced to some physical process (best treated by a medical doctor), or, as something that exists independently of first-person experience, convention, and untouched by sociocultural opinions or values.

For all the reasons outlined, in my own clinical practice I typically avoid DSM diagnostics. I am in good company. Celebrated master psychotherapist, Irvin Yalom, likewise advocates avoiding diagnosis, unless there is a need within a medical setting to communicate cross-professionally, when dealing with severe mental health issues that might have a clearer biological substrate, or when required by insurance companies or other agencies as a superficial way of determining who gets treatment. Yalom (2002) has some important words of wisdom:

“A diagnosis limits vision; it diminishes the ability to relate to the other as a person. Once we make a diagnosis, we tend to selectively inattend to aspects of the patient that that do not fit into that particular diagnosis, and correspondingly overattend to subtle features that appear to confirm an initial diagnosis. … we must tread a fine line between some, but not too much, objectivity; if we take the DSM diagnostic system too seriously, if we really believe we are truly carving at the joints of nature, then we may threaten the human, the spontaneous, the creative and uncertain nature of the therapeutic venture” (p. 5).

The most common mental illnesses (e.g., anxiety, depression) are not ‘real’ in the sense that we can point to some physical entity or process, such as a chemical imbalance or brain disease. They are real in the sense that people endure severe and protracted psychological suffering, and that we need some way to talk about it. The DSM offers one way to describe that suffering. Yet if we wish to be maximally helpful, to as many people as possible, a strong case can be made for moving beyond it. By developing a genuine understanding of the contextualized person, we may open ourselves to new possibilities, such as individually-tailored (i.e., non-manualized) therapies that help people work through and out of their psychological suffering.

[1] Again, there may be notable exceptions, where the descriptive symptoms are quite informative on their own. Examples, include the developmental disorders, schizophrenia, neurocognitive disorder, and so on.


Abbass, A., Kisley, A., & Kroenke, K. (2009). Short-term psychodynamic psychotherapy for somatic disorders. Psychotherapy and Psychosomatics, 78, 265-274.

Borkovec, T. D., & Costello, E. (1993). Efficacy of applied relaxation and cognitive-behavioral therapy in the treatment of generalized anxiety disorder. Journal of Consulting and Clinical Psychology, 61(4), 611-619.

Fernandez, A. V. (2014). Depression as existential feeling or de-situatedness? Distinguishing structure from mode in psychopathology. Phenomenology and the Cognitive Sciences, 13, 595-612.

Gupta, M. (2014). Is evidence-based psychiatry ethical? Oxford University Press.

Keefe, J. R., McCarthy, K. S., Dinger, U., Zilcha-Mano, S., & Barber, J. P. (2014). A meta-analytic review of psychodynamic therapies for anxiety disorders. Clinical Psychology Review, 34, 309-323.

Ladouceur, R., Dugas, M. J., Freeston, M. H., Leger, E., Gagnon, F., & Thibodeau, N. (2000). Efficacy of a cognitive-behavioral treatment for generalized anxiety disorder: evaluation in a controlled clinical trial. Journal of Consulting and Clinical Psychology, 68(6), 957-64.

Leichsenring, F., Salzer, S., Beutel, M. E., Herpertz, S., Hiller, W., Hoyer, J., Huesing, J., Joraschky, P., Nolting, B., Poehlmann, K., Ritter V., Stanier, U., Strauss, B., Tefikow, S., Teismann, T., Willutzki, U., Wiltink, J., & Leibing, E. (2014). Long-term outcome of psychodynamic therapy and cognitive-behavioral therapy in social anxiety disorder. American Journal of Psychiatry, 171(10), 1074-1082.

Malhi, G. S., Parker, G. B., Greenwood, J. (2005). Structural and functional models of depression: from sub-types to substrates. Acta Psychiatrica Scandinavica, 111, 94-105.

Parker, G. (2006). Through a glass darkly: The disutility of the DSM nosology of depressive disorders. Canadian Journal of Psychiatry, 51(14), 879-886.

Walsh, R. T., Teo, T., & Baydala, A. (2014). A critical history and philosophy of psychology. New York, NY: Cambridge University Press.

Yalom, I. (2002). The gift of therapy: An open letter to a new generation of therapists and their patients. New York, NY: Harper Perennial.

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