How Do We Know What Is Normal?

Medicine and psychiatry have not developed models that sufficiently acknowledge normal variations, and how these may relate to psychopathology. While normality can be defined in different ways, it is important to realize that people respond to life circumstances in ways that closely resemble mental disorders. The difference is that normal responses are either more transient, or reversible if circumstances change. The failure to recognize normative distress a leads to over-medicalization and over-treatment.

The DSM and Its Discontents

DSM-5 aimed to provide psychiatry with a more scientifically based classification system, based on neurobiology. However, this goal could not be achieved in the absence of more convincing data. This is why the manual is not dramatically different from its predecessors. Attempts to make diagnoses dimensional, to put them in spectra, and to relate them to changes in the brain are premature at our present state of knowledge. While the National Institute of Mental Health has developed its own system. However, we do not have the data at this point to develop a classification that would be consistent with neurobiology. Moreover, diagnosis need not reduce complex mental phenomena to a cellular or endophenotypic level.

Where Do We Go From Here?

The problem of overdiagnosis reflects physician biases, and the wish to explain complex clinical presentations. Overdiagnosis has also become part of a broader cultural trend in which all human problems are seen as requiring medical treatment. Evidence-based practice, accompanied by a tolerance of uncertainty, can help to reduce the frequency of this problem. The diagnostic manuals of the future will probably not look very much like DSM-5. I expect that they will be based on a deeper and more thorough understanding of disease. But that will take many decades, and we have to remain humble and patient.

How Major Is Major Depression?

Major depression, as defined in DSM-5, is not necessarily “major.” Its history can be traced back to a unitary theory of dépression in which all symptoms are seen as falling on a continuum. The danger is that sadness, if it lasts for any length of time, will be diagnosed as depression. This approach has supported treatment practices that are not evidence-based. Not all patients meeting diagnostic criteria can be successfully treated with antidepressant medication. Psychiatry cannot become a clinical science unless it can separate what is pathological from what is normal.

Overdiagnosis and Over-Treatment

Current neurobiological models of mental illness, accompanied by an increased use of drugs to control symptoms, tend to favor overdiagnosis. This trend has been supported by DSM-5. Yet it is often forgotten that diagnostic manuals are not a guide to treatment. The pigeon-holing of patients with a wide range of psychological symptoms into categories (such as bipolar disorder or ADHD) has been used to justify pharmacological interventions that have been empirically tested in clinical populations who have classical forms of mental disorder, as opposed to falling within spectra. The result is that treatments for this wider range of patients may or may not be valid.

Post-traumatic Stress Disorder

Post-traumatic stress disorder (PTSD) is a diagnostic epidemic affecting contemporary mental health practice. Overdiagnosis can lead to inappropriate treatment It does not lead to pharmacological treatment, but can be associated with misdirected psychotherapy. It is not widely understood that most psychological traumas, even severe ones, do not produce lasting symptoms. Patients who develop PTSD have previous vulnerability to mental disorder, and should not be seen as reacting simply to external évents.

Science, Philosophy, and Diagnosis

Mental disorders need not be seen as “real” in the same way as medical diagnoses. Current categories of mental disorder are not well validated, and can best be considered as heuristics. Overdiagnosis ignores these limitations, sometimes leading to diagnostic epidemics in which many different phenomena are seen as belonging to the same category. The use of DSM-5 as a gold standard has also distorted psychiatric epidemiology, which has been based on syndromal definitions rather than empirically validated categories. These concepts have made it all too easy to diagnose almost everyone with some form of mental disorder.

Other Disorders in Which Overdiagnosis Is a Risk

Other disorders that can suffer from overdiagnosis include autistic spectrum disorders, anxiety disorders, and mild neurocognitive disorders. Autism in particular threatens to become a diagnostic epidemic as patients with a wide range of symptoms are seen as falling in the spectrum. While there is no pharmacological treatment for this condition, disability payments can be an issue. Generalized anxiety disorder and mild neurocgnitive disorder are also quite broadly defined in DSM-5.In each case, it can be difficult to distinguish these conditions from other mental disorders or from normality.

Diagnosis in Psychiatry

Diagnosis in psychiatry lacks precision because disorders have fuzzy boundaries with each other and with normality. Validity is problematic because diagnosis is entirely based on signs and symptoms; there are no biological markers for any of the major mental disorders. Clinicians can under-diagnose or overdiagnose disorders, but the problem of overdiagnosis is more prevalent and more problematic. At the present state of knowledge, psychiatry does not need hundreds of diagnoses, only a few of which have established validity. Overdiagnosis is an attempt to short-circuit a process of scientific discovery that will require many more decades of research.

Personality and Personality Disorder

Personality disorders are difficult to distinguish from normal variations in personality traits. They tend to be under-diagnosed because of a focus on overt symptoms such as dépression or anxiety rather than on psychosocial or interpersonal dysfunction. There is also a danger of overdiagnosis, which has emerged from epidemiological research in which criteria have been too broad. The DSM-5 definitions of personality disorder are rather complex, both in their traditional form, and in an altérative model now included in Section III of the manual: many clinicians find them difficult to apply. There is also a tendency to favor diagnoses of mood disorders that are believed to be susceptible to psychopharmacological intervention.