Why Does the DSM Exist?

DSM can guide with diagnosis, but the patient always comes first.

Source: Luis Fernandes/Pexels

Why do psychiatrists, psychologists, and others seek to “diagnose” specific mental disorders? Isn’t everyone unique? Isn’t it hugely unlikely that anyone’s particular psychological distress will map onto “one-size-fits-all” categories delineated by committees? Whose interests are really served by elaborate diagnostic systems such as the American Psychiatric Association’s controversial Diagnostic and Statistical Manual (DSM)?

The DSM presents lists of symptoms that need to be present to a specified degree of severity for a specified period of time in order for a given diagnosis to be made. For example, a DSM diagnosis of “major depressive disorder” requires five or more out of nine key symptoms, for more than a fortnight, and this must represent a change from previous functioning.

The nine key symptoms are depressed mood, reduced pleasure or interest, significant weight change, sleep disturbance, feeling physically agitated or slowed down, fatigue, feelings of guilt or worthlessness, reduced concentration and recurring thoughts of self-harm, suicide or death.

While this list of symptoms appears logical and reasonable, and accords with most people’s idea of “depression,” a fundamental question still arises: why are such lists of symptoms needed in the first place? Do they not reduce complex, changeable human states to lists and diagnostic codes, removing the humanity, complexity, and beauty of each person, replacing them with cold, impersonal categorization? Are diagnostic systems simply tools for the “invention” of new mental illnesses and the marketing of new pharmaceutical products?

These are all valid concerns, but judicious diagnosis is still important for four key reasons.

First, diagnosis creates a common language for sharing experiences of mental disorders. How? Diagnosis of most mental disorders is based primarily on the person’s history and symptoms rather than biological tests such as blood tests or brain scans. As a result, it is necessary to identify clusters of symptoms that commonly occur together, in order to ensure some consistency in clinical diagnosis.

In other words, if mental disorders are ever to be understood, it is necessary that when someone in the US mentions “panic disorder” they know they are talking about roughly the same thing as someone in Denmark or China who mentions “panic disorder.” We need to be able to talk about it, in order to reach out.

Second, diagnosis makes it possible to study new treatments for mental illnesses. When people present to mental health services, it is necessary for healthcare professionals to have some guide as to which treatments will best address particular collections of symptoms. Diagnosis and classification are necessary in order to perform research studies and clinical trials to collect evidence about the best treatments for these collections of symptoms.

Third, diagnosis facilitates the study of the causes of mental disorders. If research in Peru links depression with poverty, we need a common concept of “depression” if we are to investigate similar links in Canada. Of course, each individual case is different, but there is also significant commonality. Understanding these commonalities helps identify patterns and, hopefully, causes.

Fourth, diagnosis protects human rights. Most countries have laws that permit involuntary admission and treatment of people with severe mental disorders when they present a serious risk to themselves or others. These laws affect only a small minority of patients, but there is still a strong need for as much clarity as possible about diagnosis in order to ensure appropriate intervention, treatment, and accountability.

Other potential benefits of diagnosis include reducing stigma, alleviating the blame or guilt that individuals or families may feel, guiding patients and families in choosing treatments, and assisting with the creation of networks of people and families affected by similar symptoms.

The media commonly describe DSM as the “psychiatrists’ bible,” despite the fact that DSM warns sternly against “tick-box” diagnosis. Nonetheless, the description is not entirely without truth: the majority of people in most religious traditions engage with their “bible” or scripture in a highly nuanced fashion, taking certain sections literally, interpreting other sections metaphorically, and completely ignoring other sections. It is useful, sensible and necessary to look at DSM in a similar fashion.

DSM can guide with diagnosis, but the patient always comes first.