Differential diagnosis of ADHD in adults
Differential diagnosis is a term perhaps most associated in pop culture with the character of Dr. Gregory House, a stylized modern-day Sherlock Holmes-like brilliant physician-diagnostician working at the fictional Princeton-Plainsboro Teaching Hospital. And while the serialized process of diagnosing disorders portrayed in "House" is a bit too sensationalistic, it captures the core idea of a diagnostic approach focused on reliability and accuracy.
It is by no means the case that differential diagnosis is something different or separate from standard clinical psychological diagnosis, i.e., one that deals with mental health and functioning. Rather, it is a part of it, a necessary step or facet of the process, allowing for the organization of the information gathered and the formulation of the most appropriate conclusions possible. It is the case with many mental health disorders (if not every disorder) that they share some of their symptoms with other individuals. The diagnostician should therefore not only determine which symptoms are actually present in the client's daily functioning, but also identify their actual basis by eliminating other possibilities by pointing out key elements of the proposed disorders that are not apparent in the collected data.
This kind of analysis can be presented using the example of admiring a painting or other work of art in an art gallery - in order to answer the question of what trend it belongs to, we identify its features and compare them to those characteristic of specific schools in terms of the choice of color palette, materials used, perspective adopted, subject depicted, time of creation, social context, etc., while keeping in mind that each artist has a unique style, just as we ourselves are undoubtedly more than the sum of our experiences or the diagnosis given to us.
In other words, the point of differential proceedings is not to look only for arguments "for" a given diagnosis (which can lead to serious errors), but also to invent alternative explanations of the difficulty under consideration and then rule them out.
So why is differentiation in the diagnosis of ADHD so important? Unfortunately, according to a growing number of scientific publications appearing in recent years, we are beginning to see "overdiagnosis" (and misdiagnosis) of various disorders, including ADHD in particular (Kazda et al., 2021; Merten et al., 2017), but also autism spectrum disorders (Ulbricht, 2024) and others (Dyck, 2019).
Certainly, receiving a diagnosis has many benefits: first of all, it is an opportunity for a person to learn the cause of the difficulties he or she is experiencing. Diagnosis also helps in selecting the right forms of support for the client (including pharmacotherapy and psychotherapy), and enables the person to find a community of other people facing a similar situation and exchange experiences. However, it is not a neutral service - the feedback one receives at the end of the diagnostic procedure often has a great impact on one's own perception of oneself, but also that of others; it also happens that some institutions and workplaces (e.g., the military, police, etc.) prefer job candidates without psychiatric diagnoses. In addition to this, unfortunately, people facing named mental health difficulties are still sometimes socially discriminated against and stigmatized.
Nevertheless, as mentioned earlier, simply receiving a diagnosis carries a therapeutic benefit and opens up new possibilities for improving one's mental health. The responsibility of the diagnostician, in turn, is to make the diagnosis as accurate as possible.
Attention-deficit hyperactivity disorder, or ADHD, is characterized by symptoms on the one hand belonging to the group of hyperactivity, and on the other concerning cognitive functioning, i.e. processes of attention, impulse control, memory, planning, etc. As we get older, we "learn" to compensate for or mask certain behaviors, so the picture of ADHD in a child and an adult can differ significantly (Kooij, 2021). All the more reason to pay attention to other explanations of symptoms in adult diagnosis (Szaniawska, 2010), as they can also be caused, for example, by depression (difficulty with concentration and attention, hyperactivity), abuse of smart equipment (concentration and attention disorders, emotional dysregulation), an episode of mania or hypomania (impulsivity, hyperactivity), or anxiety disorders (motor restlessness, susceptibility to distraction, difficulty with concentration).
Diagnosing ADHD on the basis of a single tool is flawed, if not impossible. The diagnostic psychologist should gather as much information as possible about the difficulty experienced and the client's functioning in order to formulate an adequate and clear description. At the Center for Professional Help, we make sure that psychological diagnosis is carried out according to the highest standards advocated by global organizations related to mental health, and that our clients have the feeling of being listened to, understood and confident in the feedback they receive.
