People who experience a similar event (e.g., trauma) can have disparate outcomes that depend on other factors (e.g., financial resources, societal views of survivors). This is called multifinality. Meanwhile, people with similar outcomes (e.g., posttraumatic stress disorder) can arrive there via distinct pathways (e.g., surviving sexual assault, a car accident, being the victim of gun violence). This is captured with the term equifinality.
I highly recommend this article by Beltz, Wright, Sprague, and Molenaar (2016) for detailed definitions of these terms:For example, imagine that a client gets diagnosed with obsessive-compulsive disorder (OCD). In order to figure out the best way to help, a therapist begins with nomothetic information (e.g., the diagnosis) to select a treatment. A randomized clinical trial suggests that a type of cognitive-behavioral therapy called exposure and response prevention (EX/RP) leads to significant improvement among 80% of people with OCD after 17 sessions. Based on available information, EX/RP is a good place to start. However, it’s possible that the client will be among the 20% of people who don’t respond to EX/RP. Therefore, therapists must also pay attention to idiographic information after initiating treatment (e.g., by regularly assessing the client’s OCD symptoms over time). If the client’s not responding to therapy, the idiographic data signal that the therapist must figure out why and make appropriate changes.
For more information on nomothetic and idiographic approaches, check out:
I’ve described frameworks that clinical psychologists use to understand people’s mental health needs at multiple levels while respecting their individuality. The dedicated people working hard to alleviate suffering in the face of these challenges give me hope for the future of the field.
In “Why I Do Not Attend Case Conferences,” Paul Meehl (1973) described reasoning errors that emerge during case conceptualization conversations among mental health professionals. One of the issues Meehl discussed at length (pp. 272-281) was an antinosological bias, defined as “an animus against diagnosis.” Here’s his response to a common objection to diagnostic labels:
Meehl described his style there as “highly critical and aggressively polemic,” which he justified by saying, “If you want to shake people up, you have to raise a little hell.” The second section has a much more constructive tone. Both sections are valuable, and I agree with his overall thesis that compassionate, effective mental health care requires clearheaded case conceptualization. Meehl is also correct that 1) meaningful diagnostic systems are crucial for advancing the field and 2) some critiques of the Diagnostic and Statistical Manual of Mental Disorders (DSM) reflect misunderstandings of the diagnostic process. I’ll discuss some of the major criticisms and benefits below.
However, we should also consider that appropriate diagnoses have helped people access beneficial services (e.g., children with intellectual disabilities or autism receiving accommodations in school and other public places). Additionally, the DSM specifically instructs clinicians to only assign diagnoses when a cluster of multiple symptoms: 1) causes clinically significant distress and/or impairment, 2) is persistent and severe for a length of time, 3) deviates significantly from developmental expectations, and 4) cannot be attributed to other factors (e.g., medical, cultural). These types of safeguards reduce the likelihood of pathologizing nonpathological behavior.
3. Classification decisions are made by people with conflicts of interest.
There have been some egregious examples of psychiatry researchers receiving large sums of money from pharmaceutical companies and not properly disclosing them. One instance is covered in a PBS Documentary and in this New York Times article:
In an effort to address this problem,DSM-5 panel members were required to disclose conflicts of interests. Cosgrove and Krimsky (2012) made a compelling case that further action was needed:
To be clear, psychiatric medications have helped numerous people and are warranted in particular circumstances. However, steps must be taken to reduce potential biases driven by the pharmaceutical industry.
4. Labeling someone with a mental disorder is stigmatizing.
2. Diagnoses convey useful information when derived from appropriate assessment procedures.
Accurate diagnoses point to literature on the causes, correlates, and effective treatments for specific mental health problems. If an adolescent girl is accurately diagnosed with anorexia nervosa, we learn that she has an increased risk for bone fractures, arrythmias, depression, and suicide and should be monitored for each of these dangers. Importantly, we also know that family-based treatment is likely to be a good treatment option for her and that her parents can connect with parents experiencing similar struggles. To learn more about the process for evaluating levels of empirical support for therapies, look here for youth treatments and here for adult treatments.
4. Diagnostic labels enhance communication between treatment team members and aid continuity in care.
Diagnostic labels ease the transition for clients from one therapist to another (e.g., by saving them from having to repeat assessment procedures) and by communicating efficiently to other members of their treatment team (e.g., social workers, psychiatrists, physicians, clergy).
5. The DSM-5 has improved since the original version and has built-in mechanisms for change.
Despite the hindrances mentioned above, the DSM has formal, built-in processes for evolving with new scientific discovery. New versions are created with the explicit goal of making the classification system better reflect nature. Hyman (2010) argued that we should not reify existing diagnostic constructs. Instead, we must remember that diagnoses are constructed for clinical and scientific purposes. Therefore, improving the DSM requires openness to change and flexibility.
In conclusion, despite the concerns highlighted above, I agree with Meehl that antinosological biases impede progress and that mental health classification systemsshould be improved rather than abandoned altogether. I’m grateful for the dedicated clinicians and scientists working to deepen our understanding of mental health and feel encouraged by efforts to use that information to improve people’s lives.
In an effort to keep this post relatively brief, I highlighted some main points and examples. Some of the more technical, in-depth things I’ve co-written about classification are linked below: