I promise this will be the last pro-diagnosis-sounding post I make for the time being. I have been cooking up a piece examining the debate from the other side, but for the sake of neatness I want to present this argument first.
In the last post I suggested that diagnosis had some rude utility as a measure of the risk someone poses for suicide. Certain DSM diagnoses indicate a higher risk than others, and even when there are better and more specific ways to assess for suicidality, it doesn't seem unreasonable to retain diagnostic information as a rough and ready measure for clinicians.
However, it is in the realm of psychological and psychiatric treatment that diagnosis is actually supposed to be helpful. The theory is that if you know the nature of a person's problem you can better offer them appropriate help.*
It is true that therapy is not particularly diagnosis specific (a wide range of different "disorders" are amenable to similar therapeutic approaches, i.e. CBT), but if even only a few existing diagnoses can sensibly pick out types of problem with specific treatment indications, the practice still might have a useful role.
Here are two examples of categories where this seems to apply:
1. So called "Borderline Personality Disorder" (a phrase that is deeply unpleasant, for its implications that the sufferer is both somehow "fringe-y" and "disordered" at the very level of their personality):
For a long time, "BPD" was regarded as untreatable, and those so designated were locked away in seclusion and more or less given up on. The psychologist Marsha Linehan experienced this first hand (here's a New York Times article on her experience) and ultimately went on to develop a psychological treatment approach that dealt specifically with the problems she had encountered. That treatment, DBT, has gone on to be immensely successful, helping other people in a similar situation to Linehan, and the words "similar situation" are an important part of the phrase. Doctors are constantly being confronted by people who are asking them for help and who would find in this treatment the help they are seeking. Unless those doctors are able to tell those people apart, to pick them out from others who would find shorter/easier treatments helpful, then they can't know what to offer. This where diagnosis comes in. We could change the name of the problem ("Abusive Relational Trauma Sequelae" might be appropriate) and we could adapt the criteria somewhat if we wanted (DSM's criteria don't really get at the person's experience and so miss an essential part of the picture), but as long as we are clustering people together according to shared characteristics and offering a kind of assistance based on the aetiology of the problem, then what we are doing is diagnosis.
2. Psychosis (note, this is too broad to be a DSM category, but it has never been the project of this blog to examine DSM per se, but rather diagnosis more broadly-which can be done using multiple alternative classification systems):
Psychosis is a very distinctive part of the human experiential repertoire. There remains enormous contention around who is and who isn't psychotic, how long it is likely to last and what might be the best way to help them. We do know that some people, some of the time, find the neuroleptic medications to be helpful in dealing with the intense and overwhelming disruption in their experience of reality. This is pretty sketchy detail as far as diagnosis goes, but it still seems there is some useful information contained in the distinction "Psychosis" vs "No-Psychosis". I would argue that the most important information is not:
(i) "Those designated as experiencing psychosis may benefit from neuroleptics"
(ii) "Those not designated as experiencing psychosis certainly won't benefit from neuroleptics"
Given the toxicity of so called "anti-psychotic" medications (and "anti-psychotic" is extremely over-optimistic given what these drugs actually do) it seems extremely important to rule out their use in anyone for whom it can definitely be said they won't be of any benefit.
These two examples generalise to some extent, but some diagnoses are more useful than others. DSM gets ever fuller with needlessly specific "disorders", and as Lucy Johnstone has pointed out, many of them are merely descriptions rather than diagnoses proper. What I am exploring here is not whether we should keep the DSM or not (I'm all for its abolition), but whether it should be replaced with an alternative form of diagnosis or an alternative to diagnosis.
*Some readers' answer to this will be that psychiatrists/psychologists aren't able to help anyone anyway. I am extremely sympathetic to anyone whose encounters with the "professionals" have left them feeling this way. The self disclosure in my Bio will alert you to the fact that I have a greater degree of optimism on this question. I have found therapy very helpful in the past, and I have spoken to a few others who claim to have found it transformative. Many people may be better served by non-medical/non-psychological interventions.