What does DSM stand for?
Plus: experiencing AVATAR therapy, a new trial of the keto diet, and risk factors for postpartum depression
What does DSM stand for?
The American Journal of Psychiatry has published a series of articles on progress towards a new DSM. As a reminder, the DSM is the Diagnostic and Statistical Manual of Mental Disorders, an immense tome produced by the American Psychiatric Association that provides consensus criteria for psychiatric diagnoses. I’ve seen it called “psychiatry’s bible”, which I think is a pretty bad description. Okay, it's a weighty publication found on many a bookshelf, set out in chapter and verse, and written by a committee. But DSM doesn’t promote any particular view on what causes mental health problems (although one could argue that its very existence implies a medical framework). And it’s by no means the be-all and end-all of practice, either in the US—where, as elsewhere, diagnosis should be only one component of care—or globally, where the WHO’s ICD system is in common use.
Nevertheless, for good or ill, DSM has become emblematic of modern psychiatry. So it’s fascinating to see how the new committee are thinking about DSM-6. This piece offers a guide to their initial strategy, outlining the advantages and disadvantages of the current system, and describing the various work packages. But the real material of interest is towards the end, in which the authors set out some intriguing possibilities for the future of DSM, including:
· Moving away from the agnostic approach, and “embracing biology and environment and their interactions as key determinants of mental disorders.” So besides description, the new DSM will find a way to incorporate biomarkers and mechanisms.
· Avoiding the perception that disorder categories are set in stone, through flexible definitions, transdiagnostic dimensions, and educational efforts.
· Changing the name! It’ll still be the DSM, but the “s” will stand for “scientific”, not “statistical”.
My initial impressions are, first, that writing DSM-6 will be a long and complex process, and the resulting manual will probably the biggest change since 1980’s DSM-III; and second, that it won’t take the form of a doorstopper printed volume. Goodbye to paper and ink; hello to a living, web-based platform?
Experiencing AVATAR therapy
A neat little JMIR:MH paper takes a qualitative lens to the experience of AVATAR therapy for psychosis, in which the therapist builds a digital representation of a distressing voice, and then guides the patient to better manage its presence.
There are some useful findings here. The main negative experiences described by participants were issues with the realism and accuracy of the avatars (specifically “the need for improvements to the tailoring of avatars across different ethnicities and genders”) and anxiety when the experience just seemed too real. As the authors point out, better avatars might also be more anxiety-inducing; they therefore emphasise the need for flexible, patient-centred therapists, and possible integration of anxiety management within sessions.
The keto diet: à chacun son goût
Interpretations of this new JAMAPsych trial of the keto diet (KD) for treatment-resistant depression will vary. On the one hand, six weeks of keto diet led to a slightly greater change in PHQ-9 scores than did a control “phytochemical” diet (total n=88). On the other hand, the small difference between groups (2.2 points) is probably below clinical significance, ketone concentrations were not associated with depression improvement, and—a big issue for me—“once the provision of KD meals and support ended, only 9% of participants reported diet continuation.”
My reading is that this means uncertain benefit and real challenges with sustainability; on the other hand, as the authors point out, “A meta-analysis showed that antipsychotic augmentation in [treatment-resistant depression] yielded a mean placebo-adjusted reduction in PHQ-9 score of about 3.” So not that much better than keto diet in this trial, and a change in diet might well be more acceptable than antipsychotics. With caution, I think this avenue of investigation is worth pursuing further. Yet again, it’s one of those situations where biomarkers to target treatment would be really helpful.
Risk factors for treatment-resistant postpartum depression
A new Nature Mental Health paper analyses data from 58,618 patients with first-ever postpartum depression between 2006 and 2021. Naturally, this is a Swedish cohort; the Scandinavians continue to be kings and queens of the register-based study.
Treatment-resistant postpartum depression turned out to be pretty common; it was seen in 6% (3522) of this cohort. Associated factors included “Lower educational level, lower household income, being non-cohabiting, smoking in early pregnancy, delivery by cesarean section, pre-existing physical conditions and pre-existing psychiatric disorders”. Quite a list of social, psychological, and biological factors there; and plenty to work with in determining risk and devising new treatments.
The future
As some of you will know, I’m changing jobs this month. This will be the last Thought Formation, at least for a while. I’ve really enjoyed sharing these weekly selections with you for the past two years, and appreciate all the kind comments I’ve received via email and LinkedIn. Many, many thanks for reading.