A Study Without a Control Group? Evidence for Enhanced Cognitive Behavioural Therapy for Adults with Anorexia Nervosa

Here’s a quick tip: when a study that purports to find evidence of treatment effectiveness–preliminary or not–doesn’t have a control group (a group that doesn’t undergo treatment but is otherwise similar to the group that does), you should raise your eyebrows. Or shake your head. Or roll your eyes. Whichever you prefer.

Why do we need a control group? If the treatment works, we will see improvement in the patients, so isn’t that evidence enough? Well, no.

[T]he whole idea of an experiment is to identify two identical groups of people and then to manipulate something. One group gets an experimental treatment, and one does not. If the group that gets the treatment (e.g., a drug, exposure to a violent video game) behaves differently than the control group that did not get the treatment, we can attribute the difference to the treatment – but only if we can rest assured

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More on the Problematic EDNOS Category (and Diagnostic Crossover)

I’ve been thinking a lot lately about the eating disorder not otherwise specified (EDNOS) category. ED-NOS is a diagnostic category for all individuals with subthreshold anorexia or bulimia nervosa or those with a mix of symptoms that don’t fit neatly into AN or BN. ED-NOS is essentially everything else. A mixed bag, if you will. It doesn’t tell the clinician nor the researcher anything useful, outside of what it isn’t. So, is there any use for it? If it doesn’t tell the clinician about patient symptoms or guide choice of treatment, why even bother? Does it help researchers understand EDs or do they just want to avoid this messy and heterogenous group (that by the way makes up most of those with eating disorders)? In this entry (and many more to come), I want to further explore these questions.

There’s been a push by researchers to minimize the … Continue reading →