Sit back, relax, and enjoy this week's smorgasbord!

Classification of eating disorders in children and adolescents

As I mentioned earlier this week, the draft version of the DSM-V was released. In addition, a research article was published in the European Eating Disorders Review about proposed changes to diagnostic criteria for EDs in children and adolescents. Says the working group:

The consensus opinion of an international workgroup of experts on the diagnosis and treatment of child and adolescent eating disorders is that (a) lower and more developmentally sensitive thresholds of symptom severity (e.g. lower frequency of purging behaviours, significant deviations from growth curves as indicators of clinical severity) be used as diagnostic boundaries for children and adolescents, (b) behavioural indicators of psychological features of eating disorders be considered even in the absence of direct self-report of such symptoms and (c) multiple informants (e.g. parents) be used to ascertain symptom profiles. Collectively, these recommendations will permit earlier identification and intervention to prevent the exacerbation of eating disorder symptoms.

And since earlier intervention means (in general) better outcomes, these changes may help prevent ED chronicity.

Anxiety Disorder Impairs Emotional Control

Thus was the title of a PsychCentral news story on an article from the American Journal of Psychiatry titled "Failure of Anterior Cingulate Activation and Connectivity With the Amygdala During Implicit Regulation of Emotional Processing in Generalized Anxiety Disorder." The lead author on the study said that (quoting from the PsychCentral story):

“Patients experience anxiety and worry and respond excessively to emotionally negative stimuli, but it’s never been clear really why,” said Amit Etkin, MD, PhD, acting assistant professor of psychiatry and behavioral sciences and first author of the study.

Etkin said clinical data have suggested that adult GAD patients initially register negative stimuli in a largely normal way, but have deficits in how they then control negative emotions.

...For the study, Etkin recruited 17 people with GAD and 24 healthy participants and used functional magnetic resonance imaging and a behavioral marker to compare what happened when the two groups performed an emotion-based task.

The task involved viewing images of happy or fearful faces, overlaid with the words “fear” or “happy,” and using a button box to identify the expression of each face. Not all the words matched up — some happy faces featured the word “fear,” and vice versa — which created an emotional conflict for participants.

...in the GAD patients, the reaction-time effect seen in healthy patients was absent — and in the most anxious patients, reaction time actually worsened when there were two incongruent images in a row.

“GAD patients had decreased ability to use emotional content from previous stimuli to help them with the task,” said Etkin.

He said the differences between the two groups were striking. “By looking at reaction times alone, we could classify who was a patient and who was a control,” he said, adding that this represented the first solid demonstration that a psychiatric population has a deficit in a form of unconscious emotion regulation.

This is especially interesting to me as previous research has suggested that difficulties with emotion regulation also accompany eating disorders. No one knows in what ways these difficulties are similar or different from GAD, but it seems an interesting area of research.

Exercise/Depression Link

I initially got hooked on exercise, oh so many years ago, because I found it a good way to decrease my anxiety and improve my mood. Which wasn't a bad thing, and it took several years (and the formal onset of my eating disorder) before my exercise habits approached anything resembling pathological. But research has shown that people who exercise regularly are less likely to report symptoms of depression than those who don't exercise regularly. (Of course, it could be that depression makes it damn hard to do anything, including exercise, so these data don't necessarily say a whole lot.) Other studies done where people with depression were randomly sorted into two different groups, one of which used exercise to augment the action of anti-depressants, and one with anti-depressants alone. And the addition of exercise did seem to improve depression.

For me, exercise was a weight loss strategy, yes. But that's not how I got hooked. I got hooked because exercise made me feel better. Here's a rather technical explanation how exercise affects the brain, from a longer story on using exercise to help treat depression:

One possible mechanism whereby exercise alleviates depressive symptoms involves the idea of an adaptable and ever-changing brain. Human imaging studies show that major depression correlates with decreased hippocampal volume; the magnitude of the change in hippocampal volume is directly proportional to the length of illness. Up to a 19% loss in hippocampal volume may occur in persons with severe, untreated depression.

Among persons who exercise and are treated with antidepressants, one sees the opposite—hippocampal volume increase. In this context, it is interesting that (at least in rodents) exercise increases levels of brain-derived neurotrophic factor (BDNF) in the hippocampus and cerebral cortex. Associated with this up-regulation of BDNF and other neurotrophic factors, exercise increases neurogenesis in the hippocampus in a manner similar to what is seen with antidepressant treatment. Endurance training (in animal models) increases cortical capillary supplies, number of synaptic connections, and development of new neurons.

I would never say that moderate/regular exercise is bad, and I do think that movement can help with symptoms of depression and anxiety, but it would be nice if people understood that the same reasons that exercise helps with depression can also make it rather addictive.

Drinkin' Ain't Chicken Pox

...or is it? A wonderful, brilliant, funny post from The Tao of Chaos looks at whether alcoholism is a disease.

So what’s this whole “alcoholism is a disease” thing, anyway? I thought a disease was something you catch, like chicken pox or leprosy. When I drank, I got money, went to the store, bought some alcohol, brought it home, opened it up, and drank the alcohol. That doesn’t sound like a disease to me.

So why does the concept of alcoholism as a disease still ring true to me?

...[Alcoholism] acts like a disease, it damages and destroys lives like a disease. Diseases need treatment. Treatments have variable outcomes and variable prescriptions. Back to the medical professionals: ask them and you will find that the treatment for a given disease is effective for most; some demand alternate treatments for one reason or another...Whether or not you buy the disease theory, keep this in mind: if it waddles like a duck, has feathers like a duck, has a beak like a duck, it might be a duck. Even if you’re wrong and it’s a goose, it still browns up nice in the oven like a duck.

Eating when hungry improves health and works better than dieting

We will now pause while the scientific/health/medical world dies of shock. From the abstract of a paper titled "Sustained self-regulation of energy intake. Loss of weight in overweight subjects. Maintenance of weight in normal-weight subjects." :

Over a 5 month period [a pattern of meals that began with hunger before eating] resulted in significant loss of weight in [overweight] subjects compared to controls practicing dietary restraint. [Normal weight] subjects maintained weight overall, however [normal weight subjects with lower pre-meal hunger] also lost weight compared to controls.

(I apologize for the odd wording- the authors of the study used a LOT of abbreviations, and I tried to get the general idea across without adding several paragraphs of information.)

I hope you enjoyed your smorgasbord! Stay tuned for next week's collection of tasty tidbits and delicious morsels.