It's not every day that I have an epiphany about anorexia nervosa.  But today I was (re)taught something by a young man I know, respect and treat.  It wasn't entirely new information — I had been taught something similar by younger patients in the hospital -- yet I had apparently either forgotten it or not realized its full implications until today.

That epiphany is this:  severe eating disorders can present in many guises beyond the obvious ones described in the DSM-IV and in textbooks of psychiatry. They can twist and morph and look like other illnesses.  Their symptom constellations can fool doctors, patients and their families.

It's not good to fool doctors because when they make the wrong diagnosis, they use the wrong treatment, including—especially including— the wrong medication.

What am I talking about?  I am talking about:

1.    depression
2.    panic attacks
3.    anxiety
4.    social phobia
5.    "stress" reactions
6.    psychosis
7.    "oppositionality"
8.    attention deficit disorder
9.    attention deficit disorder with hyperactivity
10.  obsessive compulsive disorder

In the world of those who treat eating disorders it is well known that a starved patient can look like anything:  they can look severely depressed, they can even look psychotic.  Once re-feed, with their brain functioning, you realize that they are not psychotic or even severely depressed, but just brain starved.  Or as we like to say: give food a chance!

The connection I hadn't yet made was that we are also mis-diagnosing patients who are no longer starved as having "co-morbid" psychiatric diagnoses when they actually have nothing more and nothing less than delusional eating disorder thoughts.  An example would be the young patient who kicks and screams when brought to our office or when their parents try to bring them to other offices, who then carries a diagnosis of "oppositional defiant disorder", but who is actually deathly afraid of being the fattest person in the waiting room.  Don't believe it?  Ask someone with anorexia nervosa.

How does this work?  Let's take our heads out of psychiatry for a moment and look at regular somatic medicine.  Let's think about tuberculosis and pneumococcal pneumonia.  Could you have both?  Of course.  Is it common?  No.  But does one (TB) set you up for experiencing (catching) the other?

The young man who was my teacher on this day carries a diagnosis of social phobia and anxiety disorder.  Today he refused to go to college.  He didn't want to face the kids there.  He refused to talk to his mother about it, responding in his angry "oppositional" way to her questions.  It was only during his conversation with his therapist in my presence that it hit me in the face:  he was being forced to regain weight after a recent weight loss and was scared the kids in his class would think he had become fat.  His actual weight gain had been minimal so far, but that doesn't matter.  What matters is that he thought he was fat.  This delusional thought, straight out of anorexia nervosa's playbook, would not have responded to treatment with an SSRI such as we had been considering for his  "social phobia".  We had tried an SSRI for his "anxiety disorder" in the past and it hadn't worked either.

Well, no wonder.  He doesn't actually have those diagnoses; what he has is anorexia nervosa which morphs and changes and disguises itself, assuming the constellation of symptoms we call by those other diagnostic names.  Could he have other "co-morbid" diagnoses, as we call them?  Yes, he could.  But I think this co-morbidity may be much rarer than we suppose.

Why does it matter?  Because my thinking that this young man has a diagnosis (anxiety disorder) that would respond to an SSRI  (Prozac, Paxil, Lexapro, etc. ) will inevitably lead to treatment failure when what he really needs is treatment with medication that targets delusional anorexia nervosa, a medication like Olanzepine (Zyprexa).  And/or he needs CBT (cognitive behavioral therapy) aimed directly at the irrational thoughts and cognitions of AN.

In medicine the wrong diagnosis will lead to the wrong treatment, and we must avoid it at all costs--even on those days when we swim upstream against the current of prevailing notions.