I'm going to start with a little history of psychiatry in America and the DSMIV. Up into the 60s and 70s, psychiatry in America was heavily influenced by psychoanalysis - Freudian stuff (patient is on a couch free-associating, and the therapist is a "blank screen" - theoretically, though it hardly ever worked out like that), primarily because most of the psychoanalysts fled Germany during WWII and set up shop in London and New York and Boston - these places are still hotspots of psychoanalysis today and the center of East Coast academic training in psychiatry. Psychoanalysts spend a lot of time talking about rage and repression and the unconscious and the mind, all very interesting, if you like that sort of thing. But psychoanalysis isn't exactly neuroscience, and when biological correlates to some of the major psychiatric disorders started coming out, psychiatry swung the other direction.
In some respects there is a lot to admire about psychoanalysis as a science - Freud, a Victorian, met his match in a young girl with symptoms of hysteria named Ida (he called her Dora), and he came up with all sorts of Victorian theories about repression and sexuality to explain her symptoms of not being able to speak, and some neurological hand problems. The case is often studied in academic feminism as an example as to why psychoanalytic theory is patriarchal and misogynist. And yes, it certainly was, because that was the prevailing idea of the time. However, it is often missed that the whole reason Freud published Dora was to present a failure of his therapy. He missed the boat, he knew it, as a Victorian he didn't quite understand why. In that respect, Dora is a humble case study and real medical science circa 1901. Now we would get to the brass tacks that Dora at the age of 14 was by her account repeatedly sexually propositioned by the father of the children she babysat, and the children's mother was also the lover of Dora's father. Such a situation would be difficult now - imagine when one could not speak of such things and would not have been believed in any event.
Well. Dora has a lot of dream analysis in it, and maybe that was a Victorian indirect way to get to the truth. In 2011 we prefer more direct methods - saves time. And I certainly prefer to look at much of psychiatric pathology from a neuroscience perspective, as it seems only rational. The analysts will say we have lost the art of listening and all the modern psychiatrist does is shove pills down people's throats. The biologic psychiatrist will say that psychiatric illness has more causes than just mental distress and to ignore those causes is unscientific and unconscionable. The analyst will say the biologist is "mindless," the biologic psychiatrist will say the analyst is "brainless."
The truth of the matter is that we cannot afford to lose our ability to listen to patients - that is the problem in all of medicine at this time, and psychiatrists may be the last bastion of listening. On the other hand, we can't afford to base psychiatric treatment on medical science circa 1901 (I'm being a little unfair here - hardly any analysts are Freudian drive-based anymore, most use a mix of more modern theoretical concepts derived from attachment theory, relational therapy, and even chaos theory). So into the fray between biologic sorts and analytic sorts came the DSMIII and IV. These books were written to be atheoretical. Causes (whether it be genes and inflammation or history of trauma and personality style) are left out, on purpose, I think in part due to the fight between the analysts and the biologic psychiatrists. I came into training rather at the end of this "war" but apparently it raged for decades. (One of my teachers, an analyst, said of another, a biologic psychiatrist, "I don't think he even believes in the unconscious!" Another teacher talked about how he was forced as a resident to give psychoanalysis to actively psychotic individuals in state mental hospitals, and when it didn't work, was blamed for his failure.)
The DSMIV is merely a recipe book of traits. Have the traits, match it up to the diagnosis, and there you go. Mostly it was intended for research - since we don't have lab tests to define psychiatric illness, psychiatrists in one research center needed to be studying the same disorders as in another center - thus a checklist of sorts. And then psychiatrists in the field needed to be talking about the same sort of problem that the researchers were studying treatments for. It all makes perfect sense, but the DSMIV is maddeningly boring and the atheoretical part makes it a lightning rod for critics. Then managed care and insurance and services based on diagnosis came along and the DSMIV became way more important than it should have been.
But the DSMIV is what we have, and there are certain definitions for bipolar disorder. Bipolar I is when you have a manic episode (a period of insomnia, hypersexuality, impulsivity, rapid speech, increased religiosity, irritability, racing thoughts, manic psychosis often with religious delusions or grandiose delusions, increased energy, and euphoria - you don't need all of these to be manic, just enough of them, and to be mania, it needs to be serious enough for you to be psychotic or hospitalized.) Bipolar I people usually have major depressive episodes also, but they don't have to. Some people are only manic.
Then there is Bipolar II, where people tend to be depressed most of the time but occasionally have hypomanic episodes - mostly insomnia, irritability, increased goal-directed behavior, impulsivity, euphoria - but not as serious as a full manic episode. Bipolar II is a little hard to sort from regular depression - most of the people who show up at your clinic will be depressed, and hypomanic symptoms are often forgotten about, even when you ask directly about them.
Neither of these are the same thing as "moody." Being moody and irritable does not make you bipolar, though if you are bipolar, you will likely be more moody and irritable than average during an episode. In a lot of ways, bipolar disorder overlaps (and sometimes exists at the same time with) other disorders - substance abuse, personality disorders, anxiety, depression, ADHD, which makes it all the more controversial.
Bipolar symptoms also tend to be different at different stages in life. Kids will tend to cycle very rapidly between mood states and could hit many in the same day. Adults tend to stick with one for several weeks or more. (Bipolar disorder in kids is a bit controversial - it's called bipolar disorder because the same criteria fit to describe the behaviors, and often kids with bipolar symptoms do grow up to be adults with standard adult bipolar disorder, so it seems to be the same animal. It is also highly genetic. However, every kid with a temper or a bratty streak is not bipolar. Bipolar in kids tends to be very serious - these kids are often kicked out of school (or preschool) for behavior problems.)
In a lot of ways, bipolar disorder is poorly understood.
Which brings me to the paper I'm blogging about today, "An admixture analysis of the age at index episodes in bipolar disorder." In this study, researchers interviewed 390 people with bipolar disorder in Canada about the history of illness, threw a bunch of data into a number cruncher, and came out with some interesting correlates.
First off, people with early onset bipolar disorder (average onset age 18) tended to be more likely to have a family history of bipolar disorder, and more likely to have psychosis, anxiety, suicidal thoughts and behaviors, and a chronic and rapid cycling course, and were more likely to have migraines. People with late onset (usually starting around age 33) disease were more likely to also have diabetes. Typically, bipolar disorder begins with a depressive episode, and often earlier in women than in men (which would match up with women's greater vulnerability to mood disorders in general). I can add further speculation that the later onset bipolar being more associated with diabetes would suggest that it is possibly part of metabolic syndrome in certain vulnerable people. Early onset bipolar disorder may be more it's own animal. I do think in both cases, inflammatory Western diets may be contributory, and there is some (bad epidemiologic) evidence that doesn't dispute that speculation. Also interesting is the connection between bipolar disorders and migraines - both can respond to medications for epilepsy and theoretically from a ketogenic diet.
A modern psychiatrist is hamstrung without time to get a good history and the psychological savvy to establish an excellent rapport with the patient and the understanding of basic human nature - but a modern psychiatrist is also crippled by a lack of knowledge of neuroscience, nutrition, and general medicine. We need to pursue both threads in 2011. It all comes back together for the betterment of everyone.