Ultimately, psychological diagnosis is one of the ways modern societies make sense of particular sets of behavior, usually behaviors that are seen as problematic in some way. Although these sets of behaviors may have biological and neurological root-causes, the behavior may be interpreted in different ways depending on cultural context, and the interpretations may shift quite dramatically depending on that context. It is tempting for a medievalist, working in a period long before the development of psychology, to simply reject psychology as a useful tool. However, a nuanced use of psychology as a way to interpret medieval culture, rather than to diagnose Saint So-and-So, can represent an opportunity to understand medieval culture.

Trying to use psychology presents, I think, two major problems for the historian. The first is whether to adopt a specific diagnosis and try to apply it to the past. The second is how to interpret behavior that we would associate with specific psychological conditions within the cultural context of the past in which it occurred – whether it is aberrant from our perspective or the perspective of the past.

As regards specific diagnoses, I have the most reservations about trying to apply modern psychological diagnoses to the Middle Ages. Some historians do indeed attempt to investigate the psychological conditions of historic individuals, but this seems dangerous. Often the accounts that we have of an individual’s psychological state are second or even third hand (and medieval sources are not assessments of the psychological state at all). They lack the objectivity of a trained observer, and sometimes the descriptions were written by people who were hostile or overly dedicated to the individual. Rarely if ever are they first person accounts. Further, most historians have no training in the field of psychology, and often approach the subject with the knowledge of intelligent but untrained lay-people. These issues alone are enough to make an attempted diagnosis dangerous. Even though we can surmise that many people in the past did indeed suffer from psychological illness, in the medieval period we do not have the types of information necessary to definitively diagnose a particular individual, so much so that it is almost pointless as a historical exercise.

Additionally, the goalposts of diagnosis are always being adjusted by the psychiatric community. Most of us would be appalled now to read a profile from the 1960s which identified a historical figure as a sexual deviant based on the criteria for homosexuality laid out in the DSM-II, or a historical paper from 1890 investigating the prevalence of hysteria in twelfth century women. We risk creating similarly dated work, although perhaps not so appalling, trying to apply fairly dynamic psychological diagnoses to the past in any authoritative way.

The cultural application of psychology is perhaps more fruitful, but the technique is most useful when it’s not attempting to impose modern psychology onto the past. Any medieval historian considering this topic will immediately think of the discussion, going back to the mid-1980s, about holy anorexia, anorexia mirabilis, or inedia prodigiosa. The 1980s saw the publication of two major books on the subject, more or less, of anorexia in the Middle Ages. The first, Holy Anorexia by Rudolph Bell, argued that female medieval saints exhibited the symptoms of clinical anorexia. The second Caroline Walker Bynum’s Holy Feast and Holy Fast: The Religious Significance of Food to Medieval Women looked at some of the same women but contextualized their behavior within contemporary medieval society, rather than explicitly attempting to diagnose any particular saint with anorexia. Although both books were well received, Bynum’s book is regarded as one of the leading pieces of scholarship produced within her generation of medievalists.

Bynum’s approach, although not eschewing modern psychology entirely, was one of cultural and historical analysis rather than attempted diagnosis. While Bell in some ways cast the religious aspects of Holy Anorexia as almost incidental to the mental illness, Bynum investigated it as a religious practice – which is how the young women at the time interpreted it. Rather than attempting to prove a diagnosis, Bynum was able to explain why medieval people celebrated a set of behaviors that we modern people consider disordered. She demonstrates that the young women practicing inedia, most notably Catherine of Siena, were using it as a devotional practice. Inedia represented an extreme form of fasting in which they subverted the desires of the body for the purification of the soul and the service of God. Further, she contextualizes inedia, a uniquely female practice, within the gendered spaces of food and religion in the Middle Ages. Bynum points out that men and women had separate roles surrounding food and religion. Women were specifically responsible for preparing and serving food. Men controlled the religious hierarchy and instructed women in how to be devout, while women meekly participated.

By participating in fasting, women stepped outside of or even inverted these structures. As Bynum points out,

In the long course of Western history, economic resources were controlled by husbands, fathers, uncles, or brothers. Yet human beings can renounce, or deny themselves, only that which they control. Thus, in periods such as the later Middle Ages in which world-denial was a favorite religious response, women found it easier to renounce food than anything else.

Further, by choosing to fast, especially to extremes, the women were able to invert the control that priests usually exerted over religious women. As the men around these women became concerned over the extremes of their fasting, they would be seen as attempting to dampen the devotional fervor of the woman. When the woman continued to deny herself food, she was simply responding to her call to asceticism over the fears and temptations of her male protectors.

An approach like Bynum’s potentially provides a much more satisfying methodology for addressing questions of psychological disorder in the past. Bell finds himself speculating about hypothalmic lesions, tabulating data pulled out of Saint’s Lives, and ultimately concluding that Holy Anorexia existed as a disease parallel to anorexia nervosa (although he cannot confirm anorexia nervosa as a definitive diagnosis). Bell falls into some of the pitfalls that I suggested above when it comes to analyzing sources. While Saints Lives provide some of the only quasi-biographical information available in great quantity in the Middle Ages, they are not in any way psychological profiles. For example, Bell notes that high percentages of his saints had hostile relationships with their parents, but he fails to consider the fact that the hostile family is a trope of the female Saint’s Life. It is impossible to tell which of the descriptions of hostile parents were true indicators of hostile parents and which were examples of biographers relying on typical indicators of saintliness in order to demonstrate the saintliness of their particular subject.

Even if we assume that the underlying neurological causes were the same over time, the culturally determined valences and manifestations of those conditions are what is visible to the historian, not the firing of the neurons. An approach situated in the culture seems ultimately to be much more useful to the historian. It helps us make sense of what we might otherwise find to be extremely strange behavior. It also helps us pinpoint what specific behaviors people in the past celebrated or feared rather than searching for medieval PTSD or medieval depression. A quest to diagnose medieval PTSD by sussing out any symptoms that we might be able to attribute to the disorder makes us feel better about PTSD in our own time – but it tells us nothing about how medieval people perceived soldiers, how soldiers interacted with their society, what concerns medieval people had about war or about soldier’s well-being. History is far more interesting when it can uncover and explain the incongruities of the past than when it is impressing our concerns backward onto the past.

This is somewhat out of my field to a certain extent, but it is tangential and important to my field as a whole, so I am here to talk about how you cannot sexualize history. What do I mean by sexualizing history?

Well, it's quite simple in description but quite complicated in effect. To explain: you cannot assign sexual identities to groups of people who did not have a societal concept of sexual identity.

What this means is that you cannot call Alexander the Great, for example, homosexual because he was a man who had sex with men. While at first it might seem simple to assign this label to him (a man who has sex with men is obviously a homosexual!), its an invalid and dangerous presupposition because Ancient Greeks, for one, had no concept of sexuality or sexual roles in that manner. Indeed, the concept of heterosexuality and homosexuality were roles and ideas that only devloped in the mid-1800s with the work of pioneering sexologists in Germany (Richard von Krafft-Ebbing) and England (Havelock Ellis) and then later showhorned into developing ideas of psychology by Sigmund Freud and Karl Jung.

People in pre-1800s times didn't concern themselves with sexuality and categorizing sexuality in the ways that we do, and indeed these 1800s categories come with many presuppositions that we could consider ridiculous today. Krafft-Ebbing, for example, believed that the purpose of sexual desire was for procreation and procreation alone, and that any sexual activity that was fun was very dangerous and a perversion of sex. Furthermore, he believed that homosexuals were created through early use of masturbation. Havelock Ellis was a bit better, because he refused to criminalize or pathologize homosexual relationships:

I realized that in England, more than in any other country, the law and public opinion combine to place a heavy penal burden and a severe social stigma on the manifestations of an instinct which to those persons who possess it frequently appears natural and normal. It was clear, therefore, that the matter was in special need of elucidation and discussion.

This refusal quickly lead to the banning and prosecution of his book under the Obscene Publications Act of 1857.

So when you see people discussing how this or that historical figure was gay or straight, I hope it becomes easier to realize that the entire debate is premised on wrong ideas.

I have a particularly narrow and strong stance on this issue. I'm convinced that it's deeply inaccurate and fundamentally wrong for historians to apply psychological models, disease concepts, and theories that have been developed in the social and cultural context of the 20th/21st Century to periods, places, and cultures where those concepts did not exist.

Since saying that usually gets me into an argument, let me be clear what I mean about that: I'm not saying that it's incorrect to discuss mental illness in the context of the past, or to discuss the psychological trauma and suffering that people in the past experienced. What I'm saying is that when we take modern understandings and definitions of psychological illness and try to apply them to people in the past, we run the risk of severely distorting history.

Our modern understanding of psychological illnesses and conditions like PTSD are just that; understandings - they are social and cultural constructions in the same way that genderized and racialized concepts like "woman" and "black" are. Just as there's a difference between "female" and being "a woman," or between being of African origin and being "black," there's a fundamental distinction between our concept of a psychological disease/disorder and the "actual" condition that a given individual is suffering from or experiencing. The former describes and gives meaning to the latter, but they are emphatically not the same thing. To me, it seems incredibly hubristic and inexcusably presentist to assume that we understand the human mind, people in the past, and people in the present so incredibly well that we now know what x person in the past was "really" suffering from, based on what we think we know about the psychology of people in the present.

There are a number of big problems with doing this:

• Our understanding/definition of a disease could be wrong, and will almost certainly change. As the OP points out in this very thread, homosexuality was considered a mental illness a few short decades ago. The specific disorder that we call PTSD was not "invented" (ie: defined as we currently understand it) until the late twentieth century. Our understanding of disorders like ADD and Autism is constantly changing even today. History is full of examples ailments which we no longer even believe exist, but which were very real to the people who thought they were experiencing them and to the doctors and healers who treated that illness in the past. See the history of lovesickness as a disease for a fascinating example of this. Clearly, people's ideas about illness and mental illness changes over time - by projecting our own modern notions of a particular (modern) disorder onto people in the past, we are privileging our perspective over everyone else's in history, often in situations where we know very well that our ideas and interpretations wouldn't have made a lick of sense to the people we're studying.
• Historical records are very very rarely (if ever) detailed or accurate enough for us to draw conclusions or make assumptions about exactly what kind of condition a person in the past was suffering from, let alone to "diagnose" them with a modern psychological disorder. No psychologist today would diagnose someone based on such thin evidence, and historians aren't even psychologists; we're kidding ourselves by thinking we can determine whether or not someone in the past was suffering from a specific disorder.
• Psychological diseases and disorders often have physical or biological causes; but they are also shaped by the culture and environment in which a person lives, or the lived experiences which they've had. The lines between these different causes of psychological illness are often (if not always) blurred. As a result, we often have no way of knowing how much illness x (or the symptoms of illness x) are a product of biology, of life in our society, or of specific experiences or environments that a specific individual has had. We can't always (and I'd argue ever) separate the disease from the culture and environment in which person lives - as a result, it's wholly inaccurate to assume that a particular psychological illness is historically constant or unchanging. Bottom line, we don't know and can never know if someone who was displaying some of the symptoms of a modern psychological illness in the past had that illness. The illness as we understand it is very likely shaped by the culture of the people who suffer from it, by the experiences that they have in the modern world, and potentially by their own or our own understanding of the illness itself.

As a historian of childhood, I have had particularly bad experiences with historians who have tried to apply modern notions of psychological illness (and especially of psychological trauma) to the past. As anyone who knows anything about the history of psychology and psychiatry can tell you, the notion that childhood experiences shape personality, and that childhood trauma can cause psychological illness, is and has been a core component of psychological theory for a very long time. Well, much of the earliest work on the history of childhood was informed by this perspective; historians like Llyod Demause wrote some of the earliest broad, in-depth explorations of the history of childhood, but they did it through the theoretical lens of what they called psychohistory: they believed that we could use psychoanalytic and psychological knowledge about how humans develop and how the mind works to better understand and explain the past. For those of you who are Dan Carlin fans, his "Suffer the Children" episode was based on one of Demause's books.

Basically, Demause argued that since people have not had the same concept of childhood had we do throughout history, did not always see children as uniquely innocent and vulnerable, and - most importantly -did not always treat children as if they were innocent and vulnerable, that this meant that children had been routinely and endemically abused throughout the course of human history. More than that, he argued that we could therefore use modern psychoanalytic and psychological theories about how children respond to abuse in the present to explain the actions and the mindset of not just individuals in the past, but whole past societies.

Hopefully the problems with doing this kind of analysis are pretty clear: Demause was basically bending history to fit his model, rather than starting form the evidence and working towards a theory. Historians who study the history of childhood have wholly demolished his ideas in more recent years, by focusing on the actual evidence from the past about how children were treated, and looking at how they responded to their own environment and experiences.

The last thing I'll say in my initial comment here is that studying the very recent history of childhood is also one of the things that makes me incredibly cautious about using modern psychological theories and knowledge to interpret the past. The psychology of childhood and child development has been changing incredibly rapidly over the past century or so - it really is not that long ago that widely respected, very authoritative psychologists thought some men turned gay or became delinquents because their mothers were too assertive and not submissive enough to their husbands. People have said and argued a lot of stuff about child development that is patently crazy from our present perspective - but they've done it surprisingly recently, with a straight face, and won a huge amount of acclaim for doing so. I'm not saying this to disparage the field of psychology or anything - the point I'm trying to make is simply that ideas change, and that psychology is one area of study were theories and disease concepts evolve extremely rapidly. As historians, we're supposed to be particularly conscious of how much things change over time - it seems fundamentally wrong-headed to me for us to try to argue that things change, but that the human mind and psychological conditions don't - that they are constant and can be applied to other times and cultures.

I remember one of the more interesting discussions I had with my therapist was the question of whether or not the resulting goals of therapy as it's taught and practiced now were themselves a means for maintaining the mental stability of workers intended for a capitalist system. Especially considering that the goals were focused on internal adaptation (reducing anxiety) of an external system (the corporate workplace) that could be said as the ultimate cause of stress.

Because from there, we compared what would be different approaches toward "mental health" if one were in a religious society where priests would be the primary "therapists" with an eye toward the adherence of a particular dogma or alternately, what if one were in a revolutionary communist society, and how different the advice offered for the channeling of anxieties could be?

So I guess this goes back into those constant questions about historicism. Are we to evaluate mental health on the basis of our perceptions of what they should be, or that society's perception of itself? Or are both perhaps, incomplete in some way?

I am uncomfortable with the description of anorexia as being purely culturally caused because there is a growing body of evidence which points to anorexia nervosa and bulimia nervosa as being co-morbid with autism spectrum disorders and other cognitive processing disorders such as ADHD and OCD.

To the extent that some autism specialists are now suggesting that ASDs may be as common in girls as they are in boys (the current rates of diagnoses is about 4:1) but that ASD is often missed in girls because it manifests in other ways, such as in eating disorders, rather than through the classic textbook symptoms. (There are also many other reasons why diagnoses might be missed in girls, the key one being the notion that ASD is a typically 'male' condition.)

Whilst it is self-evident that the association of low body weight with success is culturally determined and therefore someone driven to seek 'perfection' is much more likely to develop an eating disorder in certain cultural contexts, there is likely not just one cause for these eating disorders, rather in many cases (if not the majority) they probably result from an interplay between biological and cultural factors.

Below I've linked a relatively small study conducted by Simon Baron-Cohen who is the director of the Autism research centre at Cambridge which explores the links between ASDs and eating disorders in female adolescents. There are other larger scale studies in the literature but I've chosen this one because the methodology and potential short-comings thereof is well explained.

http://www.molecularautism.com/content/4/1/24

There is also the basic question of access to diagnostics, medical professionals may be less likely to notice a psychological cause for malnourishment if they are seeing lots of cases of malnourishment caused through medical or economic problems. The provision of mental health care and diagnostics is generally poor in poorer countries and eating disorders could be being missed because of that, especially since they don't manifest in ways stereotypically associated with severe mental illnesses.

I realize I'm a little late to the party, but since I'm overseas doing fieldwork and spent yesterday and today outside all day supervising a bulldozer, I'll say it's ok.

It is very difficult to diagnose any sort of internal or mental or psychological disorder in the distant past. Prior to writing, we have literally no way of telling if someone was mentally ill or suffered from some form of psychological issue or not. It's not something that can show up in the archaeological record. All we can see are the material results of people's actions, and often we must interpret these as the actions of a sane, rational-thinking person. For example, in a number of ancient skulls we see evidence of a practice called trepanation, which it the drilling of a hole into the bone of the skull of a living person to provide relief of some sort. Now, this practice took place mainly before the development and widespread use of writing, so we have little information about why trepanation would have been administered. Some scholars have suggested that the practice was used as an early method of treating mental illness or other illnesses of the head (such as migraines), to let the badness out (Nolen-Hoeksema, Abnormal Psychology, 6e, McGraw-Hill Education, 2014). Could it have been to relieve headaches? Or to release demons that are tormenting a person? Or are they the same thing? All we know is that people drilled into other people and many of them survived and the holes were at least partially healed.

Second, we must be careful when diagnosing ancient mental illnesses with our modern understanding of the mind and how it works today. Ancient people had extremely different worldviews from the way we understand the world today. Superstition and religion played much larger parts in explaining how things worked. In ancient Assyria, life was difficult, and the entire male population was subject to military service every three years. A number of them suffered from symptoms they believed were caused by the ghosts of the enemies they had killed during battle. Modern scholars reconstruct these symptoms as what we today call Post-Traumatic Stress Disorder. Does that mean the ancient people were wrong and we are right? I don't think so. We learn so much more about them when we understand what they think is happening, and we can only make a diagnosis from afar, based on whatever symptoms they decide to write down and share with us. This is very important to remember. We cannot directly diagnose anyone. Also, conditions were different in the past, and I would be extremely wary of projecting modern stresses into the past. Cultural dynamics are often very specific to a time and place, and to project the psychological disorders of this time and place into the past is a very tricky thing. Is PTSD deriving from modern stresses and violence the same disorder that might be caused by ancient stresses and violence? Are there unique subtleties that distinguish the two? We will most likely never know.

So, when the King of Elam's mind "changed" after a war, was it PTSD or the ghosts of his enemies? I say the answer is yes to both. We must understand the mental illness the way it was perceived in the ancient past, even if it is a diagnosis we think would be horribly wrong to pronounce today. We also are able to understand the symptoms preserved in ancient writing, and put them in paradigms we ourselves understand in our modern society. In the end, the outcome of both belief systems is the same.

(Abdul-Hamid, Walid Khalid, and Jamie Hacker Hughes. "Nothing New under the Sun: Post-Traumatic Stress Disorders in the Ancient World." Early science and medicine 19.6 (2014): 549-557.)

The rising (or even dominant) paradigm in mental illness lately is neurological, or somatic - stuff that the body is doing or not doing that is affecting the mind and the personality.

I'm thinking of Oliver Sacks writing about Spalding Gray's depression as a consequence of physical trauma to the brain as a recent example of this way of thinking about illness, but it's also present in all kinds of hard research.

I'm curious if this way of looking at mental illness - the biological, pharmacological cause/effect chain - has revealed anything interesting in anyone's historical research. Traces of stimulants found in remains that might have explained a monarch's weird decisions? Scarring on a skull that could shed light on a famous bout of depression?

Does the bio-psychological help history?