‘Abandon all hope, you who enter!’
- Dante Alighieri’s inscription at the entrance to Hell
We don’t know much about hell. In Supernatural’s universe it is a place where one month becomes a decade. It is a ‘prison made of bone and flesh and blood and fear.’ It is ‘a pit of despair’, where human souls are turned into demons via endless years of agony.
All we have seen of hell are a few peeks, as Dean, after being torn up by hellhounds, hung suspended from hooks violently forced through his wrists and ankles, shoulder and abdomen, screaming for help and for the one soul who meant everything to him – Sam. No one heard him. No one cared. Another glimpse of hell was given by flashbacks Dean experienced when he awoke in his coffin, remembering fragments of his time there – his panic stricken, wide open eyes, blood everywhere, accompanied by jarring screams.
And we are aware of what he told Sam: ‘…they sliced and carved and tore at me in ways that you… until there was nothing left. And then suddenly, I would be whole again, like magic. Just so they could start in all over. And Alistair… at the end of every day, every one, he would come over and he would make me an offer: to take me off the rack, if I put souls on. If I started the torture. And every day I told him to stick it where the sun shines… For thirty years I told him. But then I couldn’t do it anymore, Sammy, I couldn’t… And I got off that rack. God help me, I got right off and I started ripping them apart. I lost count of how many souls. The things that I did to them… … how I feel? This…. inside me… I wish I couldn’t feel anything, Sammy. I wish I couldn’t feel a damn thing.’
We don’t need to become familiar with any more details. To watch Dean and his reactions to the memories coming over him is more than enough. And, frankly, does anyone of us really want to know what the demons of hell did to him? What ever it was – it changed Dean profoundly. The man who returned from hell was still, essentially, Dean Winchester, loving brother and hunter of the paranormal, but he was also a broken, stunned and devastated survivor of torture. Being that, his reaction to an abnormal and unspeakable experience was absolutely normal and natural – in clinical terms it is described as posttraumatic stress.
Before explaining more about that, I will take a look at torture and the psychology of it. I believe it imperative to understand the phenomenon to be able to realize what it does to a person subjected to torture.
The invasion of torture
An official United Nations document, the ‘Manual on Effective Investigation and Documentation of Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment’, known as the ‘Istanbul Protocol’, describes it as follows:

‘One of the central aims of torture is to reduce an individual to a position of extreme helplessness and distress that can lead to a deterioration of cognitive, emotional and behavioural functions. Thus, torture is a means of attacking an individual’s fundamental modes of psychological and social functioning. Under such circumstances, the torturer strives not only to incapacitate physically a victim but also to disintegrate the individual’s personality. By dehumanizing and breaking the will of its victims (…) torture can profoundly damage intimate relationships between spouses, parents, children and other family members and relationships between the victims and their communities.’
The disintegration of Dean’s personality happened over the course of three decades, and eventually he did what he (given normal circumstances) never would have even considered while alive: torture others to save himself. The Dean we got to know throughout this show would have rather died. 
The World Medical Association defined torture in its ‘Declaration of Tokyo’ as this: ‘the deliberate, systematic or wanton infliction of physical or mental suffering by one or more persons acting alone or on the orders of any authority, to force another person to yield information, to make a confession, or for any other reason.’
The declared goal of Alistair and his torturing bunch was not to get information of any kind, but to get Dean to break the first seal, to start the apocalypse. That’s what they needed him to do (but, of course they did not tell him. It’s safe to assume, given what we know about Alistair, that he tortured Dean without even telling him why. Torture is commonplace in hell, usually without any further purpose. And, eventually, they managed to weaken Dean enough to get him to pick up the blade and be the ‘righteous man’ who ‘sheds blood in hell’, thereby ‘jumpstarting the apocalypse.’
The human body is the one place where we know our privacy and inviolability to be safe. We are in control of it (as far as that is possible, of course). We decide how to dress it, feed it and in which manner to take care of it. It is our own country, one we take with us wherever we go.

During torture, this safe region is invaded and violated by acts of perverted intimacy, as the pain is inflicted via e.g. physical methods, psychological, pharmacological, but also sexual violence. It is done repeatedly, often publicly. The sadistic, deliberate manner in which torture is administered results in long-lasting, often irreversible and devastating effects to the victim’s body and soul, as the torturer invades the sufferer’s psyche to claim his mind, bereft of any control or freedom.
Torture is a means to destroy a person’s soul and directed towards establishing a profound sense of powerlessness and terror in victims. As the human soul often possesses a huge amount of resilience, it might take some time to be broken.  With Dean the demons needed three decades. And just as in real life medical personnel often participating during sessions of torture ensure that the victim will live long enough, the demons made Dean ‘whole again, like magic, just so they could start in all over’.
Surviving torture long enough will often culminate in the sufferer’s change of his exegesis of reality. Everything he believed to be true will be twisted, and the victim will be open to be indoctrinated by the torturer’s view and goals. Before that the victim will have experienced depersonalization and derealization, often hallucinations and dissociation, basically strategies of the human mind to construct a kind of alternative reality to mentally survive horrific periods such as torture.  In the course of which the victim’s identity will begin to fragment and anything he held on to will eventually crumble under perpetual agony.  When the sufferer is deprived of other human interaction, he will often bond with the tormentor, sometimes trying to become one with him (what psychologists call introject).
Alistair and Dean probably formed a dyad – we know only of Alistair torturing Dean, which is considered to be one very effective method of torture as it produces interdependency between tormentor and victim, another perverted form of intimacy.
Eventually the sufferer will swallow the torturer’s view of him and plans for him – for instance, believing that he has ‘such promise’ and that he should become a torturer himself. And sometimes inflicting torture can serve as a strategy to reclaim control over one’s life, as a means to – however twisted – regulate their self-worth.

After having changed during thirty years of agony, Dean had to find a way to survive mentally – not realizing, though, that he was giving his mental stability away by succumbing to Alistair’s offer. He perhaps did not see that he most likely channelled his humiliation, agony, aggression, fear into inflicting pain, a misplaced venting: ‘I tortured souls and I liked it. All those years. All that pain. Finally getting to deal some out yourself. I didn’t care who they put in front of me. Because that pain I felt… it just slipped away.’
In his case, for a while, Dean found relief by putting others through agony. It is safe to assume that he did not think about his former self’s conscience. His psyche will have provided him with ‘liking’ what he did, in order to protect him from realizing what he was doing, which is a form of suppression. His deeds might have surfaced later, back in life, haunted by screams he caused – which is evidence that hell had not yet managed to really turn Dean, that the values he held dear were still there, now providing the kind of torture only guilt is able to muster up.

Consequences of torture
All survivors of torture suffer from physical and/or psychological effects, and many never fully recover from the experience. Life is often described in terms of ‘before’ and ‘after I was tortured’; as the survivor’s personal history suffered an incision at that point. Although everyone who had to undergo torture in whatever form is affected by it, not every person develops a mental condition within diagnostic clinical vocabulary. Not everyone shows symptoms of posttraumatic stress.
Now, what about Dean?
Dean survived not only the physical trauma during the time he was tortured, but also the psychological trauma which accompanied the physical pain and proved to be more severe (in particular becoming a torturer himself, a massive inconsistency with the protective and caring nature of his).
Typical posttraumatic sequelae and symptoms of experienced trauma and coping problems are e.g. recurrent re-experiencing of the traumatic events which will occur in nightmares, hallucinations, flashbacks (even during the day sometimes memories will befall the survivor and he will go through a traumatic moment as if it was happening that very instant which often results in panic, erratic behaviour, sometimes even thoughts of suicide).
Dean was often confronted with acoustic (mostly screams) and visual hallucinations (blood red colours, perhaps he even saw something he did or was subjected to, but we, as viewers, were not explicitly informed about it). The moment he experienced those, he got confused and distracted, if only for a couple of minutes (for instance in ‘It’s The Great Pumpkin, Sam Winchester’, the masks hanging from the teacher’s ceiling made him remember something from hell and he stopped in his tracks, a reaction Sam misinterpreted as Dean being reminded of his teenage angst). Those masks, though, served as so-called triggers to open memories of horrific events.
Other symptoms include the persistent avoidance of stimuli associated with the trauma and numbing of general responsiveness. Survivors will try to avoid any contact with thoughts, activities, places, people that might arouse recollections of the trauma. A variation of avoidance will often be the increased misuse of drugs, alcohol or medication (sedatives and analgesics in particular).

They will also often be incapable of recalling important aspects of the experience, show diminished interest or participation in activities formerly important to them, and they will feel detached or estranged from others. Also their range of showing emotion will mostly be restricted.
  Furthermore, survivors of trauma will frequently feel to have a foreshortened future, not expecting to succeed in their jobs, relationships or even having a ‘normal’ life span.

Additionally, survivors will complain of difficulties falling or staying asleep, nightmares, generally increased arousal, thereby often suffering from outbursts of anger or irritability.
The avoidance observable with Dean was expressed by his refusal to talk about his time in hell. In fact, he lied to Sam from the moment he came back, denying to remember anything, which he, unfortunately did. No merciful oblivion here. Memory flashes jumped at him in the coffin, in front of the mirror in the fill-up joint, inspecting the mark of Castiel’s hand on his shoulder, etc. 
Dean also showed less interest in hunting, and his reactions changed. For instance in ‘On the Head of a Pin’ the brothers, returning from Pamela’s funeral, talked in the car – Dean was tired, emotionally drained. Before his stint in hell Dean would have been enraged, not unlike Sam. But here we saw only a shadow of his former self. Even the anger he mustered up in defiance of the angels was not full-hearted. In fact, the quiet moment with Castiel, shortly before Dean started to torture Alistair shows in a nutshell the psychophysical state Dean was in at that time (I recommend the extended scene on the dvd).
When I work with patients who survived torture of whatever kind (or trauma in general), we don’t talk about the events right away. One of the most important part of therapy lies in the building of a relationship between the patient and myself which will allow him to feel completely safe, respected and understood and – very importantly – which will allow him to assume that I am capable of bearing what he has to tell (when he (or she) will be ready to talk about it). To my experience, that is crucial. Often survivors don’t speak about what they underwent because they feel that they might overtax others, primarily their loved ones, trying to protect them. Furthermore, they need to learn how to stabilize themselves when being overwhelmed by flashbacks.
Considering Dean’s relationship with Sam it is most likely that he did not talk about hell for three reasons: a) he was hardly able to handle his memories and afraid of looking back, b) he wanted to protect Sam from the unbearable knowledge of what his brother had to endure (and perhaps protect him from the increase of bad conscience, because Sam had not been able to save Dean from that fate) and c) he was afraid of having to tell the whole truth – that he had become some kind of monster himself.
Instead he tried to quiet those inner voices and the nightmares with alcohol. We’ve seen him drink a lot more that he used to, and he got a drink first thing in the morning after waking up. It took him ten episodes into the fourth season to finally open up, at least a little, about his four decades of hell time.
I need to sing Jensen’s praises here once again – the manner in which he played that scene could have been taken directly from my work. I’ve seen this on a daily basis so often, and it’s heartbreaking how authentically Jensen delivered those lines. I am in awe whenever I watch him play that moment. However he did it… this is very much how a person in such a situation might react.
At first Dean tried to establish some stability with an initial chat, having a beer, slowly beginning to get into the story. All the while not looking at Sam. To be able to speak about it at all, he wasn’t able to see Sam’s face, his feared reaction. Dean started to recount the events in a matter-of-fact way, desperately trying to split away any emotion that might overwhelm him. And Dean managed to do that quite well until he came to the part where he had to admit (once again to himself) what he had done. .’ God help me, I got right off and I started ripping them apart. I lost count of how many souls. The things that I did to them… … how I feel? This…. inside me… I wish I couldn’t feel anything, Sammy. I wish I couldn’t feel a damn thing.’
Of course he was wishing to be numb, to not feel anything, as what he carried on his shoulders was more than he felt capable of bearing.
But he did.
Although there are symptoms of posttraumatic stress to be found, Dean is still functioning on a high level. Those survivors who develop a mental condition clinical psychiatrists/psychologists/therapists call posttraumatic stress disorder usually don’t. They might be able to go about their lives in some way, but very often – from my experience – they are not fit for work (or need a long time to get there), sometimes their relationships fall apart.
Dean has undoubtedly been in danger of that. But there are many factors on his side that protected him from getting sucked in by that disorder. He found himself still efficient, capable of doing what he had done from his youth on (fighting the paranormal world), even though the scars, physical and mental, will need more time to heal (if they ever do entirely). I will elaborate that in another article.
You might have noticed that, after referring to tortured people as victims, I called them survivors in the second part. I did that deliberately, because I found it essential when dealing with people who have experienced the kind of hell torture provides to help them see that they are above all – survivors.  Some inner strength helped them to stay alive, albeit wounded beyond description. And, hopefully, they will find that again. But the path is stony.
It holds true for Dean. He managed to survive, but he will have to learn to live again, having become more than he was before he entered hell. He will learn to defeat the ‘hidden enemy’ of the wounds his soul still carries, fed by guilt, his possible future as Michael’s vessel or the danger of having to kill Sam eventually, should he succumb to the devil, as we have been warned about.