Dissociative identity disorder (DID) —what was historically known by the controversial name of "multiple personality disorder"— is one of the most complex and human responses that exist to extreme pain. Forget the Hollywood films and the exaggerated characters of the cinema; the reality is very different. According to the data in the MSD Manual (Spiegel, 2024), this disorder is present in between 1% and 1.5% of the world population, and it affects men and women equally. It is not a manufacturing fault in the brain, but a desperate and evasive strategy of a child's mind to survive a hostile environment.

The origin of the fragmentation: traumatic betrayal

None of us is born with an already unified identity. As children, our identity is put together little by little thanks to stable and secure experiences. But when a child lives in a state of chronic and overwhelming stress —something that happens in 70% to 100% of clinical cases due to severe physical, sexual or emotional abuse (Simeon and Putnam, 2022)— that process of integration breaks.

Imagine growing up with caregivers who sometimes give you affection and other times harm you in a completely unpredictable way. This is called traumatic betrayal. To defend itself, the child learns to "be absent", to hide inside its own mind. Over time, the memories, emotions and thoughts that should have come together into a single "self" remain separated. This is how different identity states or "parts" are born, taking turns at control. This disconnection is so real that it leaves a mark on the brain: a reduction has been observed in an area of the hippocampus (the CA1 region), which is responsible for storing and retrieving memories.

A new perspective: DID as a spectrum of the divided mind

This article seeks to propose another approach, a different understanding of what dissociative identity disorder really is. In the field of psychology we face an important limitation: we have no blood tests or X-rays to diagnose the mind. We depend almost exclusively on the criteria of the manuals and on a handful of questionnaires.

At times, the lack of objective tools makes clinical practice rigid. Most psychologists do not read much about dissociation and do not usually have this clinical eye trained. For that reason, they believe that to diagnose this disorder you have to see something exaggeratedly severe or visible, as if the patient had to be called one name one day and another the next, changing clothes or drastically changing tone of voice.

But DID is not a closed box; it works as a spectrum. A fragmented identity is also a dissociative identity disorder, even if it does not have movie characters switching between one another. Having a fragmented identity simply means that the person lives with a lack of unity in their sense of self in daily life.

Under this new approach, a prior diagnosis of trauma or PTSD (post-traumatic stress disorder) is not needed in order to diagnose DID. Expecting a patient to tell you their whole history of abuse in the first session is to misunderstand how dissociation works. A child who grows up in a cold family, where they are invalidated, rejected or mistreated constantly, normalizes that reality because it is the only one they know. Our own society normalizes family dynamics that are very destructive and rigid.

When that person grows up and goes to a psychology consultation, they are not going to tell you "I have a trauma", because their own dissociative system took charge of blocking, covering and separating that pain so that they could go on living. The professional does not have to look for a giant catastrophe in the account; what they must do is learn to observe and assess the loose threads of the fragmented identity that are present in the session itself. That the patient cannot explain their suffering does not prove that they have no complex past; on the contrary, it is the direct manifestation that dissociation is operating in that very moment.

Clinical reality versus the rigidity of the DSM-5

Here it is essential to understand a contradiction between the textbooks and what happens inside the consultation. If we look at the DSM-5, we see that the manual does not classify dissociative identity disorder under labels of "mild, moderate or severe". It frames it almost as all or nothing. However, day-to-day clinical practice shows us something very different.

In daily practice, you come across patients who meet some of the DSM-5 criteria perfectly, but do not have those very marked or identified identities as if they changed drastically from one person to another or from one entity to another. There is no obvious switch that makes a different "character" jump out. And even so, that person has a dissociative identity disorder.

In the same way, the patient does not necessarily present all the classic symptoms required to diagnose post-traumatic stress disorder (PTSD). The mistake of rigid psychology is to rule out dissociation only because the patient does not fit the perfect mold of visible trauma or because their "parts" are more subtle. The internal fragmentation is still there, sabotaging the person's life, even if it does not follow the strict script of the manuals.

The danger of blind diagnosis and the face of fragmented identity

DID changes a great deal depending on the cultural context, which complicates its detection even further. In the West, clinical bias tends to look for the non-possession form, which is very hidden and covert. By contrast, in non-Western cultures or religious contexts, the possession form usually occurs, where the alternate identities are expressed as if an external agent —a spirit or an ancestor— had taken physical control of the person. If this experience is involuntary and causes distress, it is still the expression of dissociative trauma.

But let us return to the non-possession form, which is the most common and the one that demands a better clinical eye. What does fragmented identity look like in real life? It shows up in subtle but very distressing ways in the patient's daily life. For example:

  • Feeling like an observer: the person feels they are watching their life from the outside, as if they were a mere spectator of their own words and actions, seeing how "someone else" operates their body.
  • Radical changes with no explanation: suddenly they act in ways they do not recognize as their own. They can be a submissive person at work and, from one moment to the next, react with an aggressiveness or a maturity completely alien to their usual personality, feeling afterward a total strangeness about themselves (who was that speaking for me?).
  • Everyday amnesias: experiencing memory gaps in daily life. Not remembering what they did a few hours ago, finding clothes in their wardrobe they do not remember buying, or notes written in their own handwriting whose message they do not recognize.
  • Emotional disconnection: knowing perfectly well that they lived through a sad or important event, but feeling an absolute emptiness, as if it had happened to someone else (emotional amnesia).
  • Massive internal conflicts: internally hearing arguments, opinions or opposing voices that they do not experience as their own thoughts, but as if "other parts" inside their mind were fighting for control.

Because this disorder is so expert at hiding, it often disguises itself behind other problems. The consensus study by Dorahy and colleagues (2014) makes clear that DID comes accompanied by a high rate of comorbidity: depression, chronic physical problems from the wear on the nervous system and, very frequently, substance use disorders.

This is where the great danger of blind diagnosis occurs. Many psychologists think that drug use is the main problem and that all of the patient's symptoms are due to the addiction. There is a false idea that the erratic behaviors, the amnesias or the disconnection are only after-effects of being high or the effects of withdrawal.

However, clinical reality tells us something else: substance abuse frequently operates as a smokescreen (McDowell, Levin and Nunes, 1999). The patient turns to alcohol or drugs as a mechanism of self-medication. They do not use on a whim; they use to quiet these internal parts. Drugs are the psychological anesthesia that the system uses to silence the chaos, the conflicting voices and the anguish generated by the internal fragmentation. If the professional stops only at treating the chemical dependency, they will leave the dissociative patient invisible, unprotected and untreated.

References

Dorahy, M. J., Brand, B. L., Şar, V., Krüger, C., Stavropoulos, P., Martínez-Taboas, A., and Middleton, W. (2014). Dissociative identity disorder: an empirical overview. Australian & New Zealand Journal of Psychiatry, 48(5), 402-417. — McDowell, M. D., Levin, F. R., and Nunes, E. V. (1999). Dissociative identity disorder and substance abuse: the forgotten relationship. Journal of Psychoactive Drugs, 31(1), 71-83. — Simeon, D., and Putnam, F. (2022). Pathological Dissociative Experiences in the National Comorbidity Survey Replication (NCS-R). Journal of Trauma & Dissociation, 23(5), 490-503. — Spiegel, D. (2024). Dissociative identity disorder. MSD Manual, professional version.