“As an undergraduate student in psychology, I was taught that multiple personalities were a very rare and bizarre disorder. That is all that I was taught on ... It soon became apparent that what I had been taught was simply not true. Not only was I meeting people with multiplicity; these individuals entering my life were normal human beings with much to offer. They were simply people who had endured more than their share of pain in this life and were struggling to make sense of it.”

― Deborah Bray Haddock, The Dissociative Identity Disorder Sourcebook

Cooperation, Integration, and Fusion

Image: "Doctor Advises Patient" by Bill Branson

Dissociation versus Integration

Integration in its most basic form occurs any time that information is processed. When an individual incorporates a fact into their understanding of their self or an event into their understanding of their personal history, that's integration. Dissociation can be seen as a failure of integration. When an individual is struggling with depersonalization or derealization, they're having difficulty processing relevant information about their self or environment in real time. When an individual has dissociative amnesia, their memory of the traumatic or stressful event(s) are kept separate from their other memories and may be accessible only through dissociative flashbacks. When an individual has dissociative identity disorder (DID) or other specified dissociative disorder subtype 1 (OSDD-1), information is stored in separate dissociated parts, known as alters.

Every individual who has been through trauma must integrate to some extent as part of healing. This means accepting that the trauma occurred, making it part of one's personal narrative, and making it accessible in a way that does not cause intense re-experiencing of trauma elements. In doing so, an individual may have to accept thoughts, feelings, and urges associated with their trauma. For example, an individual with posttraumatic stress disorder (PTSD) may find that as they integrate their trauma history into their personal narrative, they have to also process feelings of helplessness, betrayal, fear, or anger. In terms of structural dissociation, the individual has to integrate the emotional part(s) associated with their trauma, and that means having to take ownership of everything that the part(s) contained.

Integration of Alters (Fusion)

For individuals with DID or OSDD-1, some or all of their parts likely go beyond simple containers of traumatic materials, and the parts may have strongly developed independent senses of autonomy and self. The individual must then make the choice of to what extent they want to integrate their alters as part of their healing. Again, some degree of integration is inevitable. The individual must integrate traumatic materials in order to heal from PTSD. As well, enough integration between alters must occur to allow for easy communication, a lack of dissociative amnesia between parts, and a consistent sense of being grounded in the present and in the body. The individual must be able to take responsibility for all of the system's actions, and all alters in the system should work together towards the same goals. Another goal of reduced dissociative barriers between parts is being able to freely access skills, memories, and traits without these being dependent on the alter present.

In order to fully integrate two or more alters (which the ISST-D refers to as "fusion," with "final fusion" referring to a complete integration of all dissociated parts), the individual needs to take ownership of all thoughts, feelings, memories, urges, skills, and other traits that were previously associated with those parts of the self. Integration is complete when there are no subjective differences between the parts involved; only one sense of self remains. This can happen spontaneously, when conflicts or dissonance between the alter and one or more other alters are resolved; with the help of "fusion rituals", such as imagery representing unification; or after negotiation between parts and an agreement to integrate.

Integration of alters can be experienced in different ways. For fragments (parts with only minimal differentiation), integration may simply entail other alters being able to access what those parts held without a switch being necessary. There may be no major change in how other alters perceive themselves or the world. Even with more developed alters, one alter may seem to integrate into the other so that the resulting part retains the identity of one of the alters involved but gains some of the skills, traits, preferences, or views of the other. Another possibility is that the integration of two or more alters may lead to the creation of a seemingly "new" alter that contains some combination of traits from the parts that integrated. This alter may feel like all or none of the alters involved but is regardless an acknowledgment that what the alters held no longer needs to be kept separate. Finally, an integration may indicate a shift that has already occurred in the system. For example, if an alter primarily held acceptance of same sex desires, that alter may no longer be perceived as separate as the system as a whole moves towards accepting their sexuality.

It must be noted that not every trait that an alter held will be experienced in the resulting integrated part in the exact same way as it was prior to integration. Traits such as gender identity, sexuality, or religion may have differed between parts, and the individual will need to figure out for themself their integrated stance on these and other points of conflict. Some preferences that alters had may be muted when no longer contained in relative isolation; for example, the integration of an alter who really loved hard rock is unlikely to completely change the musical preferences of an individual who loves classical music, but the individual might find that the integration results in a greater tolerance for rock music or widens the range of music that they enjoy. Some traits may be lost entirely, such as an alter's unhealthy ability to ignore pain at the expense of respecting one's physical limits. Finally, some skills or abilities that alters excelled at may require additional practice as an integrated individual before they can be fully expressed.

Even when some traits are lost, integration that was not forced or rushed should not feel like a loss in the long-term. Healthy integrations feel like what they are: an acceptance of aspects of oneself that one wasn't previously able to fully accept. Some individuals do need to take some time to mourn the loss of experiencing an alter as separate, but others experience integration as joyous! Alters may want to integrate so that they no longer miss out on so much of the system's life, so that their emotional range is no longer limited, or so that they can consistently contribute to the system's functioning and safety. Overall, integration leads to a more stable and well-rounded individual who has consistent access to all parts of themself. As the individual learns to connect with all of their thoughts, feelings, and behaviors, they will learn to rely less on dissociation, and their general dissociative symptoms will decrease. An individual who is fully integrated and has achieved final fusion may be less vulnerable to increased dissociation or splitting into new parts as a result of future stress.

That said, it must be acknowledged that sometimes, a decrease in dissociation can be experienced as very negative either temporarily or in the long-term, such as if increasing integration decreases an individual's ability to shut off awareness of chronic pain. While the integration is still healthy and allows the individual to better respect their body's limits, it can nonetheless be stressful or upsetting, especially at first. Similarly, an individual may have to process a lot of grief when they have to accept that no part of them is truly free from the trauma and resulting emotional pain and disability that the system as a whole experiences. In some cases, personality changes as a result of integration may be highly beneficial for the individual but disrupt their existing relationships, such as family and friends not approving of the individual gaining assertiveness and the ability to maintain healthy boundaries.

Partial Integration (Resolution or Functional Multiplicity)

Some systems choose to stop at what the ISST-D calls resolution, or what may also be called functional multiplicity. In this case, systems may retain any number of independently acting alters. The current rates of complete integration and functional multiplicity may be very similar. A 2017 study (Myrick et al.) followed up on 61 therapists about the well-being of specific patients of theirs after 6 years; 12.8% of therapists reported that their patients had terminated therapy due to achieving stable integration, and exactly the same percentage reported that their patients had terminated therapy due to resolution of symptoms without full integration. The rate of complete integration might be lower than it was in the past because many therapists are now less insistent that full integration is the only possible treatment for DID. This is a good thing even for those who want to fully integrate because it prevents the process from being rushed. Permanent integration cannot be forced, and an integration that occurs before the system was ready for it is very likely to fall apart. This can make the system more hesitant to try again or can make it difficult to identify what the individual has truly processed versus is only claiming to have processed to please their therapist (Kluft, 1986). 

Reasons for choosing not to fully integrate can include: feeling that full integration is unnecessary; not understanding what integration actually entails and being afraid of "losing" or even "killing" alters; uncertainty over how to navigate the world as one integrated person; fear of not being able to handle future traumas without relying on dissociation; being used to having alters around for company, entertainment, or support; alters having their own unique relationships that they're hesitant to lose; alters wanting to remain separate for their own sakes; or the individual not wanting to lose attention, support, or a sense of being unique that they feel is associated with remaining dissociated. In some cases, friends and family may overtly or covertly communicate that they prefer the individual to remain multiple, possibly because of attachment to individual alters or because of disliking how the individual's personality shifts as they fuse. If the system is in spaces oriented towards those with DID/OSDD-1, integrating may fundamentally alter their relationships and place in the community. Some individuals with DID/OSDD-1 question if integration is even permanently possible, which of course makes it harder to achieve (ISST-D, 2011; Kluft, 1986).

Unfortunately, even some individuals who might otherwise want to integrate can find it impossible to integrate all of their parts or to maintain one integrated personality over time. This can occur when an individual is in a highly stressful or unsafe environment, can't bring themself to fully accept or process their trauma history, can't bring themself to fully admit to their degree of fragmentation or dysfunction, can't access treatment from professionals who are knowledgeable about DID, can't afford to continue treatment, or experiences intense interference from symptoms of comorbid personality or other disorders. Finally, in some cases, the system as a whole may appear or claim to want integration, but individual parts may disagree and openly or secretly try to remain separate; sometimes, this is temporary and only lasts until all parts of the individual are truly convinced that they can function as a unified whole (ISST-D, 2011; Kluft, 1986).

Even individuals with DID who are vocal about their desire not to integrate are likely to spontaneously integrate some alters and fragments as they process and heal, and many systems willingly integrate down to a few alters (including well known systems such as Robert Oxnam). Kluft found it noteworthy that systems that prioritized cooperation naturally moved towards integration even if they originally desired to remain multiple, convincing him that the mind desires and will work towards unity. However, not all integrations are stable. Integrations might fall apart if the alters involved weren't completely ready yet, if a stressor arises that one alter in particular was created to handle, or if the alters involved need influence from other alters in order to remain stable in their unity (e.g., an internal helper part is needed to handle a stressful period of time to prevent greater problems, distress, and subsequent dissociation). Even if an integration falls apart, it may be quickly re-achieved with the right support (Kluft, 1986).

Full Integration

Many individuals who are fully integrated are convinced that integration is the best option, and there is research supporting that this is the case. For example, Ellason and Ross (1997) found that complete integration was associated with reduced overall dissociation, amnesia, somatic symptoms, Schneiderian first-rank symptoms, borderline symptoms, depression, and suicidality. Coons and Bowman (2001) also found that compared to unintegrated individuals, integrated individuals are less depressed, less affected by somatic symptoms, have less posttraumatic stress, and are overall less dissociative to the extent that their symptoms match those of the general population. Additionally, they have fewer hospitalizations and less anxiety compared to those who are unintegrated. However, it's worth noting that those who achieved integration in this study were also less symptomatic upon entering treatment.

It must be noted that even if an individual successfully fully integrates, it is possible for the integration to temporarily dissolve during times of stress or conflict. In the short term, this is very likely if the stabilization phase of therapy wasn't sufficient and the individual lacks the coping skills necessary to handle life without relying on dissociation. Even one or two years out, another trauma, the death of an abuser, or the loss of an important individual may all lead to the return of fragmentation. In some cases, an integration that appeared complete may actually not have been so, and more alters may emerge only when the individual is stable and strong enough to handle the alters' traumatic memories or resolve the protective behaviors they engage in. For example, only once an individual has sufficiently processed traumatic memories related to childhood sexual abuse might an alter be revealed who previously used over-eating to attempt to look unattractive and prevent being an object of sexual interest. It's important to keep in mind that all of this is a normal part of the progression of integration and is not a bad sign or a setback. It's also worth noting that alters that return during relapse events are often less separate and re-fuse rapidly. Treatment by dissociation specialists may make integrations more likely in general and more likely to be permanent (Kluft & Donne, 1984; Kluft, 1986).

In 1986, Coons examined DID clients treated by different therapists, the majority of whom had no prior experience treating DID, and found that of 18 patients after on average 39 months, 5 had fully integrated and remained integrated, 2 had temporarily integrated but re-fragmented after additional trauma, and 2 had partially integrated. In a 10 year follow-up study of 12 individuals with DID (Coons & Bowman, 2001), 4 had completely integrated, and 2 had integrated but re-fragmented due to stress. The 2 patients who had dropped out of treatment remained unintegrated, and integration was also less likely in those who had to switch between several therapists post-diagnosis. Additionally, although it took 5.4 years on average for the individuals to integrate, both teenager participants did so in 2 or fewer years. Interestingly, integrated and unintegrated individuals in the study had experienced a similar number of life events during the follow-up period, but the integrated individuals viewed these events positively while the unintegrated group viewed them negatively.

Kluft defined integration as a full 27 month period with no amnesia or signs of identity fragmentation (including observed signs of multiplicity, a subjective sense of having parts, or disowning opinions or traits previously associated with alters). This is because he found that 60% of individuals who integrate and remain integrated for at least 3 months show no future return of dissociation, and this figure continues to rise throughout the 27 month period. In a 10 year follow-up of 123 individuals with DID treated by Kluft (Kluft & Donne, 1984), 33 achieved this strict definition of full and stable integration, and another 50 were fully integrated but had not met this strict criteria; of these 50, 16 simply hadn’t hit 27 months yet, and 20 couldn’t be contacted again to see whether or not they met the criteria. Two years later, Kluft published an additional follow-up (Kluft, 1986) which included the previous 33 patients and a new 19 patients who had experienced stable fusion for at least 27 months. In this case, the pool included another 54 patients who had been integrated for at least 3 months but had not achieved stable fusion. Of the 52 individuals with allegedly stable integrations, only 11 had had a “relapse event,” which only indicated full alters and amnesia in 3 cases. By the time of publication, only 2 of the 11 were still dissociative, with others having achieved stable integration after additional therapy. Of 13 individuals who maintained integration for 5 or more years, only 1 experienced an easily resolved relapse of vaguely differentiated parts, and another found a part that had previously been dormant and so had not had its materials integrated. Stable integration was more likely and more easily achieved for males and for individuals with smaller systems (fewer than 18 alters). Larger systems took longer to treat and tended to have more relapse events. However, these systems are still capable of integrating with the right treatment, as are even those with severe borderline features. 

Like Coons and Bowman, Kluft found that children often integrate very rapidly compared to adults and even adolescents. In a study of 5 male children between the ages of eight and eleven (Kluft, 1985), 4 achieved apparent integration. Some integrations were spontaneous, and others involved creative imagery to engage the children and help them understand the process. In the two children for whom follow-up was possible, integration had been maintained for 22 and 69 months respectively. Kluft believed that alters may continue to develop throughout childhood and adolescence, meaning that childhood presentations of DID may not be fully formed (i.e., lack parts that fully switch out or are well elaborated) and be less complex (i.e., lack parts with highly specialized functions or internal arrangements of parts) and so may be much easier to treat. Even when fully formed alters are present, they're usually less invested in their continued existence than alters often are in teenagers and adults. Children with DID/OSDD-1 are often confused, frightened, and upset by periods of amnesia, being accused of uncharacteristic behavior, and feeling impulses from other parts, and their alters may be eager to step back when made aware of the negative impacts of their attempts to help. They often express a desire to integrate and become "normal." 

Post-Fusion Therapy and Integrative Work

After an attempt at final fusion, it might take some time for the individual to become used to living as one integrated identity. Like everything else, learning a new way of viewing oneself and learning how to rely on responses other than dissociation take practice! Additionally, it is vital to understand that final fusion in of itself is not a cure. Only once an individual has fully processed all memories and experiences no meaningful fragmentation can they be said to be fully integrated. This requires more than the fusion of discrete alters alone.

Once all alters have joined together as one, the individual has to process having access to their full trauma narrative from an integrated, first-person perspective for the first time. They have to deal with the full range of associated emotions and cognitions, including grief over the opportunities lost due to trauma and the individual’s resulting dysfunction. That needs to be acknowledged and addressed in treatment. Additionally, the individual must be helped to accept other memories, traits, or actions that their alters previously held. Acknowledging, remembering, and taking full ownership of all emotional pain, weaknesses, disabilities, harms caused to others, self-harm, and self-sabotage previously associated with alters can be difficult and painful. Integration may not fix negative core beliefs, such as feelings of being worthless or harmful to others; in contrast, these beliefs which may not have seemed to affect the daily life parts before may need to be fully addressed once they can be understood and felt through the lens of what all alters held. Finally, integration may lead to shifts in important relationships that need to be addressed, and an individual may only be stable enough to address adult-life concerns like intimate partnerships or employment once they're fully integrated.

Treatment should continue for a while after an individual has achieved final fusion in order to support this process. In some cases, post-fusion treatment may be longer than the work preceding it. Additionally, even after terminating or "graduating" from therapy, an individual may need to briefly return to therapy in order to address temporary lapses in integration, an increase in dissociation in response to new stressors, or other novel problems.

Other Resources on Integration Versus Cooperation

Here is a blog post from a therapist who specializes in trauma and dissociation and who believes that integration is neither necessary nor always helpful.

Here is an article by an individual with DID who wants to integrate. It details the difference between wanting alters to disappear (which is impossible) and accepting them fully (which is necessary for integration).

Here is an article by an individual who had DID and chose to integrate. It details what integration is and why the author views it as the best goal for healing.

Other Useful Resources on Treatment for DID/OSDD-1

For dissociative individuals:

  • Alderman, T. & Marshell, K. (1998). Amongst ourselves: A self-help guide to living with dissociative identity disorder. New Harbinger Publications.
  • A. T. W. (2005). Got parts?: An insider’s guide to managing life successfully with dissociative identity disorder. Loving Healing Press.
  • Boon, S., Steele, K., & van der Hart, O. (2011). Coping with trauma-related dissociation: Skills training for patients and therapists. W W Norton & Co.

For clinicians:

  • Chefetz, R. A. (2015). Intensive psychotherapy for persistent dissociative processes: The fear of feeling real. W W Norton & Co.
  • Chu, J. A. (2011). Rebuilding shattered lives: Treating complex PTSD and dissociative disorders (2nd ed.). John Wiley & Sons, Inc.

  • Howell, E. F. (2011). Understanding and treating dissociative identity disorder: A relational approach. Routledge/Taylor & Francis Group.

  • Steele, K., Boon, S., & van der Hart, O. (2017). Treating trauma-related dissociation: A practical, integrative approach. W W Norton & Co.


Coons, P. M. (1986). Treatment progress in 20 patients with multiple personality disorder. The Journal of Nervous and Mental Disease, 174(12), 715-721. doi: 10.1097/00005053-198612000-00002

Coons, P. M. & Bowman, E. S. (2001). Ten-year follow-up study of patients with dissociative identity disorder. Journal of Trauma and Dissociation, 2(1), 73-89. doi: 10.1300/J229v02n01_09

Ellason, J. W. & Ross, C. A. (1997). Two-year followup of inpatients with dissociative identity disorder. American Journal of Psychiatry, 154(6), 832-839. doi: 10.1176/ajp.154.6.832

International Society for the Study of Trauma and Dissociation [Chu, J. A., Dell, P. F., Van der Hart, O., Cardeña, E., Barach, P. M., Somer, E., Loewenstein, R. J., Brand, B., Golston, J. C., Courtois, C. A., Bowman, E. S., Classen, C., Dorahy, M., ̧ Sar, V., Gelinas, D. J., Fine, C. G., Paulsen, S., Kluft, R. P., Dalenberg, C. J., Jacobson-Levy, M., Nijenhuis, E. R. S., Boon, S., Chefetz, R.A., Middleton, W., Ross, C. A., Howell, E., Goodwin, G., Coons, P. M., Frankel, A. S., Steele, K., Gold, S. N., Gast, U., Young, L. M., & Twombly, J.]. (2011). Guidelines for treating dissociative identity disorder in adults, third revision. Journal of Trauma & Dissociation, 12(2), 115–187.

Kluft, R. P. (1985). Hypnotherapy of childhood multiple personality fisorder. American Journal of Clinical Hypnosis, 27(4), 201-210. doi: 10.1080/00029157.1985.10402608

Kluft, R. P. (1986). Personality unification in multiple personality disorder: A follow-up study. In B. G. Braun (Ed.), Treatment of multiple personality disorder (pp. 29-60). American Psychiatric Press, Inc.

Kluft, R. P. & Donne, J. (1984). Treatment of multiple personality disorder: A study of 33 cases. Psychiatric Clinics of North America, 7(1), 9-29. doi: 10.1016/S0193-953X(18)30777-9

Myrick, A. C., Webermann, A. R., Loewenstein, R. J., Lanius, R., Putnam, F. W., & Brand, B. L. (2017). Six-year follow-up of the treatment of patients with dissociative disorders study. European Journal of Psychotraumatology, 8(1), 1344080. doi: 10.1080/20008198.2017.1344080

"Dissociating feels like building a jig-saw puzzle and you're missing a piece. It bothers you that the picture will never be complete despite how hard you try to look at it. The best thing to do is focus on how beautiful that incomplete picture can be."


“I believe the perception of what people think about DID is I might be crazy, unstable, and low functioning. After my diagnosis, I took a risk by sharing my story with a few friends. It was quite upsetting to lose a long term relationship with a friend because she could not accept my diagnosis. But it spurred me to take action. I wanted people to be informed that anyone can have DID and achieve highly functioning lives. I was successful in a career, I was married with children, and very active in numerous activities. I was highly functioning because I could dissociate the trauma from my life through my alters. Essentially, I survived because of DID. That's not to say I didn't fall down along the way. There were long term therapy visits, and plenty of hospitalizations for depression, medication adjustments, and suicide attempts. After a year, it became evident I was truly a patient with the diagnosis of DID from my therapist and psychiatrist. I had two choices.

First, I could accept it and make choices about how I was going to deal with it. My therapist told me when faced with DID, a patient can learn to live with the live with the alters and make them part of one's life. Or, perhaps, the patient would like to have the alters integrate into one person, the host, so there are no more alters. Everyone is different.

The patient and the therapist need to decide which is best for the patient. Secondly, the other choice was to resist having alters all together and be miserable, stuck in an existence that would continue to be crippling. Most people with DID are cognizant something is not right with themselves even if they are not properly diagnosed. My therapist was trustworthy, honest, and compassionate. Never for a moment did I believe she would steer me in the wrong direction. With her help and guidance, I chose to learn and understand my disorder. It was a turning point.”

― Esmay T. Parker, A Shimmer of Hope