“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
Time loss is defined as a period of time that one or more alters cannot account for due to another alter having been active in the body or mind in their place. Time loss can span from a few seconds to a few years but may not be complete. For example, if Alter A is the host from ages 7-9 and Alter B is not present at all during this time period, Alter B may have no idea of anything that occurred during this period when they become active again at age 10. On the other hand, once Alter B has awakened, they may be able to access Alter A's or another alter's memories in order to get some idea of what transpired in their absence. It is also possible that while they were not active from ages 7-9, Alter B may have gotten flashes of information about the outside world within this time period. Dissociative barriers between alters are not tangible, literal things, and more information can bleed through them than some might expect.
A specific form of time loss occurs when an alter is blacked out. A black out is when one or more alters are unaware of anything while one or more other alters use the body. Some alters may have a vague sense of time passing or feel as if they're trapped in darkness, but many may experience a complete episode of time loss in which they do not exist. Time loss in the form of black outs can be frightening for many to notice. Often, black outs are perceived as overwhelming evidence that one has either dissociative identity disorder (DID) or some non-traumagenic but likely neurological problem. Black outs can feel confrontational and may induce episodes of denial in which the individual or alter cannot accept that they have DID, were abused, or are anything other than a liar, fake, or lunatic.
Black outs are associated with dissociative amnesia. Like individuals who suffer from dissociative amnesia, alters who have blacked out may not recognize or acknowledge that they have lost time and may become aggressive or distressed if confronted with evidence of blanks in their memory. Amnesia can cover amnesia, leaving an individual convinced that they never lose time up until the moment in which it becomes undeniable. Evidence of time loss can include finding possessions, art, or writings that the individual does not recognize, being called an unknown name by strangers who act in a familiar manner towards them, or being confronted about their supposed actions that they cannot remember. Sometimes, an alter might experience dissociative fugue and suddenly find themself in a different location with no explanation of how they got there. There might be periods of their life that they can’t recall. Their entire childhood might be blank, or they might suddenly realize that they cannot remember anything before they left their house at age 18.
Though all alters that are blacked out are losing time, not all alters that are losing time are blacked out. An alter may not be aware of the outside world for a period of time but still be to some degree active and aware in an internal world. As internal worlds do not always run parallel to the outside world, an alter may spend what feels to them like a week inside only to return to the outside world and find that months have passed in their absence. In such a case, the alter was not completely unaware of anything, but they were not aware of the outside world or its happenings.
Not all switches lead to time loss. Many systems have developed some degree of co-consciousness, or the ability for two or more alters to remain present in the body or aware of the outside world at once. Alters that are co-conscious, or co-con, with each other might have varying degrees of control over the body and may or may not be aware of each others' thoughts and feelings to varying degrees. Some systems are naturally more co-con than others. Some may need to work for years to achieve a working state of co-consciousness between a few highly communicative alters while others may find that they can so easily become co-conscious that they have a hard time not going into denial that they ever lose time at all.
However, even within one system, co-consciousness is not necessarily extended to all alters. It may be that Alters A and B are always co-con with each other but only Alter A is co-con with Alter C. Meanwhile, Alter D may be able to watch the other alters though they are not aware of Alter D and their activities in return, and Alter E might not be aware of any of the other alters nor any of the other alters aware of Alter E! Finally, Alters F and G might be co-conscious with each other but have to leave post-it notes for the rest of the system in order to communicate, and Alter H might be co-conscious with Alter A only some of the time or under certain conditions while Alter I has the ability to allow or not allow others to be co-conscious with them as they choose.
A specific form of co-consciousness is known as co-fronting. When two or more alters are in control of the body at the same time to varying degrees, they are said to be co-fronting. Alters may be aware of each others' actions or own each others' actions as their own to varying degrees.