DID - Dissociative Identity Disorder.

OSDD-1 - Other Specified Dissociative Disorder type 1. We make sure to specify the -1 when talking about OSDD-1 systems, as there are several classifications of OSDD that are completely unrelated to being a system!

System - A collective of several individuals in one body. These individuals can be called people, members, alters, headmates, parts, or plenty of other terms depending on the system and the individual. For the purposes of this blog, we usually use the term "system" to mean "a person with DID or OSDD-1"

Alter - One term for a member of a system. This is the term that we prefer to use for ourselves and for our blog, but please be sure to ask other people their preferred term before calling them an alter! See also: headmate

Headmate - One term for a member of a system. See also: alter

Fronting - When a member in a system takes control of the physical body and interacts with the outside world. If multiple system members are fronting at the same time, it's referred to as co-fronting! Some systems refer to this position as the front.

Integration - The process of lowering dissociative barriers for better communication and cooperation between the system. Not the same as fusion.

Dissociative barrier - A "wall" between system members which limits communiation, memories, skills, trauma, and more from crossing the barrier. Can be lowered through integration work.

System member - A member of a system. Other names include people, alters, headmates, parts, and more. We use this term because even though it's a little clunky, it's the most inclusive we can find.

Fusion - The result of completely lowering the barriers between two system members, so that they become indistinguishable. If all system members fuse, this is called final fusion. Fusion is one possible outcome of integration work, but not the only outcome.

Healthy multiplicity -

Blackout - When, after a switch, a system member has no idea what happened when another system member was fronting. This is the most common depiction of switches in media, but in actual DID/OSDD-1 systems, it's uncommon to have complete blackouts.

Switching - When the system member that's fronting changes.

Intra-system - Something that happens internally, between members of a system.

Internal communication - The ability for system members to communicate with one another. This can be through thoughts, speaking aloud, writing, and many other techniques.

Singlet - Someone who isn't a system, and doesn't have alters/headmates/etc.

Asynchronous communication - Communication between members of a system that takes place over a period of time, with gaps in between. The opposite of real-time.

Positive trigger - Something that can draw a member of the system closer to the front. These are usually things that they enjoy or are associated with, like activities or songs.

Inner world - A mental "place" that someone can retreat to, often for therapy, relaxation, accessing memories, or communicating between system members. Inner worlds can be created by anyone, not just systems, but they're especially helpful tools for us!

Grounding - The process of stepping away from flashbacks or negative thoughts, in order to refocus on the present. Often considered the opposite of dissociation.

System Roles

System role - A specific function or "job" that a member of a system carries out. This is often, but not always, directly related to traumatic experiences. Not all system members fit a role, roles can change over time, and someone can fit the definition of a role and still choose not to identify with it! It's just an optional way of categorizing common patterns and behaviors for better understanding and communication.


Caretaker - A system role that involves taking care of the rest of the system, physically, emotionally, or both. Often associated with taking care of younger system members specifically.

Mascot - A system member that's closest to the singular person the entire system presents as. Similar definition to "host", but we prefer this term. We'll do a blog post on why soon!

Protector - A system member that protects the rest of the system, often from existing trauma, or from the potential for further traumatic events. They will often front during triggering or other stressful times, in order to protect more vulnerable members of the system. They might also fight back against verbal abuse, or physically defend the system if necessary. Caretakers are a subtype of protector.

Other Conditions

Psychosis - A condition that affects the way your brain processes information, typically involving a disconnection from reality. Common examples of psychosis include hallucinations, delusions, and disorganized thoughts or speech. Psychosis is a symptom of several disorders, but not a disorder itself!

Catatonia - A mental state characterized by abnormal movements (or abnormal lack of movement). Subcategories of catatonia include withdrawn (immobility, unresponsiveness, blank staring), excited (repetitive involuntary movements, impulsivity, mimicry), and malignant (any of the above symptoms, plus severe life-threatening symptoms such as fever and increased heart rate). Catatonia is usually associated with psychotic disorders such as schizophrenia, but is actually more commonly seen in mood disorders such as depression or bipolar disorder.

Dysphoria - Dysphoria is a general state of unease or dissatisfaction, but we typically use it to refer to physical dysphoria. Examples can include gender dysphoria, feeling like you should be a different age or species, or general discomfort with your body.