Derealization is a symptom of dissociation, a mental process causing a lack of connection in a person’s thoughts, memory, feelings, or sense of identity. While it involves a dramatic change in how the world is perceived, this experience is fundamentally different from a true hallucination, which is a core feature of a psychotic episode. This distinction centers on the ability to determine what is real and what is not, offering a clear boundary between these two types of distressing experiences.
Understanding Depersonalization and Derealization
Depersonalization (DP) and derealization (DR) are closely related dissociative symptoms that often occur together. Depersonalization involves feelings of detachment from oneself, making a person feel like an outside observer of their own thoughts, body, or actions. This can manifest as feeling emotionally numb, robot-like, or experiencing the self as unreal.
Derealization, by contrast, is characterized by a feeling of detachment from one’s surroundings, making the external world seem unreal, foggy, distant, or dreamlike. Objects may appear visually distorted, seeming flat or unnaturally colored. Time perception can also be altered, with moments feeling either sped up or drastically slowed down.
These experiences are considered defense mechanisms the mind employs, typically in response to overwhelming stress, trauma, or panic attacks. Although the feelings are profoundly disturbing, they are categorized as dissociative rather than psychotic phenomena. The symptoms focus on an alteration of perception of the self or the environment, but the underlying sensory input remains present.
Defining True Hallucinations and Psychosis
A true hallucination is defined as a sensory perception that occurs without an actual external stimulus. This means a person sees, hears, smells, tastes, or feels something not physically present in the environment. Auditory hallucinations, such as hearing voices, are the most commonly recognized type, but visual or tactile experiences also occur.
Hallucinations are a hallmark symptom of psychosis, which involves a significant loss of contact with reality. During a psychotic episode, the individual genuinely believes the false perception is real and originated from an external source. Psychosis is not an illness itself but a symptom of various mental or medical conditions, including schizophrenia, severe bipolar disorder, or substance use.
The defining characteristic of psychosis is the inability to distinguish between subjective experience and objective reality. This break from reality means the person often cannot be reasoned with about their perception, as their brain registers the false sensation as factual. This stands in sharp contrast to the internal experience of derealization.
Sensory Distortion Versus Intact Reality Testing
While derealization involves intense sensory distortions, these are not considered true hallucinations because of intact reality testing. Reality testing is the cognitive ability to differentiate between inner thoughts and the external world. A person experiencing derealization knows the world is supposed to look and feel normal, even though their current perception is distorted.
For example, an individual with derealization might see their hand as unnaturally large or the street as a movie set. However, a part of their mind recognizes that this perception is “wrong” or a symptom of their current state. They maintain the awareness that the floor is not actually moving or that the person they are talking to is not a robot, despite the intense feeling that they are. This critical self-awareness distinguishes it from a psychotic state.
In contrast, an individual experiencing a true hallucination has lost this reality testing ability regarding that perception. They do not merely feel that an object is there; they are sensorily convinced it is present. Derealization is a distortion of existing reality, whereas a hallucination is the creation of a sensory experience with no external basis, which the person accepts as real.
Underlying Causes and Co-occurring Conditions
Derealization does not spontaneously cause true hallucinations; however, they can co-occur when both symptoms manifest from a shared, underlying condition. Dissociative symptoms like DR and DP are prevalent in people with severe anxiety disorders, panic disorder, or post-traumatic stress disorder (PTSD). They can also be triggered by extreme sleep deprivation or certain medications.
When a person experiences both derealization and hallucinations, it is typically because the underlying disorder is one that can cause both dissociative and psychotic features. Conditions such as schizophrenia, schizoaffective disorder, or severe mood disorders with psychotic features can produce both kinds of symptoms. In these instances, the hallucinations and derealization stem from the broader illness, not from derealization progressing into psychosis.
The presence of any confirmed loss of reality testing, where the individual believes their false perceptions are real, signals a need for immediate professional evaluation. Rapid onset or severe functional impairment accompanying these symptoms also warrants swift medical attention. A professional diagnosis is necessary to determine whether the symptoms are purely dissociative, or if they are part of a more complex condition that requires different treatment approaches.