Differences between Delusion and Hallucination
Delusion vs. Hallucination[edit]
Delusion and hallucination are both symptoms of psychosis, but they are distinct phenomena.[1][2] The primary difference lies in their nature: a delusion is a false, fixed belief, while a hallucination is a false sensory perception.[3] In simple terms, delusions are a disturbance of thought, whereas hallucinations are a disturbance of perception.[1] Both can occur in a number of psychiatric and medical conditions, including schizophrenia, bipolar disorder, and dementia.[1][4]
A delusion is a firm and fixed belief that is maintained despite being contradicted by reality and evidence.[5] These beliefs are not accounted for by the person's cultural or religious background.[5] For example, a person with a persecutory delusion may believe government agents are spying on them, even with no evidence. In delusional disorder, a person experiences delusions for one month or longer, but does not typically have other prominent psychotic symptoms like disorganized speech or behavior.
A hallucination is a sensory experience that occurs in the absence of any external stimulus.[1][5] To the person experiencing it, the perception feels real.[1] Hallucinations can involve any of the five senses. Auditory hallucinations, such as hearing voices when no one is speaking, are the most common type in schizophrenia. Visual hallucinations, seeing people or objects that are not present, are also common. Other types include tactile (feeling sensations on the skin), olfactory (smelling odors), and gustatory (tasting things) hallucinations.
Comparison Table[edit]
| Feature | Delusion | Hallucination |
|---|---|---|
| Core Nature | A disorder of thought content; a false, fixed belief.[1][3] | A disorder of perception; a false sensory experience.[1][3] |
| Basis in Reality | A belief held despite contradictory evidence; it is not based in reality.[5] | A sensory perception without any external physical stimulus.[5] |
| Involvement of Senses | Not applicable. It is a belief, not a sensory event. | Involves one or more of the five senses: auditory, visual, tactile, olfactory, or gustatory. |
| Common Example | Believing one is being poisoned by family members. | Hearing voices that are not there.[1] |
| Patient Insight | The person is convinced their belief is real and true.[4] | The person may or may not have insight that the sensory experience is not real. |
| Typical Subtypes | Persecutory, grandiose, erotomanic, somatic, jealous. | Auditory, visual, tactile, olfactory, gustatory. |
Co-occurrence[edit]
Delusions and hallucinations can occur at the same time and can influence one another.[1] This is common in conditions like schizophrenia.[1] For instance, a person may have a delusion that they are being infested with parasites, which is reinforced by tactile hallucinations of insects crawling on their skin. Another example would be a person who believes they can communicate with the deceased, a belief that is strengthened by hearing voices they attribute to spirits. Research indicates that in schizophrenia-spectrum disorders, a majority of individuals who experience hallucinations do so in a single modality, most frequently auditory. About one-third have hallucinations in two modalities, commonly auditory and visual combined.
References[edit]
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 "amfmtreatment.com". Retrieved January 26, 2026.
- ↑ "verywellmind.com". Retrieved January 26, 2026.
- ↑ 3.0 3.1 3.2 "healthline.com". Retrieved January 26, 2026.
- ↑ 4.0 4.1 "dementiahelp.ca". Retrieved January 26, 2026.
- ↑ 5.0 5.1 5.2 5.3 5.4 "medbullets.com". Retrieved January 26, 2026.
