Delusion vs Hallucination: What’s the Difference?

Delusions and hallucinations are sometimes grouped together. The terms may even be used interchangeably, and while they can occur as part of the same disorder, in some cases, there are differences. When comparing a delusion vs hallucination, the critical difference is that a hallucination is a sensory perception that seems real to the person. A delusion means someone has a false belief they think is true.

Both delusions and hallucinations can fall into the larger category of the medical condition of psychosis. With psychosis, a person loses touch with reality.

The medical conditions most often associated with psychosis include:

• Alcohol and some drugs, during use and also withdrawal
• Some brain diseases like Huntington and Parkinson diseases
• Dementia, including Alzheimer’s
• HIV and infections that affect the brain
• Prescription drugs such as stimulants and steroids
• Forms of epilepsy
• Stroke
• Schizophrenia
• Bipolar disorder or severe depression
• Some types of personality disorders

Delusion vs. Hallucination

What Are Delusions?

Delusions are false beliefs that are not based on reality. Even though the evidence indicates that something isn’t true, someone experiencing delusions can’t let go of the thoughts. Many times, when a person is experiencing delusions, paranoia may exist too. Delusions may occur along with visual or auditory hallucinations, frequently as part of psychotic disorders. Delusions can include things that could theoretically actually be true but aren’t. They can also be bizarre beliefs that could not be true.

There are types of delusions, which include:

• Erotomanic: This type of delusion is characterized by a person’s belief that someone is in love with them. This is usually someone famous or well-known. A person with erotomanic delusions will believe that the person, such as an actress, is giving them secret signals indicating their love for them.

• Grandiose: In a grandiose delusion, someone believes they are extraordinarily talented, powerful, wealthy, or famous. For example, someone with grandiose delusions could believe that they are on earth to save it from some sort of threat.

• Persecutory: Someone experiencing these delusions might believe they’re being followed, drugged, or spied on, for example.

• Jealous: One with jealous delusions falsely believes their partner is cheating on them. They might think that every time they go to a certain location, their love interest is meeting them there, or other people are passing messages between the two.

• Somatic: With somatic delusions, a person may believe there is something physically or bodily that they’re experiencing, such as a parasitic invasion in their body.

As is the case with many psychiatric conditions, researchers believe delusional states arise from a combination of biological, psychological, genetic, and environmental factors. 

Psychotic disorders such as schizophrenia do tend to run in families. Brain abnormalities such as an imbalance of neurotransmitters, trauma, and stress can all be part of a delusional state.

What Are Hallucinations?

A sensory experience, hallucinations are things that someone thinks are real even when they’re not.

Hallucinations can be visual, auditory, or tactile. They can also be olfactory, which means they’re related to the sense of smell, or gustatory, which is the sense of taste.

Examples of these include:

• Visual: With visual hallucinations, a person may see things that aren’t there. It could be someone they see as being in the room or maybe flashing lights or patterns.
• Olfactory: Olfactory hallucinations is the belief that they’re smelling a foul or pungent odor or thinking that someone smells bad.

• Gustatory: Someone may taste unpleasant or strange things that aren’t there. For example, they may experience a metallic taste.

• Auditory: This is the most common type of hallucination. Someone could hear voices that are telling them what to do, or they might hear repeated sounds in their home.

• Tactile: An example of this could be feeling bugs crawling on the skin.

Comparing a Delusion vs. Hallucination

When looking at a delusion vs. a hallucination, the similarities between the two are that they can both be a symptom of psychosis. They’re also removed from reality, and they tend to occur together.

Each has its own symptoms, however.

Hallucinations, as has been touched on, are a sensory experience. Delusions are untrue beliefs.

Treating Psychotic Disorders

The treatments for mental illness or mental disorders that involve symptoms like delusions and hallucinations are broad. If someone is experiencing psychotic symptoms because of substance abuse, for example, then those symptoms may start to subside when they stop using the drug causing them. If someone is experiencing hallucinations during alcohol withdrawal, eventually, that will end as well.

If someone has a longer-term psychotic disorder, there are treatments available.

Antipsychotic drugs can be one of the first-line treatments. Antipsychotics don’t cure the condition, but they do help a person manage the symptoms.

Summing Up

While they do tend to occur together, there are key differences in a delusion vs. a hallucination. Treatment for the symptoms of either depends on the underlying condition, which can be short-term, such as an effect of using a drug, or long-term, as is the case for people with schizophrenia. 

If you’re experiencing either of these symptoms, contact one of the mental health professionals at the Mental Health Center of San Diego for a free consultation.