A delusion is a fixed false belief that persists despite clear evidence to the contrary and is not explained by a person's cultural or religious background. Delusions are a hallmark symptom of psychotic conditions including schizophrenia, schizoaffective disorder, and delusional disorder. Understanding the different types helps with accurate diagnosis and appropriate treatment — different types appear in different conditions and respond to different therapeutic approaches. If you or someone close to you is experiencing delusional thinking, contact the Cadabam's team for an assessment.
What Are the Main Types of Delusions?
The DSM-5 and ICD-11 recognise several primary types of delusions, classified by the content of the false belief. Seven main categories appear consistently across psychiatric literature. Persecutory delusions are the most common across psychotic conditions — they occur in up to 50% of schizophrenia cases.
The sections below cover each of the seven main types in turn, followed by the conditions they appear in and how they are treated.
1. Persecutory Delusions (Most Common)
Persecutory delusions are the most prevalent type. The person holds a fixed belief that they are being watched, followed, poisoned, harassed, or conspired against.
Typical examples include the belief that neighbours are spying through walls, that coworkers are plotting to get them fired, or that food is being tampered with. The fear and distress are genuine — the person is not pretending. Persecutory delusions appear most often in paranoid schizophrenia and delusional disorder, and also in severe depression with psychotic features.
2. Grandiose Delusions
Grandiose delusions involve an inflated, false belief in one's own importance, power, wealth, genius, or special connection — often to a deity or historical figure.
Examples include believing one has a secret world-saving mission, possesses superhuman abilities, is the rightful heir to a kingdom, or is a famous person in disguise. Grandiose delusions occur in schizophrenia, bipolar disorder during a manic episode, and delusional disorder (grandiose type). They are often less distressing to the person experiencing them than persecutory delusions, but they cause significant social and occupational impairment.
3. Somatic Delusions
Somatic delusions centre on the body — the false belief that the body is diseased, infested, malformed, or not functioning correctly, despite clear medical evidence to the contrary.
Common examples include believing the body is infested with parasites or insects, that internal organs are rotting, or that a body part has changed shape. Somatic delusions are seen in delusional disorder (somatic type) and in severe depression with psychotic features. They are often deeply distressing and lead to repeated medical investigations before a psychiatric cause is identified.
4. Erotomanic Delusions (De Clérambault'S Syndrome)
Erotomanic delusions involve the fixed false belief that another person — usually of higher social status — is secretly in love with the individual.
The "target" is often a celebrity, public figure, employer, or distant acquaintance. The person interprets ordinary behaviour as coded signals of love. In some cases this leads to stalking behaviour, repeated unwanted contact, or legal trouble. For a deeper look at this condition, see our guide to erotomania.
5. Jealous Delusions (Othello Syndrome)
Jealous delusions are the pathological, fixed belief that a romantic partner is being unfaithful, despite no real evidence.
This is not the same as ordinary jealousy. The conviction is unshakeable and does not respond to reassurance, evidence, or rational discussion. The person may go to great lengths to "catch" the partner — surveillance, repeated questioning, or examining belongings. Othello syndrome is associated with alcohol use disorder, Parkinson's disease, dementia, and psychotic disorders. It carries real safety risks for the accused partner.
6. Referential Delusions
Referential delusions involve the belief that external events, people, or media are sending special messages directly to the person.
Examples include believing that a news anchor is speaking to them personally, that song lyrics on the radio contain coded instructions, or that strangers' offhand comments are full of hidden meaning. Referential delusions are a common early symptom in schizophrenia — they may appear before more dramatic symptoms and are often missed.
7. Nihilistic Delusions
Nihilistic delusions involve the false belief that the self, others, or the world does not exist or is about to be destroyed.
A specific severe form is Cotard's delusion, in which the person believes they are dead, that parts of their body have ceased to exist, or that their internal organs have stopped functioning. Nihilistic delusions are seen most often in severe depression with psychotic features, and they require urgent psychiatric assessment because of the associated suicide risk.
What Conditions Cause Delusions?
Delusions are symptoms of underlying conditions, not standalone diagnoses. The most common conditions in which they appear are:
- Schizophrenia — particularly the paranoid presentation, where persecutory and referential delusions are common.
- Schizoaffective disorder — combining mood disturbance with delusions.
- Delusional disorder — non-bizarre delusions without other prominent psychotic symptoms.
- Severe depression with psychotic features — typically nihilistic, somatic, or guilt-themed delusions.
- Bipolar disorder — grandiose delusions during mania, nihilistic during severe depression.
- Dementia, especially Alzheimer's — persecutory delusions about theft or partner infidelity.
- Substance-induced psychosis — from stimulants, cannabis, alcohol withdrawal, or hallucinogens.
How Are Delusions Treated?
Delusions respond best to combined medication and therapy.
Antipsychotic medication is the primary treatment. Second-generation antipsychotics such as risperidone and olanzapine target delusions across most underlying conditions. CBT for psychosis (CBTp) helps the person gently examine the evidence for their beliefs without direct confrontation — direct argument tends to entrench delusions rather than weaken them. Family psychoeducation helps loved ones respond in ways that support rather than escalate. Inpatient care during acute episodes provides safety and rapid stabilisation. One of the central clinical challenges is engaging someone in treatment when they do not believe they are unwell — Cadabam's team has long experience with this delicate work. You can contact our team to begin.
Responding to Each Type of Delusion — the Family Action Guide
Once you can name the type of delusion your loved one is experiencing, the natural next question is: what do I actually do about it? The reassuring part is that the same core principle works across every type — and the practical part is that each type has a slightly different emotion underneath, so knowing the type helps you aim your response.
The principle the team teaches families through the Family Psycho-Education Support Group (FPSG) at Cadabam's Amitha is one line that holds for all of them:
Validate the emotion, not the belief.
A delusion is a firm, fixed belief that cannot be changed by evidence or logic. That is why the two most natural responses both backfire: arguing ("that's not true") turns the moment into a confrontation and leaves the person more alone, while agreeing ("yes, you're right") reinforces the belief. Instead, you meet the feeling underneath — and the feeling is different for each type:
| Type of delusion | The emotion usually underneath | What to say (validate the feeling) |
|---|---|---|
| Persecutory / paranoid ("I'm being watched / followed / poisoned") | Fear, feeling unsafe | "I can see this is really frightening for you. I'm here with you." |
| Grandiose ("I've been chosen / I have special powers") | A need to feel valued, significant, or in control | "It sounds like this matters a great deal to you. Tell me more about it." |
| Jealous ("my partner is being unfaithful") | Insecurity, fear of loss | "I can see how painful and worrying this feels for you right now." |
| Somatic ("something is wrong inside my body") | Fear about health, distress | "That sounds really distressing. I want to understand what you're feeling." |
| Referential ("the TV / strangers are sending me messages") | Confusion, feeling singled out | "That sounds overwhelming. I'm here, and you're safe with me." |
| Control ("someone is controlling my thoughts / actions") | Loss of agency, helplessness | "That must feel frightening — like things are out of your control. I'm with you." |
Notice what none of these responses do: none of them confirm the belief, and none of them argue it. Validation is not agreement. Saying "I can see how frightening this is" is not the same as saying "yes, they really are after you." One acknowledges a real emotion; the other endorses a false belief. You can do the first without ever doing the second — and that is exactly what families are encouraged to do, whatever the type.
Whatever the type, your first move is to slow the moment down. The team teaches a simple technique called PAUSE — pause, acknowledge the emotion, understand the situation, stay calm, engage respectfully — an adaptation of principles from Dialectical Behaviour Therapy (DBT), Motivational Interviewing, and crisis de-escalation. For the full step-by-step approach — including what to say and what to avoid, the PAUSE and 3L techniques in detail, worked examples, and what to do if your loved one demands a straight yes-or-no answer — see our complete guide on how to respond when a loved one has a delusion.
And remember: you are not meant to resolve a fixed delusion in a single conversation. Keep your loved one safe, validate the feeling, and bring the belief into a structured session with the treating psychiatrist or clinical psychologist. If there is any risk of harm to your loved one or anyone else, keep a safe distance and call our 24/7 helpline: 97414 76476.
Why Choose Cadabam'S Hospitals?
Cadabam's psychiatrists specialise in diagnosing and treating psychotic disorders, including schizophrenia and delusional disorder. Comprehensive care includes medication management, CBT for psychosis, family support, and long-term rehabilitation across Bangalore, Hyderabad, and Mysore. To begin, contact our team or explore our centres.