Schizophrenia (Psychiatric GWAS Consortium, 2011) – Is psychosis genetic?

Brain artwork schizophrenia

Nebula Genomics DNA Report for Psychosis

Is psychosis genetic? We created a DNA report based on a study that attempted to answer this question. Below you can see a SAMPLE DNA report. To get your personalized DNA report, purchase our Whole Genome Sequencing!

An example of report on psychosis from Nebula Genomics
An example of report on genetic variants in psychosis from Nebula Genomics

Additional Information

What is Psychosis? (Part 1 of Is psychosis genetic?)

Psychosis describes an abnormal illness of the mind that is made up of a combination of symptoms, which include hallucinations, delusions, loss of contact with reality or ego disorders. The main characteristic of the disorder is that the person has an impaired relationship with reality. There may also be incoherent speech, inappropriate behaviors, sleep problems, social withdrawal, lack of motivation, and difficulties carrying out daily activities. During a period of psychosis, a person is said to be undergoing a psychotic episode. 

These different symptom types can occur individually or in combination. Causes include mental illness, such as schizophrenia or bipolar disorder, sleep deprivation, some medical conditions, certain medications, and drugs such as alcohol or cannabis. Psychosis can be a one-off experience caused by a temporary agent or part of a long-term mental health condition. 

During psychosis, a person loses touch with reality
Psychosis is represented by a loss of contact with reality.

According to the National Institute of Mental Health, the three most common signs of psychosis include hallucinations, delusions, and cognitive experiences, or disturbed thoughts. 

Hallucinations are seeing, hearing, or feeling things that aren’t really there. A person may hear voices, have strange sensations, or see glimpses of objects or people that are not there

Delusions are strong false beliefs that are not consistent with the person’s culture, are unlikely to be true and may seem irrational to others. A person may believe an external force is controlling them, believe that trivial remarks, events, or objects have personal meaning or significance, or think that they have special powers. Many other examples can be made of delusions. 

Cognitive experiences relate to mental action. People with psychosis may find it difficult to learn, remember, make decisions, or concentrate. 

Epidemiology (Part 2 of Is psychosis genetic?)

According to the National Alliance on Mental Illness, as many as 3 in 100 people will have a psychosis episode at some point in their life, although this does not mean that they will have a psychotic disorder. Even though in the U.SApproximately 100,000 young people experience psychosis of some type each year, less than 1% of the U.S. population lives with a psychotic disorder. 

Women are at a higher risk of psychosis after giving birth. Around 2 out of 1000 births result in postpartum psychosis. The condition usually develops during adolescence or early adulthood with the average age of onset being 24 years. 

Causes (Part 3 of Is psychosis genetic?)

There is no single cause of psychosis. The current belief is that a combination of genetic and environmental factors contribute to psychosis. Specifically, any existing predisposition (disposition; genetic or prenatal) interacts with subsequent stress, which is assumed to be the trigger. Stressors include:

  • Pre- and perinatal factors such as maternal stress during pregnancy
  • Influences on the immune system (childhood infections),
  • Socialization and psychological development of the child
  • Anatomical and functional deviations in the structure of the brain and brain cells
  • Mechanical impact on the brain (e.g. through craniocerebral trauma or brain tumors),
  • Hormonal influences
  • Drugs and medicines
  • Various somatic diseases (autoimmune/rheumatic, endocrine)

Is psychosis genetic?

People are more likely to experience psychosis if a family member, such as a parent or sibling, has the condition. Children born with the genetic mutation known as 22q11.2 deletion syndrome are at risk for developing a psychotic disorder, especially schizophrenia. In most cases, multiple genetic factors, each with a small effect, combine to increase the risk of developing the disorder. 

The two most studied forms of psychosis in this regard are schizophrenia and bipolar disorder, both associated with overproduction of the neurotransmitter dopamine in the brain. Other studies have been conducted that investigate genes related to the functioning of this chemical in the brain. A 2019 study revealed that a cluster of epigenetic markers, which switch genes on and off, affect a gene called IGF2, which plays a role in synaptic development. The enhancer also regulates dopamine. This revelation could explain why dopamine-based illnesses are often accompanied by a disruption of brain synapses. 

A nuerotransmitter
Psychosis is most often associated with overproduction of the neurotransmitter dopamine in the brain. Attribution-Share Alike 4.0 International.

The genetics of schizophrenia and other psychosis conditions are areas of active research. It is most likely that genetic predispositions in combination with environmental factors, especially stressors, bring on psychosis episodes. 

Types of psychosis (Part 5 of Is psychosis genetic?)

Psychosis can be divided into two main categories that separate neurocognitive disorders describing reduced brain function due to illnesses not psychiatric in nature and those that are psychiatric disorders.

Neurocognitive disorders

  • Degenerative brain diseases (Alzheimer’s or Lewy Body type dementias, vascular dementia),
  • Brain injuries (craniocerebral trauma)
  • Focal processes (epilepsy, stroke)
  • Malignant neoplasms (tumors both primarily in the brain and as metastases)
  • Infections (meningitis, neurolues)
  • Autoimmune diseases (anti-NMDA receptor encephalitis, Hashimoto’s thyroiditis, lupus erythematosus, multiple sclerosis, vasculitis)
  • Endocrine diseases (hypo- and hyperthyroidism, hypo- and hyperparathyroidism)
  • Congenital or acquired metabolic disorders (leukodystrophy, lysosomal storage diseases, mucopolysaccharidoses, porphyria)
  • Other metabolic disorders (hypo- and hypernatremia, hypoglycemia)
  • Poisoning with medicines or drugs, drug withdrawal
  • Parasites (neurocysticercosis)
  • Special forms like the postpartum psychosis

Psychiatric disorders

  • Schizophrenia or diseases of the schizophrenic for
  • Persistent delusional disorder
  • Acute or temporary psychotic disorders
  • Induced delusional disorder
  • Schizoaffective disorder
  • Affective psychoses (this includes some forms of bipolar disorder or severe depression)

Substance-induced psychosis 

Another form of psychosis is substance-induced psychosis that is a psychotic disorder caused by one or more psychotropic substances. Psychotic states can normally be reversible or only temporary. Some categories of these substances include alcohol, amphetamines, benzodiazepines, caffeine, cocaine, and LSD. 

Characteristics and Symptoms (Part 6 of Is psychosis genetic?)

According to healthline, psychosis is a combination of symptoms. In general, the three main symptoms that characterize psychosis are hallucinations, delusions, and confused and disturbed thoughts. Some of the specific symptoms of people experiencing psychosis:

  • Difficulty concentrating
  • Depressed mood or mood disorders
  • Sleeping too much or not enough
  • Anxiety
  • Suspiciousness
  • Withdrawal from family and friends
  • Delusions
  • Hallucinations
  • Disorganized speech, such as switching topics erratically
  • Depression
  • Suicidal thoughts or actions
A person affected by a mental illness
The three hallmarks of psychosis are hallucinations, delusions, and disturbed thoughts. ScienceonTap. CC BY-NC-SA 4.0.  

Early psychosis usually occurs as a gradual onset of symptoms. It is sometimes referred to as first-episode psychosis (FEP) and is characterized as a time in which someone first shows signs of beginning to lose contact with realty. Early warning signs can be difficult to distinguish from normal young adult behavior. It is important to see a health care provider if psychosis is suspected. Some signs strongly indicative of a psychotic episode are:

  • Hearing, seeing, tasting or believing things that others don’t
  • Persistent, unusual thoughts or beliefs that can’t be set aside regardless of what others believe
  • Strong and inappropriate emotions or no emotions at all
  • Withdrawing from family or friends
  • A sudden decline in self-care
  • Trouble thinking clearly or concentrating

Not every person with psychosis develops the same symptoms and the symptoms in one person can vary over time. 

Diagnosis (Part 7 of Is psychosis genetic?)

There is no test to positively diagnose psychosis. However, a doctor will normally ask about symptoms and possible causes. Questions may focus on the person’s experiences, family history of psychiatric illness, and medicinal and recreational drug use. They may also do additional lab and imaging tests to rule out other factors. Blood tests and brain imaging (such as MRI scans) are common tests when diagnosing psychosis. 

If there is no physical reason for the symptoms, a doctor may refer the patient to a psychiatrist or psychologist. These mental health professionals can determine if the observed symptoms are caused by a mental health condition by performing a psychological evaluation that includes a specially designed interview and assessment tools. 

The sooner that psychosis is diagnosed and treated, the better the ultimate prognosis becomes. 

Treatment (Part 8 of Is psychosis genetic?)

Exact treatment for psychosis depends on the underlying disease. Common forms of treatment include antipsychotics and psychotherapy. All of which are used in various combinations depending on the causative disease. 


These drugs alleviate the symptoms but do not cure the disease. They are the main form of treatment for people with a psychotic illness and work by blocking the effect of dopamine. Examples of medications include:

  • haloperidol (Haldol)
  • chlorpromazine (Thorazine)
  • clozapine (Clozaril)

Antipsychotics should not be used in all cases. They can often negatively interfere with other conditions, such as epilepsy or heart disease. Antipsychotics can start reducing anxiety rather quickly, but may take several days or weeks to reduce psychotic symptoms, such as hallucinations and delusions. 

Some antipsychotics are taken orally while others can be administered by injections. Several slow release medications delivered via injection only need to be taken every 1 to 4 weeks. 

Like many medications, side effects differ among patients. Some common side effects from antipsychotics include:

  • drowsiness
  • shaking and trembling
  • weight gain
  • restlessness
  • muscle twitches and spasms – where your muscles shorten tightly and painfully
  • blurred vision
  • dizziness 
  • constipation
  • loss of sex drive (libido)
  • dry mouth 

Always consult a doctor before stopping medication such as antipsychotics as suddenly stopping a prescription may result in a relapse of symptoms.


These treatments do not reduce the primary symptoms of psychosis, but can help reduce intensity and anxiety experienced by patients. Cognitive behavioral therapy (CBT) and family intervention are common approaches to help patients and their families treat the symptoms of psychosis. 

While psychosis symptoms may make everyday activities difficult and pose serious health risks, these mental disorders are treatable and most people have a good recovery with treatment (especially with early intervention) and close follow up care. With early treatment, many people do not continue to have psychotic episodes and go on to live productive lives. 

More information on psychosis can be found at the National Library of Medicine

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