​Family history of a major psychotic disorder (such as schizophrenia, schizoaffective disorder, bipolar disorder, or depression with psychotic features) remains the single best predictor that a person will develop a psychotic disorder. Individuals with multiple affected family members are at even higher risk. That said, the vast majority of these individuals will NOT develop a psychotic disorder. Young people with a known family history of psychosis warrant careful monitoring for changes in either functioning or mental health. Screening and early detection of symptoms can help to identify those in need of specialized treatment early enough to prevent the suffering and disability that a relative may have experienced. Youth with a family history of major mental illness are likely to benefit from education about mental health and treatment options, and from support from others who have been in their shoes.

CATEGORY	EVIDENCE-BASED RISK FACTORS
Biophysical	Genetic abnormalities & interactions, Neurocognitive dysfunction, Early social & motor abnormalities, Structural brain alterations
Neurodevelopmental	​Perinatal complications, Head injuries, Malnutrition, Hypoxia, Viruses
​Socioenvironmental	Urbanicity, Migration, Minority stress, Familial conflict
Substance Use*	Stimulants, Hallucinogens, Psychedelics, MDMA, Phencyclidine, Cannabis

* Distinguishing between substance-induced psychosis and a primary psychotic disorder can be challenging in young people. A careful review of the person’s symptoms along with a period of sustained abstinence is typically needed if symptoms do not quickly remit.

Asking about Family History

​Many people may not know their family mental health history, but may have pieces of information that are relevant. To gather these pieces, we recommend asking several different questions. It is often helpful to get a list of all first and second degree relatives and have the patient think about all of them for each question. For any positive responses, ask the patient to tell you what they know of the person’s symptoms and ​ask specifically about hallucinations and unusual beliefs.

Do you know of any family members who have:

• Been diagnosed with a major mental illness such as schizophrenia, bipolar disorder, or major depression?
• Been hospitalized for mental health reasons?
• Been unable to go to work or school for more than a couple of weeks?
• Had very few friends or seemed like loners?
• Seemed odd or eccentric in behavior or appearance?
• Seen visions, heard voices, or had beliefs that seem strange or unreal?
• Had problems with their nerves or emotions? Seen a doctor or taken medication for this?

RELATIVE WITH SCHIZOPHRENIA	RISK OF SCHIZOPHRENIA
Identical Twin	48%
Fraternal Twin (especially if same sex)	17%
2 Parents	35%
1 Parent	13%
Full Sibling	9%
Half Sibling	6%
Cousin, Uncle, Aunt, Grandparent	2%
General Population	1%

Young Children with Family History of Psychosis

​​For young children with a positive family history of psychotic symptoms or disorder, it is important to help caregivers consider options for enhancing general protective factors to support mental health (e.g., structure, warmth, open communication). The challenge is to help caregivers understand that the child is at higher risk for serious mental health issues without triggering unproductive anxiety or a sense that psychosis is inevitable.

​Families might take advantage of local chapter activities or resources of the National Alliance on Mental Illness (NAMI), or establish a relationship with a mental health clinician knowledgeable about both child development and serious mental illness who can provide education, support, and relevant intervention for mental health challenges if and as they emerge. Establishing a relationship in which the monitoring and addressing of mental health issues is a priority for the child’s healthcare is perhaps the most important task.