Family Psychiatric History: Risk, Heritability, and How to Ask
This is Part 1 in our series on Family History.
Family psychiatric history is not optional background information: it’s genetic risk assessment. Certain psychiatric disorders show strong familial transmission, meaning your patient’s risk is substantially elevated if a first-degree relative (parent, sibling, child) has the disorder.
Understanding familial patterns helps you refine your differential diagnosis, anticipate treatment response, identify high-risk patients, and provide genetic counseling for patients planning families.
Learning Objectives
After reading this section, you should be able to:
- Explain why family psychiatric history functions as genetic risk assessment
- Describe relative risk patterns for at least three highly heritable psychiatric disorders
- Identify relevant chart sources for family psychiatric history before interviewing the patient
- Conduct systematic screening for family psychiatric and medical history
- Recognize dimensional clustering of psychiatric disorders across family members
Why Family Psychiatric History Matters
Understanding familial patterns helps you:
Refine your differential diagnosis: A family history of bipolar disorder makes bipolar disorder more likely than unipolar depression when your patient presents with depressive symptoms.
Anticipate treatment response: Patients often respond to the same medications that worked for affected relatives.
Identify high-risk patients: A strong family history of schizophrenia or bipolar disorder in a young adult with emerging symptoms should prompt closer monitoring.
Provide genetic counseling: Patients planning families deserve to understand transmission risks.
The Most Heritable Psychiatric Disorders
The relative risk compares the likelihood that an individual will develop a disorder if a first-degree relative has that disorder, compared with the general population (baseline risk = 1.0). For example, if your patient’s father has bipolar disorder, your patient is approximately 25 times more likely to develop bipolar disorder than someone without that family history.
| DSM-5 Disorder | Relative Risk (First-Degree Relative) | Lifetime Prevalence (General Population) |
|---|---|---|
| Bipolar I–II disorders | 25× risk | 4% |
| Schizophrenia | 19× risk | 1% |
| Bulimia nervosa | 10× risk | 2% |
| Panic disorder | 10× risk | 5% |
| Obsessive-compulsive disorder | 9× risk | 2% |
| Alcohol use disorder | 7× risk | 13% |
| Generalized anxiety disorder | 6× risk | 6% |
| Anorexia nervosa | 5× risk | 1% |
| Specific phobia | 3× risk | 12% |
| Social anxiety disorder | 3× risk | 12% |
| Major depressive disorder | 3× risk | 17% |
| Agoraphobia | 3× risk | 5% |
💡 Clinical Pearl: Psychiatric disorders often cluster dimensionally. When multiple relatives have overlapping anxiety, mood, or substance-use disorders, consider a shared familial temperament or polygenic vulnerability rather than isolated single-gene transmission.
Start With Chart Review
Before interviewing the patient, review available documentation for family history information:
- Initial psychiatric evaluations: Often contain the most detailed family history, especially if completed during a thorough intake process
- Old intake forms: Many systems use check-box family history sections that capture basic information
- Genetic consult notes: If present, these provide detailed pedigree information and risk estimates
- Past suicide risk assessments: These frequently document family history of suicide or attempts
- Pediatric or developmental records: May flag parental mental illness or substance use affecting the home environment
- Prior hospitalization discharge summaries: Often include family history relevant to the presenting diagnosis
💡 Clinical Pearl: If old notes document “negative” family history but the patient now reports positive history, explore what changed. Either the patient has new information (a relative was recently diagnosed or disclosed), or they previously minimized or were unaware. Both scenarios have clinical implications.
Interview the Patient
Screening for Psychiatric Disorders
- “Has any blood relative, including parents, siblings, children, grandparents, aunts, or uncles, ever had problems with nervousness, depression, mania, anxiety, psychosis, schizophrenia, obsessive-compulsive disorder, eating disorders, alcohol or drug problems, suicide attempts, or psychiatric hospitalization?”
Screening for Medical and Neurologic Disorders
- “Has any blood relative ever had medical or neurologic problems like heart disease, stroke, diabetes, cancer, seizures, dementia, Alzheimer’s disease, Parkinson’s disease, or movement disorders?”
🧠 Special Consideration: Focus on biological family members, not stepfamily or adoptive relatives. You’re assessing genetic risk. Psychosocial influences from non-biological relationships matter for other reasons and should be explored separately in social history.
Follow-Up Questions for Positive Responses
When a patient reports family psychiatric history:
- “Which relative was affected?”
- “What was the diagnosis, or what symptoms did they have?”
- “How old were they when it started?”
- “Were they hospitalized?”
- “What treatments did they receive, and did anything work well?”
- “Are they still alive? If not, what did they die from?”
💡 Clinical Pearl: Patients often know behaviors better than diagnoses. “Grandma was always nervous and couldn’t leave the house” is more useful than “I think she had anxiety.” Ask for observable patterns.
Why This Information Matters
Family psychiatric history transforms your differential diagnosis from probability-based guessing to risk-informed reasoning. A patient presenting with first-episode depression and a strong family history of bipolar disorder warrants different monitoring and treatment considerations than one with no family psychiatric history.
Heritability data also guides medication selection. When a patient’s mother responded well to a specific antidepressant, that medication becomes a rational first choice. When multiple relatives required mood stabilizers, you should consider whether your patient’s “depression” might be the depressive pole of an emerging bipolar spectrum disorder.
Systematic family history assessment ensures you’re not missing genetic signals that would change your clinical approach.
Next in this series: Part 2 – Using Family History for Formulation, Risk, and Medication Choice
