Bipolar disorder, formerly known as manic depressive illness, is a mental health condition characterized by extreme mood swings. People with bipolar disorder alternate between emotional highs (mania) and lows (depression). Unlike the normal ups and downs most people experience, bipolar mood swings can be severe and interfere with everyday life.
Bipolar disorder is complex and there is no single test that can diagnose it. However, blood tests may be used as part of an evaluation to rule out other potential causes of symptoms or to check for related health issues. Here is a look at whether bipolar disorder shows up in blood work.
Overview of bipolar disorder
Bipolar disorder affects about 2.8% of American adults each year. Symptoms typically start between early adolescence and the mid-30s, with an average onset around 25 years old. However, diagnosis can happen at any age. Bipolar disorder is characterized by:
- Manic episodes – feeling euphoric, full of energy, restless, reckless behavior
- Hypomanic episodes – similar to mania but less severe
- Depressive episodes – feeling sad, hopeless, low energy, trouble concentrating
- Potential psychosis – delusions, hallucinations
- Changes in sleep, activity, speech
Episodes can last for days to months and can be so severe that hospitalization is required. Between episodes, most people return to their usual level of functioning.
There are several types of bipolar disorder based on the pattern of mood episodes:
- Bipolar I – manic episodes with or without depression
- Bipolar II – hypomania with depression, no full mania
- Cyclothymic disorder – hypomania and depression lasting 2+ years
- Rapid cycling – 4+ episodes per year
While the exact cause is unknown, bipolar disorder often results from a combination of genetics, brain structure and functioning, and life experiences. Imbalances in neurotransmitters like serotonin and dopamine in the brain may also play a role.
Can blood tests diagnose bipolar disorder?
There is no blood test that can affirmatively diagnose bipolar disorder. The diagnosis is made based on the person’s symptoms, course of illness, family history, and a psychiatric evaluation.
However, blood tests may be used to rule out other potential causes of symptoms that mimic bipolar disorder. Tests can also screen for related health issues that often accompany bipolar disorder.
Ruling out medical mimics
Certain medical conditions can produce symptoms that look like bipolar mania or depression. Blood tests may help identify these conditions, referred to as “medical mimics.” Examples include:
- Thyroid problems – Both hypothyroidism and hyperthyroidism can cause mood instability.
- Adrenal disorders – Such as Cushing’s or Addison’s disease.
- Hormonal changes – Like menopause or postpartum state.
- Brain tumors or seizure disorders.
- Immune disorders like systemic lupus erythematosus.
- Vitamin deficiencies – Such as B12, folate.
- Infections – Viruses, HIV, syphilis.
- Substance use – Alcohol, drugs, medications.
- Traumatic brain injury.
Testing thyroid, adrenal, and reproductive hormone levels can identify many endocrine mimics. Looking at vitamin levels, antibodies, proteins, and infectious disease markers may point to other medical conditions. A drug screening can detect substance-induced symptoms as well.
Checking for related health issues
People with bipolar disorder are at increased risk for certain medical conditions, likely due to genetics, lifestyle factors, and medication side effects. Blood work can screen for accompanying health problems such as:
- Obesity
- Diabetes
- Heart disease
- High cholesterol
- Liver disease
- Kidney disease
Tests for blood sugar, lipids, liver enzymes, and kidney function may identify any related conditions. Monitoring weight and vital signs is also important.
Common blood tests
While no single blood test can confirm bipolar disorder, the following are examples of common tests used as part of an evaluation:
Complete blood count (CBC)
A CBC measures levels of different cells in the blood like red blood cells, white blood cells, and platelets. It provides an overview of a person’s general health status. CBC findings that may be relevant in someone with possible bipolar symptoms include:
- Anemia – Can cause fatigue that mimics depression
- Elevated white blood cells – Could indicate infection
- Thrombocytosis – High platelets seen in iron deficiency
Comprehensive metabolic panel
This test looks at electrolytes, kidney function, blood sugar, and liver enzymes. Abnormal sodium, calcium, or liver enzymes could point to medical mimics of bipolar disorder.
Thyroid panel
Measures TSH and thyroid hormones T3 and T4 to identify hyperthyroidism or hypothyroidism. Thyroid disorders often cause mood disturbance.
Lipid panel
Evaluates cholesterol levels, which may be elevated in bipolar disorder due to genetics, obesity, diet, smoking, and medication effects.
Pregnancy test
For women of childbearing age, to rule out pregnancy-related mood changes.
Drug screening
Checks for alcohol, recreational drugs, and medications that could cause manic or depressive symptoms.
Cortisol
Screens for Cushing’s syndrome or Addison’s disease. Cortisol is a stress hormone produced by the adrenal glands.
Vitamin B12 and folate
Important for neurological health. Deficiencies can lead to psychiatric symptoms.
Inflammatory markers
Such as sedimentation rate or C-reactive protein to detect autoimmune disorders like lupus.
Syphilis screening
Syphilis infection can progress to neurosyphilis with psychiatric effects if untreated.
HIV test
Rule out HIV/AIDS which can have neurological complications.
Key takeaways
In summary, while blood tests cannot provide a definitive diagnosis of bipolar disorder, they have an important role as part of an evaluation by:
- Screening for medical conditions that can mimic bipolar disorder
- Checking for related health issues like heart disease or diabetes
- Monitoring for medication side effects
By helping rule out mimics and revealing potential comorbidities, bloodwork supports prompt, accurate identification and management of bipolar disorder.
Conclusion
Bipolar disorder is a complex mental health condition with no single diagnostic test. However, blood tests provide valuable supporting information by screening for medical mimics and related health issues.
While blood tests alone cannot definitively diagnose bipolar disorder, they play an important role in the evaluation process. Looking for clues in bloodwork that point to other potential causes of symptoms or accompanying conditions can improve diagnostic accuracy and optimize treatment.
In combination with a detailed history, psychiatric assessment, and other testing if needed, bloodwork helps clinicians accurately identify bipolar disorder. This allows for timely intervention, which gives patients the greatest chance of managing this chronic, challenging condition.