Differential Diagnosis for Bipolar Disorder

When considering a differential diagnosis for bipolar disorder, it's crucial to evaluate a range of potential conditions to ensure accurate diagnosis and treatment. The differential diagnoses can be categorized as follows:

• Single Most Likely Diagnosis
  • Major Depressive Disorder (MDD): Often, bipolar disorder is initially misdiagnosed as MDD because the depressive episodes can be more frequent or prominent than manic/hypomanic episodes. A thorough history and observation for manic or hypomanic episodes are essential for differentiation.
• Other Likely Diagnoses
  • Borderline Personality Disorder: Characterized by mood instability, impulsivity, and intense interpersonal relationships, which can mimic the mood swings seen in bipolar disorder.
  • Attention Deficit Hyperactivity Disorder (ADHD): Symptoms of inattention, hyperactivity, and impulsivity can be confused with the manic or hypomanic phases of bipolar disorder.
  • Schizoaffective Disorder: A condition that combines symptoms of schizophrenia (such as delusions or hallucinations) with mood disorder symptoms (depressive or manic episodes), which can be challenging to distinguish from bipolar disorder.
• Do Not Miss Diagnoses
  • Neurosyphilis: A rare but potentially treatable condition that can cause psychiatric symptoms, including mania.
  • Hypothyroidism: Severe hypothyroidism can cause psychiatric symptoms, including depression and, less commonly, mania.
  • Substance-Induced Mood Disorder: Various substances (e.g., cocaine, amphetamines, steroids) can induce manic or depressive episodes that mimic bipolar disorder.
  • Traumatic Brain Injury (TBI): TBI can lead to mood instability and symptoms that resemble bipolar disorder.
• Rare Diagnoses
  • Cushing's Syndrome: A rare endocrine disorder caused by excess cortisol, which can lead to mood changes, including mania and depression.
  • Multiple Sclerosis: This autoimmune disease can cause a wide range of neurological symptoms, including mood changes that might be mistaken for bipolar disorder.
  • Wilson's Disease: A genetic disorder that leads to copper accumulation in the body, potentially causing psychiatric symptoms, including mood swings.

Each of these diagnoses requires careful consideration of the patient's history, physical examination, laboratory tests, and sometimes imaging studies to accurately diagnose and treat the underlying condition.