Week 7 - Bipolar Disorder

What is bipolar disorder?

Mood disorder characterized by extreme mood swings

How frequent is bipolar disorder in the population?

1-2%

What % of patients with bipolar disorder receive treatment?

Less than 30%

How is bipolar I classified?

At least 1 manic episode with or without major depression

How is bipolar II classified?

At least 1 hypomanic episode and at least 1 major depressive episode

How is cyclothymia classified?

Multiple hypomanic and depressive episodes

What are symptoms of a manic episode (high)?

• Impulsivity and grandiosity

• Euphoria

• Inflated self-esteem

• Racing thoughts, excessive talkativeness

• Risky behaviors

How do neurotransmitter levels contribute to bipolar disorder?

• Decreased GABA and SE

• Increased NE and DA

How does increased inositol signaling lead to BPD?

By producing changes in NT release and gene expression

How does lithium stabilize mood in BPD?

• Decreases inositol signaling

• Increases brain serotonin

What are the pharmacokinetic characteristics of lithium?

• Rapidly absorbed

• Slow entry into cells

• Half life of about 20 hours

• No metabolism => excreted entirely in urine

What are side effects of lithium?

Neurologic symptoms (tremors, ataxia, aphasia), sedation, polyuria

Why can anti-seizure drugs be used to treat BPD?

• Inhibits Na+ channels => decreases neuronal hyperexcitability