What condition is contraindicated for St. John's wort herbal therapy?

St. John's wort is contraindicated for individuals taking certain medications, particularly those that are metabolized by the liver enzyme CYP450, such as antidepressants, anticoagulants, and some antiretrovirals. It can lead to reduced effectiveness of these medications due to its induction of enzyme activity. Additionally, it may exacerbate certain psychiatric disorders, so individuals with Bipolar disorder or those at risk for mania should avoid its use. Always consult a healthcare professional before starting any herbal therapy.