If medication works immediately on day one, does that confirm the diagnosis was correct?

How quickly and strongly someone responds to a first dose varies a lot based on individual metabolism, the specific medication and formulation, and starting dose, which is usually conservative and increased gradually rather than optimized immediately. Some people do notice a difference on day one; many others need several weeks of dose adjustments before landing on an effective, well-tolerated dose. A slow or muted first response doesn't mean the diagnosis was wrong, and a strong first response doesn't confirm it either, diagnosis and medication response are assessed through different processes for exactly this reason. FasTreat also offers private online ADHD assessment and ongoing care, depending on your needs and clinical assessment. Related reading: https://www.fastreat.com/en/adhd-faq References: https://www.caddra.ca/wp-content/uploads/Canadian-ADHD-Practice-Guidelines-4.1-January-6-2021.pdf