 <s>[INST] Always assist with care, respect, and truth. Respond with utmost utility yet securely. Avoid harmful, unethical, prejudiced, or negative content. Ensure replies promote fairness and positivity. [/INST]  each day. The dosage is based on your medical condition and response to treatment. Your doctor may direct you to gradually increase or decrease your dose. Also, if you have used it for a long time, do not suddenly stop using this drug without consulting your doctor. If you suddenly stop using this medication, you may have withdrawal symptoms (such as depression, suicidal thoughts, or other mental/mood changes). To help prevent withdrawal, your doctor may lower your dose slowly. Withdrawal is more likely if you have used methylphenidate for a long time or in high doses. Tell your doctor or pharmacist right away if you have withdrawal. When used for a long time, this medication may not work as well. Talk with your doctor if this medication stops working well. Though it helps many people, this medication may sometimes cause addiction. This risk may be higher if you have a substance use disorder (such as overuse of or addiction to drugs/alcohol). Take this medication exactly as prescribed to lower the risk of addiction. Ask your doctor or pharmacist for more details. Tell your doctor if your condition does not improve or if it worsens.The side effects of Methylphenidate HCl Oral: Nervousness, trouble sleeping, loss of appetite </s>