Which therapeutic agent is categorized as Schedule II because of its risk of dependency?

Methylphenidate is classified as a Schedule II controlled substance primarily due to its potential for abuse and dependency. Schedule II drugs are recognized for their high potential for addiction, and they are typically used for severe medical conditions where the benefits outweigh the risks associated with their use. Methylphenidate is commonly prescribed for attention deficit hyperactivity disorder (ADHD) and narcolepsy, but it can lead to psychological or physical dependence, which is why strict regulations govern its prescription and dispensing.

In contrast, the other therapeutic agents listed do not fall under the same category. Sertraline and fluoxetine are both selective serotonin reuptake inhibitors (SSRIs) used for treating depression and anxiety disorders, and they are classified as non-controlled substances due to their lower potential for abuse. Levothyroxine, a medication used to treat hypothyroidism, also does not present a risk of dependency and is classified as a non-controlled substance. This distinction is critical in understanding pharmaceutical regulations and the need for careful monitoring of substances with a higher risk of dependency.