Methylphenidate hydrochloride (Ritalin / Concerta XL / Equasym XL) is a stimulant drug related to amphetamine that is approved in the United States for the treatment of attention deficit disorders in children.

Methylphenidate is sometimes used to alleviate symptoms of HIV-associated brain impairment and dementia: studies have shown that it can improve the slowing of thought and emotional deficits seen in some patients with HIV infection^[1][2]. A randomised, controlled study has also shown that the drug can improve fatigue in HIV-positive patients, with subsequent improvements in depression, psychological distress and quality of life^[3]. It can also relieve depression and anxiety in HIV-positive patients as an alternative to licensed anti-depressant drugs^[4].

Side-effects include nervousness and insomnia.