Can an 18 year old have multiple sclerosis? she has depression, numb fingertips, vertigo, her brain has slowed down at this very young age. constant stress? she is just struggling to focus, remember, process information and when speaking, she forgets?

This sounds more like simple depression than MS. Either way a visit to the doctor for a proper evaluation is needed to start the assessment.

Of course, an 18 yo could develop MS, but the usual age of onset is 29-30 yrs. I too would wonder about an emotional disorder, and your best approach is to see your regular doctor and investigate cause of symptoms. Psychological intervention could well be a dramatically successful approach.

A Neurologic evaluation is recommended. The vertigo and memory loss should be further investigated. A head CT may be indicated. Your physician can refer you to a specialist.