Accutane was the best medicine I ever took. It resolved my acne (permanently) in a matter of weeks. I felt elated afterwards and never experienced mental side effects.

However, prior to the drug, I'd experienced several of the listed side effects, due to the acne itself and its devasting effect on my self-esteem.

For many teenagers suffering from serious acne, they'd also have mental side effects due to the skin disorder, meaning there would be a strong correlation between Accutane use and people suffering mental episodes. And if the wonder drug didn't cure the acne, as promised, I can imagine that failure might push some acne sufferers over the edge.

So, Accutane itself could be harmless, but the circumstances of its use might suggest causal link to mental side effects which are not causal at all.