No causal link has been established, but a small number (less than 1%) of Accutane patients have reported psychiatric problems whilst taking the drug. Even more rarely, patients with
existing depression have reported it worsening whilst on Accutane
For me personally, the benefit of virtually clear skin outweighed the potential side effects.
In the UK, where I live, you need a prescription for Differin. We pay for medical care out of our taxes instead of needing medical insurance.