These people who need the medications are usually victims of mental torture. They are the ones who mostly give up on life and lose expectations. "unicorn" is a term for a horse with a horn. it is basically non-existent but it symbolizes something unexpected, something people thing does not exist. these people who give up on themselves or are mentally tortured and need help, they are like unicorns but they exist and they have hope, which is, these medication which are provided by the company.