That often happens with sleeping pills. Clinical practitioners are often reluctant to prescribe benzodiazepines to treat sleep problems because of the potential for abuse and dependency. Based on what we know, in any event, this type of medication is not really effective for military personnel, probably because they have a hypervigilance that the civilian population doesn't have, including those people who have chronic insomnia that isn't linked to post-traumatic stress syndrome.
I forgot the start of your question.