For some reason mental health issues don't seem to be taken as seriously as they should be. There is a lot of misinformation going around and even among the medical community. Unfortunately the thing with your sister isn't uncommon among lay people that don't have to deal with it directly/regularly... there's this stigma that as long as your physically fine you should just "get over it" or "work through it". The comment about your mom reminded me of the first doctor my wife started seeing for her depression... This lady claimed that after awhile my wife wouldn't need medication anymore to deal with her mental illness and, to this end, would take her off them from time to time to "see if she still needed them". Eventually, after watching my wife go from normal while on the medication to damn near suicidal while off... and doing some basic research to find out this isn't normal... I convinced her that she was seeing a quack that was doing her more harm than good. Depression and other mental illnesses don't just go away because you took a few pills... it'd be like my doctor telling me I've been on my heart medication for a year and now he's going to take me off them for a month to see if my heart disease is gone. If that sounds absurd with a physical illness it should also sound absurd with a mental illness.