How do You Know Whether or not Someone Tried to Kill Themselves? How do You Know it's Not a Gesture?

Good question.
Too bad trying to kill yourself isn't like high blood pressure.....
Too bad there's not a suicide cuff that can be strapped on and pumped up... But, of course there isn't such a thing.
A few things that might give some insight into the intent, if any. Did the person think whatever they did was lethal? If a person took pills and felt that they would die, whether the dose was lethal or not, that might well be an attempt to die.
How did anyone find out? You know, if they took a bunch of pills, how did they end up at the emergency room? Usually, the person calls someone. Is that an attempt to die? No. Of course, the problem is, they may have taken enough pills or what-have-you to cause physical damage. They obviously didn't want to die (they called someone) but their behaviour is so reckless that they may pose a danger to themselves.
Someone who drinks a lot poses a danger....not that they necessarily want to die or kill themselves, but the drinking can dull everything to the point that they don't know what they are doing. They pose a danger to themselves as they may accidentally take an over dose or play with a gun....and so on.
OK wise guy. What in your opinion constitutes an attempt to kill oneself?
An easy example. Fred and Sarah have been married for 20 years. In the 20 years Fred has worked for the same company and his schedule is as predictable as the trains in Singapore. He leaves the same time every morning and returns home the same time every evening.
Give or take a few minutes, he, for the last 20 years has left his home at 8:00AM and give or take a few minutes, he returns home at 5:30PM. As usual, today Fred kissed Sarah goodbye, and left their home at 8:02AM.
As soon as Fred leaves, Sarah grabs a bottle of vodka, and scoops up all of her medication in addition to everything that's in the medicine cabinet, aspirin, Fred's heart medication and so on. Every pill she can find. She puts on the hifi to a classical music station, sits in the middle of the living room floor and starts taking the pills and drinking the vodka. A couple of hours after Fred leaves, Sarah is sprawled in the living room in a coma-like state.
Fred, in the meantime, realizes that he forgot an important presentation that he has to have for an afternoon meeting. He speeds home and finds Sarah unconscious.
Yes, ladies and gentlemen, that is truly an attempt.