As last year I used a colour to symbolise danger this year I suggested we used a theme, however instead of portraying the theme obviously, show it through symbolism.
Our theme is Religion.
At the end there is a shot of an apple rolling into the pool of medicine. This is taken from Adam and Eve. The apple was the temptress, it rolling into the pills shows the end of not just the story but of the couple.
When Ryan gets into the bath we use the water as it is washing away sins. He goes for a bath because he needs to clear his head of paranoia.
Also the marriage is a very obvious theme of religion, however the viewer decides the time span from which the couple met to getting married because of the graphic match. This decides whether it was too fast to get married or not.
Through most of the filming Grace will be wearing white clothes which symbolise innocense.
Our most relevant religious symbolism is when Ryan has his flashback and see's himself hanging like Jesus did.
Lastly the soundtrack that we use at the end while Ryan has his flashback is a gregorian chant. This sounds like it is religious, sung by monks.