I think they generally direct patients to take Lexapro in the morning. There are some people, however, who find Lexapro to be extremely sedating. Some people it has no effect on in that regard. Others can barely keep their eyes open. I had this problem and have known two other people who had the same problem. I also know other people who take Lexapro in the AM with no sedating effect whatsoever. When I took Lexapro and found myself too tired to function, my doctor had me switch to taking it at night and said that it has that effect on some people but there is no way to know until they try it. Even taking it at night, I still found it to be too sedating and had to discontinue.