It is impossible for your healthcare provider to know whether you will develop insomnia while taking Lexapro. Also, in some cases, if a person does develop insomnia, it is difficult to know whether the insomnia is because of his or her condition or Lexapro itself. This is because insomnia happens often in people with the conditions that Lexapro is used to treat. For example, a number of people with depression report insomnia.
If you are taking Lexapro and insomnia becomes a problem, make sure to talk with your healthcare provider. There are other treatments that he or she may be able to recommend, including adjusting the Lexapro dosage or trying another anxiety or depression medicine.