It is impossible for your healthcare provider to know whether you will develop insomnia while taking Marplan. Also, in some cases, if a person does develop insomnia, it is challenging to know whether these problems are because of the condition or Marplan itself. This is because insomnia is common with depression.
If you develop insomnia while taking Marplan, make sure to talk with your healthcare provider. There are other treatments that he or she may be able to recommend, including adjusting the Marplan dosage or trying another depression medication.