It is impossible for your healthcare provider to know beforehand whether you will develop insomnia while taking Nardil. Also, in some cases, if a person does develop insomnia, it is difficult to know if these problems are caused by the condition or by Nardil itself. This is because insomnia is common with depression.
If you develop insomnia while taking Nardil, talk with your healthcare provider. He or she may be able to recommend other things, including adjusting your Nardil dosage or trying another depression medication.