I have been taking nortriptyline for a month and have had nightmares almost every night. could this med be the cause? 50 mg

Medication: Yes the medication can be responsible for your nightmares. See your doctor for other possibilities

Tell your provider: Whatever new experiences you have after beginning a new treatment may be reactions that you need to tell your provider about. Sleep disturbances are known side effects. I did not hear about nightmares, but they'd count - right? In any case - tell your provider and ask for explanations of what to expect and what might do better for you. Therapy may help your depression w/out side effects.