DEAR DR. ROACH: I am an 82-year-old female who has a hard time staying asleep. I have been taking melatonin to help. I read recently that if you have taken melatonin for a long time, you could have a danger of heart problems. Should I stop?

I started taking 1/8 of a gummy with CBD instead. It helps me sleep but makes me feel dopey and dizzy. Do you have any sleep aid recommendations?

• F.S.

ANSWER: An unpublished study that was presented at a recent American Heart Association meeting found that people taking melatonin had a 4.6% risk of heart failure, compared to a 2.7% risk among people who did not take melatonin. While it is possible that the melatonin predisposed people to develop heart failure, this was not found in previous safety studies on melatonin. The type of analysis that was done cannot prove that melatonin is causing the apparent increase in heart failure.

In my opinion, it is more likely that people who have heart failure do not sleep well and are more likely to take melatonin. Heart failure symptoms classically worsen when a person is lying down, which often makes people uncomfortable. It is also reasonable that people with existing but untreated sleep disorders (such as obstructive sleep apnea) are likely to take medication to help them sleep better.

My level of concern about melatonin being dangerous is low, but I absolutely agree on the fact that this deserves further study to evaluate the possibility of whether melatonin really is harmful.

I am concerned about the “dopey and dizzy” feeling you get with your cannabidiol (CBD) supplement. CBD is not psychoactive. Unlike smoked cannabis, it doesn’t make people “high.” This effect comes from a different component, tetrahydrocannabinol (THC). Many of the CBD supplements that are sold contain undeclared THC. I am a bit surprised that you are having these symptoms with such a tiny amount of one gummy.

My first-line treatment for sleep disorder is cognitive behavioral therapy for insomnia. Unfortunately, it is not widely available and can be expensive. I have recently downloaded (for free) the CBT-I app developed by the Department of Veterans Affairs called CBT-I Coach, just to test it. Some of my colleagues who work in the VA have found it effective. (But as one said, “You get out of it what you put in.”)

Readers may email questions to ToYourGoodHealth@med.

cornell.edu.