No increase in depression or self-harm with drugs to stop smoking
A study has confirmed that people who take stop-smoking medicines are not at higher risk of depression or self-harm than people who use nicotine replacement therapy (NRT).
BMJ Group News
What do we know already?
Most people who smoke find it hard to stop, because they are addicted to nicotine, but you can get help to overcome the addiction. This may include taking medicines that help reduce the cravings or the withdrawal, or help to wean you off nicotine.
There are two main types of treatment. NRT replaces the nicotine from cigarettes with nicotine in gum, lozenges, nasal sprays, patches, and inhalers. You take NRT to avoid nicotine withdrawal symptoms while you stop smoking.
The other type of medicine acts on your brain to reduce cravings for tobacco. This type comes as two forms of tablet, bupropion and varenicline. Previous research has raised fears that these tablets may have unwanted effects on mood. Some people taking the medicines have reported depression, thoughts about harming themselves or suicide, or attempting to harm themselves or commit suicide.
It’s hard to know whether these mood changes are caused by the medicines, however. This new study compared people taking varenicline or bupropion to help them quit smoking with people taking NRT, to see if these medicines actually increased the chances of people getting depression or harming themselves.
What does the new study say?
People who took bupropion or varenicline were no more likely to have depression, or to try and harm themselves, than people who took NRT.
It was very rare for people to try to harm themselves. In the whole group of about 120,000 people, the researchers recorded 92 incidents of people harming themselves within the first three months of having treatment.
How reliable is the research?
Earlier studies have been too small to rule out a link between taking varenicline or bupropion and a small increase in the risk of suicidal thoughts, self-harm, or depression compared with people who took other treatments. This study is much larger than previous studies. Larger studies are more likely to detect a genuine link between treatments and very rare events like suicide and self-harm. So this should make the results more reliable than previous research.
However, only about 6 in 100 people in this study were taking bupropion. As people in the study were not randomly chosen to have different treatments, doctors may have avoided giving bupropion or other treatments to people if they had concerns about their mental health. We can’t be sure if this affected the results.
The researchers used patients’ medical records to get information about which treatments they were prescribed, but we can’t be sure if people took them. If people took any other treatments, such as over the counter treatments, this wasn’t recorded and may have affected the results.
What does this mean for me?
The results of this study are reassuring for people taking varenicline or bupropion to help them stop smoking, or for people who would like to stop smoking.
In the UK, the Medicines and Healthcare products Regulatory Agency, the organisation that checks drugs for safety in the UK, has included safety warnings about mood changes with packets of varenicline and bupropion. The agency has also warned doctors to be aware of these risks when advising about treatments to people who want to stop smoking.
For all treatments, you have a better chance of stopping smoking if you get professional support from a doctor, nurse, pharmacist, or smoking cessation counsellor.