Medicines that affect mood

Key points about medicines that affect mood

Some medicines can improve your mood, while others may worsen it, eg, they can cause low mood, depression, changes in behaviour and sleep problems.
Changes in mood only occur for some people and can vary depending on the individual and the medicine.
If you're taking a medicine and you're worried about changes to your mood, don't stop taking your medicine suddenly. Instead, discuss this with your doctor or pharmacist.

The following are examples of mood changes related to taking medicines:

Low mood: Some medicines may cause low mood, which may mean that you feel sad, teary and lose interest in activities that you usually enjoy. Low mood usually tends to lift after a few days or weeks.
Depression: If the feelings of low mood don't go away, it can be a sign of depression. This can affect your everyday activities, eg, eating, sleeping and concentration. If it's severe, it could result in having suicidal thoughts or thoughts about harming yourself.
Behaviour changes: Some medicines can change your behaviour and cause symptoms including irritability, agitation, restlessness, euphoria (feeling of intense excitement and happiness), confusion, aggression, hostility, paranoia, hallucinations and delusional thoughts.
Sleep problems: Trouble falling asleep or staying asleep (insomnia), nightmares.

If you're taking a medicine and you're worried about changes to your mood, don't stop taking your medicine suddenly:

Instead discuss this with your doctor or pharmacist.
Sometimes there might be a different dose or a different medicine you can take that has less effect on your mood.
Keep in mind that people close to you may notice a change in your behaviour before you see it in yourself.
If other people say they've noticed something, it's probably a good idea to ask for help.

If you have thoughts of harming yourself or others, call your doctor immediately or phone Healthline 0800 611 116 or text 1737

The information on this page is about medicines that we know can cause changes to your mood as a side effect. All changes in mood need to be discussed with a healthcare provider as there are many factors, including medicines, that may be contributing towards how you are feeling.

It’s important to have a comprehensive review to thoroughly investigate all possible causes. They can review your history and discuss any potential investigations or treatment options tailored to your needs. Read more about how medicine-related mood changes are diagnosed.

The following is a list of medicines that are known to cause mood changes.

Note: This isn't a complete list. If you're unsure if the medicine you are taking can cause mood changes, ask your doctor or pharmacist.
Changes in mood only occur in some people and can vary depending on the individual and the medicine.
They may happen when you start the medicine, during an increase in dose, or when you stop taking a medicine.
Very old and very young people and those with past or present mental health problems may be more at risk of these effects.

Medicines that are known to cause low mood, depression or behaviour change for some people

Steroid medicines eg, prednisone, dexamethasone
Combined oral contraceptive pills (birth control pills)
Beta-blockers eg, metoprolol, bisoprolol
Calcium channel blockers eg, amlodipine, diltiazem
ACE inhibitors eg, enalapril, quinapril
Isotretinoin for acne
Antihistamines eg, cetirizine, promethazine
Proton pump inhibitors eg, omeprazole, pantoprazole
Other examples include tacrolimus, montelukast, digoxin, oxybutynin, metronidazole, valaciclovir

Medication-related mood changes can happen when you start a medicine, during an increase in dose, or on withdrawal of a medicine (when you stop taking it). They are more likely if you have a history of mental illness or depression. If you've had mental illness or depression in the past, always ask your doctor or pharmacist about possible side effects before starting any new medicines.
Very old and very young people are more at risk of these effects.
Taking multiple medicines with a side effect of altered mood can make the problem worse.
Alcohol and recreational drugs can alter your mood. Taking some medicines together with alcohol and recreational drugs can make changes in mood worse. Read more about alcohol and mental health.

Since not all changes in mood are caused by medicines, working out whether your mood changes are caused by your medicine is not always easy. Sometimes changes in your mood may be related to the condition you're being treated for, or other things going on in your life.

Your doctor or nurse prescriber will look at your medicine list to see whether you're taking any that can cause mood changes. If you started getting noticeable mood changes after you began one of these medicines, it could be due to that.

Talk to your healthcare provider

If you're worried about changes in your mood, discuss this with your doctor, nurse prescriber or pharmacist immediately. Sometimes a more suitable dose or medicine can be found. Some medicines need to be stopped gradually, as stopping suddenly can make your symptoms worse. Always ask for advice before you stop.

If your medicine is causing a change to your mood, your mood should improve after stopping the medicine, and changes are likely to return if the medicine is tried again.