This information is for people who have bipolar disorder. It tells you about chlorpromazine to treat mania, a treatment used for bipolar disorder. It is based on the best and most up-to-date research.
Does it work?
We don't know. There isn't enough good research to tell us if chlorpromazine works for treating mania in people with bipolar disorder.
What is it?
Chlorpromazine belongs to a group of drugs called antipsychotic drugs. They have a calming effect when you're agitated or having strange or distressing thoughts.
Doctors also use chlorpromazine to treat a condition called schizophrenia. With schizophrenia, you can lose touch with reality. You may get symptoms known as delusions or hallucinations. These are also called psychotic symptoms. But antipsychotic drugs are also used to treat mania, even if you don't have psychotic symptoms.
There are two groups of antipsychotic drugs, older ones and newer ones. Chlorpromazine belongs to the group of older ones. That group also includes haloperidol. The older drugs have been used for many years. But they can have bad side effects in some people. For example, they can cause stiffness and shaking of your muscles. 
Chlorpromazine comes as tablets, a liquid, or an injection. The brand name is Largactil. Doctors may use the injection if they think you need treatment but you are too agitated to take tablets. You can't be given treatment against your will, except in special cases covered by the law. For more information, see The Mental Health Act.
Doctors usually give chlorpromazine along with another drug for mania such as lithium or valproate. 
How can it help?
We're not sure it can. One small study compared chlorpromazine, a dummy treatment (placebo), and an antidepressant.  After seven weeks, the symptoms of mania had improved more in the people taking chlorpromazine than in the people taking a placebo or the ones taking the antidepressant.
How does it work?
Your brain has lots of nerve cells. They send messages to each other using chemicals. These chemicals are known as neurotransmitters. Antipsychotic drugs work on one called dopamine.
Dopamine makes certain parts of your brain more active. Doctors think that the agitated mood you get with mania may happen because dopamine makes your brain too active.
Antipsychotic drugs like chlorpromazine dampen the effect of dopamine. This makes you calmer.
Can it be harmful?
Yes. Chlorpromazine does have side effects. If you take this drug, you may get: 
Antipsychotic drugs can cause problems with your muscles, too.  They can make your muscles very stiff. And they can cause shaking of your muscles that you can't control. Doctors call this tremor.
If you get these symptoms together, it is sometimes call parkinsonism. This is because these are the same symptoms that people with Parkinson's disease get. But having parkinsonism does not mean you have Parkinson's disease.