Antipsychotics: Indications, Mechanism of Action, Types, Alternatives and Frequently Asked Questions

They are a variety of medications that are used for some types of mental disorders, mainly schizophrenia and manic depression.

They can also be used to treat severe anxiety or depression .


Antipsychotics can help in the following cases:

  • The experience of hearing voices: hallucinations.
  • Ideas that distress you and do not seem to be based on reality : delusions.
  • Difficulty thinking clearly – Thought disorder.
  • The extreme mood swings of manic depression / bipolar disorder.
  • Some can help with severe depression.

Mechanism of action

All antipsychotics affect the action of various chemicals in the brain called neurotransmitters, chemicals that brain cells need to communicate with each other.

Dopamine is the main neurotransmitter affected by these drugs. It is involved in how we feel:

  • That something is significant, influential, or interesting.
  • Satisfaction.
  • Motivation.

It is also involved in the control of muscle movements.

If parts of the dopamine system become overactive, they appear to play a role in producing hallucinations, delusions, and thought disorders.


Although these medications were known as “major tranquilizers” in the past, they are not designed to make you more calm or sleepy, so they are not the same as medications such as Valium or sleeping pills.

The primary goal is to help you feel better without feeling sluggish or sleepy. However, high doses can make you feel very tired or high.

They can be used in higher doses if you become very hyperactive, agitated, or distressed, but this should generally only be for a short time.

Types of antipsychotic medications

For the last ten years or so, doctors have talked about two different groups of antipsychotics:

  • Typical:  the oldest drugs.
  • Atypical: the newest drugs.

Recent extensive independent research studies (not paid for by drug companies) suggest that the new drugs are not different but are, in some situations, easier to use.

Most antipsychotics appear to be equally good at controlling psychotic symptoms – Clozapine is the exception and is described later.

Still, individuals react differently to them, particularly with side effects.

We cannot predict how well a particular person will respond to a specific drug, even if a new or old drug will be more helpful.

It can often take time, negotiation, and “trial and error” to find the best antipsychotic for a particular person.

Older Antipsychotics – These first appeared in the mid-1950s. These older medications are often called “typical” or “first-generation” antipsychotics. All block the action of dopamine, some more than others.

Side effects include:

  • Stiffness and tremors, such as Parkinson’s disease.
  • Feeling slow and sluggish in your thinking.
  • Uncomfortable restlessness (akathisia).
  • Some can affect your blood pressure and make you feel dizzy.
  • Problems with your sex life.
  • Problems with swelling or tenderness in the breasts.

If you have any of these symptoms, you are probably taking too high a dose. Usually, it should be reduced until the side effects wear off.

If you need a higher dose to stay well, these side effects can be controlled with anticholinergic medications, which are used to treat Parkinson’s disease.

Orphenadrine and procyclidine are the two most commonly used anticholinergics.

A longer-term problem is a tardive dyskinesia (TD) – continuous movements of the mouth, tongue, and jaw.

This affects about 1 in 20 people who take these drugs.

The following are some older “typical” antipsychotics:

Tablets of:

  • Chlorpromazine.
  • Haloperidol.
  • Pimozide.
  • Trifluoperazine.
  • Sulpiride.

The newest antipsychotics: In the last ten years, newer drugs have appeared. They still block dopamine, but much less than older drugs.

They also work on different chemical messengers in the brain (such as serotonin) and are often called “atypical” or “second-generation” antipsychotics. This is misleading – they have many of the same effects as previous medications.

The newer antipsychotics are also used to help treat depression in some people. There is growing evidence that this can be effective when combined with an antidepressant.

Your psychiatrist will discuss with you if this is an option to consider.

Some side effects are:

  • Drowsiness and slowness.
  • Weight gain.
  • Interference with your sex life.
  • Greater chance of developing diabetes.
  • Some can affect your blood pressure and make you feel dizzy.
  • Some have the same parkinsonian side effects as older drugs (stiffness of the limbs) in high doses.
  • Long-term use can cause movements of the face (tardive dyskinesia) and, rarely, of the arms or legs.

Compared to older drugs, they seem:

  • Less likely to cause parkinsonian side effects.
  • Less likely to produce late dyskinesia.
  • More likely to cause weight gain.
  • More likely to cause diabetes.
  • More likely to give you sexual problems.

They can also help “negative symptoms” (lack of motivation, lack of interest, lack of self-care), in which older medications have little effect.

Some people find the side effects less of a problem than previous medications.

Some of the newer “atypical” antipsychotics are:

Tablets of:

  • Amisulpride.
  • Aripiprazole.
  • Clozapine.
  • Olanzapine.
  • Quetiapine.
  • Risperidone

Clozapine: seems to be the only antipsychotic medicine that works better than any of the others.

It also appears to reduce suicidal feelings in people with schizophrenia.

It has many of the same side effects as other newer antipsychotics, but it can also cause you to produce more saliva.

It is different in that it appears to have little or no effect on the dopamine systems that control movement. Therefore, it causes almost none of the stiffness, tremors, or sluggishness you can get with other antipsychotics.

Although it tends to cause drowsiness, some people are willing to put up with this because it makes them feel less sluggish than older antipsychotics.

It also does not appear to produce the longer-term problem of tardive dyskinesia and can be used to help alleviate this.

Some side effects are:

The main drawback is that it can affect your bone marrow, leading to a shortage of white blood cells.

This makes you vulnerable to infections. If this happens, the drug is stopped immediately to heal the bone marrow.

Therefore, if you take Clozapine, you will need weekly blood tests for the first six months and two weekly blood tests.

It can also cause:

  • Weight gain.
  • Constipation.
  • Excessive saliva production.
  • Make epileptic seizures more likely.

These problems mean that Clozapine is generally only suggested after at least two other antipsychotics have been tried.

It is a problematic drug to control and can be challenging to take, but some people find that, overall, it gives them a much better quality of life.

Deposit antipsychotics

The word depot means that the medicine is not given in tablets but rather as an injection every 2 to 4 weeks. Release the medicine slowly during this time.

The effects are generally the same as medications taken by mouth.

What’s so great about having a depot injection?

Unlike tablets, you only have to think about it from time to time. Since someone else reminds you, it may be easier to remember than take pills.

What’s wrong with having depot injections?
  • Nobody likes injections, even though the pain is mild and doesn’t last long.
  • It takes a long time to know the effect of changing the dose. If the amount is changed, you may not know what the impact of this change is for several weeks or months; it may take four or so injections for the transition to come to an end.
  • Lowering it may make a slight difference for several weeks if a particular dose gives you side effects.
How are the injections given?
  • A nurse will give you the injection. Usually, there is no one else in the room, just you and the nurse.
  • The first injection is usually a tiny dose of the medicine to check for side effects.
  • If there are no problems, about a week later, you can start regular injections with a higher amount.
  • After each injection, the medicine will stay in your body for several weeks.
  • The interval between injections is usually between 2 and 4 weeks.
Where can I get my injections?

You can usually decide where to place the injections. This could be:

  • At your local doctor’s surgery.
  • At a community mental health center.
  • At a special outpatient clinic.
  • At home, when a nurse visits him.

Some standard depot antipsychotics.

Deposit injections:

  • Haloperidol Decanoate.
  • Flupentixol Decanoate.
  • Fluphenazine Decanoate.
  • Pipotiazine palmitate.
  • Zuclopenthixol Decanoate.
  • Risperidone (newer antipsychotic).

Work is in progress to make new depot drugs for second-generation antipsychotics.

Frequent questions

How well does the medication work?

  • About 4 out of 5 people get help from them. They control the symptoms, but they don’t get rid of them. It would help if you kept taking medicine to prevent the symptoms.
  • Even if the medicine helps, symptoms may come back. This is much less likely to happen if you continue to take medication, even when you feel fine.

How long should I take an antipsychotic?

This depends on several factors:


If you’ve had just one episode of schizophrenia, you have about a 1 in 4 chance that your symptoms won’t return after they get better. Therefore, you may not need to continue taking an antipsychotic.

For most people with schizophrenia, symptoms will continue or come and go over the years.

Some things to consider are:

You may find that antipsychotic medication eliminates your symptoms. They are more likely to make the symptoms less severe and easier to manage.

As with any medicine, you need to balance the help you get from it against any side effects it gives you.

For many people, symptoms seem to come and go for no apparent reason, so there may be times when taking such medications is most helpful and times when you don’t need them as much.

If you have had more than one period of psychotic symptoms and stop taking the medication, the symptoms will usually return within six months.

There is evidence that if major long-term problems develop, they will do so in the first five years. Therefore, your doctor may find it essential to use medications to keep you healthy during these early years.

Bipolar disorder

Bipolar disorders will almost always return, although, during the first episode, it is difficult to predict how often this will happen.

What happens if I stop taking antipsychotic medications?

Symptoms will usually return, not immediately, but usually within 3 to 6 months.

How do I stop taking it?

If you decide to stop taking an antipsychotic, talk to your psychiatrist. You and the psychiatrist may disagree on this, but there is a way to help both parties feel happier.

You can:

  • Make a list of feelings/thoughts/behaviors that may warn you that your symptoms are returning. The pattern of symptoms is often very similar from episode to episode.
  • Make a similar list, with someone you trust and who knows you well, of what other people might notice if your symptoms start to return.

Antipsychotics are not addictive, but your body gets used to having them in your system, and stopping them suddenly can make you feel physically and mentally ill.

If you decide to quit smoking, reduce the medication gradually, giving each reduction a few weeks.

This means that your symptoms probably won’t come back suddenly. If they start to worsen again, you can think about what to do next while still okay.

If you stop the medication completely, stay in contact with your psychiatrist or mental health worker, even if you have been fine for a few months without a prescription.

What alternatives are there?

The evidence is evident that nothing else works as well as antipsychotic medications in treating the most troublesome symptoms of psychotic illness.

For many people, antipsychotics alone are not enough to bring them back to a whole and active life. Other forms of help will be added to the antipsychotic treatment rather than replacing it.

These include:

Cognitive behavior therapy (CBT)

This is a talking treatment that can be helpful if you have distressing psychotic symptoms. It can help you control them and feel less distressed about them.

It can also be used to help you identify if your symptoms reappear.


This helps you learn more about your disorder, manage it, and the treatments available. The goal is to help everyone (including families) better understand the disease so that they can better cope with it and be more supportive.

Family therapy

Professionals will meet with the whole family. The objectives are:

  • To reduce tensions between the person with a psychiatric illness and those who care for them.
  • Give the family practical ways to deal with everyday problems.

We know that these stresses can make symptoms more likely to get worse.

Voice group hearing

People who have similar experiences of hearing voices come together to discuss their experiences and how to deal with them.

Not all of these are available in all areas, and they may not be helpful for everyone – if you think any of these might be beneficial to you, talk to your psychiatrist or mental health worker.

Which antipsychotic is right for me?

There are no antipsychotics that are clearly “better” than any other. Clozapine is more effective, but it has potentially dangerous side effects and means that you need to have regular blood tests.

There are suggestions that one of the newer antipsychotics should be tried first and then one of the older ones, depending on how well the drug works for you and what side effects they cause.

It is best to weigh the benefits and risks of different medications with your psychiatrist. Write down the things that worry you before the appointment, so you don’t forget anything important.