Last reviewed:
30th Mar 2023
PhD
Antipsychotics are medications typically used to treat schizophrenia and may also be used in the treatment of several other conditions. There are many types of antipsychotic medication that may have differing effects depending on the individual’s response to the medication, the severity of their condition, and the concurrent use of other therapeutic or medicinal treatments.
Antipsychotics are a group of medications that are often used to treat schizophrenia and psychosis, in particular hallucinations and delusions [1].
Hallucinations often involve seeing or hearing things that are not really there, but can involve any of the five senses. Delusions are a strong belief in something that is not based in reality or shared by others, which sometimes involves paranoid ideas.
Delusions and hallucinations are referred to as positive symptoms of schizophrenia and are often the most noticeable signs of a psychotic episode. Antipsychotics are often very effective at treating positive symptoms, but may be less effective at treating negative symptoms of schizophrenia, which can include social withdrawal, impaired concentration, and low mood [2].
Antipsychotic medications are categorized as typical and atypical antipsychotics, all of which work in similar ways but have different effects depending on the condition and the individual’s response to the medication [3].
The aim of antipsychotic medication is to effectively treat the symptoms of the individual’s condition, with few unpleasant side effects.
People who require antipsychotic medication may need to try more than one treatment before finding one that works well for them [4].
Antipsychotic medications can be taken as a tablet, capsule, liquid, or injection. They can be used to manage acute episodes of psychosis, for which they might only be required for a short time, or in other cases, they may be used to manage chronic conditions such as schizophrenia and can be required for long-term or lifelong use [1].
Some people who require long-term antipsychotic treatment might be prescribed a depot injection, which is usually administered every 2-4 weeks. This can help reduce the need to remember daily medication, improve compliance, and reduce hospitalization [4].
Most antipsychotic medications work by affecting the neurotransmitter called dopamine, which is often referred to as the ‘pleasure chemical’ of the brain, as it is responsible for the pleasure response experienced by food, sensory experiences, and illicit drugs. Dopamine also affects movement, sleep, memory, cognition, and learning [5].
When dopamine is overactive in the brain it can lead to psychotic symptoms, such as hallucinations and delusions. Antipsychotic medications impact dopamine by reducing its activity and transmission, to regulate and reduce these symptoms [1][6].
Antipsychotics are categorized as typical and atypical antipsychotics, also known as first-generation and second-generation. Typical, or first-generation, antipsychotics were produced as the first treatment for psychosis, but were found to often cause serious side effects. Following this, atypical, or second-generation, antipsychotics were created and generally cause fewer side effects [3].
While typical antipsychotics affect only dopamine, atypical antipsychotics affect both dopamine and serotonin, which is a neurotransmitter responsible for mood regulation. Because of this, atypical antipsychotics can not only reduce positive symptoms, but have also been found to be effective at managing negative symptoms and mood dysregulation [3][6].
The effect of atypical antipsychotics on serotonin is also believed to be responsible for the reduction in side effects of this generation of medications, particularly extrapyramidal side effects related to movement [6]. As such, atypical antipsychotics are now more commonly prescribed than typical antipsychotics, although they can sometimes cause other side effects, such as weight gain [1].
Typical antipsychotics include chlorpromazine, haloperidol, loxapine, pimozide, and thiothixene.
Atypical antipsychotics include risperidone, quetiapine, aripiprazole, olanzapine, and paliperidone.
Clozapine is an atypical antipsychotic but works differently from all other antipsychotic medications. It is known to be very effective at managing the symptoms of schizophrenia, with few of the usually seen side effects of antipsychotics. However, it does also carry the risk of serious physical health complications [2].
Clozapine can cause serious heart issues including rapid heart rate and can also cause low white blood cell count, which increases the risk of infection and serious health issues, and can be fatal [7].
Because of these risks, clozapine is only prescribed if at least two other antipsychotic medications have been prescribed for treatment of schizophrenia and were ineffective [1]. When it is prescribed, doctors are required to closely monitor physical health to ensure the safety of the individual and must stop clozapine treatment if serious side effects occur.
The side effects caused by antipsychotics can vary depending on the medication, and people may have differing responses to the various medications [4]. Often when starting a new medication, it is common to experience side effects as your body adjusts to the medication, but they will typically subside within a few weeks.
Common side effects of antipsychotics include [1][8]:
However, some side effects can be more serious or persistent and can cause concern. It is important to contact your doctor immediately if you experience any concerning side effects from your medication, as you may need a reduced dose or a change of medication.
In general, first-generation (typical) antipsychotics cause more side effects than second-generation (atypical) antipsychotics, particularly side effects related to movement, known as extrapyramidal side effects, although all antipsychotic medications can cause these effects [7].
Some of the more serious side effects associated with antipsychotic medications include:
Metabolic syndrome includes weight gain, diabetes, high blood pressure, and high cholesterol, although not all of these symptoms need to be present for a diagnosis of metabolic syndrome. The risk of these symptoms occurring is increased by antipsychotic medications, so it is necessary to have regular physical health checks during treatment to monitor and regulate these risks [8].
Second-generation antipsychotic medications are more likely to cause weight gain than first-generation. Commonly, olanzapine and clozapine cause the most weight gain, by increasing appetite and causing sedation [7].
Antipsychotics can cause changes in hormone levels, particularly prolactin. Increased prolactin can lead to sexual dysfunction, such as decreased libido, breast tenderness, milk production and secretion, and irregular or missed menstruation [7][8].
Generally, second-generation antipsychotics are less likely to increase prolactin levels, aside from risperidone [3].
Antipsychotics can create side effects in the muscles, caused by decreased dopamine levels, such as stiffness, weakness, spasms, shaking or tremors, and restlessness [8].
These effects are more common with first-generation antipsychotics and with higher doses of medication [4].
Antipsychotic medications have an effect on the nervous system, leading to symptoms known as tardive dyskinesia, which include abnormal, repetitive, and involuntary movements of the body or face, similar to tics [9].
Tardive dyskinesia is more common with first-generation antipsychotics and with prolonged use [5][7]. However, there are medications that can be prescribed to reduce these symptoms [9].
NMS is very rare but is a very serious, and sometimes fatal, neurological condition that can be caused by antipsychotic medications. Symptoms of NMS include severe muscle rigidity, organ failure, confusion, fever, and breathing difficulties. If NMS occurs, antipsychotic medication must be stopped immediately, and the condition treated [1][8].
NMS is more common with first-generation antipsychotics, but all antipsychotic medications can cause NMS [1].
Antipsychotic medications can increase the risk of harm to the heart, including increased or irregular heartbeat and prolonged QT interval [7].
This risk is greater with first-generation antipsychotics but can occur with any antipsychotic medication [1].
All antipsychotic medications can increase the risk of seizures, so they are generally not recommended for use in those with a history of epilepsy or seizures [8].
All antipsychotic medications can increase the risk of glaucoma, a serious eye condition, so it is advised to have regular eye tests throughout this treatment to monitor any concerning changes in eye health [8].
Certain antipsychotics are approved by the US Food & Drug Administration (FDA) to treat various conditions, depending on the specific medication, including [1][10]:
Medications are also prescribed off-label, which means that the FDA has not approved these uses, but it has been deemed necessary for treatment by a medical professional.
Off-label uses of antipsychotic medications include [11][12]:
As there are several different antipsychotic medications, you may need to try several before you find one that works well for you.
Depending on your condition and response to the medication, you may need more than one antipsychotic, or you might require other types of medication to help manage your condition, such as antidepressants, mood stabilizers, and anxiolytics [1][10].
Your doctor will help you find the right medication or combination of medications to manage your symptoms, and it is important that you take your medication exactly as prescribed, to prevent adverse effects.
Talking therapies are often effective at managing mental health conditions, such as psychosis, alongside medicinal treatments. This could include [2][14]:
You may be able to reduce the impact of your symptoms or prevent a reoccurrence of a psychotic episode by improving and maintaining your physical and mental wellbeing with self-help techniques, such as [2][4]:
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