Antipsychotic Medications: Types, Uses & Side Effects
📊 Quick Facts About Antipsychotic Medications
💡 Key Takeaways About Antipsychotic Medications
- Two main types exist: First-generation (typical) antipsychotics block dopamine receptors, while second-generation (atypical) antipsychotics also affect serotonin, often causing fewer movement side effects
- Full effect takes time: While sedation may occur quickly, the full antipsychotic effect typically develops over 2-6 weeks of consistent treatment
- Never stop suddenly: Abrupt discontinuation can cause relapse, withdrawal symptoms, or rebound psychosis - always taper gradually under medical supervision
- Side effects vary by medication: Typical antipsychotics may cause more movement disorders; atypical antipsychotics may cause more weight gain and metabolic changes
- Long-acting injectables available: For patients who prefer not to take daily pills, injections given every 2-12 weeks provide consistent medication levels
- Regular monitoring essential: Blood tests, weight checks, and movement assessments help detect and manage side effects early
- Treatment is often long-term: Maintenance therapy significantly reduces the risk of relapse in schizophrenia and other psychotic disorders
What Are Antipsychotic Medications?
Antipsychotic medications are prescription drugs that treat psychotic disorders by reducing symptoms such as hallucinations, delusions, paranoia, and disorganized thinking. They work primarily by blocking dopamine receptors in the brain, with newer medications also affecting serotonin pathways.
Antipsychotic medications, sometimes called neuroleptics or major tranquilizers, represent one of the most important advances in psychiatric treatment. Before their introduction in the 1950s, severe mental illness often required long-term hospitalization with few effective treatment options. The discovery of chlorpromazine revolutionized psychiatry by demonstrating that psychotic symptoms could be effectively managed with medication, allowing many patients to live in their communities rather than institutions.
These medications are primarily used to treat schizophrenia, a chronic mental disorder affecting approximately 1% of the global population. However, antipsychotics are also prescribed for bipolar disorder, severe depression with psychotic features, treatment-resistant depression, dementia-related behavioral disturbances, and certain anxiety disorders. The choice of medication depends on the specific condition being treated, individual patient factors, previous medication responses, and the side effect profile of each drug.
Understanding how antipsychotics work requires knowledge of brain chemistry, particularly the role of dopamine. In psychotic disorders, there appears to be excessive dopamine activity in certain brain pathways, particularly the mesolimbic pathway. By blocking dopamine receptors, antipsychotics reduce this overactivity and thereby diminish psychotic symptoms. However, this same mechanism can affect other dopamine pathways, leading to various side effects including movement disorders and hormonal changes.
The Dopamine Hypothesis of Psychosis
The dopamine hypothesis remains the foundation of our understanding of how antipsychotics work. This theory proposes that positive symptoms of schizophrenia (hallucinations, delusions, disorganized thinking) result from excessive dopamine activity in the mesolimbic pathway. All effective antipsychotic medications block dopamine D2 receptors, and the degree of D2 receptor occupancy correlates with clinical efficacy. Research shows that approximately 60-70% D2 receptor blockade is needed for antipsychotic effect, while blockade above 80% increases the risk of movement side effects.
However, dopamine is not the complete picture. Second-generation antipsychotics also affect serotonin receptors, particularly the 5-HT2A receptor. This serotonin blockade may contribute to their effectiveness against negative symptoms (social withdrawal, reduced emotion, lack of motivation) and their lower risk of movement disorders. The interaction between dopamine and serotonin systems helps explain why different antipsychotics have different clinical profiles.
What Are the Different Types of Antipsychotic Medications?
Antipsychotics are divided into two main classes: first-generation (typical) antipsychotics like haloperidol and chlorpromazine, which primarily block dopamine receptors, and second-generation (atypical) antipsychotics like risperidone, olanzapine, and clozapine, which also affect serotonin receptors and generally cause fewer movement-related side effects.
The classification of antipsychotics into first-generation (typical) and second-generation (atypical) categories reflects both historical development and pharmacological differences. First-generation antipsychotics were developed starting in the 1950s and work primarily by blocking dopamine D2 receptors. Second-generation antipsychotics, introduced from the 1990s onward, have a broader receptor profile that includes significant serotonin (5-HT2A) receptor blockade in addition to dopamine effects.
First-Generation (Typical) Antipsychotics
First-generation antipsychotics remain effective medications that are still widely used, particularly in acute settings and when cost is a significant factor. They are highly effective for positive symptoms but less effective for negative and cognitive symptoms. Their main limitation is a higher risk of extrapyramidal symptoms (EPS) - movement disorders caused by dopamine blockade in the motor pathways.
Common first-generation antipsychotics include haloperidol (Haldol), which is often used in emergency settings due to its rapid onset and effectiveness for acute psychosis; chlorpromazine (Thorazine), the first antipsychotic discovered; fluphenazine (Prolixin), available in long-acting injectable form; and perphenazine (Trilafon), which offers a balance of efficacy and tolerability. These medications vary in their potency and side effect profiles - high-potency drugs like haloperidol cause more movement problems but less sedation, while low-potency drugs like chlorpromazine cause more sedation and anticholinergic effects but fewer movement disorders.
Second-Generation (Atypical) Antipsychotics
Second-generation antipsychotics have become the most commonly prescribed class due to their improved side effect profile, particularly regarding movement disorders. They work by blocking both dopamine D2 receptors and serotonin 5-HT2A receptors. This dual mechanism is thought to reduce motor side effects while potentially improving negative symptoms and cognition. However, many second-generation antipsychotics carry significant metabolic risks including weight gain, diabetes, and elevated cholesterol.
Risperidone (Risperdal) was one of the first atypical antipsychotics and remains widely used. It has good efficacy for positive and negative symptoms and is available in long-acting injectable form. At higher doses, it behaves more like a typical antipsychotic with increased EPS risk. Olanzapine (Zyprexa) is highly effective but carries substantial weight gain and metabolic risk. Quetiapine (Seroquel) is sedating and has a lower EPS risk, making it useful for patients sensitive to movement side effects and for sleep. Aripiprazole (Abilify) has a unique mechanism as a partial dopamine agonist, causing less weight gain and metabolic effects than other atypicals.
| Medication | Generation | Movement Risk | Weight Gain | Sedation |
|---|---|---|---|---|
| Haloperidol | First (Typical) | High | Low | Low-Moderate |
| Chlorpromazine | First (Typical) | Moderate | Moderate | High |
| Risperidone | Second (Atypical) | Low-Moderate | Moderate | Low-Moderate |
| Olanzapine | Second (Atypical) | Low | High | Moderate-High |
| Quetiapine | Second (Atypical) | Very Low | Moderate | High |
| Aripiprazole | Second (Atypical) | Low | Low | Low |
| Clozapine | Second (Atypical) | Very Low | Very High | High |
Clozapine: A Special Case
Clozapine (Clozaril) deserves special mention as the most effective antipsychotic available, particularly for treatment-resistant schizophrenia. Studies show that 30-60% of patients who do not respond to other antipsychotics will improve with clozapine. It is also the only antipsychotic proven to reduce suicide risk in schizophrenia. However, clozapine carries a risk of agranulocytosis (dangerously low white blood cell count), requiring regular blood monitoring. It also causes significant weight gain, metabolic effects, and sedation, but has the lowest risk of movement disorders among all antipsychotics.
How Do Antipsychotic Medications Work in the Brain?
Antipsychotics work by blocking dopamine D2 receptors in the brain's mesolimbic pathway, reducing the excessive dopamine signaling that causes hallucinations and delusions. Second-generation antipsychotics also block serotonin 5-HT2A receptors, which may improve negative symptoms and reduce movement-related side effects.
The mechanism of action of antipsychotic medications is primarily centered on the neurotransmitter dopamine, though these drugs also affect numerous other brain chemicals. Dopamine plays crucial roles in reward, motivation, movement, and cognition. In psychotic disorders, there is believed to be abnormal dopamine activity - too much in some brain pathways (causing positive symptoms) and potentially too little in others (contributing to negative and cognitive symptoms).
When you take an antipsychotic medication, the drug molecules travel through your bloodstream and cross the blood-brain barrier into your brain. There, they bind to dopamine receptors, particularly the D2 subtype, and block dopamine from activating these receptors. This reduces dopamine signaling in the mesolimbic pathway, which connects the midbrain to limbic structures involved in emotion and motivation. By dampening overactive dopamine transmission in this pathway, antipsychotics reduce hallucinations, delusions, and disorganized thinking.
However, dopamine receptors exist throughout the brain, and blocking them in other pathways causes various side effects. Blocking dopamine in the nigrostriatal pathway (which controls movement) can cause extrapyramidal symptoms and tardive dyskinesia. Blocking dopamine in the tuberoinfundibular pathway (which regulates hormone release) can increase prolactin levels, causing breast enlargement, milk production, and menstrual irregularities. Blocking dopamine in the mesocortical pathway may worsen negative symptoms and cognitive problems.
The Role of Serotonin Receptor Blockade
Second-generation antipsychotics distinguish themselves by also blocking serotonin 5-HT2A receptors. Serotonin is a neurotransmitter involved in mood, anxiety, sleep, and various other functions. The 5-HT2A receptor modulates dopamine release in several brain regions. By blocking this receptor, atypical antipsychotics can increase dopamine activity in the prefrontal cortex (potentially improving negative symptoms and cognition) while maintaining dopamine blockade in the mesolimbic pathway (maintaining antipsychotic efficacy).
This serotonin-dopamine interaction also helps explain why atypical antipsychotics cause fewer movement disorders. Serotonin normally inhibits dopamine release in the motor pathways. By blocking 5-HT2A receptors, atypical antipsychotics disinhibit dopamine release in the motor system, partially counteracting the dopamine blockade caused by D2 receptor antagonism. This results in a more selective dopamine blockade that affects psychotic symptoms while sparing motor function.
What Conditions Are Treated With Antipsychotic Medications?
Antipsychotics are primarily used to treat schizophrenia and other psychotic disorders, but they are also prescribed for bipolar disorder (both manic and depressive episodes), severe depression with psychotic features, treatment-resistant depression, certain anxiety disorders, and behavioral symptoms of dementia.
While antipsychotic medications were originally developed for schizophrenia, their use has expanded significantly over the decades. Understanding the range of conditions these medications treat helps clarify both their utility and the complexity of psychiatric medication management. The decision to use an antipsychotic depends on the specific diagnosis, symptom severity, previous treatment response, and individual patient factors.
Schizophrenia and Schizoaffective Disorder
Schizophrenia remains the primary indication for antipsychotic medications. This chronic mental disorder affects how a person thinks, feels, and behaves, causing symptoms divided into three categories: positive symptoms (hallucinations, delusions, disorganized speech and behavior), negative symptoms (reduced emotional expression, lack of motivation, social withdrawal), and cognitive symptoms (impaired memory, attention, and executive function). Antipsychotics are highly effective for positive symptoms, moderately effective for negative symptoms, and have limited effect on cognitive symptoms.
Treatment guidelines recommend starting antipsychotic medication promptly after a first episode of psychosis, as early treatment is associated with better long-term outcomes. For many patients, long-term maintenance treatment is necessary to prevent relapse. Studies show that patients who discontinue antipsychotic medication have a 5-fold higher relapse rate compared to those who continue treatment.
Bipolar Disorder
Many second-generation antipsychotics are approved for treating bipolar disorder, including both acute manic episodes and, for some medications, bipolar depression and maintenance therapy. During manic episodes, antipsychotics can rapidly reduce agitation, grandiosity, decreased need for sleep, and psychotic symptoms. Some atypical antipsychotics (quetiapine, lurasidone, olanzapine-fluoxetine combination) are also approved for bipolar depression, where they can improve depressive symptoms without triggering mania.
Major Depression With Psychotic Features
When depression is accompanied by delusions or hallucinations, adding an antipsychotic to an antidepressant is often necessary. This combination is more effective than either medication alone for psychotic depression. Common combinations include an SSRI or SNRI antidepressant plus an atypical antipsychotic such as quetiapine, risperidone, or aripiprazole.
Treatment-Resistant Depression
For patients with depression that does not respond adequately to antidepressants alone, adding an antipsychotic can be helpful. Aripiprazole, brexpiprazole, and quetiapine XR are specifically approved as adjunctive treatments for major depression. These are typically used at lower doses than for psychosis and work through mechanisms not fully understood, possibly involving modulation of dopamine and serotonin systems.
Antipsychotics are sometimes used to manage severe behavioral symptoms in dementia, such as aggression, agitation, or psychosis. However, these medications carry a black box warning about increased risk of death in elderly patients with dementia-related psychosis. They should only be used when non-pharmacological approaches have failed and symptoms are severe enough to pose a danger to the patient or others. Regular reassessment and attempts to discontinue the medication should be made.
What Are the Side Effects of Antipsychotic Medications?
Common side effects of antipsychotics include weight gain, drowsiness, dry mouth, constipation, and blurred vision. Movement disorders (extrapyramidal symptoms) are more common with first-generation antipsychotics, while metabolic effects (weight gain, diabetes, high cholesterol) are more common with second-generation antipsychotics. Rare but serious side effects include tardive dyskinesia and neuroleptic malignant syndrome.
Understanding the side effects of antipsychotic medications is crucial for both patients and caregivers. These medications can cause a wide range of adverse effects, some of which are merely inconvenient while others can be serious or potentially life-threatening. The side effect profile varies significantly between different antipsychotics, which influences medication selection and makes individualized treatment important.
Movement Disorders (Extrapyramidal Symptoms)
Movement disorders caused by dopamine blockade in the motor pathways are collectively called extrapyramidal symptoms (EPS). These are more common with first-generation antipsychotics and with higher doses of any antipsychotic. Acute dystonia involves sustained, painful muscle contractions, often affecting the neck, eyes, tongue, or limbs. This can occur within days of starting medication and requires immediate treatment with anticholinergic medications.
Akathisia is a distressing sense of inner restlessness and inability to sit still. Patients may pace, shift their weight, or feel an urge to move constantly. This side effect is often underrecognized but can significantly impact quality of life and medication adherence. Parkinsonism refers to symptoms similar to Parkinson's disease: tremor, rigidity, slowed movement, and shuffling gait. These symptoms typically develop over weeks and may improve with dose reduction or addition of anticholinergic medications.
Tardive Dyskinesia
Tardive dyskinesia (TD) is a potentially irreversible movement disorder that can develop after prolonged antipsychotic use. It typically involves involuntary, repetitive movements of the face, tongue, and jaw (such as lip smacking, tongue protrusion, or chewing movements), but can also affect the limbs and trunk. The risk increases with duration of treatment, older age, female sex, and use of first-generation antipsychotics.
Prevention is key - using the lowest effective dose, regular monitoring for early signs, and switching to medications with lower TD risk when possible. If TD develops, treatment options include reducing or switching antipsychotics (if clinically feasible) and using VMAT2 inhibitors (valbenazine or deutetrabenazine), which are specifically approved for treating TD.
Metabolic Side Effects
Second-generation antipsychotics, particularly olanzapine and clozapine, carry significant metabolic risks. Weight gain is extremely common and can be substantial - patients may gain 10-30 pounds or more. This occurs through multiple mechanisms including increased appetite, changes in metabolism, and effects on satiety hormones. Weight gain is not just a cosmetic concern; it increases the risk of cardiovascular disease, the leading cause of premature death in people with schizophrenia.
Diabetes risk is elevated with atypical antipsychotics, independent of weight gain. These medications can directly impair insulin secretion and sensitivity. New-onset diabetes and diabetic ketoacidosis have been reported, sometimes early in treatment. Regular glucose monitoring is essential. Dyslipidemia, including elevated triglycerides and LDL cholesterol and reduced HDL cholesterol, also occurs with many atypical antipsychotics.
NMS is a rare but life-threatening reaction to antipsychotics characterized by high fever, severe muscle rigidity, altered consciousness, and autonomic instability (rapid heart rate, blood pressure changes, sweating). It can occur at any point during treatment but is more common early on or after dose increases. NMS requires immediate medical attention and hospitalization. Treatment involves stopping the antipsychotic, supportive care, and sometimes specific medications like dantrolene or bromocriptine.
Other Common Side Effects
Sedation is common, particularly with chlorpromazine, clozapine, olanzapine, and quetiapine. While sometimes useful for agitation and insomnia, excessive sedation can impair daily functioning. Taking sedating medications at bedtime may help. Anticholinergic effects include dry mouth, constipation, urinary retention, and blurred vision. These are more common with low-potency first-generation antipsychotics and clozapine. Drinking water frequently, using sugar-free gum, and ensuring adequate fiber intake can help manage these symptoms.
Hyperprolactinemia (elevated prolactin hormone) results from dopamine blockade in the pituitary gland and is particularly common with risperidone and first-generation antipsychotics. Symptoms may include breast enlargement, milk production (galactorrhea), menstrual irregularities, and sexual dysfunction. Long-term elevation may affect bone density. Sexual dysfunction, including decreased libido, erectile dysfunction, and difficulty achieving orgasm, can occur through multiple mechanisms including prolactin elevation and direct effects on other neurotransmitters.
How Is Antipsychotic Treatment Started and Monitored?
Treatment starts with a comprehensive psychiatric evaluation and baseline laboratory tests. Medication is typically begun at a low dose and gradually increased over days to weeks. Regular monitoring includes symptom assessment, side effect evaluation, weight checks, and periodic blood tests for metabolic parameters. Full therapeutic effect usually takes 2-6 weeks.
Initiating antipsychotic treatment requires careful consideration of the patient's diagnosis, symptoms, medical history, and preferences. The process involves shared decision-making between the patient (and often family members) and the healthcare team. Proper starting and monitoring procedures help optimize outcomes while minimizing risks.
Before Starting Treatment
A comprehensive evaluation should precede antipsychotic initiation. This includes confirming the diagnosis through thorough psychiatric assessment, reviewing medical history for conditions that might influence medication selection (cardiovascular disease, diabetes, seizures, liver/kidney function), and obtaining baseline laboratory tests. Standard baseline labs typically include a complete blood count, comprehensive metabolic panel, fasting glucose and lipid panel, thyroid function tests, and sometimes an electrocardiogram (ECG), particularly for medications that can affect heart rhythm.
Discussion of treatment options should cover the expected benefits, potential side effects, available medications and their differences, and the patient's preferences regarding pill versus long-acting injectable formulations. Setting realistic expectations is important - while antipsychotics are effective, they do not work immediately, and finding the right medication and dose often requires patience and adjustment.
Dose Titration
Antipsychotics are typically started at a low dose and gradually increased (titrated) over days to weeks. This approach minimizes side effects while allowing the medication to reach therapeutic levels. The rate of titration depends on the urgency of the clinical situation, the specific medication being used, and patient tolerance. In acute settings (such as hospitalization for severe psychosis), titration may be faster than in outpatient settings.
Most antipsychotics require 2-6 weeks at an adequate dose before their full effect is apparent. Patients and families should understand that improvement may be gradual and that it takes time to determine whether a medication is working. Some symptoms (agitation, insomnia) may improve sooner than others (delusions, hallucinations).
Ongoing Monitoring
Regular monitoring during antipsychotic treatment includes assessment of symptom control and side effects at each visit; weight and waist circumference monthly for the first three months, then quarterly; fasting glucose and lipid panel at 12 weeks after starting, then annually (or more frequently if abnormal); blood pressure at each visit; and movement disorder screening using standardized scales such as the Abnormal Involuntary Movement Scale (AIMS) at baseline and every 6-12 months.
Clozapine requires special monitoring due to the risk of agranulocytosis. Weekly blood counts are required for the first 6 months, every two weeks for months 7-12, then monthly thereafter. Patients on clozapine must be enrolled in a monitoring registry program.
What Should I Know About Long-Term Antipsychotic Treatment?
Long-term antipsychotic treatment is often necessary to prevent relapse in psychotic disorders. Maintenance therapy reduces relapse risk by approximately 80% compared to placebo. Decisions about long-term treatment should balance the benefits of relapse prevention against the risks of side effects, particularly metabolic effects and tardive dyskinesia.
For many patients with schizophrenia and other psychotic disorders, antipsychotic medication is a long-term or lifelong treatment. Understanding the rationale for continued treatment, the risks of stopping, and strategies for managing long-term medication helps patients make informed decisions about their care.
Why Maintenance Treatment Is Important
Research consistently shows that continuing antipsychotic medication dramatically reduces the risk of relapse in schizophrenia. Without maintenance treatment, approximately 80% of patients will relapse within one year, compared to about 20% who continue medication. Each relapse can cause significant harm - disruption to work, relationships, and daily functioning; potential for dangerous behavior during psychosis; and possible long-term worsening of illness trajectory.
The duration of recommended maintenance treatment depends on individual factors. After a first episode of psychosis, guidelines typically recommend at least 1-2 years of continued treatment before considering a carefully monitored taper. For patients with multiple episodes or chronic illness, indefinite maintenance treatment is often recommended given the high relapse risk.
Long-Acting Injectable Antipsychotics
For patients who struggle with daily pill-taking, long-acting injectable antipsychotics (LAIs) offer an important alternative. These formulations are administered every 2 to 12 weeks depending on the specific medication and release into the body slowly over time. LAIs eliminate the need for daily adherence, ensure consistent medication levels, and may reduce hospitalization rates.
Available LAI formulations include first-generation options (haloperidol decanoate, fluphenazine decanoate) and second-generation options (risperidone, paliperidone, olanzapine, aripiprazole). The choice depends on which oral medication the patient has responded well to (patients should be stable on the oral form before switching to LAI), tolerability, and patient preference regarding injection frequency.
Addressing Treatment Non-Adherence
Non-adherence to antipsychotic medication is common, affecting 40-60% of patients with schizophrenia. Reasons include side effects, lack of insight into illness, complexity of medication regimens, substance use, and cognitive impairments that affect remembering doses. Strategies to improve adherence include simplifying medication regimens (once-daily dosing, fewer medications), addressing side effects promptly, using LAIs when appropriate, involving family members in treatment, and providing education about the importance of continued treatment.
Abruptly stopping antipsychotic medication can cause withdrawal symptoms, rebound psychosis, and significantly increase relapse risk. If you and your doctor decide to discontinue medication, it should be tapered very gradually over months, with close monitoring. Even gradual discontinuation carries relapse risk, so this decision should be made carefully with full understanding of the potential consequences.
Are There Special Considerations for Certain Patient Groups?
Special considerations apply to elderly patients (increased sensitivity, higher metabolic and cardiovascular risks), pregnant and breastfeeding women (need to balance maternal treatment with fetal/infant exposure), children and adolescents (greater metabolic side effects), and patients with medical conditions (dose adjustments may be needed for liver/kidney disease).
While antipsychotics are used across all age groups and in patients with various medical conditions, certain populations require special consideration in terms of medication selection, dosing, and monitoring.
Elderly Patients
Older adults are generally more sensitive to antipsychotics and require lower starting doses and slower titration. They are at higher risk for orthostatic hypotension (blood pressure drop when standing), falls, sedation, anticholinergic effects, and metabolic side effects. The risk of stroke and death is increased in elderly patients with dementia who take antipsychotics, leading to black box warnings on all antipsychotics. When antipsychotics are necessary in elderly patients, the lowest effective dose should be used for the shortest necessary duration.
Pregnancy and Breastfeeding
Managing psychotic disorders during pregnancy requires balancing the risks of medication exposure to the fetus against the risks of untreated maternal illness. Untreated psychosis can lead to poor prenatal care, nutritional deficiencies, dangerous behaviors, and inability to care for the newborn. Most antipsychotics appear to have relatively low teratogenic risk based on available data, though information is limited for newer medications.
Generally, the recommendation is to use the lowest effective dose and continue treatment if the patient is stable on a medication before pregnancy. Avoiding medication changes during pregnancy minimizes exposure to multiple drugs. Some antipsychotics (particularly risperidone and paliperidone) elevate prolactin, which can affect fertility. Most antipsychotics pass into breast milk; the decision to breastfeed should be individualized based on the specific medication and the mother's clinical situation.
Children and Adolescents
Antipsychotics are used in children and adolescents for schizophrenia, bipolar disorder, autism-associated irritability, and severe behavioral disturbances. However, young people are particularly susceptible to metabolic side effects, with more rapid and pronounced weight gain compared to adults. Prolactin elevation and its effects on developing bodies are also a concern. Close metabolic monitoring and emphasis on healthy lifestyle are essential when children take antipsychotics.
Frequently Asked Questions About Antipsychotic Medications
Typical (first-generation) antipsychotics primarily block dopamine D2 receptors and are effective for positive symptoms but often cause movement-related side effects like tremor, rigidity, and tardive dyskinesia. Atypical (second-generation) antipsychotics block both dopamine and serotonin receptors, causing fewer movement side effects but potentially more metabolic side effects like weight gain and increased diabetes risk. Both types are effective for treating psychosis, and the choice depends on individual patient factors, previous responses, and side effect concerns.
Some effects may be noticed within days, particularly sedation and reduced agitation. However, the full antipsychotic effect typically takes 2-6 weeks to develop. Hallucinations and delusions may gradually decrease over this period. It's important to continue taking the medication as prescribed even if improvement isn't immediate. Treatment should be evaluated after 4-6 weeks at an adequate dose before determining whether the medication is effective or a change is needed.
Common side effects include weight gain, drowsiness, dry mouth, constipation, and blurred vision. Movement disorders (extrapyramidal symptoms such as tremor, stiffness, and restlessness) may occur, especially with typical antipsychotics. Metabolic changes including increased blood sugar and cholesterol are common with some atypical antipsychotics. Sexual dysfunction and hormonal changes can also occur. The specific side effect profile varies by medication, and working with your doctor to find the best-tolerated medication is important.
Never stop antipsychotic medication suddenly without medical supervision. Abrupt discontinuation can cause relapse, withdrawal symptoms, or rebound psychosis. If you and your doctor decide to stop the medication, it should be tapered gradually over weeks to months with careful monitoring. Long-term maintenance treatment is often recommended to prevent relapse, as studies show the relapse rate without medication is approximately 80% within one year compared to about 20% with continued treatment.
Tardive dyskinesia (TD) is a movement disorder that can develop after long-term antipsychotic use, typically after months to years of treatment. It causes involuntary, repetitive movements, often of the face, tongue, and jaw (such as lip smacking, tongue protrusion, or chewing movements), though it can also affect the limbs. The risk is higher with typical antipsychotics and increases with duration of treatment. TD may be irreversible in some cases, which is why regular monitoring and using the lowest effective dose is important. Treatment options exist if TD develops.
Long-acting injectable antipsychotics (LAIs) are given every 2-12 weeks instead of daily pills. They ensure consistent medication levels in the body, eliminate the need for daily pill-taking, and can improve adherence. LAIs may reduce hospitalization rates in some patients. However, pill form allows more flexibility in dose adjustment and may be preferred by patients who dislike injections. The choice between LAIs and oral medication depends on individual circumstances, preferences, and clinical factors.
References & Medical Sources
This article is based on current international guidelines and peer-reviewed research:
- American Psychiatric Association (2020). Practice Guideline for the Treatment of Patients With Schizophrenia. APA Guidelines
- National Institute for Health and Care Excellence (2014, updated 2024). Psychosis and schizophrenia in adults: prevention and management. NICE guideline CG178. NICE Guidelines
- Hasan A, et al. (2022). World Federation of Societies of Biological Psychiatry (WFSBP) Guidelines for Biological Treatment of Schizophrenia. World Journal of Biological Psychiatry.
- Leucht S, et al. (2017). Comparative efficacy and tolerability of 15 antipsychotic drugs in schizophrenia: a multiple-treatments meta-analysis. Lancet. 382(9896):951-962.
- World Health Organization (2023). WHO Model List of Essential Medicines. Geneva: WHO.
- Correll CU, et al. (2015). Cardiometabolic risk of second-generation antipsychotic medications during first-time use in children and adolescents. JAMA. 302(16):1765-1773.
- Tiihonen J, et al. (2017). Real-World Effectiveness of Antipsychotic Treatments in a Nationwide Cohort of 29,823 Patients With Schizophrenia. JAMA Psychiatry. 74(7):686-693.
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This article was written and reviewed by the iMedic Medical Editorial Team, which includes board-certified psychiatrists and psychopharmacology specialists with extensive experience in treating psychotic disorders.
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