Tardive dysphrenia is characterized by a worsening of psychiatric symptoms that can be directly traced to the administration of antipsychotic medication.

Six symptoms are considered when diagnosing tardive dysphrenia:

A) The patient shows:

B) The symptoms are present for a full four weeks (full two weeks if successfully treated by immediate reinstitution or augmentation with a more potent drug and/or the rising of the previous drug) and contain any of these patterns:

C) Criteria A & B signs and symptoms emerge progressively with the administration of an oral antipsychotic drug or during the four-weeks period that follows its withdrawal (8 weeks for dépôt formulations).

D) There has been any exposure to a typical and/or atypical antipsychotic drug for at least three full months (full 12 weeks), or 1 full month (full 4 weeks) if the patient is sixty years old or older.

E) The clinical signs and symptoms cannot be attributed to another psychiatric condition, neurological condition, somatic illness, or severe stress. Also, exposure to other psychosis-inducing medicines must be excluded.

F) The signs and symptoms could not be better explained by an eventual previous psychiatric/neurological condition unfavorable natural evolution (i.e., Primary Refractory or poor prognosis Schizophrenia; severe Acute Mania; Dementia with Psychotic Symptoms) or by Neuroleptic Dysphoria.

As with other neuroleptic-induced tardive syndromes, there is no definite treatment for tardive dysphrenia. The continuing to take the drug or changing the dosage of the atypical antipsychotic drug in use, or augmenting it with a typical antipsychotic, can alleviate symptoms temporarily. However, these solutions carry the risk of worsening or perpetuating the iatrogenesis in the long term.

Some patients could gradually benefit from changing to a dopamine D2 receptor partial agonist agent like clozapine. These drugs do not induce up-regulation, instead acting as a prophylactic.

Prevention of tardive dyskinesia is achieved by using the lowest effective dose of a neuroleptic for the shortest time. However, with diseases of chronic psychosis such as schizophrenia, this strategy must be balanced with the fact that increased dosages of neuroleptics are more beneficial in preventing recurrence of psychosis. If tardive dyskinesia is diagnosed, the causative drug should be discontinued. Tardive dyskinesia may persist after withdrawal of the drug for months, years or even permanently. Some studies suggest that physicians should consider using atypical antipsychotics as a substitute to typical antipsychotics for patients requiring medication. These agents are associated with fewer neuromotor side effects and a lower risk of developing tardive dyskinesia.

Recent studies have tested the use of melatonin, high dosage vitamins, and different antioxidants in concurrence with antipsychotic drugs (often used to treat schizophrenia) as a way of preventing and treating tardive dyskinesia. Although further research is needed, studies reported a much lower percentage of individuals developing tardive dyskinesia than the current prevalence rate for those taking antipsychotic drugs.

Anticholinergic drugs have been reported to be extremely effective in 40% of the patients with the Pisa syndrome. Patients with Pisa syndrome that is resistant to anticholinergic drugs is mostly resolved by the reduction of the administration of the antipsychotic drugs as previously mentioned. While the specific pathology underlying idiopathic Pisa syndrome is unknown, the administration of anticholinergic drugs has provided resolution in known cases.

There are two lines of treatment for Pisa syndrome. The first line entails discontinuation or reduction in dose of the antipsychotic drug(s). The second line of treatment is an anticholinergic medication. A pharmacological therapy for Pisa syndrome caused by prolonged use of antipsychotic drugs has not been established yet.

Published epidemiological data for akathisia are mostly limited to treatment periods preceding the arrival of second-generation antipsychotics. Sachdev (1995) reported an incidence rate of acute akathisia of 31% for 100 patients treated for 2 weeks with antipsychotic medications. Sachdev (1995) reported a prevalence range from 0.1% to 41%. In all likelihood, rates of prevalence are lower for current treatment as second-generation antipsychotics carry a lower risk of akathisia.

Tardive dyskinesia most commonly occurs in patients with psychiatric conditions who are treated with antipsychotic medications for many years. The average prevalence rate has been estimated to be around 30% for individuals taking antipsychotic medication, such as that used to treat schizophrenia. A study being conducted at the Yale University School of Medicine has estimated that "32% of patients develop persistent tics after 5 years on major tranquilizers, 57% by 15 years, and 68% by 25 years." More drastic data was found during a longitudinal study conducted on individuals 45 years of age and older who were taking antipsychotic drugs. According to this research study, 26% of patients developed tardive dyskinesia after just one year on the medication. Another 60% of this at-risk group developed the disorder after 3 years, and 23% developed "severe" cases of tardive dyskinesia within 3 years. According to these estimates, the majority of patients will eventually develop the disorder if they remain on the drugs long enough.

Elderly patients are more prone to develop tardive dyskinesia, and elderly women are more at-risk than elderly men. The risk is much lower for younger men and women, and also more equal across the sexes. Patients who have undergone electro-convulsive therapy or have a history of diabetes or alcohol abuse also have a higher risk of developing tardive dyskinesia.

Several studies have recently been conducted comparing the prevalence rate of tardive dyskinesia with second generation, or more modern, antipsychotic drugs to that of first generation drugs. The newer antipsychotics appear to have a substantially reduced potential for causing tardive dyskinesia. However, some studies express concern that the prevalence rate has decreased far less than expected, cautioning against the overestimation of the safety of modern antipsychotics.

A physician can evaluate and diagnose a patient with tardive dyskinesia by conducting a systematic examination. The physician should ask the patient to relax, and look for symptoms like facial grimacing, eye or lip movements, tics, respiratory irregularities, and tongue movements. In some cases, patients experience nutritional problems, so a physician can also look for a gain or loss in weight.

Apart from the underlying psychiatric disorder, tardive dyskinesia may cause afflicted people to become socially isolated. It also increases the risk of dysmorphophobia and can even lead to suicide. Emotional or physical stress can increase the severity of dyskinetic movements, whereas relaxation and sedation have the opposite effect.

The presence and severity of akathisia can be measured using the Barnes Akathisia Scale, which assesses both objective and subjective criteria. Precise assessment of akathisia is problematic, as it is difficult to differentiate from a multitude of disorders with similar symptoms. In a study of movement disorders induced by neuroleptics, akathisia was found in only 26% of patients originally diagnosed with akathisia. The primary distinguishing features of akathisia in comparison with other syndromes are primarily subjective characteristics, such as the feeling of inner restlessness. Akathisia can commonly be mistaken for agitation secondary to psychotic symptoms or mood disorder, antipsychotic dysphoria, restless legs syndrome (RLS), anxiety, insomnia, drug withdrawal states, tardive dyskinesia, or other neurological and medical conditions.

Additionally, the controversial diagnosis of "pseudoakathisia" is given, as noted by Mark J. Garcia. In his article discussing akathisia among adults with severe and profound intellectual disability, he describes pseudoakathisia as "comprising all the symptoms of abnormal movements seen with akathisia, but without a sense of restlessness".

Surgery, such as the denervation of selected muscles, may also provide some relief; however, the destruction of nerves in the limbs or brain is not reversible and should be considered only in the most extreme cases. Recently, the procedure of deep brain stimulation (DBS) has proven successful in a number of cases of severe generalised dystonia. DBS as treatment for medication-refractory dystonia, on the other hand, may increase the risk of suicide in patients. However, reference data of patients without DBS therapy are lacking.

The health care provider will perform a physical exam. Detailed questions will be asked about the symptoms.

If a streptococcus infection is suspected, tests will be done to confirm the infection. These include:

- Throat swab

- Anti-DNAse B blood test

- Antistreptolysin O (ASO) blood test

Further testing may include:

- Blood tests such as ESR, CBC

- MRI or CT scan of the brain

The degree of tremor should be assessed in four positions. The tremor can then be classified by which position most accentuates the tremor:

During a physical exam a doctor can determine whether the tremor occurs primarily during action or at rest. The doctor will also check for tremor symmetry, any sensory loss, weakness or muscle atrophy, or decreased reflexes. A detailed family history may indicate if the tremor is inherited. Blood or urine tests can detect thyroid malfunction, other metabolic causes, and abnormal levels of certain chemicals that can cause tremor. These tests may also help to identify contributing causes, such as drug interaction, chronic alcoholism, or another condition or disease. Diagnostic imaging using CT or MRI imaging may help determine if the tremor is the result of a structural defect or degeneration of the brain.

The doctor will perform a neurological examination to assess nerve function and motor and sensory skills. The tests are designed to determine any functional limitations, such as difficulty with handwriting or the ability to hold a utensil or cup. The patient may be asked to place a finger on the tip of her or his nose, draw a spiral, or perform other tasks or exercises.

The doctor may order an electromyogram to diagnose muscle or nerve problems. This test measures involuntary muscle activity and muscle response to nerve stimulation. The selection of the sensors used is important. In addition to studies of muscle activity, tremor can be assessed with accuracy using accelerometers .

Symptoms can last for more than 4 weeks and typically resolve within a day of restoring the medication.

Treatment of tics present in conditions such as Tourette’s syndrome begins with patient, relative, teacher and peer education about the presentation of the tics. Sometimes, pharmacological treatment is unnecessary and tics can be reduced by behavioral therapy such as habit-reversal therapy and/or counseling. Often this route of treatment is difficult because it depends most heavily on patient compliance. Once pharmacological treatment is deemed most appropriate, lowest effective doses should be given first with gradual increases. The most effective drugs belong to the neuroleptic variety such as monoamine-depleting drugs and dopamine receptor-blocking drugs. Of the monoamine-depleting drugs, tetrabenazine is most powerful against tics and results in fewest side effects. A non-neuroleptic drug found to be safe and effective in treating tics is topiramate. Botulinum toxin injection in affected muscles can successfully treat tics; involuntary movements and vocalizations can be reduced, as well as life-threatening tics that have the potential of causing compressive myelopathy or radiculopathy. Surgical treatment for disabling Tourette’s syndrome has been proven effective in cases presenting with self-injury. Deep Brain Stimulation surgery targeting the globus pallidus, thalamus and other areas of the brain may be effective in treating involuntary and possibly life-threatening tics.

Anticholinergic drugs are used to control neuroleptic-induced EPS, although akathisia may require beta blockers or even benzodiazepines. If the EPS are induced by an antipsychotic, EPS may be reduced by dose titration or by switching to an atypical antipsychotic, such as aripiprazole, ziprasidone, quetiapine, olanzapine, risperidone, or clozapine. These medications possess an additional mode of action that is believed to negate their effect on the nigrostriatal pathway, which means they are associated with fewer extrapyramidal side-effects than "conventional" antipsychotics (chlorpromazine, haloperidol, etc.), although some research has shown that second generation neuroleptics cause EPS at the same rate as the first generation drugs.

Commonly used medications for EPS are anticholinergic agents such as benztropine (Cogentin), diphenhydramine (Benadryl), and trihexyphenidyl (Artane). Another common course of treatment includes dopamine agonist agents such as pramipexole. These medications reverse the symptoms of extrapyramidal side effects caused by antipsychotics or other drugs that either directly or indirectly inhibit dopaminergic neurotransmission.

Studies are yet to be undertaken on the optimum dosage of the causative drugs to reduce their side effects (extrapyramidal symptoms (EPS)).

Treatment of primary dystonia is aimed at reducing symptoms such as involuntary movements, pain, contracture, embarrassment, and to restore normal posture and improve the patient’s function. This treatment is therefore not neuroprotective. According to the European Federation of Neurological Sciences and Movement Disorder Society, there is no evidence-based recommendation for treating primary dystonia with antidopaminergic or anticholinergic drugs although recommendations have been based on empirical evidence. Anticholinergic drugs prove to be most effective in treating generalized and segmental dystonia, especially if dose starts out low and increases gradually. Generalized dystonia has also been treated with such muscle relaxants as the benzodiazepines. Another muscle relaxant, baclofen, can help reduce spasticity seen in cerebral palsy such as dystonia in the leg and trunk. Treatment of secondary dystonia by administering levodopa in dopamine-responsive dystonia, copper chelation in Wilson’s disease, or stopping the administration of drugs that may induce dystonia have been proven effective in a small number of cases. Physical therapy has been used to improve posture and prevent contractures via braces and casting, although in some cases, immobilization of limbs can induce dystonia, which is by definition known as peripherally induced dystonia. There are not many clinical trials that show significant efficacy for particular drugs, so medical of dystonia must be planned on a case-by-case basis. Botulinum toxin B, or Myobloc, has been approved by the US Food and Drug Administration to treat cervical dystonia due to level A evidential support by the scientific community. Surgery known as GPi DBS (Globus Pallidus Pars Interna Deep Brain Stimulation) has come to be popular in treating phasic forms of dystonia, although cases involving posturing and tonic contractions have improved to a lesser extent with this surgery. A follow-up study has found that movement score improvements observed one year after the surgery was maintained after three years in 58% of the cases. It has also been proven effective in treating cervical and cranial-cervical dystonia.

Different medications are tried in an effort to find a combination that is effective for a specific person. Not all people will respond well to the same medications. Medications that have had positive results in some include: diphenhydramine, benzatropine and atropine. anti-Parkinsons agents (such as ropinirole and bromocriptine), and muscle relaxants (such as diazepam).

- Anticholinergics

Medications such as anticholinergics (benztropine), which act as inhibitors of the neurotransmitter acetylcholine, may provide some relief. In the case of an acute dystonic reaction, diphenhydramine is sometimes used (though this drug is well known as an antihistamine, in this context it is being used primarily for its anticholinergic role).. See also Procyclidine.

- Baclofen

A baclofen pump has been used to treat patients of all ages exhibiting muscle spasticity along with dystonia. The pump delivers baclofen via a catheter to the thecal space surrounding the spinal cord. The pump itself is placed in the abdomen. It can be refilled periodically by access through the skin. Baclofen can also be taken in tablet form

- Botulin toxin injection

Botulinum toxin injections into affected muscles have proved quite successful in providing some relief for around 3–6 months, depending on the kind of dystonia. Botox or Dysport injections have the advantage of ready availability (the same form is used for cosmetic surgery) and the effects are not permanent. There is a risk of temporary paralysis of the muscles being injected or the leaking of the toxin into adjacent muscle groups, causing weakness or paralysis in them. The injections have to be repeated, as the effects wear off and around 15% of recipients will develop immunity to the toxin. There is a Type A and a Type B toxin approved for treatment of dystonia; often, those that develop resistance to Type A may be able to use Type B.

- Muscle relaxants

Clonazepam, an anti-seizure medicine, is also sometimes prescribed. However, for most, their effects are limited and side-effects like mental confusion, sedation, mood swings, and short-term memory loss occur.

- Parkinsonian drugs

Dopamine agonists: One type of dystonia, dopamine-responsive dystonia, can be completely treated with regular doses of L-DOPA in a form such as Sinemet (carbidopa/levodopa). Although this does not remove the condition, it does alleviate the symptoms most of the time. (In contrast, dopamine antagonists can sometimes cause dystonia.)

Ketogenic Diet

A Ketogenic diet consisting of 70% fats (focusing on medium chain triglycerides and unsaturated fats), 20% protein and 10% carbohydrates (any sugar) has shown strong promise as a treatment for Dystonia.

Antidepressants, including SSRIs, can cross the placenta and have the potential to affect the fetus and newborns, presenting a dilemma whether pregnant women should take antidepressants at all, and if they do, whether tapering them near the end of pregnancy could have a protective effect for the newborn.

Postnatal adaptation syndrome (PNAS) (originally called “neonatal behavioral syndrome”, “poor neonatal adaptation syndrome”, or "neonatal withdrawal syndrome") was first noticed in 1973 in newborns of mothers taking antidepressants; symptoms in the infant include irritability, rapid breathing, hypothermia, and blood sugar problems. The symptoms usually develop from birth to days after delivery and usually resolve within days or weeks of delivery.

Treatment of Sydenham's Chorea is based on the following principles:

1. The first tenet of treatment is to eliminate the streptococcus at a primary, secondary and tertiary level. Strategies involve the adequate treatment of throat and skin infections, with a course of penicillin when Sydenham's Chorea is newly diagnosed, followed by long-term penicillin prophylaxis. Behavioural and emotional changes may precede the movement disorders in a previously well child.

2. Treatment of movement disorders. Therapeutic efforts are limited to palliation of the movement disorders. Haloperidol is frequently used because of its anti-dopaminergic effect. It has serious potential side-effects, e.g., tardive dyskinesia. In a study conducted at the RFC, 25 out of 39 patients on haloperidol reported side-effects severe enough to cause the physician or parent to discontinue treatment or reduce the dose. Other medications which have been used to control the movements include pimozide, clonidine, valproic acid, carbamazepine and phenobarbitone.

3. Immunomodulatory interventions include steroids, intravenous immunoglobulins, and plasma exchange. Patients may benefit from treatment with steroids; controlled clinical trials are indicated to explore this further.

4. There are several historical case series reporting successful treatment of Sydenham's Chorea by inducing fever.

Meige's is commonly misdiagnosed and most doctors will have not seen this condition before. Usually a neurologist who specializes in movement disorders can detect Meige's. There is no way to detect Meige's by blood test or MRI or CT scans. OMD by itself may be misdiagnosed as TMJ.

The lack of prompt response to anticholinergic drugs in cases of idiopathic Meige's syndrome is important in differentiating it from acute dystonia, which does respond to anticholinergics.

Extrapyramidal symptoms (EPS), also known as extrapyramidal side effects (EPSE), are drug-induced movement disorders that include acute and tardive symptoms. These symptoms include dystonia (continuous spasms and muscle contractions), akathisia (motor restlessness), parkinsonism (characteristic symptoms such as rigidity), bradykinesia (slowness of movement), tremor, and tardive dyskinesia (irregular, jerky movements). Antipsychotics are often discontinued due to inefficacy and intolerable side effects such as extrapyramidal symptoms.

Since it is difficult to measure extrapyramidal symptoms, rating scales are commonly used to assess the severity of movement disorders. The Simpson-Angus Scale (SAS), Barnes Akathisia Rating Scale (BARS), Abnormal Involuntary Movement Scale (AIMS), and Extrapyramidal Symptom Rating Scale (ESRS) are rating scales frequently used for such assessment and are not weighted for diagnostic purposes; these scales can help physicians weigh the benefit/expected benefit of a medication against the degree of distress which the side effects are causing the patient, aiding in the decision to maintain, reduce, or discontinue the causative medication/s.

Spasmodic torticollis is one of the most common forms of dystonia seen in neurology clinics, occurring in approximately 0.390% of the United States population in 2007 (390 per 100,000). Worldwide, it has been reported that the incidence rate of spasmodic torticollis is at least 1.2 per 100,000 person years, and a prevalence rate of 57 per 1 million.

The exact prevalence of the disorder is not known; several family and population studies show that as many as 25% of cervical dystonia patients have relatives that are undiagnosed. Studies have shown that spasmodic torticollis is not diagnosed immediately; many patients are diagnosed well after a year of seeking medical attention. A survey of 59 patients diagnosed with spasmodic torticollis show that 43% of the patients visited at least four physicians before the diagnosis was made.

There is a higher prevalence of spasmodic torticollis in females; females are 1.5 times more likely to develop spasmodic torticollis than males. The prevalence rate of spasmodic torticollis also increases with age, most patients show symptoms from ages 50–69. The average onset age of spasmodic torticollis is 41.

Spasmodic torticollis is a form of focal dystonia, a neuromuscular disorder that consists of sustained muscle contractions causing repetitive and twisting movements and abnormal postures in a single body region. There are two main ways to categorize spasmodic torticollis: age of onset, and cause. The disorder is categorized as early onset if the patient is diagnosed before the age of 27, and late onset thereafter. The causes are categorized as either primary (idiopathic) or secondary (symptomatic). Spasmodic torticollis can be further categorized by the direction and rotation of head movement.

Since 1979, the disorder has been recognized by the American Academy of Sleep Medicine:

- "Diagnostic Classification of Sleep and Arousal Disorders" (DCSAD), 1979: Non-24-Hour Sleep–Wake Syndrome; code C.2.d

- "The International Classification of Sleep Disorders", 1st & Revised eds. (ICSD), 1990, 1997: Non-24-Hour Sleep–Wake Syndrome (or Non-24-Hour Sleep–Wake Disorder); code 780.55-2

- "The International Classification of Sleep Disorders", 2nd ed. (ICSD-2), 2005: Non-24-Hour Sleep–Wake Syndrome (alternatively, Non-24-Hour Sleep–Wake Disorder); code 780.55-2

Since 2005, the disorder has been recognized by name in the U.S. National Center for Health Statistics and the U.S. Centers for Medicare and Medicaid Services in their adaptation and extension of the WHO's "International Statistical Classification of Diseases and Related Health Problems" (ICD):

- ICD-9-CM: Circadian rhythm sleep disorder, free-running type; code 327.34 became effective in October 2005. Prior to the introduction of this code, the nonspecific code 307.45, Circadian rhythm sleep disorder of nonorganic origin, was available, and as of 2014 remains the code recommended by the DSM-5.

- ICD-10-CM: Circadian rhythm sleep disorder, free running type; code G47.24 is due to take effect October 1, 2014.

Since 2013, the disorder has been recognized by the American Psychiatric Association:

- DSM-5, 2013: Circadian rhythm sleep–wake disorders, Non-24-hour sleep–wake type; ICD-9-CM code 307.45 is recommended (no acknowledgment of 327.34 is made), and ICD-10-CM code G47.24 is recommended when it goes into effect.

The disorder can be considered very likely in a totally blind person with periodic insomnia and daytime sleepiness, although other causes for these common symptoms need to be ruled out. In the research setting, the diagnosis can be confirmed, and the length of the free-running circadian cycle can be ascertained, by periodic assessment of circadian marker rhythms, such as the core body temperature rhythm, the timing of melatonin secretion, or by analyzing the pattern of the sleep–wake schedule using actigraphy. Most recent research has used serial measurements of melatonin metabolites in urine or melatonin concentrations in saliva. These assays are not currently available for routine clinical use.