Psychosis as a symptom of a psychiatric disorder is first and foremost a diagnosis of exclusion. So a new-onset episode of psychosis "cannot" be considered to be a symptom of a psychiatric disorder until other relevant and known medical causes of psychosis are excluded, or ruled out. Many clinicians improperly perform, or entirely miss this step, introducing avoidable diagnostic error and misdiagnosis.

An initial assessment includes a comprehensive history and physical examination. Although no biological laboratory tests exist which confirm schizoaffective disorder, biological tests should be performed to exclude psychosis associated with or caused by substance use, medications, toxins or poisons, surgical complications, or other medical illnesses. Since non-medical mental health practitioners are not trained to exclude medical causes of psychosis, people experiencing psychosis should be referred to an emergency department or hospital.

Delirium should be ruled out, which can be distinguished by visual hallucinations, acute onset and fluctuating level of consciousness, indicating other underlying factors which includes medical illnesses. Excluding medical illnesses associated with psychosis is performed by using blood tests to measure:

- Thyroid-stimulating hormone to exclude hypo- or hyperthyroidism,

- Basic electrolytes and serum calcium to rule out a metabolic disturbance,

- Full blood count including ESR to rule out a systemic infection or chronic disease, and

- Serology to exclude syphilis or HIV infection.

Other investigations which may be performed include:

- EEG to exclude epilepsy, and an

- MRI or CT scan of the head to exclude brain lesions.

Blood tests are not usually repeated for relapse in people with an established diagnosis of schizoaffective disorder, unless there is a specific "medical" indication. These may include serum BSL if olanzapine has previously been prescribed, thyroid function if lithium has previously been taken to rule out hypothyroidism, liver function tests if chlorpromazine has been prescribed, CPK levels to exclude neuroleptic malignant syndrome, and a urinalysis and serum toxicology screening if substance use is suspected. Assessment and treatment may be done on an outpatient basis; admission to an inpatient facility is considered if there is a risk to self or others.

Because psychosis may be precipitated or exacerbated by common classes of psychiatric medications, such as antidepressants, ADHD stimulant medications, and sleep medications, prescribed medication-induced psychosis should be ruled out, particularly for first-episode psychosis. This is an essential step to reduce diagnostic error and to evaluate potential medication sources of further patient harm. Regarding prescribed medication sources of patient harm, Yale School of Medicine Professor of Psychiatry Malcolm B. Bowers, Jr, MD wrote:

Illicit drugs aren't the only ones that precipitate psychosis or mania—prescribed drugs can too, and in particular, some psychiatric drugs. We investigated this and found that about 1 in 12 psychotic or manic patients in an inpatient psychiatric facility are there due to antidepressant-induced psychosis or mania. That's unfortunate for the field [of psychiatry] and disastrous for some of our patients.

Substance-induced psychosis should also be ruled out. Both substance- and medication-induced psychosis can be excluded to a high level of certainty while the person is psychotic, typically in an emergency department, using both a

- Broad spectrum urine toxicology screening, and a

- Full serum toxicology screening (of the blood).

Some dietary supplements may also induce psychosis or mania, but cannot be ruled out with laboratory tests. So a psychotic person's family, partner, or friends should be asked whether he or she is currently taking any dietary supplements.

Common mistakes made when diagnosing psychotic patients include:

- Not properly excluding delirium,

- Missing a toxic psychosis by not screening for substances "and" medications,

- Not appreciating medical abnormalities (e.g., vital signs),

- Not obtaining a medical history and family history,

- Indiscriminate screening without an organizing framework,

- Not asking family or others about dietary supplements,

- Premature diagnostic closure, and

- Not revisiting or questioning the initial diagnostic impression of primary psychiatric disorder.

Only after these relevant and known causes of psychosis have been ruled out can a psychiatric differential diagnosis be made. A mental health clinician will incorporate family history, observation of a psychotic person's behavior while the person is experiencing active symptoms, to begin a psychiatric differential diagnosis. Diagnosis also includes self-reported experiences, as well as behavioral abnormalities reported by family members, friends, or significant others. Mistakes in this stage include:

- Not screening for dissociative disorders. Dissociative identity disorder and psychotic symptoms in schizoaffective disorder have considerable overlap, yet a different overall treatment approach.

Schizophrenia is diagnosed based on criteria in either the American Psychiatric Association's (APA) fifth edition of the "Diagnostic and Statistical Manual of Mental Disorders" (DSM 5), or the World Health Organization's International Statistical Classification of Diseases and Related Health Problems (ICD-10). These criteria use the self-reported experiences of the person and reported abnormalities in behavior, followed by a clinical assessment by a mental health professional. Symptoms associated with schizophrenia occur along a continuum in the population and must reach a certain severity and level of impairment, before a diagnosis is made. As of 2013 there is no objective test.

Bipolar disorder is commonly diagnosed during adolescence or early adulthood, but onset can occur throughout the life cycle. The disorder can be difficult to distinguish from unipolar depression and the average delay in diagnosis is 5–10 years after symptoms begin. Diagnosis of bipolar disorder takes several factors into account and considers the self-reported experiences of the symptomatic individual, abnormal behavior reported by family members, friends or co-workers, observable signs of illness as assessed by a clinician, and often a medical work-up to rule-out medical causes. In diagnosis, caregiver-scored rating scales, specifically the mother, has been found to be more accurate than teacher and youth report in predicting identifying youths with bipolar disorder. Assessment is usually done on an outpatient basis; admission to an inpatient facility is considered if there is a risk to oneself or others. The most widely used criteria for diagnosing bipolar disorder are from the American Psychiatric Association's (APA) "Diagnostic and Statistical Manual of Mental Disorders", Fifth Edition (DSM-5) and the World Health Organization's (WHO) "International Statistical Classification of Diseases and Related Health Problems", 10th Edition (ICD-10). The ICD-10 criteria are used more often in clinical settings outside of the U.S. while the DSM criteria are used clinically within the U.S. and are the prevailing criteria used internationally in research studies. The DSM-5, published in 2013, included further and more accurate specifiers compared to its predecessor, the DSM-IV-TR. Semi structured interviews such as the Kiddie Schedule for Affective Disorders and Schizophrenia (KSADS) and the Structured Clinical Interview for DSM-IV (SCID) are used for diagnostic confirmation of bipolar disorder.

Several rating scales for the screening and evaluation of bipolar disorder exist, including the Bipolar spectrum diagnostic scale, Mood Disorder Questionnaire, the General Behavior Inventory and the Hypomania Checklist. The use of evaluation scales cannot substitute a full clinical interview but they serve to systematize the recollection of symptoms. On the other hand, instruments for screening bipolar disorder tend to have lower sensitivity.

In 2013, the American Psychiatric Association released the fifth edition of the DSM (DSM-5). To be diagnosed with schizophrenia, two diagnostic criteria have to be met over much of the time of a period of at least one month, with a significant impact on social or occupational functioning for at least six months. The person had to be suffering from delusions, hallucinations, or disorganized speech. A second symptom could be negative symptoms, or severely disorganized or catatonic behaviour. The definition of schizophrenia remained essentially the same as that specified by the 2000 version of DSM (DSM-IV-TR), but DSM-5 makes a number of changes.

- Subtype classifications – such as catatonic and paranoid schizophrenia – are removed. These were retained in previous revisions largely for reasons of tradition, but had subsequently proved to be of little worth.

- Catatonia is no longer so strongly associated with schizophrenia.

- In describing a person's schizophrenia, it is recommended that a better distinction be made between the current state of the condition and its historical progress, to achieve a clearer overall characterization.

- Special treatment of Schneider's first-rank symptoms is no longer recommended.

- Schizoaffective disorder is better defined to demarcate it more cleanly from schizophrenia.

- An assessment covering eight domains of psychopathology – such as whether hallucination or mania is experienced – is recommended to help clinical decision-making.

The ICD-10 criteria are typically used in European countries, while the DSM criteria are used in the United States and to varying degrees around the world, and are prevailing in research studies. The ICD-10 criteria put more emphasis on Schneiderian first-rank symptoms. In practice, agreement between the two systems is high. The current proposal for the ICD-11 criteria for schizophrenia recommends adding self-disorder as a symptom.

If signs of disturbance are present for more than a month but less than six months, the diagnosis of schizophreniform disorder is applied. Psychotic symptoms lasting less than a month may be diagnosed as brief psychotic disorder, and various conditions may be classed as psychotic disorder not otherwise specified, while schizoaffective disorder is diagnosed if symptoms of mood disorder are substantially present alongside psychotic symptoms. If the psychotic symptoms are the direct physiological result of a general medical condition or a substance, then the diagnosis is one of a psychosis secondary to that condition. Schizophrenia is not diagnosed if symptoms of pervasive developmental disorder are present unless prominent delusions or hallucinations are also present.

Research efforts are focusing on prevention in identifying early signs from relatives with associated disorders similar with schizophrenia and those with prenatal and birth complications. Prevention has been an ongoing challenge because early signs of the disorder are similar to those of other disorders. Also, some of the schizophrenic related symptoms are often found in children without schizophrenia or any other diagnosable disorder.

There are several other mental disorders with symptoms similar to those seen in bipolar disorder. These disorders include schizophrenia, major depressive disorder, attention deficit hyperactivity disorder (ADHD), and certain personality disorders, such as borderline personality disorder.

Although there are no biological tests that are diagnostic of bipolar disorder, blood tests and/or imaging may be carried out to exclude medical illnesses with clinical presentations similar to that of bipolar disorder. Neurologic diseases such as such as multiple sclerosis, complex partial seizures, strokes, brain tumors, Wilson disease, traumatic brain injury, Huntington's disease, and complex migraines can mimic features of bipolar disorder. An EEG may be used to exclude neurological disorders such as epilepsy, and a CT scan or MRI of the head may be used to exclude brain lesions. Additionally, disorders of the endocrine system such as hypothyroidism, hyperthyroidism, and Cushing's disease are in the differential as is the connective tissue disease systemic lupus erythematosus. Infectious causes of mania which may appear similar to bipolar mania include herpes encephalitis, HIV, influenza, or neurosyphilis. Certain vitamin deficiencies such as pellagra (niacin deficiency), Vitamin B12 deficiency, folate deficiency, and Wernicke Korsakoff syndrome (thiamine deficiency) can also lead to mania.

A review of current and recent medications and drug use is considered to rule out these causes; common medications that can cause manic symptoms include antidepressants, prednisone, Parkinson's disease medications, thyroid hormone, stimulants (including cocaine and methamphetamine), and certain antibiotics.

The most widely used criteria for diagnosing schizoaffective disorder are from the American Psychiatric Association's "Diagnostic and Statistical Manual of Mental Disorders-5".

The DSM-IV schizoaffective disorder definition was plagued by problems of being inconsistently (or unreliably) used on patients; when the diagnosis is made, it doesn't stay with most patients over time; and it has questionable diagnostic validity (that is, it doesn't describe a distinct disorder, nor predict any particular outcome). These problems have been slightly reduced (or "modestly improved") in the DSM-5 according to Carpenter.

When psychotic symptoms are confined to an episode of mania or depression (with or without mixed features), the diagnosis is that of a “psychotic” mood disorder, namely either bipolar disorder or major depression). Only when psychotic states persist in a sustained fashion for two weeks or longer without concurrent affective symptoms is the diagnosis schizoaffective disorder or schizophrenia.

The second cardinal guideline in the DSM-5 diagnosis of schizoaffective disorder is one of timeframe.

These two changes are intended by the DSM-5 workgroup to accomplish two goals:

- Increase the diagnosis' consistency (or reliability) when it is used;

- Significantly decrease the overall use of the schizoaffective disorder diagnosis.

If the schizoaffective diagnosis is used less often, other diagnoses (like psychotic mood disorders and schizophrenia) are likely to be used more often; but this is hypothetical until real-world data arrive. Validity problems with the diagnosis remain and await further work in the fields of psychiatric genetics, neuroimaging, and cognitive science that includes the overlapping fields of cognitive, affective, and social neuroscience, which may change the way schizoaffective disorder is conceptualized and defined in future versions of the DSM and ICD.

Paranoid schizophrenia is an illness that typically requires lifelong treatment with neuroleptics to allow someone to have a relatively stable and normal lifestyle. In order to be successfully treated, a person with schizophrenia should seek help from family or primary care doctors, psychiatrists, psychotherapists, pharmacists, family members, case workers, psychiatric nurses, or social workers, provided he or she is not unable to do so, due to many people with schizophrenia having the inability to accept their condition. Non-compliance with neuroleptics may also occur if the patient considers the side effects (such as extrapyramidal symptoms) to be more debilitating than the condition itself. The main options that are offered for the treatment of paranoid schizophrenia are the following: neuroleptics, psychotherapy, hospitalization, electroconvulsive therapy, and vocational skills training.

There are many different types of disorders that have similar symptoms to paranoid schizophrenia. There are tests that psychiatrists perform to achieve a correct diagnosis. They include "psychiatric evaluation, in which the doctor or psychiatrist will ask a series of questions about the patient's symptoms, psychiatric history, and family history of mental health problems; medical history and exam, in which the doctor will ask about one's personal and family health history and will also perform a complete physical examination to check for medical issues that could be causing or contributing to the problem; laboratory tests in which the doctor will order simple blood and urine tests can rule out other medical causes of symptoms".

There are side effects associated with antipsychotic medication. Neuroleptics can cause high blood pressure and high cholesterol. Many people who take them exhibit weight gain and have a higher risk of developing diabetes.

According to the Mayo Clinic, it is best to start receiving treatment for paranoid schizophrenia as early as possible and to maintain the treatment throughout life. Continuing treatment will help keep the serious symptoms under control and allow the person to lead a more fulfilling life. This illness is typically unpreventable.

It has a strong hereditary component with a first degree parent or sibling. There is some possibility that there are environmental influences including "prenatal exposure to a viral infection, low oxygen levels during birth (from prolonged labor or premature birth), exposure to a virus during infancy, early parental loss or separation, and verbal, physical or sexual abuse in childhood". Eliminating any of these factors could help reduce an individual's future risk of developing paranoid schizophrenia.

The same criteria are used to diagnose children and adults. Diagnosis is based on reports by parents or caretakers, teachers, school officials, and others close to the child.

A professional who believes a child has schizophrenia usually conducts a series of tests to rule out other causes of behavior, and pinpoint a diagnosis. Three different types of exams are performed: physical, laboratory, and psychological. Physical exams usually cover the basic assessments, including but not limited to; height, weight, blood pressure, and checking all vital signs to make sure the child is healthy. Laboratory tests include electroencephalogram EEG screening and brain imaging scans. Blood tests are used to rule out alcohol or drug effects, and thyroid hormone levels are tested to rule out hyper- or hypothyroidism. A psychologist or psychiatrist talks to a child about their thoughts, feelings, and behavior patterns. They also inquire about the severity of the symptoms, and the effects they have on the child's daily life. They may also discuss thoughts of suicide or self-harm in these one-on-one sessions. Some symptoms that may be looked at are early language delays, early motor development delays and school problems.

Many of persons with childhood schizophrenia are initially misdiagnosed as having pervasive developmental disorders (autism spectrum disorder, for example).

Schizophreniform disorder is equally prevalent among men and women. The most common ages of onset are 18–24 for men and 18–35 for women. While the symptoms of schizophrenia often develop gradually over a period of years, the diagnostic criteria for schizophreniform disorder require a much more rapid onset.

Available evidence suggests variations in incidence across sociocultural settings. In the United States and other developed countries, the incidence is low, possibly fivefold less than that of schizophrenia. In developing countries, the incidence is substantially higher, especially for the subtype "With Good Prognostic Features". In some of these settings schizophreniform disorder may be as common as schizophrenia.

The "Diagnostic and Statistical Manual of Mental Disorders" (DSM-IV) recognizes two types of bipolar disorders—bipolar I and bipolar II. People with bipolar I disorder suffer from at least one manic or mixed episode, and may experience depressive episodes. On the contrary, as noted above, people with bipolar II disorder experience a milder form of a manic episode, known as a hypomanic episode as well as major depressive episodes. Although bipolar II is thought to be less severe than bipolar I in regards to symptom intensity, it is actually more severe and distressing with respect to episode frequency and overall course. Those with bipolar II often experience more frequent bouts of depressive episodes. Specific criteria defined by the DSM-IV for a bipolar II diagnosis is as follows:

- The presence of a hypomanic or major depressive episode.

- If currently in major depressive episode, history of a hypomanic episode. If currently in a hypomanic episode, history of a major depressive episode. No history of a manic episode.

- Significant stress or impairment in social, occupational, or other important areas of functioning.

Studies have identified major differences between bipolar I and bipolar II in regards to their clinical features, comorbidity rates and family histories. According to Baek et al. (2011), during depressive episodes, bipolar II patients tend to show higher rates of psychomotor agitation, guilt, shame, suicidal ideation, and suicide attempts. Bipolar II patients have shown higher lifetime comorbidity rates of DSM axis I diagnoses such as phobias, anxiety disorders, substance & alcohol abuse, and eating disorders and there is a higher correlation between bipolar II patients and family history of psychiatric illness, including major depression and substance-related disorders. The occurrence rate of psychiatric illness in first degree relatives of bipolar II patients was 26.5%, versus 15.4% in bipolar I patients.

Screening instruments like the Mood Disorders Questionnaire (MDQ) are helpful tools in determining a patient's status on the bipolar spectrum and getting families involved can also improve chances of an accurate diagnosis and acknowledgment of hypomanic episodes. In addition, there are certain features that have been shown to increase the chances that depressed patients are suffering from a bipolar disorder including atypical symptoms of depression like hypersomnia and hyperphagia, a family history of bipolar disorder, medication-induced hypomania, recurrent or psychotic depression, antidepressant refractory depression, and early or postpartum depression.

Several studies have shown that the risk of suicide is higher in patients who suffer from Bipolar II than those who suffer from Bipolar I, and especially higher than patients who suffer from major depressive disorder.

In results of a summary of several lifetime study experiments, it was found that 24% of Bipolar II patients experienced suicidal ideation or suicide attempts compared to 17% in Bipolar I patients and 12% in major depressive patients. Bipolar disorders, in general, are the third leading cause of death in 15- to 24-year-olds. Bipolar II patients were also found to employ more lethal means and have more complete suicides overall.

Bipolar II patients have several risk factors that increase their risk of suicide. The illness is very recurrent and results in severe disabilities, interpersonal relationship problems, barriers to academic, financial, and vocational goals, and a loss of social standing in their community, all of which increase the likelihood of suicide. Mixed symptoms and rapid-cycling, both very common in Bipolar II, are also associated with an increased risk of suicide. The tendency for Bipolar II to be misdiagnosed and treated ineffectively, or not at all in some cases, leads to an increased risk.

As a result of the high suicide risk for this group, reducing the risk and preventing attempts remains a main part of the treatment; a combination of self-monitoring, close supervision by a therapist, and faithful adherence to their medication regimen will help to reduce the risk and prevent the likelihood of a completed suicide.

The exact cause of the disorder remains unknown, and relatively few studies have focused exclusively on the etiology of schizophreniform disorder. Like other psychotic disorders, a diathesis–stress model has been proposed, suggesting that some individuals have an underlying multifactorial genetic vulnerability to the disorder that can be triggered by certain environmental factors. Schizophreniform disorder is more likely to occur in people with family members who have schizophrenia or bipolar disorder.

These are the current criteria:

The ICD is currently in revision and ICD-11 is expected to come out in 2018. In the preliminary Beta Draft version, there is no longer a diagnostic category of simple schizophrenia and all subtypes have been eliminated.

Those suffering from post-schizophrenic depression are also commonly at risk for suicidal tendencies. There is a trend correlated between suicide and post-schizophrenic depression according to Mulholland and Cooper's research in "The Symptoms of Depression in Schizophrenia and its Management." Furthermore, depression and schizophrenia have both been studied individually to try to determine if there is a correlation, and research has indicated that there is a very strong tendency for people with depression or schizophrenia to attempt suicide. Statistically, out of all patients suffering from schizophrenia, "10%...commit suicide. Depressed patients with schizophrenia are at a particularly high risk for suicide the first few months after diagnosis and after hospital discharge." Risk factors increasing the chance of suicide are, from highest to lowest, previous depressive orders, previous suicide attempts, drug abuse, and several other factors. Surprisingly, the suicide risk actually decreased with the presence of hallucinations. "The ICD-10 Classification of MEntal and Behavioural Disorders" officially recognizes suicide as being a prominent aspect of post-schizophrenic depression. Because of this drastic increase in suicide, it can be difficult to study post-schizophrenic depression as many of its victims tragically take their own lives.

Accurately assessing for a specific Depressive Disorder diagnosis requires an expenditure of time that is deemed unreasonable for most primary care physicians. For this reason, physicians often use this code as a proxy for a more thorough diagnosis. There is concern that this may lead to a "wastebasket" mindset for certain disorders. In addition reimbursement through Medicare may be lower for certain non specific diagnosis.

There is no clear cause to how certain patients with schizophrenia develop post-schizophrenic depression while others may surpass this stage. However, there are a few theories as to possible causes. Those suffering from post-schizophrenic depression often suffer from social isolation due to their illness, which may increase depression levels. There is strong evidence of stigma-related isolation against those suffering from mental illnesses in a variety of societies, especially those with schizophrenia as they are often viewed as dangerous and unpredictable. Because of this isolation and studies linking social isolation and depression, it is possible that patients under these stigmas eventually develop post-schizophrenic depression. Depression in patients with schizophrenia may also be caused by substance abuse, which is fairly common among those suffering from schizophrenia, as depressants such as alcohol and cannabis can relax the patient. Furthermore, with what little information is currently known about post-schizophrenic depression, the onset may be caused by not giving patients with schizophrenia antipsychotic medications. After being taken off of antipsychotic medication, schizophrenic patients' antidepressant medication had to be increased, while those under antipsychotic medication reported suffering fewer depressive symptoms, further giving reason to believe that a lack of antipsychotic medication in earlier stages of schizophrenia may lead to post-schizophrenic depression. However, some psychology professionals still push for the reduction of neuroleptic drugs, as there is a popular belief that post-schizophrenic depression is caused by neuroleptic treatment. Therapists are also believed to engage the depression in people with schizophrenia, having given too much psychotherapy after the patient had overcome their schizophrenic symptoms. Schizophrenia itself should not be overlooked as a key player in causing post-schizophrenic depression, though. A study done over a two-year time period shadowing patients with schizophrenia and monitoring their depression was unable to locate possible triggers such as the ones previously listed, so it is possible the nature of schizophrenia itself is the primary cause of post-schizophrenic depression.

There is limited evidence that caffeine, in high doses or when chronically abused, may induce psychosis in normal individuals and worsen pre-existing psychosis in those diagnosed with schizophrenia.

Studies suggest that the prevalence of paraphrenia in the elderly population is around 2-4%.

Fink and Taylor developed a catatonia rating scale to identify the syndrome. A diagnosis is verified by a benzodiazepine or barbiturate test. The diagnosis is validated by the quick response to either benzodiazepines or electroconvulsive therapy (ECT). While proven useful in the past, barbiturates are no longer commonly used in psychiatry; thus the option of either benzodiazepines or ECT.

Individuals who develop paraphrenia have a life expectancy similar to the normal population. Recovery from the psychotic symptoms seems to be rare, and in most cases paraphrenia results in in-patient status for the remainder of the life of the patient. Patients experience a slow deterioration of cognitive functions and the disorder can lead to dementia in some cases, but this development is no greater than the normal population.

According to the DSM-5, "Catatonia Associated with Another Mental Disorder (Catatonia Specifier)" (code 293.89 [F06.1]) is diagnosed if the clinical picture is dominated by at least three of the following:

- stupor (i.e., no psychomotor activity; not actively relating to environment)

- catalepsy (i.e., passive induction of a posture held against gravity)

- waxy flexibility (i.e., allow positioning by examiner and maintain position)

- mutism (i.e., no, or very little, verbal response [exclude if known aphasia])

- negativism (i.e., opposition or no response to instructions or external stimuli)

- posturing (i.e., spontaneous and active maintenance of a posture against gravity)

- mannerisms (i.e., odd, circumstantial caricature of normal actions)

- stereotypy (i.e., repetitive, abnormally frequent, non-goal-directed movements)

- agitation, not influenced by external stimuli

- grimacing (i.e. making a grimace like children)

- echolalia (i.e., mimicking another's speech)

- echopraxia (i.e., mimicking another's movements)

Other disorders (used additional code 293.89 [F06.1] to indicate the presence of the comorbid catatonia):

- Catatonia associated with autism spectrum disorder.

- Catatonia associated with schizophrenia spectrum and other psychotic disorders.

- Catatonia associated with brief psychotic disorder

- Catatonia associated with schizophreniform disorder

- Catatonia associated with schizoaffective disorder

- Catatonia associated with substance-induced psychotic disorder

- Catatonia associated with bipolar and related disorders.

- Catatonia associated with major depressive disorder

- Catatonic disorder due to another medical condition.

If catatonic symptoms are present but they are don't form the catatonic syndrome, a medication-induced or substance-induced aetiology should first be considered.

Treatment consists of supportive care during the acute intoxication phase: maintaining hydration, body temperature, blood pressure, and heart rate at acceptable levels until the drug is sufficiently metabolized to allow vital signs to return to baseline. Typical and atypical antipsychotics have been shown to be helpful in the early stages of treatment. This is followed by abstinence from psychostimulants supported with counseling or medication designed to assist the individual preventing a relapse and the resumption of a psychotic state.

The WHO first listed the condition in the 6th revision of the International Classification of Diseases ICD-6 (1949) and it stayed in the manual until the present version ICD-10.