SCT is currently not an official diagnosis in DSM-5. But there are rating scales that can be used to screen for SCT symptoms such as the "Concentration Inventory" (for children and adults) or the "Barkley Sluggish Cognitive Tempo Scale-Children and Adolescents (BSCTS-CA)". The "Comprehensive Behaviour Rating Scale for Children" (CBRSC), an older scale, can also be used for SCT as this case study shows.

Although having no diagnosic code either, ICD-10 mentions the SCT group as a reason for why it did not replace the term ""Hyperkinetic Disorder"" with ""ADHD"."

Other mental disorders may produce similar symptoms to SCT (e.g. excessive daydreaming or "staring blankly") and should not be confused with it. Examples might be conditions like depersonalization disorder, dysthymia, thyroid problems, absence seizures, Bipolar II disorder, Kleine–Levin syndrome, forms of autism or schizoid personality disorder. However, the prevalence of SCT in these clinical populations has yet to be empirically and systematically investigated.

The prognosis of SCT is unknown. In contrast, much is known about the adolescent and adult outcomes of children having ADHD. Those with SCT symptoms typically show a later onset of their symptoms than do those with ADHD, perhaps by as much as a year or two later on average. They have as much or more difficulty with academic tasks and far fewer social difficulties than do people having ADHD. They do not have the same risks for oppositional defiant disorder, conduct disorder, or social aggression and thus may have different life course outcomes compared to children with ADHD-HI and Combined subtypes who have far higher risks for these other "externalizing" disorders.

However, unlike ADHD, there are no longitudinal studies of children with SCT that can shed light on the developmental course and adolescent or adult outcomes of these individuals.

Assessment of patients with DES can be difficult because traditional tests generally focus on one specific problem for a short period of time. People with DES can do fairly well on these tests because their problems are related to integrating individual skills into everyday tasks. The lack of everyday application of traditional tests is known as low ecological validity.

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.

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 Behavioural Assessment of the Dysexecutive Syndrome (BADS) was designed to address the problems of traditional tests and evaluate the everyday problems arising from DES. BADS is designed around six subtests and ends with the Dysexecutive Questionnaire (DEX). These tests assess executive functioning in more complex, real-life situations, which improves their ability to predict day-to-day difficulties of DES.

The Dysexecutive Questionnaire (DEX) is a 20-item questionnaire designed to sample emotional, motivational, behavioural and cognitive changes in a subject with DES. One version is designed for the subject to complete and another version is designed for someone who is close to the individual, such as a relative or caregiver. Instructions are given to the participant to read 20 statements describing common problems of everyday life and to rate them according to their personal experience. Each item is scored on a 5-point scale according to its frequency from "never" (0 point) to "very often" (4 points).

Once the patient and family have been educated about the nature, management and treatment of the disorder and a decision has been made to treat, the European ADHD Guidelines group recommends medication rather than behavioral training as the first treatment approach; and the UK's National Institute for Health and Clinical Excellence recommends medication as first line treatment for those with hyperkinesis/severe ADHD, and the provision of group parent-training in all cases of ADHD.

Thought disorder (TD) or formal thought disorder (FTD) refers to disorganized thinking as evidenced by disorganized speech. Specific thought disorders include derailment, poverty of speech, tangentiality, illogicality, perseveration, and thought blocking.

Psychiatrists consider formal thought disorder as being one of two types of disordered thinking, with the other type being delusions. The latter involves "content" while the former involves "form". Although the term "thought disorder" can refer to either type, in common parlance it refers most often to a disorder of thought "form" also known as formal thought disorder.

Eugen Bleuler, who named schizophrenia, held that thought disorder was its defining characteristic. However, formal thought disorder is not unique to schizophrenia or psychosis. It is often a symptom of mania, and less often it can be present in other mental disorders such as depression. Clanging or echolalia may be present in Tourette syndrome. Patients with a clouded consciousness, like that found in delirium, also have a formal thought disorder.

However, there is a clinical difference between these two groups. Those with schizophrenia or psychosis are less likely to demonstrate awareness or concern about the disordered thinking. Clayton and Winokur have suggested that this results from a fundamental inability to use the same type of Aristotelian logic as others. On the other hand, patients with a clouded consciousness, referred to as "organic" patients, usually do demonstrate awareness and concern, and complain about being "confused" or "unable to think straight"; Clayton and Winokur suggest that this is because their thought disorder results, instead, from various cognitive deficits.

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.

The rate in school age children is thought to be about 1.5%, compared with an estimated 5.3% for ADHD.

There are no published or suggested studies on drug treatments for PTED. Selective serotonin reuptake inhibitors (SSRI's) are antidepressants like: Prozac, Paxil, Lexapro, Zoloft, Celexa, and Luvox. They have some benefit in PTED due to their antiobsessional properties. Anafranil, a TCA, is also used extensively.

PTED is a psychological adjustment-reactive disorder more severe than just being embittered in the colloquial sense. It can be qualitatively measured with high scientific reliability and repeatability. Related concepts include (ordinary) embitterment and reactive embitterment. Reactive embitterment may be specific, diffuse or non-PTED. Various ratings, assessment scales, and distinctions have been investigated.

According to the St. Louis system for the diagnosis of schizophrenia, tangentiality is significantly associated with a low IQ prior to diagnosis (AU Parnas "et al" 2007).

The use of antipsychotic medication is commonly the first line of treatment; however, the effectiveness after treatment is in question.

L-DOPA is effective against reduced affect display and emotional withdrawal, aloofness from society, apathy.

In the mental health field, schizophasia or word salad is language that is confused and often repetitious, symptomatic of various mental illnesses.

It is usually associated with a manic presentation of bipolar affective disorder and other symptoms of serious mental illnesses, such as psychosis, including schizophrenia. It is characterized by an apparently confused usage of words with no apparent meaning or relationship attached to them. In this context, it is considered to be a symptom of a formal thought disorder. In some cases schizophasia can be a sign of asymptomatic schizophrenia; e.g. the question "Why do people believe in God?" could elicit a response consisting of a series of words commonly associated with religion or prayer but strung together with no regard to language rules.

Schizophasia should be contrasted with another symptom of cognitive disruption and cognitive slippage involving certain idiosyncratic arrangements of words. With this symptom, the language may or may not be grammatically correct depending on the severity of the disease and the particular mechanisms which have been impacted by the disease.

The American diagnostic codes, from the "DSM-IV", do not specifically code for this disorder although they include it as a symptom under the diagnosis of schizophrenia.

The concept of thought disorder has been criticized as being based on circular or incoherent definitions. For example, thought disorder is inferred from disordered speech, based on the assumption that disordered speech arises because of disordered thought. Incoherence, or word salad, refers to speech that is unconnected and conveys no meaning to the listener.

Furthermore, although thought disorder is typically associated with psychosis, similar phenomena can appear in different disorders, potentially leading to misdiagnosis—for example, in the case of incomplete yet potentially fruitful thought processes.

It has been suggested that individuals with autism spectrum disorders (ASD) display language disturbances like those found in schizophrenia; a 2008 study found that children and adolescents with ASD showed significantly more illogical thinking and loose associations than control subjects. The illogical thinking was related to cognitive functioning and executive control; the loose associations were related to communication symptoms and to parent reports of stress and anxiety.

In most instances, stating categorically that an individual is malingering requires an explicit admission by that individual. Legally the term may be considered prejudicial and excluded on that basis. No current research exists regarding the frequency, behaviour or detection of successful malingerers. No neuropsychological inventories exist that can be used to conclusively determine if a patient is malingering, or to exclude a determination of malingering. Genuine neurological and psychiatric conditions may return false positives. Testing inventories cannot distinguish between exaggeration and fabrication. Psychological inventories rely on naivety. Criminally, an assessment may lead to punishment enhancement, and medically, to denial of future treatment. The DSM-V criteria faces scrutiny for providing poor guidelines. As such physicians ultimately rely on their intuition and gut feeling for any assessment, which is subject to prejudice and cognitive dissonance, and which has been shown to be unreliable in synthetic tests.

Malingering presumes an exhaustive diagnostic procedure has been performed. Exhaustive diagnostics are neither practical nor economically viable or judged to be in the best interests of the patient's health. Radiological and invasive exploratory procedures can be necessary for an accurate diagnosis yet pose a health risk to the patient. Radiographic diagnostics expose the patient to radiation and surgical diagnostic procedures can carry a high risk of complications and mortality, such as a lumbar puncture, the only reliable diagnostic procedure for diagnosing rare terminal forms of parasitization, which the CDC reports as only being diagnosed "post mortem" 75% of the time. A physician invariably faces limitations in the realms of resources, time and liability. Because an assessment, formal or informal, of malingering ceases the medical process, it may seem an attractive option for the physician and help them to cope with cognitive dissonance over their failure to effectively diagnose and treat a patient within constraints.

Patients with unresolved illness may be adversarial towards physicians, attempting to game the triage system in order to receive specialist care. Such cases fit the criteria for malingering, yet the patient is still in need of medical care.

For example, in a gatekeeper system, primary care physicians may restrict the availability of HIV testing to only patients who report high risk activity. A patient may then falsely report sexual and/or drug history and/or symptoms in order to elevate priority which can then go on to serve as diagnostically relevant history for an inaccurate path of further diagnosis.

Medical practitioners often believe that they can detect deception. In two studies, experienced medical practitioners including psychiatrists failed to perform better than chance when asked to detect lying and simulated patients. In 12 other studies, detection rates of simulated patients ranged between 0 and 25%. It's impossible to detect malingering from a clinical perspective.

This form of schizophrenia is typically associated with early onset (often between the ages of 15 and 25 years) and is thought to have a poor prognosis because of the rapid development of negative symptoms and decline in social functioning.

Use of electroconvulsive therapy has been proposed; however, the effectiveness after treatment is in question.

Psychosis is first and foremost a diagnosis of exclusion. So a new-onset episode of psychosis "cannot" be considered a symptom of a psychiatric disorder until other relevant and known causes of psychosis are properly 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 by a physician, psychiatrist, psychiatric nurse practitioner or psychiatric physician assistant. Biological tests should be performed to exclude psychosis associated with or caused by substance use, medication, toxins, surgical complications, or other medical illnesses.

Delirium should be ruled out, which can be distinguished by visual hallucinations, acute onset and fluctuating level of consciousness, indicating other underlying factors, including 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 include:

- EEG to exclude epilepsy, and an

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

Because psychosis may be precipitated or exacerbated by common classes of medications, medication-induced psychosis should be ruled out, particularly for first-episode psychosis. Both substance- and medication-induced psychosis can be excluded to a high level of certainty, using a

- Urinalysis and a

- Full serum toxicology screening.

Because some dietary supplements may also induce psychosis or mania, but cannot be ruled out with laboratory tests, a psychotic individual's family, partner, or friends should be asked whether the patient is currently taking any dietary supplements.

Common mistakes made when diagnosing people who are psychotic include:

- Not properly excluding delirium,

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

- Not obtaining a medical history and family history,

- Indiscriminate screening without an organizing framework,

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

- 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 relevant and known causes of psychosis are excluded, a mental health clinician may make a psychiatric differential diagnosis using a person's family history, incorporating information from the person with psychosis, and information from family, friends, or significant others.

Types of psychosis in psychiatric disorders may be established by formal rating scales. The Brief Psychiatric Rating Scale (BPRS) assesses the level of 18 symptom constructs of psychosis such as hostility, suspicion, hallucination, and grandiosity. It is based on the clinician's interview with the patient and observations of the patient's behavior over the previous 2–3 days. The patient's family can also answer questions on the behavior report. During the initial assessment and the follow-up, both positive and negative symptoms of psychosis can be assessed using the 30 item Positive and Negative Symptom Scale (PANSS).

The term refers simplistically to a thought disorder shown from speech with a lack of observance to the main subject of discourse, such that a person whilst speaking on a topic deviates from the topic. Further definition is of speech that deviates from an answer to a question that is relevant in the first instance but deviates from the relevancy to related subjects not involved in a direct answering of the question. In the context of a conversation or discussion the communication is a response that is ineffective in that the form is inappropriate for adequate understanding. The person's speech seems to indicate that their attention to their own speech has perhaps in some way been overcome during the occurrence of cognition whilst speaking, causing the vocalized content to follow thought that is apparently without reference to the original idea or question; or the person's speech is considered evasive in that the person has decided to provide an answer to a question that is an avoidance of a direct answer.

Medical studies conclude that certain adjunctive drugs effectively palliate the negative symptoms of schizophrenia, mainly alogia. In one study, Maprotiline produced the greatest reduction in alogia symptoms with a 50% decrease in severity. Of the negative symptoms of schizophrenia, alogia had the second best responsiveness to the drugs, surpassed only by attention deficiency. D-amphetamine is another drug that has been tested on people with schizophrenia and found success in alleviating negative symptoms. This treatment, however, has not been developed greatly as it seems to have adverse effects on other aspects of schizophrenia such as increasing the severity of positive symptoms.

Multiple complex developmental disorder (MCDD) is a research category, proposed to involve several neurological and psychological symptoms where at least some symptoms are first noticed during early childhood and persist throughout life. It was originally suggested to be a subtype of autistic spectrum disorders (PDD) with co-morbid schizophrenia or another psychotic disorder; however, there is some controversy that not everyone with MCDD meets criteria for both PDD and psychosis. The term "multiplex developmental disorder" was coined by Donald J. Cohen in 1986.

Disorganized schizophrenia, also known as hebephrenia or hebephrenic schizophrenia, is a subtype of schizophrenia, although it is not recognized in the latest version of the "Diagnostic and Statistical Manual of Mental Disorders". It's recognized only in the 10th revision of the International Statistical Classification of Diseases and Related Health Problems (ICD-10).

Disorganized schizophrenia is thought to be an extreme expression of the "disorganization syndrome" that has been hypothesized to be one aspect of a three-factor model of symptoms in schizophrenia, the other factors being "reality distortion" (involving delusions and hallucinations) and "psychomotor poverty" (lack of speech, lack of spontaneous movement and various aspects of blunting of emotion).

The current diagnostic criteria for MCDD are a matter of debate due to it not being in the DSM-IV or ICD-10. Various websites contain various diagnostic criteria. At least three of the following categories should be present. Co-occurring clusters of symptoms must also not be better explained by being symptoms of another disorder such as experiencing mood swings due to autism, cognitive difficulties due to schizophrenia, and so on. The exact diagnostic criteria for MCDD remain unclear but may be a useful diagnosis for people who do not fall into any specific category. It could also be argued that MCDD is a vague and unhelpful term for these patients.

In psychiatry, thought broadcasting is the belief that others can hear or are aware of an individual's thoughts. This differs from telepathy in that the thoughts being broadcast are thought to be available to anybody.

Thought broadcasting can be a positive symptom of schizophrenia. Thought broadcasting has been suggested as one of the first rank symptoms (Schneider's first-rank symptoms) believed to distinguish schizophrenia from other psychotic disorders.

In mild manifestations, a person with this thought disorder may doubt their perception of thought broadcasting. When thought broadcasting occurs on a regular basis, the disorder can affect behavior and interfere with the person's ability to function in society. According to an individual's personality this is considered to be a severe manifestation of thought broadcasting that is usually indicative of schizophrenia.