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.

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.

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.

Recent studies indicate that the symptoms of SCT in children form two dimensions: daydreamy-spacey and sluggish-lethargic, and that the former are more distinctive of the disorder from ADHD than the latter. This same pattern was recently found in the first study of adults with SCT by Barkley and also in more recent studies of college students. These studies indicated that SCT is probably not a subtype of ADHD but a distinct disorder from it. Yet it is one that overlaps with ADHD in 30–50% of cases of each disorder, suggesting a pattern of comorbidity between two related disorders rather than subtypes of the same disorder. Nevertheless, SCT is strongly correlated with ADHD inattentive and combined subtypes. According to a Norwegian study, "SCT correlated significantly with inattentiveness, regardless of the subtype 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.

Multiple complex developmental disorder is likely to be caused by a number of different various genetic factors. Each individual with MCDD is unique from one another and displays different symptoms. Various neuropsychological disorders can also be found in family members of people with MCDD.

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 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.

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.

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).

It has possibly the earliest onset compared to all other schizophrenias, considered to begin in some within childhood. Symptoms of "schizophrenia" "simplex" include an absence of will, impoverished thinking and flattening of affect. There is a gradual deterioration of functioning with increased amotivation and reduced socialization. It is considered to be rarely diagnosed and is a schizophrenia without psychotic symptoms.

In a study of patients in a Massachusetts hospital, persons suffering with "simple schizophrenia" were found to make attempts at reality fulfillment with respect to the more primitive needs; tending toward the achievement of fulfillment of these needs rather than engaging in fantasy as is typically found as a reaction to environmental stimuli by the psychotic person.

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 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.

Simple-type schizophrenia is a sub-type of schizophrenia as defined in the International Classification of Diseases . It is not included in the current "Diagnostic and Statistical Manual of Mental Disorders" (DSM-5). Simple-type schizophrenia is characterized by negative ("deficit") symptoms, such as avolition, apathy, anhedonia, reduced affect display, lack of initiative, lack of motivation, low activity; with absence of hallucinations or delusions of any kind.

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.

The most frequent cause of the syndrome is brain damage to the frontal lobe. Brain damage leading to the dysexecutive pattern of symptoms can result from physical trauma such as a blow to the head or a stroke or other internal trauma.

It is important to note that frontal lobe damage is not the only cause of the syndrome. It has been shown that damage, such as lesions, in other areas of the brain may indirectly affect executive functions and lead to similar symptoms. There is not one specific pattern of damage that leads to DES, as multiple affected brain structures and locations have led to the symptoms. This is one reason why the term frontal lobe syndrome is not preferred.

DES often occurs with other disorders, which is known as comorbidity. Many studies have examined the presence of DES in patients with schizophrenia. Results of schizophrenic patients on the "Behavioural Assessment of the Dysexecutive Syndrome (BADS)" test (discussed below) are comparable to brain injured patients. Further, results of BADS have been shown to correlate with phases of schizophrenia. Patients in the chronic phase of the disorder have significantly lower scores than those who are acute. This is logical due to the similarities in executive disruptions that make everyday life difficult for those with schizophrenia and symptoms that form DES.

Patients with Alzheimer's disease have been shown to exhibit impairment in executive functioning as well. The effects of DES symptoms on the executive functions and working memory, such as attentiveness, planning and remembering recently learned things, are some of the earliest indicators of Alzheimer's.

Studies have also indicated that chronic alcoholism (see Korsakoff's syndrome) can lead to a mild form of DES according to results of BADS.

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

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.

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.

In psychology, alogia (Greek ἀ-, “without”, and λόγος, “speech”), or poverty of speech, is a general lack of additional, unprompted content seen in normal speech. As a symptom, it is commonly seen in patients suffering from schizophrenia, and is considered a negative symptom. It can complicate psychotherapy severely because of the considerable difficulty in holding a fluent conversation.

Alogia is often considered a form of aphasia, which is a general impairment in linguistic ability. It often occurs with intellectual disability and dementia as a result of damage to the left hemisphere of the brain. People can revert to alogia as a way of reverse psychology, or avoiding questions.

Posttraumatic embitterment disorder (PTED) is a proposed disorder modeled after posttraumatic stress disorder. Some psychiatrists are proposing this as a mental disorder because they believe that there are people who have become so bitter, they can barely function. PTED patients do not fit the formal criteria for PTSD and can be clinically distinguished from it, prompting the description of a new and separate disorder.

German psychiatrist Michael Linden, who has conducted research on the proposed disorder, describes its effect on people: "They feel the world has treated them unfairly. It's one step more complex than anger. They're angry plus helpless." He says that people with the disorder are almost treatment resistant and that; "These people usually don't come to treatment because 'the world has to change, not me. He believes that 1 to 2 percent of people are affected at any given time, and explains that, although sufferers of the disorder tend to have a desire for vengeance, "...Revenge is not a treatment."

PTED so far has no official status and is not listed in the DSM-IV-TR or ICD-10-CM.

PTSD has significant arousal and other effects on physiological, endocrine, HPA axis, brain centers, and neurological systems. These have been the bases of treatments well known and studied for decades via both theoretical and practical descriptions of illness, rationales of treatment modalities, and mechanisms of therapeutic actions.

PTED may arouse or influence PTSD-affected systems differently or arouse different systems. Thus PTED, although modeled on PTSD, may differ to various degrees and in various ways.

There is no published work at this time on different underlying neurological, endocrinology, and physiological changes in PTED patients as an analog to PTSD.

In psychiatry, derailment (also loosening of association, asyndesis, asyndetic thinking, knight's move thinking, or entgleisen) is a thought disorder characterized by discourse consisting of a sequence of unrelated or only remotely related ideas. The frame of reference often changes from one sentence to the next.

In a mild manifestation, this thought disorder is characterized by slippage of ideas further and further from the point of a discussion. Derailment can often be manifestly caused by intense emotions such as euphoria or hysteria. Some of the synonyms given above ("loosening of association", "asyndetic thinking") are used by some authors to refer just to a "loss of goal": discourse that sets off on a particular idea, wanders off and never returns to it. A related term is tangentiality—it refers to off-the-point, oblique or irrelevant answers given to questions. In some studies on creativity, "knight's move thinking", while it describes a similarly loose association of ideas, is not considered a mental disorder or the hallmark of one; it is sometimes used as a synonym for lateral thinking.

Although disorder for written expressions skills can be difficult and an enduring problem all throughout childhood into adulthood, different types of treatment and support can help individuals who have this disorder to employ strategies and skills in the home and school environment. This includes remedial education tailored to improve specific skills, providing special academic services in the learning environment, and addressing concurrent health and mental issues. It is sometimes necessary to foster motivational techniques to maintain motivation and minimize negative thoughts or feelings. Using whatever modifications are necessary to overcome fears of failure in the early stages of writing mediation is strongly encouraged because children with learning disabilities often experience low self-esteem and confidence, which may further interfere with learning and academic success.