**2. Description of psychosis**

*Neurodevelopment and Neurodevelopmental Disorder*

tive diagnostic criteria for every type of psychosis.

description of the illness was documented [1].

pattern of schizophrenia but more complex.

cific or partly known.

schizophrenia.

the scientific efforts.

nia and psychosis [7].

including the psychotic ones.

and treatment as well as prevention strategies.

The arguments to sustain this theory (hypothesis) are:

to the onset [1].

model.

and treatment process and also for estimation of prognosis.

After more than 100 years of studies and clinical psychiatric practice, passing through numerous conceptualizations of psychosis and schizophrenia, research tries to achieve an evolutionary pattern of psychosis and to establish clear, distinc-

Psychosis is unanimously considered essential for understanding the evolution

The fact that psychosis disorders, such as schizophrenia, begin with a prodromal phase prior to the onset of frank psychotic symptoms has been known since the first

The pattern of psychosis and of the first episode of psychosis is similar to the

Strauss and Carpenter considered that schizophrenia includes an interactive, developmental, and systematic model [2–6]. By analogy, the model of the first psychotic episode can be considered an interactive, developmental, and systematic

1.Variables that interact either sequentially or simultaneously and are nonspe-

2.Genetic vulnerability is sometimes well known; in the first psychotic episode, there is a variety of genetic mechanisms with varying degrees of impact and strong expressiveness even from the prodromal or prepsychotic period. But for those with well-known genetic vulnerability, clinical expressivity may be missing, and not everyone with genetic predisposition shows

3.Perinatal factors may constitute an independent variable that increases the person's vulnerability to develop a psychotic pathology, and when interacting with genetic and environmental factors, the risk increases both in schizophre-

Due to the complexity and heterogeneity of the first psychotic episode, to conceive and to unanimously recognize it like a coherent and unitary model are extremely difficult. The unknowns of this huge puzzle are still numerous despite

The model of the first psychotic episode has a medium- or long-term impact on schizophrenia model and can be of particular relevance to both etiopathogenesis

Over the last years, the most exciting signs of progress in defining a new conceptualization of psychosis are reported by the genomic studies [8, 9]. Maps of the neurobiological circuits of cognitive functions have been designed and have tried to explain the ways in which these circuits become dysfunctional in various disorders

Recently, the area of "prodromal" research in schizophrenia and related disorders has grown considerably. From initial retrospective studies of this phase, dating back to the early twentieth century, the last decade of the century has seen the beginning and expansion of prospective studies aiming to identify the earliest manifestations of psychotic illnesses. From identification of these prodromal or "ultrahigh-risk"(UHR) individuals, the area has also developed to include intervention studies aiming to prevent, delay, or ameliorate the onset of a full-blown psychotic disorder and to investigate underlying processes that cause or contribute

**32**

Researchers from the National Institute of Mental Health (NIMH) have reported three conclusions:


These data have facilitated the explanations of the pattern of psychosis by integrating molecular biology, neuroscience, and behavioral sciences. This new approach tries to discover finally the new treatment strategies including new medications (antipsychotics) and psychological, social, and other potential interventions.

The work group for psychosis within DSM-V proposes distinct clinical domains for each psychotic disorder correlated with the neuronal circuits [10].

In 2009 Jim van Os, one of the members of work group for psychosis, proposed a new syndrome named "salience dysregulation syndrome" as a diagnostic to be used [11].

Jim van Os used the psychotic model of Kapur who considers that hallucinations and delusional ideas appear because the individual has difficulties in recognizing his or her mental experience relevance. Jim van Os used the term syndrome not disease, because a syndrome is a set of symptoms that appear simultaneous without having a common cause. The symptoms described are positive and negative symptoms, disorganization, developmental cognitive deficits, and depressive and maniacal symptoms [11].

The "salience dysregulation syndrome" was divided for diagnosis into:

