Cognitive Symtoms and Risk Factors of Schizophrenia

Abstract

Description

Schizophrenia is a mental illness characterized by recurrent or ongoing psychotic episodes. The main symptoms include delusions, disorganized thinking, and hallucinations (which usually involve hearing voices). Apathy, diminished emotional expression, and social detachment are further signs often appear gradually, start in adolescence, and become severe. A diagnosis is made based on a person's behavior, a mental history that includes the person's stated experiences, and the reports of people who are familiar with the person. There is no objective diagnostic test. For a DSM-5 or ICD-11 diagnosis of schizophrenia, symptoms and functional impairment must have been present for at least six months. In particular, drug use disorders, depressive disorders, anxiety disorders, and obsessive-compulsive disorder are frequently present in patients with schizophrenia.

A mental illness called schizophrenia is characterized by dramatic changes in perception, cognition, mood, and behaviour Positive, negative, and cognitive symptoms are used to categorize symptoms. Positive symptoms of schizophrenia, also known as psychotic symptoms, are the same for all forms of psychosis. These can occur in any of the several psychoses and are frequently sporadic, making a diagnosis of schizophrenia early on difficult. Initially Episode Psychosis (FEP) is the term used to describe psychosis that is initially noticed in a person who is later diagnosed with schizophrenia.

Cognitive abnormalities are present in around 70% of schizophrenia patients, and they are most obvious in early-onset and late-onset disease. These are frequently present in the prodromal stage far before the beginning of sickness and may start in early adolescent or childhood. While they have similarities with positive and negative symptoms, they are not thought of as essential symptoms. However, rather than relying solely on the presentation of core symptoms, their presence and level of dysfunction are seen as a more accurate measure of functionality. Cognitive deficiencies worsen during the initial psychotic episode but eventually revert to normal and stay largely steady throughout the disease.

The cognitive deficiencies are thought to be the primary cause of schizophrenia's bad psychosocial outcome and are equivalent to a potential drop in IQ from the average of 100 to 70–85.Neurocognitive (nonsocial) or social cognitive deficiencies are also possible. Neurocognition, which comprises verbal fluency, memory, reasoning, problem-solving, processing speed, and auditory and visual perception, is the capacity for taking in and remembering information. The most noticeable effects are noticed in verbal memory and concentration. The ability to relate words meanings to each other (semantic processing) is impaired in verbal memory. Episodic memory loss is another memory condition. Visual backward masking is a visual perception defect that is frequently observed in schizophrenia.

According to definitions, schizophrenia is a neurodevelopmental condition that lacks a clear aetiology and is believed to result from gene-environment interactions with risk factors. Due to the potential involvement of numerous and varied from conception through adulthood, the interactions of these risk factors are complicated. Without interplaying environmental circumstances, a genetic propensity by itself won't result in the emergence of schizophrenia. Because of the genetic component, prenatal brain development is compromised, and environmental factors have an impact on postnatal brain development. There is evidence that children who are genetically predisposed are more likely to be susceptible to the impacts of environmental risk factors.

The heritability of schizophrenia is estimated to be between 70 and 80 percent, meaning that 70 to 80 percent of individual differences in risk of schizophrenia are genetically based. The accuracy of these predictions has been questioned due to the difficulties in differentiating between genetic and environmental factors. Having a first-degree relative who has the condition increases the probability of acquiring schizophrenia by 6.5% more than 40% of identical twins of those who have the condition also have symptoms. The chance is approximately 13% if just one parent is affected, and it is almost 50% if both parents are affected.