ICD-10: F28

The ICD-10 code F28, which refers to "Other psychotic disorder not due to a substance or known physiological condition," has several alternative names and related terms. Here are some of them:

• Chronic Hallucinatory Psychosis: This term is often used to describe a persistent state of hallucinations that do not fit the criteria for schizophrenia or other specific psychotic disorders [2].
• Delusional Disorders: This encompasses various types of delusions that are not severe enough to warrant a diagnosis of schizophrenia [1][3].
• Unspecified Psychosis: This term can refer to psychotic symptoms that do not clearly fall into other defined categories, which may include F28 [8].
• Nonorganic Psychotic Disorders: This broader category includes various psychotic disorders that are not attributed to organic causes, such as substance use or known physiological conditions [1][4].

These terms help in understanding the nature of the disorder and its classification within the broader context of mental health diagnoses.

The ICD-10 code F28 refers to "Other nonorganic psychotic disorders," which includes various psychotic conditions that do not meet the criteria for schizophrenia or are not attributable to substance use or known physiological conditions. Here are the key criteria and characteristics associated with this diagnosis:

• Nonorganic Nature: The disorders classified under F28 are characterized by psychotic symptoms that are not due to any identifiable organic cause, such as a medical condition or substance abuse. This means that the psychotic features arise independently of any physiological or substance-related factors [10].

• Symptoms: Patients may experience delusions, hallucinations, or other forms of psychosis. However, these symptoms do not fulfill the criteria for schizophrenia (F20) or other specific psychotic disorders. The symptoms can vary widely in presentation and severity [11][14].

• Duration and Impact: The symptoms must be significant enough to cause distress or impairment in social, occupational, or other important areas of functioning. The duration of symptoms can vary, but they typically need to be present for a sufficient period to warrant a diagnosis [10].

• Exclusion of Other Disorders: A diagnosis of F28 requires that other psychotic disorders, such as schizophrenia or schizoaffective disorder, be ruled out. This involves a thorough clinical assessment to ensure that the symptoms do not align with these other conditions [12][14].

• Specific Types: Within the F28 category, there may be subtypes or specific presentations, such as persistent delusional disorders or hallucinatory disorders, which do not meet the full criteria for schizophrenia [11][14].

In summary, the diagnosis of F28 involves identifying nonorganic psychotic symptoms that are significant enough to impact functioning, while ensuring that these symptoms are not attributable to other known psychiatric or medical conditions.