A patient presents with one month history of abnormal hallucination and delusion. The patient lacks insight to his changed behaviour. Likely diagnosis is
**Core Concept**
The question tests the understanding of **psychotic disorders**, specifically the ability to diagnose based on symptoms such as hallucinations, delusions, and lack of insight. **Schizophrenia** is a key condition characterized by these symptoms.
**Why the Correct Answer is Right**
Given the symptoms of abnormal hallucination, delusion, and lack of insight into the changed behavior, the most likely diagnosis is **Schizophrenia**. This condition is characterized by a disintegration of the process of thinking, of contact with reality, and a disintegration of personality. The presence of hallucinations and delusions, particularly with a duration of more than a month, strongly suggests a diagnosis of schizophrenia.
**Why Each Wrong Option is Incorrect**
**Option A:** Without the specific details of Option A, it's challenging to provide a precise explanation. However, commonly, other options might include conditions like bipolar disorder or severe depression with psychotic features, which can present with hallucinations and delusions but typically have other distinguishing features.
**Option B:** Similarly, without specifics, this could potentially be a condition like substance-induced psychosis, which would have a different underlying cause and possibly a more acute onset.
**Option C:** This might be a condition such as brief psychotic disorder, which has a shorter duration of symptoms.
**Option D:** Could be a condition not typically associated with chronic hallucinations and delusions, such as anxiety disorder.
**Clinical Pearl / High-Yield Fact**
A key point to remember is that schizophrenia is diagnosed based on the presence of two or more of the following symptoms: delusions, hallucinations, disorganized speech, grossly disorganized or catatonic behavior, and negative symptoms, with at least one of the symptoms being delusions, hallucinations, or disorganized speech.
**Correct Answer:** **D. Schizophrenia**