**Question:** Delusions can be seen in all of the following except:

A. Schizophrenia
B. Bipolar Disorder
C. Major Depressive Disorder
D. Substance-induced psychosis

**Core Concept:**
Delusions are false, persistent beliefs or perceptions that are not based on reality and are resistant to logical argument or evidence. They are a core feature of certain psychiatric disorders, particularly schizophrenia and substance-induced psychosis. Delusions can be seen in various mental health conditions, but the question asks for the exception.

**Why the Correct Answer is Right:**
Delusions are commonly associated with schizophrenia (A) and substance-induced psychosis (D). Schizophrenia is a severe mental disorder characterized by distortions in thinking, emotions, perceptions, and behavior. Substance-induced psychosis is a temporary psychotic episode occurring due to the use of certain drugs or substances.

**Why Each Wrong Option is Incorrect:**
Bipolar disorder (B) is a mental health condition characterized by extreme shifts in mood, energy, and behavior, but not primarily for delusions. Major depressive disorder (C) mainly presents with mood symptoms like sadness, hopelessness, and anhedonia, not delusions.

**Clinical Pearl:**
It is essential for healthcare professionals to differentiate between different psychiatric disorders based on their specific symptoms, as appropriate treatments depend on the underlying diagnosis. For example, schizophrenia typically requires antipsychotic medication, while bipolar disorder would require mood stabilizers like lithium or lamotrigine.

**Correct Answer:**
C. Major Depressive Disorder (MDD)

**Why Each Wrong Option is Incorrect:**
A. Schizophrenia: Mental health condition characterized by distortions in thinking, emotions, and perceptions.
B. Bipolar disorder: Extreme shifts in mood, energy, and behavior; not primarily for delusions.
D. Substance-induced psychosis: Temporary psychotic episode due to substance use; not primarily for delusions.

**Why the Correct Answer is Right:**
Delusions are not a prominent feature of Major Depressive Disorder (MDD). MDD primarily presents with symptoms like persistent sadness, hopelessness, anhedonia, and changes in appetite and sleep patterns. Although delusions may occur in MDD, they are not the main presenting features, making option C (MDD) the correct answer.