A patient is brought with 6 month history of odd behaviour. There is a history of a family member having disappeared some years back. He seems to be talking to himself and sometimes muttering to himself loudly. The likely diagnosis is –
**Core Concept**
The patient's symptoms suggest a chronic psychiatric disorder characterized by disorganized thinking, abnormal behavior, and a possible family history of similar conditions. This scenario is indicative of a schizophrenia spectrum disorder, which is a group of mental health conditions that include schizophrenia, schizoaffective disorder, and schizotypal personality disorder.
**Why the Correct Answer is Right**
The patient's history of talking to himself and muttering loudly is a classic symptom of disorganized thinking and behavior, which is often seen in schizophrenia. The presence of a family member who disappeared years back may suggest a genetic predisposition to the disorder. Schizophrenia is a neurodevelopmental disorder that affects the brain's reward, stress, and motor circuits, leading to cognitive, emotional, and behavioral abnormalities.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not specifically address the patient's symptoms of disorganized thinking and behavior. While depression can have similar symptoms, it typically involves a prolonged period of low mood and loss of interest in activities.
**Option B:** This option is incorrect because it does not account for the patient's family history of a similar condition. Bipolar disorder is characterized by episodes of mania or hypomania, which are not mentioned in the scenario.
**Option C:** This option is incorrect because it does not specifically address the patient's symptoms of disorganized thinking and behavior. While anxiety disorders can have similar symptoms, they typically involve excessive worry or fear, which is not mentioned in the scenario.
**Clinical Pearl / High-Yield Fact**
Schizophrenia spectrum disorders often have a delayed onset, with symptoms typically appearing in late adolescence or early adulthood. Early recognition and treatment can significantly improve outcomes.
**Correct Answer:** C. Schizophrenia