Step 1: Understanding the Concept:
The question describes a specific behavior—frequent hand cleaning—and asks for the corresponding diagnosis. This requires knowledge of the symptoms of various mental disorders.
Step 2: Detailed Explanation:
(A) Obsessive compulsive neurosis: This is an older term for what is now known as Obsessive-Compulsive Disorder (OCD). OCD is characterized by two main components:
Obsessions: Recurrent, intrusive, and unwanted thoughts, often about contamination or germs.
Compulsions: Repetitive, ritualistic behaviors that an individual feels driven to perform to reduce the anxiety caused by the obsessions. Frequent hand washing is a classic example of a compulsion related to an obsession with germs.
(B) Hysteria is an outdated term for conversion disorder or somatic symptom disorder.
(C) Schizophrenia is a psychotic disorder with symptoms like hallucinations and delusions.
(D) Paranoia is characterized by delusions of persecution or mistrust.
Step 3: Final Answer:
Very frequent hand cleaning is a classic compulsive behavior, which is a hallmark symptom of Obsessive-Compulsive Disorder (historically called Obsessive-Compulsive Neurosis).