Anxiety is a condition of worry, tension, or uneasiness produced by the anticipation of some danger whose source is largely unknown.

Compulsion is an irresistible impulse to perform a certain action.

Delusion is a false belief that a person maintains in spite of evidence that proves it untrue.

Depression is a mental disorder characterized by feelings of deep sadness, hopelessness, and worthlessness.

Hallucination is the sensation of something that does not really exist.

Illusion is a distorted perception of reality.

Mania means a mental disorder that involves extreme optimism and excessive energy, often accompanied by uncontrollable irritability and anger.

Mood disorder is a mental illness that mainly affects a person's mood.

Neurosis is a mild mental disorder.

Obsession is a recurring thought that a person considers senseless or terrible but cannot ignore.

Organic disorder refers to a mental illness that results from a physical cause, such as a birth defect, a disease, or an injury.

Paranoia is a mental condition in which an individual unjustifiably feels threatened by other people.

Phobia means a strong, unreasonable fear of a particular object or situation.

Psychosis is a severe mental disorder characterized by delusions, hallucinations, and inability to deal with reality.

Schizophrenia is a severe mental disorder characterized by unpredictable thoughts and behaviour and a withdrawal from reality.

Unconscious refers to thoughts and feelings that a person is not directly or fully aware of.