In clinical psychology, a sudden loss of memory for important information is a symptom of which condition?

Introduction / Context:
Memory problems can appear in many different brain related disorders, but not all of them present in the same way. Some involve gradual decline, while others involve abrupt and selective loss of memory. This question asks which condition is specifically associated with a sudden loss of memory in clinical psychology and neurology, a pattern that is important to distinguish from long term degenerative conditions.

Given Data / Assumptions:

The question highlights sudden loss of memory rather than slow decline.
Alzheimer's disease and dementia are chronic, usually progressive conditions.
Amnesia is a term commonly used for marked memory loss.
We assume standard medical and psychological definitions apply.

Concept / Approach:
Amnesia refers to a condition in which a person experiences significant memory loss that is often sudden, such as after head trauma, stroke, severe psychological stress, or infection. It may affect the ability to recall past events (retrograde) or form new memories (anterograde). In contrast, Alzheimer's disease is a specific type of dementia with slow, progressive deterioration of memory and other cognitive functions over years. Dementia itself is a broader term for chronic, usually gradual, decline in cognitive abilities. Because the question focuses on sudden loss of memory, amnesia is the most accurate answer.

Step-by-Step Solution:
Step 1: Identify the key phrase in the question, which is sudden loss of memory. Step 2: Recall that Alzheimer's and most dementias usually present with gradual, progressive decline rather than abrupt onset. Step 3: Recognize that the term amnesia is used when there is a noticeable and often abrupt memory loss, either for new information or for past events. Step 4: Eliminate options that describe chronic or slowly progressing conditions and select amnesia as the best fit.

Verification / Alternative check:
Clinical case descriptions of amnesia often involve an accident or emotional shock followed by sudden inability to recall personal information or events. By comparison, diagnostic criteria for Alzheimer's and dementia emphasize slow declining memory and functioning over time, not an abrupt change. These differences confirm that amnesia is most closely associated with the sudden memory loss described in the question.

Why Other Options Are Wrong:
Alzheimer's disease: It does involve memory loss but usually develops slowly and progressively, not suddenly in most cases.
Dementia: This term refers to chronic, global cognitive decline and does not specifically imply sudden onset memory loss.
None of the above: This is incorrect because amnesia clearly matches the description of sudden memory loss.

Common Pitfalls:
A common mistake is to choose Alzheimer's disease or dementia for any question involving memory problems, because these conditions are well known. However, exam questions often use clues like sudden versus gradual onset to guide you toward more precise terms. Always pay attention to timing words such as sudden, acute, or progressive when matching symptoms to diagnoses.

Final Answer:
A sudden loss of memory is classically described as amnesia, a sudden and often selective loss of memory.