Impairment vs. Diagnosis: Unpacking the Crucial Distinction

The terms Impairment and diagnosis are often used interchangeably. However, these terms have distinct meanings and serve different purposes. While both are important, when it comes to the assessment of mental capacity and the correct implementation of the Mental Capacity Act (2005) and ‘2 Stage test’ understanding the difference is crucial.

Background

For years, people have referred to something called ‘The Diagnostic Test’ when referring to the element of the 2 stage test that instructs practitioners to identify if there is an ‘impairment or disorder to the functioning of the mind or brain’. Where the term ‘Diagnostic test’ came from, I honestly do not know but what I do know is that it has erroneously led people to believe they needed to identify a diagnosis in order to satisfy the criteria of this particular section of the test.

Let’s explore the difference between the two

What is Impairment?

The term ‘Impairment’ refers to a reduction or loss of a person's capabilities.  Impairments can result from a variety of factors, such as injury, illness, or congenital conditions, and they can manifest in different forms. When it comes to the assessment of mental capacity, we look at how the impairment manifests itself in relation to issues such as memory loss, difficulty concentrating, or trouble with decision-making. The focus with impairment is on functionality—what a person is no longer able to do or can only do to a limited extent.

We typically assess impairments through clinical tests and examinations. They are often observed and quantified based on the degree to which an individual's functioning deviates from the normal range. Often, we use scales to rate these such as numerically (between 0 – 10) or by using words such as mild, moderate, or severe.

What is Diagnosis?

A diagnosis, on the other hand, is a label that we apply to a series of symptoms that have existed over an acknowledged period. In other words, it is the formal identification, of a disease or condition based on a person’s symptoms, medical history, and the results of various diagnostic tests.

For example, if a person presents with symptoms like difficulty concentrating, irritability, and lack of interest in daily activities, a healthcare professional might diagnose them with depression. The diagnosis doesn’t necessarily quantify how much the depression is impairing their ability to function.

A person with a diagnosis of depression might experience mild, moderate, or severe impairment, depending on how much the disorder impacts their ability to work, socialize, or perform daily tasks.

The Key Difference

The key difference between impairment and diagnosis therefore lies in their focus. Impairment is about the functional limitations a person. It describes the extent to which an individual is affected in their day-to-day life. Diagnosis, however, a label for the disorder or disease that helps guide treatment and management.

While a diagnosis can indicate the nature of the illness, impairment tells us the impact that illness has on a person's life. Both are essential in understanding an individual’s health status and can be helpful when attempting to determine capacity, but not both are specifically required by the Mental Capacity Act (2005).

In summary, then. An impairment measures the how an individual's function is affected by a condition, whereas diagnosis explains the why the individual is experiencing those difficulties. Recognizing the difference is vital to understanding and applying the criteria as outlined in the Mental Capacity Act appropriately.