Cognitive Impairment in Depression: Forgetting to Remember or Remembering to Forget?

Cognitive Impairment is a complex process which affects many patients with Major Depressive Disorder. It affects functional outcomes, has a significant impact on Health-Related Quality of Life and is associated with a worse long term prognosis.

Major Depressive Disorder (MDD) is a chronic, recurring and severely debilitating mental illness, which is estimated to have a mean lifetime prevalence of between 11.1% and 14.6%. It affects not only the sufferers, but their families and caregivers, their employers and society at large. Many symptoms of depression are well known – suicidal thoughts, sad mood and tearfulness, changes in sleep and appetite and difficulties with interpersonal relationships. But there are also more pervasive symptoms, which are not as familiar as the symptoms listed above.

It affects not only the sufferers, but their families and caregivers, their employers and society at large.

Emotional blunting occurs when the patient experiences feelings of numbness. They are unable to experience any emotion, whether negative or positive. This symptom is difficult to untangle because it may be caused by the depression itself, or it may be caused by certain pharmacological treatment interventions.

 

Cognitive impairment is a complex process that can be broken down into several domains, including impairments in attention, memory and learning, executive function, and psychomotor processing. What is becoming more well known, is that cognitive impairment is the principal mediator of functional outcomes in those with MDD and has a significant impact on Health-Related Quality of Life (HRQoL). It has been noted to significantly affect the working population, as along with the associated impairment in the ability to function, it significantly increases the rates of both absenteeism and presenteeism.

The World Health Organisation (WHO) estimated that in the first year of the COVID-19 pandemic, the global prevalence of depression and anxiety disorders increased by a massive 25%.

As if depression as an illness on its own wasn’t enough to contend with and to manage and treat, along came a global pandemic, and with it, an exponential increase in the number of patients with a newly diagnosed psychiatric illness, as well as an increase in the number of relapses in patients with pre-existing mental health conditions. The World Health Organisation (WHO) estimated that in the first year of the COVID-19 pandemic, the global prevalence of depression and anxiety disorders increased by a massive 25%.  In addition, the perturbing phenomenon of long COVID, which can emerge after a COVID-19 infection, is accompanied by a physical, mental, and neurological myriad of symptoms, and the so called ‘brain fog’. These are unchartered waters for all of us.

 

Within the world of psychiatry, there has been a move towards focusing on treating cognitive impairment associated with depression. It is simply not enough anymore to aim for merely a response to therapy, but towards a complete remission of symptoms so the patient can go back to living a fully functional life. General treatment principles remain unchanged, including the mainstays of pharmacological interventions, psychotherapy and lifestyle modifications including diet, exercise, and sleep hygiene.

 

However, with new scientific evidence constantly emerging, it is realistic to believe that patients may well and truly overcome the dysfunction associated with emotional blunting, cognitive impairment, and depression itself.

Our correspondent’s highlights from the symposium are meant as a fair representation of the scientific content presented. The views and opinions expressed on this page do not necessarily reflect those of Lundbeck.

References

The above article is based on a presentation given by Professor Gregory Mattingly on 21 July 2022 as a live webinar to South African Health Care Professionals.