Can Depression Cause Memory Loss?

This week on Question Corner, Melody settles a debate between two friends—does depression cause memory loss?

Got a question for Melody?

Dear Melody, 

Please settle our debate. I say depression makes people forgetful but my friend says that’s nonsense and I’m using it as an excuse for everything. The thing is I have been finding it hard to keep track of things since I started feeling low. Am I crazy?

Sincerely,

Debator

Dear Debator,

Does depression affect memory? Yes. The biochemical and neurological changes that happen in somebody’s brain when they are depressed can disrupt their ability to make new memories or to access new ones. 

Why does depression cause memory loss?

For people suffering from depression, recalling details, in general, can become more challenging. This disruption in memory has long been noted as a significant effect of the conditions, but the underlying mechanisms have only recently begun to be unraveled. Stress, strongly linked to depression, seems to play a pivotal role in these memory impairments through its multifaceted impact on the brain.²

What’s going on in a depressed brain?

The process of hippocampal neurogenesis, which is crucial for memory formation, is affected by depression.^2,4 The hippocampus, a brain region essential for encoding and retrieving memories, suffers a reduction in the generation of new neurons under chronic stress. This impairment can lead to difficulties in consolidating and storing memories, particularly those associated with positive experiences.

The amygdala, a brain region central to emotional processing, also becomes overly sensitized in the context of depression and stress.^4,6 This heightened sensitivity amplifies the encoding and recall of negative emotions and memories, contributing to a persistent focus on unpleasant experiences.

Together, these stress-induced changes in the brain may create a vicious cycle of forgetfulness and reinforce  negative biases in memory. This in turn can contribute to the pervasive sense of hopelessness often experienced in depression.

Depression’s effect on memory doesn’t stop there

The activity of dopamine neurons is suppressed in the depressed brain.^2,5 These neurons are key players in the brain’s reward system, responsible for associating pleasure and positive emotions with experiences. Their decreased activity hinders the encoding of positive memories, making it harder for individuals to recall moments of joy or accomplishment.

How to manage memory loss from depression

Addressing memory loss with depression often involves a multi-faceted approach. Psychotherapy, such as cognitive behavioral therapy, can equip individuals with coping mechanisms to manage negative thoughts and improve mood, indirectly benefiting memory function.⁷ Antidepressant medications may also be prescribed to alleviate depressive symptoms, potentially leading to improved memory recall.⁷

Beyond clinical interventions, lifestyle modifications can play a crucial role in managing depression-related memory loss. Engaging in regular physical activity, maintaining a balanced diet, and fostering social connections, to combat depression, can all contribute to improved mood and cognitive function.^8,9

Treating depression is the first and best step to fixing memory loss. Practical strategies such as utilizing memory aids like calendars, reminders, or checklists can help you to stay organized and compensate for memory lapses. In more severe cases, seeking support from a home care provider or joining a support group can offer valuable assistance and emotional support.

References

1. Depressive disorder (depression) (no date) World Health Organization. Available at: https://www.who.int/news-room/fact-sheets/detail/depression (Accessed: 29 July 2024). 
2. Dillon DG, Pizzagalli DA. Mechanisms of Memory Disruption in Depression. Trends Neurosci. 2018;41(3):137-149. doi:10.1016/j.tins.2017.12.006
3. Hubbard NA, Hutchison JL, Turner M, Montroy J, Bowles RP, Rypma B. Depressive thoughts limit working memory capacity in dysphoria. Cogn Emot. 2016;30(2):193-209. doi:10.1080/02699931.2014.991694
4. Hickie I, Naismith S, Ward PB, et al. Reduced hippocampal volumes and memory loss in patients with early- and late-onset depression. Br J Psychiatry. 2005;186:197-202. doi:10.1192/bjp.186.3.197
5. Gujral S, Aizenstein H, Reynolds CF 3rd, Butters MA, Erickson KI. Exercise effects on depression: Possible neural mechanisms. Gen Hosp Psychiatry. 2017;49:2-10. doi:10.1016/j.genhosppsych.2017.04.012
6. Fernandez A, Quigley L, Dobson K, Sears C. Coherence of attention and memory biases in currently and previously depressed women. Cogn Emot. 2022;36(7):1239-1254. doi:10.1080/02699931.2022.2099348
7.  Psychotherapies (no date) National Institute of Mental Health. Available at: https://www.nimh.nih.gov/health/topics/psychotherapies (Accessed: 18 August 2024). Mahindru A, Patil P, Agrawal V. Role of Physical Activity on Mental Health and Well-Being: A Review. Cureus. 2023;15(1):e33475. Published 2023 Jan 7. doi:10.7759/cureus.33475
8. Molendijk M, Molero P, Ortuño Sánchez-Pedreño F, Van der Does W, Angel Martínez-González M. Diet quality and depression risk: A systematic review and dose-response meta-analysis of prospective studies. J Affect Disord. 2018;226:346-354. doi:10.1016/j.jad.2017.09.022