By Dr. David Woo - August 10, 2020
Many people may not realize that a common sign of depression can include difficulty with memory (forgetfulness) and concentration. For someone with depression, the ability to multitask, remember appointments, and make payments on-time can seem overwhelming and, at times, impossible. Depression affects many cognitive functions (thinking skills) that contribute to memory, including attention, information processing, and executive functions (like memory retrieval).
Depression Causes Physical Changes to the Brain That May Contribute to Memory Loss
Researchers believe that depression causes changes in the brain that affect memory. For example, when someone experiences a depressive episode, the body goes into a stress response and releases a hormone called cortisol. Too much cortisol in the brain inhibits the growth of new brain cells in a part of the brain called the hippocampus, causing it to shrink. (1) The hippocampus is very important for memory formation. It helps the brain form, organize, and store memories. This suggests that the stress response activated by depressive episodes may affect memory.
Depression Affects Sleep Quality, Which Affects Memory
Most people who struggle with depression complain of fatigue and changes in sleep habits. These sleep disruptions can affect cognitive function. Depression is associated with an imbalance in certain neurotransmitters that regulate mood and also regulate sleep. This imbalance of neurotransmitters may be why individuals who struggle with depression experience insomnia (trouble sleeping) or hypersomnia (sleeping too much).
A recent study shows that getting too little or too much sleep affects cognitive function, specifically visual memory and response time. In this study, researchers found that the optimal amount of sleep for the brain to perform at its best was 7 to 9 hours and that sleeping less than 7 hours or more than 9 hours a night resulted in impaired cognitive function. (2,3)
Antidepressants Can Contribute to Short-Term Memory Loss
Antidepressants can provide relief for depression symptoms. But certain antidepressants, like SSRIs and tricyclics, may cause difficulty concentrating or even short-term memory loss. (4) One study observed the effects of SSRI antidepressants in adult patients diagnosed with either depression or OCD (obsessive-compulsive disorder) over the course of 8 weeks. Study participants had no prior complaints of memory loss. To analyze cognitive function, patients completed a mini-mental state examination (MMSE) before starting medication treatment, then again at weeks 3, 5, and 8 of treatment. The MMSE, also called the Folstein test, is a widely used cognitive assessment tool that tests various cognitive functions, including attention, memory, orientation, and visual-spatial skills. (5) Researchers found that patients scored lower on their MMSE with each consecutive check-in (i.e. their cognitive function declined and they experienced memory loss) throughout their 8-week treatment course with an SSRI antidepressant. (6)
If you’re currently taking an antidepressant and are experiencing short-term memory loss, consider a medication-free depression treatment, like TMS (transcranial magnetic stimulation).
Depression Early-On Can Cause Memory Loss Later in Life
A recent study reveals that adults who experience depression and anxiety in their twenties, thirties, and forties are at risk of memory and cognitive impairment in their fifties. The study analyzed information from the National Child Development Study, which began in 1958. This study followed participants starting from childbirth, through childhood, and into late adulthood to observe physical, social, and educational development. (7) Researchers observed that one episode of depression and/or anxiety did not have a significant effect on memory function later in life. However, they found a steady decrease in memory function in older adults when they had experienced two to three, or even more, episodes of depression and/or anxiety in early adulthood. (8)
How to Seek Help for Memory Loss Associated With Depression
If you’re experiencing symptoms of depression, including forgetfulness, or if you’ve been diagnosed with depression and notice signs of memory loss, talk to your doctor. They may recommend a treatment option that is not associated with memory loss, like TMS.
If you’re struggling with managing the symptoms of depression, consider counseling or talk therapy. Connecting with a trained healthcare professional can help patients cope with depressive symptoms, including memory loss and forgetfulness.
1. Moica T, Gligor A, Moica S. The Relationship between Cortisol and the Hippocampal Volume in Depressed Patients – A MRI Pilot Study. Procedia Technology. 2016;22:1106-1112. https://www.sciencedirect.com/science/article/pii/S2212017316001572. Accessed July 30, 2020.
2. Henry A, Katsoulis M, Masi S, Fatemifar G, Denaxas S, Acosta D, Garfield V, Dale CE. The relationship between sleep duration, cognition and dementia: a Mendelian randomization study. Int J Epidemiol. 2019;48(3):849-860. https://pubmed.ncbi.nlm.nih.gov/31062029/. Accessed July 29, 2020.
3. Sleeping for too little or too long linked to poorer memory. Neurosciencenews.com. Published June 05, 2019. https://neurosciencenews.com/sleep-memory-14169/. Accessed July 29, 2020.
4. Eizadi-Mood N, Akouchekian S, Yaraghi A, Hakamian M, Soltani R, Sabzghabaee AM. Memory Impairment Following Acute Tricyclic Antidepressants Overdose. Depress Res Treat. 2015(2015):835786. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4310445/#:~:text=1.-,Introduction,anterograde%20memory%20impairment%20%5B2%5D. Accessed July 29, 2020.
5. Minnesota Department of Human Services. Mini-Mental Status Examination. Publication Date Unkown. https://www.dhs.state.mn.us/main/idcplg?IdcService=GET_FILE&RevisionSelectionMethod=LatestReleased&noSaveAs=1&Rendition=Primary&allowInterrupt=1&dDocName=dhs16_159601. Accessed July 28, 2020.
6. Sayyah M, Eslami K, AlaiShehni S, Kouti L. Cognitive Function Before and During Treatment with Selective Serotonin Reuptake Inhibitors in Patients with Depression or Obsessive-Compulsive Disorder. Psychiatry J. 2016;2016:5480391. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5002481/. Accessed July 28, 2020.
7. 1958 National Child Development Study. Centre for Longitudinal Studies. https://cls.ucl.ac.uk/cls-studies/1958-national-child-development-study/. Accessed July 30, 2020.
8. University of Sussex. Depression in 20s linked to memory loss in 50s. ScienceDaily. Published March 20, 2019. www.sciencedaily.com/releases/2019/03/190320215810.htm. Accessed July 30, 2020.