A new study funded by the Medical Research Council (MRC) and Wellcome, and published in the journal Biological Psychiatry: Cognitive Neuroscience and Neuroimaging, has found that the wakefulness-promoting drug modafinil improves memory functions in people recovering from depression.
Depression is one of the leading causes of disability worldwide, and cognitive symptoms, such as difficulty completing everyday tasks, contribute to the disability associated with depression. Almost all people with depression experience problems with attention, concentration and memory.
This cognitive impairment tends to persist even in the recovery phase of depression when mood symptoms start to improve. People with persistent cognitive symptoms often then experience poorer outcomes such as impaired work functioning and are at increased risk for relapse.
To test whether modafinil could help with these cognitive functions, researchers from the Department of Psychiatry and the Behavioural and Clinical Neuroscience Institute at the University of Cambridge, asked sixty participants who have been previously diagnosed with depression to complete computerised memory, attention and planning tasks after receiving modafinil or placebo. The results showed that the participants who received modafinil experienced significant memory improvements.
The researchers found that participants who received modafinil made fewer errors in two specific types of memory, episodic memory and working memory, both of which are important in day-to-day activities. Episodic memory is used when remembering events such as where we left our keys in the house, or remembering where we parked our car, whereas we use working memory when we are rehearsing a new telephone number or when rehearsing a new passcode to access a computer network, for example.
"These results are very promising." said the lead author Dr Muzaffer Kaser from the Department of Psychiatry. "Cognitive dysfunction is an unmet need in the treatment of depression. GPs or psychiatrists often hear complaints of concentration or memory difficulties from patients with depression. Our study demonstrated that modafinil may be a feasible option to tackle persistent cognitive problems in depression."
Dr Kathryn Adcock, head of neurosciences and mental health at the MRC, added "Preventing relapse is an integral part of any ongoing treatment strategy for depression, and some people can understandably feel hampered if they find it hard to get back to their previous capacity after experiencing depression, for example when they go back to work. The results of this research are very encouraging as they suggest there may be a way to help these people in their recovery from depression."
Professor Barbara Sahakian, a senior author of the paper added: "We now need a longer term study using modafinil to see if the drug, which improves cognition and motivation, can facilitate successful return to work following depression."
Article: Modafinil Improves Episodic Memory and Working Memory Cognition in Patients With Remitted Depression: A Double-Blind, Randomized, Placebo-Controlled Study, Kaser M, Deakin JB, Michael A, Zapata C, Bansal R, Ryan D, Cormack F, Rowe JB, Sahakian BJ, Biological Psychiatry: Cognitive Neuroscience and Neuroimaging, doi: 10.1016/j.bpsc.2016.11.009, published online 14 December 2016.