Existing drug may boost memory in depression patients

A drug used to treat excessive daytime sleepiness may also improve memory and concentration in patients recovering from depression, according to a new study which offers hope for treatment of some of the cognitive symptoms of depression. Researchers at University of Cambridge in the UK found that patients who received a dose of Modafinil experienced improvement in memory functions, compared to those on placebo.

Depression is one of the leading causes of disability worldwide. Symptoms such as difficulty concentrating or indecisiveness contribute to the disability associated with depression. Almost all patients with depression experience problems with concentration, memory and attention. At least half of all patients with depression show cognitive deficits that can be measured objectively. These deficits tend to persist in the recovery phase.

Patients with persistent cognitive problems have poorer outcomes such as impaired work functioning and increased risk for relapse. Depression can be relapsing and return periodically, often for several months at a time. Depression is associated with taking time off work, but also, in some cases, with 'presenteeism' in the workplace, where employees may not be able to work as well as usual.

People often feel distressed when they have difficulty achieving their previous level of work performance on return to work after experiencing depression. However, currently available treatments do not specifically address cognitive deficits in depression. Recent reports have highlighted the importance of defining cognition as a target for treatment in depression.

Researchers investigated the potential of modafinil to treat cognitive dysfunction in depression. Modafinil has already been shown in other studies to have beneficial effects on cognitive function in psychiatric disorders such as schizophrenia. Sixty patients aged between 18 and 65 years with remitted depression completed computerised memory, attention and planning tasks after receiving modafinil or a placebo.

The results showed that patients given a dose of modafinil experienced improvements in memory functions, compared to those patients on placebo. Specifically, patients had benefits in two types of memory - episodic memory and working memory, both of which are important in our day-to-day activities. "We use episodic memory when we are remembering where we left our keys in the house, or remembering where we parked our car," said Barbara Sahakian from University of Cambridge.

"Working memory, on the other hand, is the ability we use when we are rehearsing a new telephone number while we are trying to find a pen and paper to write it down," she said. The study demonstrated that patients receiving modafinil made fewer errors than those who received a placebo. The study was published in the journal Biological Psychiatry.