The study found that after taking a tablet of modafinil (Provigil™), patients with schizophrenia performed significantly better at memory tests involving short-term memory and, importantly, showed improved mental flexibility, a core deficit normally seen in patients with schizophrenia.
Modafinil is a medicine currently licensed in the UK for the treatment of a sleeping disorder called narcolepsy. Ms. Danielle Turner, Prof. Barbara Sahakian and others recently showed that modafinil improves mental functioning in healthy volunteers. This led the researchers to see whether modafinil might be of benefit to patients with schizophrenia. A group of 20 patients performed a number of memory tests once after they had taken a lactose placebo tablet and once after one 200 mg dose of modafinil.
After having taken modafinil, patients' short-term memory and cognition improved. For example, they were able to remember more numbers (similar to being asked to remember a telephone number) and they were able to learn new rules in a cognitive flexibility task (attentional set shifting) much more efficiently. This is similar to changing what you are doing when it is no longer the most efficient method. Using the telephone analogy, if you couldn't reach someone on the telephone, instead of repeatedly dialling the same number, you might try sending the person an email or a fax. Patients with schizophrenia can find it very difficult to switch from doing one thing to another. Difficulties in cognitive flexibility have been linked to an inability to fully rehabilitate in society, with many patients finding it impossible to hold down a full-time job or live alone.
These results are very promising because many patients with schizophrenia can find it very difficult to lead completely independent lives even after successful management of the hallucinations and other psychotic symptoms.
These results need to be confirmed in long-term studies of the effects of Modafinil in schizophrenia, to see whether these beneficial effects are maintained with chronic treatment. However, this study could have important implications for the treatment of schizophrenia.