Cognitive Enhancers in Neuroscience Medicine

Neuropsychiatric disorders cause impairment via multiple pathways. One pathway to impairment is cognitive impairment via attention problems, cognitive slowing and memory disruption.

Barbara Sahakian and colleagues recently published an interesting manuscript examining the issue of cognitive enhancement.

Their review begins by summarizing some of the research related to cognitive enhancement in four neuropsychiatric syndromes. I will summarize their main points by specific disorder.

Alzheimer's Disease (AD)

• Acetylcholinesterase inhibitors such as donepezil have been specifically developed to enhance and slow deterioration of cognitive function in AD
• NMDA receptor agonists such as memantine can also enhance cognitive function and these types of cognitive enhancement agents are typically used in later stages of the disease
• Early identification and early use of cognitive enhancement agents is estimated to decrease the cost of AD by $5000 per individual

Parkinson's Disease (PD)

• Cognitive impairment and dementia are commonly found in PD
• Dopamine agonists such as methylphenidate have been used in PD for treatment of fatigue and cognitive impairment but can worsen impulsivity/compulsive gambling problems
• Atomoxetine may hold promise in PD for psychomotor slowing, global cognition and executive functioning
• Anticholinesterase inhibitors and memantine have shown only marginal improvement in cognition in studies of PD subjects

Attention Deficit Hyperactivity Disorder (ADHD)

• Stimulant treatment of ADHD with drugs such as methylphenidate is effective in 60-70% of children and adults with ADHD
• However, new non-stimulant drug development is needed to address issues of stimulant abuse and non-response
• Methylphenidate improves spatial working memory performance in both individuals with ADHD and healthy volunteers
• Modafinil and atomoxetine may improve response inhibition in ADHD but appear to have limited effects on sustained attention and working memory

Schizophrenia

• Cognitive deficits are a hallmark of schizophrenia and the target of drug and non-drug intervention studies
• Modafanil has shown some early promise in schizophrenia with at least one study showing improvements in working memory, cognitive flexibility, emotion recognition, dorsolateral prefrontal cortex function
• Acetylcholinesterase inhibitors have shown limited effect on cognition in schizophrenia
• Non-drug interventions such as cognitive enhancement techniques (i.e. video games) may hold promise in schizophrenia

The authors go on to describe the results of a computer game study of cognition in schizophrenia using an iPad. I will describe the results of this study in my next post.

Readers with more interest in this manuscript can access the free full-text version by clicking on the PMID link in the citation below.

Follow the author on Twitter: @WRY999

Photo of Roman ruler Marcus Aurelius on horse from author's files.

Sahakian BJ, Bruhl AB, Cook J, Killikelly C, Savulich G, Piercy T, Hafizi S, Perez J, Fernandez-Egea E, Suckling J, & Jones PB (2015). The impact of neuroscience on society: cognitive enhancement in neuropsychiatric disorders and in healthy people. Philosophical transactions of the Royal Society of London. Series B, Biological sciences, 370 (1677) PMID: 26240429