Mood stabilizers in Alzheimer's disease: symptomatic and neuroprotective rationales.
OBJECTIVE
This paper provides a case study of 'reverse translational research', in which empirical clinical trials focused on relieving psychopathological symptoms of Alzheimer's disease (AD) ultimately led to mechanism-based trials addressing aspects of the underlying pathophysiology of Alzheimer's disease. AD is multi-dimensional in nature, characterized not only by cognitive and functional decline but by neuropsychiatric symptoms that develop commonly and are associated with considerable morbidity. There have been a large number of empirical trials of various pharmacological agents to reduce these symptoms, such as agitation. Although antipsychotics are used most frequently for agitation, the usual effect size is modest, and there is a range of tolerability and/or safety issues, leading to the hope that alternatives can be found. Furthermore, most clinical trials addressing psychopathology have not been mechanism-based and none have attempted an alternative approach, namely, to delay or prevent the emergence of psychopathology.


RESULTS
The evidence of clinical trials is reviewed regarding the safety, tolerability, and apparent efficacy of the mood stabilizers carbamazepine and valproate for agitation associated with AD. Possible mechanisms of action of valproate are reviewed, leading to the surprising conclusion that neuroprotective properties may account for some of its clinical effects. These mechanisms (including activation of wnt-dependent signaling and upregulation of bcl-2, among others) may be particularly relevant for long-term treatment of AD.


CONCLUSIONS
These clinical and mechanistic findings were combined in the development of a novel clinical trial examining whether chronic valproate therapy can attenuate the clinical progression of AD, which will be implemented by the Alzheimer's Disease Cooperative Study. The design addresses valproate's potential to delay or prevent the onset of agitation in patients lacking agitation to begin with, as well as to slow progressive decline in cognition and daily functioning.
Tariot
Pierre N
PN
Program in Neurobehavioral Therapeutics, Department of Psychiatry, University of Rochester School of Medicine and Dentistry, Monroe Community Hospital, 435 East Henrietta Road, Rochester, NY 14620, USA. pierre_tariot@urmc.rochester.edu
Loy
Rebekah
R
Ryan
J Michael
JM
Porsteinsson
Anton
A
Ismail
Saleem
S
D000544:Alzheimer Disease / Q000188:drug therapy* / Q000378:metabolism / Q000523:psychology*; D000818:Animals; D002986:Clinical Trials as Topic / Q000379:methods; D006801:Humans; D019964:Mood Disorders / Q000188:drug therapy / Q000378:metabolism / Q000523:psychology; D018696:Neuroprotective Agents / Q000627:therapeutic use*; D011595:Psychomotor Agitation / Q000188:drug therapy / Q000378:metabolism / Q000523:psychology; D011619:Psychotropic Drugs / Q000627:therapeutic use; D014635:Valproic Acid / Q000627:therapeutic use
D018696:Neuroprotective Agents; D011619:Psychotropic Drugs; D014635:Valproic Acid