The British Journal of =
Psychiatry=20
(2011) 198: 85-87. doi: 10.1192/bjp.bp.110.085795
=A9 2011 The Royal College of=20
Psychiatrists
Questioning the =91neuroprotective=92 hypothesis: does drug =
treatment prevent=20
brain damage in early psychosis or=20
schizophrenia?
Joanna Moncrieff, MRBS, MSc, MD, =
MRCPsych
Department of Mental Health Sciences, University =
College=20
London, 67=9673 Riding House Street, London W1W 7EJ, UK. Email: j.moncrieff{at}ucl.ac.uk
Declaration of interest =
J.M. is the co-chair person of the =
Critical=20
Psychiatry Network.
ABSTRACT
The =
idea=20
that psychotic disorders are characterised by progressive
=20
neurodegeneration that can be reversed by drug treatment is
=20
used to justify early treatment of increasing numbers of =
mostly
=20
young people. I argue that there is little evidence to =
support
=20
the view that old- or new-generation antipsychotics are=20
=91neuroprotective=92,
and some evidence that the drugs =
themselves may be=20
responsible
for the decline in brain matter observed in some=20
studies.
INTRODUCTION
Joanna Moncrieff (pictured) is a senior lecturer at=20
University College London and a consultant psychiatrist at =
the=20
North East London Foundation Trust.
Almost 7 million prescriptions for antipsychotic drugs were =
issued=20
outside hospital in England in 2008, an increase of 48% since =
1998.1 Data=20
from the USA also indicate dramatically increased rates of=20
prescription of antipsychotics to young people over recent=20
years.2 Ideas=20
about the benefits of early drug treatment in psychosis, =
along with=20
other factors such as the marketing of bipolar =
disorder,3 are=20
likely to have contributed to the increasing prescription of =
these=20
drugs.
The importance of starting drug treatment early, and of =
continuing=20
treatment in people who would like to stop, is often =
justified=20
by the prevalent belief that schizophrenia or psychosis =
involves=20
a progressive loss of brain tissue that can be arrested or=20
reduced by treatment with antipsychotic drugs.4=20
Accordingly, the drugs are sometimes referred to as having=20
=91neuroprotecive=92 properties. This belief is founded on a =
variety of=20
evidence, all of which is debatable and open to other=20
interpretations.
Brain imaging research
The =
main=20
area believed to support the =91neuroprotection=92
hypothesis =
is brain=20
imaging research illustrating that people
with schizophrenia =
or=20
psychosis show a progressive reduction
in brain volume and an =
enlargement of ventricles and cerebral
spinal fluid. All such =
studies, however, involve people who
have taken long-term=20
antipsychotic medication. A large study
showing greater =
decline in=20
brain volume in patients with first-episode
psychosis taking=20
haloperidol compared with olanzapine has been
interpreted as=20
indicating the neuroprotective effects of olanzapine.
5 The=20
authors acknowledged, however, that the study might also
be=20
interpreted as demonstrating differential drug-induced changes.
=20
Supporting the latter interpretation, a study of macaque =
monkeys
=20
treated with therapeutic doses of olanzapine and haloperidol
=20
for 18 months found an 8% reduction in mean fresh brain =
weight
=20
in monkeys treated with haloperidol and 11% in those on =
olanzapine
=20
compared with non-drug-treated controls.
6=20
The great majority of studies of individuals who are drug-naive =
or=20
have received only minimal treatment, do not show the global =
deficit=20
in brain volume commonly associated with patients who have =
received=20
drug treatment, including, most importantly, the only three =
studies=20
involving people with long-term conditions who had not been =
exposed=20
to drug treatment.7 Results=20
from two studies of people considered to be at high risk of=20
psychosis are also believed to demonstrate progressive brain =
tissue=20
loss prior to and in the early stages of psychotic illness. =
Many=20
of the Australian cohort, however, were taking antipsychotic=20
medication during some of the follow-up period.8 In the=20
Edinburgh study, high-risk individuals who progressed to =
psychosis=20
showed greater temporal lobe reduction than those who did not =
progress, but did not differ from controls.9=20
Overall, therefore, imaging studies provide little evidence =
of=20
progressive brain tissue loss in non-drug-treated patients =
with=20
schizophrenia. Moreover, the effects of drug treatment have =
not been=20
excluded as a cause of the tissue loss seen in some studies =
of=20
drug-treated patients.7=20
Neuropathological findings
Post-mor=
tem=20
studies have generally not found the large-scale
neuronal =
loss and=20
gliosis characteristic of neurodegenerative
disorders in the =
brains=20
of people with schizophrenia, although
there is some evidence =
of=20
local reduction of neuronal sub-populations
and local loss of =
dendritic spines and length.
10=20
Again, however, all studies have involved people on long-term =
medication. Some studies with drug-naive patients have found =
reduced=20
serum levels of brain derived neurotrophic factor =
(BDNF),11 but=20
this finding is not specific to schizophrenia, and BDNF has =
also been=20
found to be involved in mood disorders and the stress =
response.=20
Although schizophrenia has been suggested to involve =
increased or=20
abnormal apoptosis, several studies confirm that markers of=20
apoptosis in neurodegenerative disorders such as =
Alzheimer=92s=20
disease are not raised in post-mortem tissue from patients =
with=20
chronic schizophrenia, and the role of apoptosis earlier on =
in the=20
condition remains speculative.12=20
Duration of untreated psychosis
Another =
frequently cited, indirect strand of evidence for the =
hypothesis that=20
schizophrenia arises from progressive brain pathology that =
can be=20
arrested by drug treatment is the association found in some =
studies=20
(although not all) between the duration of untreated =
psychosis and=20
outcome. However, it has long been recognised that conditions =
with a=20
long and insidious early course are frequently more severe =
than those=20
with a sudden onset. Duration of untreated psychosis is =
strongly=20
related to mode of onset13 and=20
other characteristics of the psychosis itself,14=20
which makes it likely that it is simply a proxy measure of a=20
more severe underlying condition. Research on duration of=20
untreated psychosis and outcome has not adequately controlled =
for=20
mode of onset and other potential confounding factors.15=20
Trials of early intervention have shown some positive results, =
but=20
have not analysed the role of medication over and above other =
aspects=20
of the intervention, and long-term results are disappointing=20
(reviewed in Bosanac et al).15 Two=20
trials of drug treatment for young people at high risk of =
psychosis=20
suggested that the rate of conversion to psychosis was =
reduced,=20
although not by a statistically significant degree in the =
larger=20
of the two trials.16 A=20
larger naturalistic study has so far found that drug =
treatment has=20
not reduced the onset of psychosis.17=20
Evidence on neuroprotection
At a=20
neuropathological level, ideas about drug treatment being=20
neuroprotective developed because of evidence that some =
psychiatric=20
drugs, notably lithium, increase activity in some pathways=20
associated with neurotrophism and neurogenesis.18 The=20
functional implications of these findings are unclear, =
however. One=20
study, for example, found that although lithium reduced =
levels=20
of kainate-induced excitotoxic motor neuron cell death,=20
surviving cells were not undamaged.19 In=20
any case, evidence of antipsychotics has not consistently=20
demonstrated these sorts of effects.18=20
The view that new atypical antipsychotics have a particular=20
neuroprotective effect may derive from an animal study of =
olanzapine=20
and clozapine that detected upregulation of the =
neuroprotective=20
Bcl-2 (B-cell lymphoma 2) protein.20=20
However, Bcl-2 is also upregulated in neurodegenerative =
disorders=20
such as Alzheimer=92s disease, where it is regarded as =
evidence of a=20
compensatory mechanism. Other studies have not replicated =
this=20
finding, but one study found increased activity of the=20
pro-apoptotic protease capase-3 in animals treated with old =
and new=20
antipsychotics.21=20
Effects of antipsychotics, particularly atypicals, on cognitive=20
function is also cited as evidence of their neuroprotective=20
effects, but whether or not any antipsychotics improve =
cognition=20
independently of symptoms remains uncertain. The suggested=20
superior effects of atypical antipsychotics have also been=20
questioned by the findings of the Clinical Antipsychotic =
Trials=20
of Intervention Effectiveness (CATIE) study, in which the =
greatest=20
long-term improvements in cognitive function were seen in the =
perphenazine group.22=20
In contrast to ideas about neuroprotective effects, there is=20
suggestive evidence that antipsychotics reduce brain tissue=20
volume, as described above,7 and=20
they are known to cause the pathological brain syndrome known =
as=20
tardive dyskinesia. Research suggests that as well as =
involuntary=20
movements, tardive dyskinesia is associated with general =
cognitive=20
decline, suggesting that antipsychotics can induce =
generalised brain=20
dysfunction.23=20
Conclusions
Antipsyc=
hotics=20
are undoubtedly useful in suppressing the symptoms of =
psychotic=20
conditions, but the evidence presented here suggests there is =
little=20
basis to the belief that they reverse an underlying =
neurodegenerative=20
process in people with schizophrenia or psychosis. =
Neuropathological=20
studies do not support the idea that antipsychotic drugs, =
including=20
the new or atypical antipsychotics, have neuroprotective =
effects.=20
Some research suggests they may even contribute to the =
decline in=20
brain volume seen in people with these diagnoses, and they =
are known=20
to induce neurological damage in the form of tardive =
dyskinesia in=20
some long-term users. The idea that antipsychotic drugs are=20
neuroprotective should not therefore be used as a =
justification for=20
prescribing or continuing to prescribe them, if other =
considerations=20
do not also support their use. Psychiatrists should be =
particularly=20
cautious about the use of antipsychotics in the early or =
prodromal=20
stages of psychosis, where, as others have pointed out, there =
is=20
the potential to do much harm.15=20
REFERENCES
1=20
- Information Centre for Health and Social Care. Prescription =
Cost=20
Analysis 2008. NHS Information Centre, 2009.2=20
- Olfson M, Blanco C, Liu L, Moreno C, Laje G. National trends in =
the=20
outpatient treatment of children and adolescents with antipsychotic =
drugs.=20
Arch Gen Psychiatry 2006; 63: 679 =9685.[Abstract/Free Full Text]3=20
- Healy D. The latest mania: selling bipolar disorder. PLoS =
Med 2006;=20
3: e185.[CrossRef][Medline][Search=20
for full text]4=20
- Lieberman JA. Is schizophrenia a neurodegenerative disorder? A =
clinical=20
and neurobiological perspective. Biol Psychiatry 1999; =
46: 729=20
=9639.[CrossRef][Medline][Search=20
for full text]5=20
- Lieberman JA, Tollefson GD, Charles C, Zipursky R, Sharma T, Kahn =
RS, et=20
al. Antipsychotic drug effects on brain morphology in first-episode =
psychosis.=20
Arch Gen Psychiatry 2005; 62: 361 =9670.[Abstract/Free Full Text]6=20
- Dorph-Petersen KA, Pierri JN, Perel JM, Sun Z, Sampson AR, Lewis =
DA. The=20
influence of chronic exposure to antipsychotic medications on brain =
size=20
before and after tissue fixation: a comparison of haloperidol and =
olanzapine=20
in macaque monkeys. Neuropsychopharmacology 2005; 30: =
1649 =9661.[CrossRef][Medline][Sea=
rch=20
for full text]7=20
- Moncrieff J, Leo J. A systematic review of the effects of =
antipsychotic=20
drugs on brain volume. Psychol Med 2010; 40: 1409 =
=9622.[CrossRef][Medline][Search=20
for full text]8=20
- Takahashi T, Wood SJ, Yung AR, Soulsby B, McGorry PD, Suzuki M, et =
al.=20
Progressive gray matter reduction of the superior temporal gyrus =
during=20
transition to psychosis. Arch Gen Psychiatry 2009; 66: =
366 =9676.[Abstract/Free Full Text]9=20
- Lawrie SM, Whalley HC, Abukmeil SS, Kestelman JN, Miller P, Best =
JJK, et=20
al. Temporal lobe volume changes in people at high risk of =
schizophrenia with=20
psychotic symptoms. Br J Psychiatry 2002; 181: 138 =
=9643.[Abstract/Free Full Text]10=20
- Jarskog LF, Miyamoto S, Lieberman JA. Schizophrenia: new =
pathological=20
insights and therapies. Annu Rev Med 2007; 58: 49 =
=9661.[CrossRef][Medline][Search=20
for full text]11=20
- Chen DC, Wang J, Wang B, Yang SC, Zhang CX, Zheng YL, et al. =
Decreased=20
levels of serum brain-derived neurotrophic factor in drug-naive =
first-episode=20
schizophrenia: relationship to clinical phenotypes. =
Psychopharmacology=20
(Berl) 2009; 207: 375 =9680.[CrossRef][Search=20
for full text]12=20
- Jarskog LF, Glantz LA, Gilmore JH, Lieberman JA. Apoptotic =
mechanisms in=20
the pathophysiology of schizophrenia. Prog Neuropsychopharmacol =
Biol=20
Psychiatry 2005; 29: 846 =9658.[CrossRef][Medline][Search=20
for full text]13=20
- Morgan C, Abdul-Al R, Lappin JM, Jones P, Fearon P, Leese M, et =
al.=20
Clinical and social determinants of duration of untreated psychosis in =
the=20
=C6SOP first-episode psychosis study. Br J Psychiatry 2006; =
189:=20
446 =9652.[Abstract/Free Full Text]14=20
- Owens DC, Johnstone EC, Miller P, Macmillan JF, Crow TJ. Duration =
of=20
untreated illness and outcome in schizophrenia: test of predictions in =
relation to relapse risk. Br J Psychiatry 2010; 196: 296 =
=96301.[Abstract/Free Full Text]15=20
- Bosanac P, Patton GC, Castle DJ. Early intervention in psychotic=20
disorders: faith before facts? Psychol Med 2010; 40: 353 =
=968.[CrossRef][Medline][Search=20
for full text]16=20
- McGlashan TH, Zipursky RB, Perkins D, Addington J, Miller T, Woods =
SW, et=20
al. Randomized, double-blind trial of olanzapine versus placebo in =
patients=20
prodromally symptomatic for psychosis. Am J Psychiatry 2006;=20
163: 790 =969.[Abstract/Free Full Text]17=20
- Walker EF, Cornblatt BA, Addington J, Cadenhead KS, Cannon TD, =
McGlashan=20
TH, et al. The relation of antipsychotic and antidepressant medication =
with=20
baseline symptoms and symptom progression: a naturalistic study of the =
North=20
American Prodrome Longitudinal Sample. Schizophr Res 2009; =
115:=20
50 =967.[CrossRef][Medline][Search=20
for full text]18=20
- Hunsberger J, Austin DR, Henter ID, Chen G. The neurotrophic and=20
neuroprotective effects of psychotropic agents. Dialogues Clin =
Neurosci=20
2009; 11: 333 =9648.[Medline][Search=20
for full text]19=20
- Caldero J, Brunet N, Tarabal O, Piedrafita L, Hereu M, Ayala V, et =
al.=20
Lithium prevents excitotoxic cell death of motoneurons in organotypic =
slice=20
cultures of spinal cord. Neuroscience 2010; 165: 1353 =
=9669.[CrossRef][Medline][Search=20
for full text]20=20
- Bai O, Zhang H, Li XM. Antipsychotic drugs clozapine and =
olanzapine=20
upregulate bcl-2 mRNA and protein in rat frontal cortex and =
hippocampus.=20
Brain Res 2004; 1010: 81 =966.[CrossRef][Medline][Search=20
for full text]21=20
- Jarskog LF, Glantz LA, Gilmore JH, Lieberman JA. Apoptotic =
mechanisms in=20
the pathophysiology of schizophrenia. Prog Neuropsychopharmacol =
Biol=20
Psychiatry 2005; 29: 846 =9658.[CrossRef][Medline][Search=20
for full text]22=20
- Keefe RS, Bilder RM, Davis SM, Harvey PD, Palmer BW, Gold JM, et =
al.=20
Neurocognitive effects of antipsychotic medications in patients with =
chronic=20
schizophrenia in the CATIE Trial. Arch Gen Psychiatry 2007; =
64:=20
633 =9647.[Abstract/Free Full Text]23=20
- Waddington JL, O=92Callaghan E, Larkin C, Kinsella A. Cognitive =
dysfunction=20
in schizophrenia: organic vulnerability factor or state marker for =
tardive=20
dyskinesia? Brain Cogn 1993; 23: 56 =9670.[CrossRef][Medline][Search=20
for full text]
Received for publication =
August=20
11, 2010. Accepted for publication September 15, 2010.
eLetters:
Read all eLetters=
- Reaching Cells=20
- Dr Peter John Gordon=20
- BJP Online, 9 Feb 2011 [Full=20
text]