British Journal of Medical Pgchology (1994),67, 259-271 Printed in Great Britain 259

0 1994 The British Psychological Society

Cognitive behavioural therapy for

drug-resistant psychosis
P. A. Garety*, L. Kuipers, D. Fowler, F. Chamberlain and
G. Dunn
Departments of Psychology and Biostatistics, Institute of Psychiatry, London and the
Department of Psychology, Fulbourn Hospital, Cambridge, UK

A small controlled trial of cognitive behaviour therapy for drug-resistant psychosis

is reported. The study was designed as a pilot study for a future larger and longer
randomized controlled trial. The therapy was offered to patients with a diagnosis
of schizophrenia or schizo-affective psychosis who presented unremitting positive
symptoms. An average of 16 sessions were delivered over a six-month period. The
results of this pilot study are promising. Rates of engagement in therapy were high.
The treatment group also improved significantly on a number of key symptom
measures when compared with the controls. These were reductions in delusional
conviction, general symptomatology and depression scores. Future studies should
offer therapy over a longer period, targeting social as well as symptom change, and
considering factors which will enhance maintenance of improvement.

A significant proportion of patients with psychotic illness experience persistent

positive symptoms resistant to medication. Harrow, Carone & Westermeyer (1985)
report that, at a two-year follow-up, between 55 and 60 per cent of patients with
schizophrenia continue to be deluded to some extent. In a seven-year follow-up
study, 23 per cent of patients were found to be experiencing florid symptoms
(Curson, Barnes, Bamber, Platt, Hirsch & Duffy, 1985). In-patients in hospitals
present similarly high rates of drug-resistant psychotic symptoms (Curson, Patel,
Liddle & Barnes, 1988). These symptoms are both distressing (Breier & Strauss,
1983; Garety & Hemsley, 1987) and disabling (Harrow, Rattenbury & Stoll, 1988).
In addition, affective symptoms are found in 25 to 40 per cent of those with psychosis
(D. R. Hemsley, 1992, personal communication, ‘Anxiety and depression in
schizophrenia’; Johnstone, Owens, Frith & Leavy, 1991) and the risk of suicide in
schizophrenia is now increasingly being recognized (Briera, Schreiber, Dyder &
Pickard, 1991; Hirsch, 1982). The cost of these persistent symptoms in terms of lost
individual potential, family burden and service use is thus very great.
In the past five years, there have been a small number of single-case and
uncontrolled studies of a new approach to these problems, and a growing consensus
that a range of psychological treatments can be beneficial. While some work has been
a development of cognitive behavioural strategies of problem solving and coping

*Requests for reprints to: Dr P. A. Garety, Department of Psychology, Institute of Psychiatry, De Crespigny Park,
London, SE5 8AF, UK.
260 P. A . Garety et af.

(e.g. Tarrier, Beckett, Harwood, Baker, Yusopoff & Ugarteburu, 1993; Tarrier,
Harwood, Yusopoff, Beckett & Baker, 1990), other studies have also drawn on and
adapted cognitive behavioural techniques originally developed to challenge negative
thinking in depression (Beck, Rush, Shaw & Emery, 1979; Teasdale, Fennell,
Hibbert & Amies, 1984) to apply these to the disorders of thinking, delusional ideas,
hallucinations and affective symptoms found in people with psychosis (Chadwick &
Lowe, 1990; Fowler, 1992; Fowler and Morley, 1989; Kingdon & Turkington,
1991). Recent theoretical and empirical studies of delusions have also identified
reasoning and attributional biases which lend support to a cognitive approach
(Bentall, Kaney & Dewey, 1991; Garety, Hemsley & Wessely, 1991), although much
further work is needed to extend our theoretical understanding (Garety, 1992).
In this paper we present a controlled trial of cognitive behavioural therapy for
psychosis, which was designed as a pilot study for a future larger and longer
randomized controlled trial. The purpose of the present investigation was to obtain
further evidence for the effectiveness of cognitive behavioural therapy for psychotic
patients, by means of a comparison with a group of patients receiving treatment as
usual, on the waiting list for our therapy. Teasdale e t af. (1984) have offered a
convincing rationale for first comparing a novel treatment approach with the current
usual treatment, thereby controlling for the effects of spontaneous remission, for any
effects of reassessment on the dependent measures and for the beneficial effects of
treatments other than cognitive behavioural therapy that the patient might normally
receive. Our interest was to establish the benefits of this therapy rather than to
conduct a component analysis of the therapy.

Method
Subjects
The study was conducted at the Maudsley Hospital, London and at Fulbourn Hospital, Cambridge.
Subjects were recruited by seeking referrals from psychiatrists of patients with a diagnosis of
schizophrenia or schizo-affectivedisorder who presented unremitting (at least six months), drug-resist-
ant positive psychotic symptoms, i.e. delusions, hallucinations or passivity phenomena. In the light of
earlier work, we sought also patients who expressed some distress at their symptoms, and excluded
any with only negative symptoms (Fowler, 1992). Patients for whom alcohol, drug or organic problems
were primary were also excluded. Fourteen patients were referred who fulfilled these criteria and 13
were sucessfully assessed on our full package of measures. One patient was excluded, a man with a
20-year history of unremitting psychotic experiences, whose attention and concentration were too poor
to complete the assessments. The control group consisted of seven people subsequently referred for
therapy and placed on the waiting list. An eighth person was excluded since she did not have clear
positive symptoms. All assessments were conducted only after the patient had signed the informed
consent form. They were conducted by an independent assessor, who was not blind to the group
assignment.

Design
The study was designed as a non-random allocation controlled trial, in which the first subjects referred
for therapy were placed in the experimental group (N = 13) and the subjects subsequently referred
(N = 7) were placed in the waiting-list group. These waiting-list subjects were all offered therapy after
the trial ended.
 Cognitive behavioural therapy for psychosis 26 1
Assessments
Subjects were assessed on a battery of measures. These measures rated a variety of aspects of mental
state and social functioning and were included not only to provide change data but also to examine
their sensitivity to change and feasibility for use in such a trial. Before and within one-month
post-treatment subjects were assessed on the Present State Examination (9th version) (PSE; Wing,
Cooper & Sartorius, 1974) to elicit current symptoms and to derive a Catego classification. They were
also given the Maudsley Assessment of Delusions Schedule (MADS; Buchanan e t ul., 1993), an Insight
measure (David, 1990) and the Rosenberg Self Esteem Scale (Rosenberg, 1965).
A further measure rated two important aspects of patients’ conscious appraisals of their problems.
We have called this the Appraisal of Problems Questionnaire. Firstly, statements about the patients’
more salient problems were elicited by structured interviewing. Secondly, patients were asked to rate
(a) the degree to which such problems caused interference with their lives and (b) the degree to which
such problems caused distress, on a three-point Likert scale. Previous work has shown these ratings
to be both stable and consistent. Highly significant Pearson r correlations were found for ratings taken
on the same subjects two weeks apart: r = .82 (p < .01) and r = .85 (p < .01) respectively. Finally,
an informant (relative or key worker) completed the Life Skills Profile (Rosen, Hadzi-Pavlovic &
Parker, 1989), an assessment of current social functioning.
Before, and at monthly intervals throughout the trial, subjects were also given the following
assessments: the Brief Psychiatric Rating Scale (Overall & Gorham, 1962), the Beck Depression
Inventory (Beck, Ward, Mendelson, Mock & Erbaugh, 1961), the Social Avoidance and Distress Scale
(Watson & Friend, 1969), the Hustig & Hafner (1990) Hallucinations Assessment, and a series of
personal questionnaires (PQ), assessing key symptoms identified by the PSE.
Personal questionnaires have been developed to provide a reliable method for assessing change in
delusions (Brett-Jones, Garety & Hemsley, 1987; Garety, 1985) and have been used in previous
outcome studies with psychotic patients to assess delusions, hallucinations and affective states
(Chadwick & Lowe, 1990; Fowler et ul., 1989). The methodological advantages of the use of PQs are
that they are suitable for repeated administration at frequent intervals (e.g. weekly) and that they are
constructed in the clients’ own words, which is particularly useful with psychotic subjects. The
construction of the PQs was as described in Brett-Jones et ul. (1987); for each delusion, the intensity
of conviction, preoccupation and distress was measured.
An estimate of premorbid and current intellectual functioning was also made before the trial using
the National Adult Reading Test (NART; Nelson, 1982) and subtests of the Wechsler Adult
Intelligence Scale-Revised (WAIS-R; Wechsler, 1981). In order to extend our understanding of the
reasoning biases of psychotic patients, subjects also completed two reasoning tasks (Garety e t al., 1991;
S. Jones, personal communication: ‘A within-subjects measure of the Kamin Blocking Effect’) which
will be reported elsewhere.

Treatment
Therapy was conducted by three clinical psychologists experienced in working with psychotic patients
(D.F., L.K. and P.A.G.). All had training in general cognitive behavioural therapy and in rehabilitation
approaches for people with long-term psychotic disorders. They followed a treatment manual (Fowler,
Garety & Kuipers, in preparation) which describes four main components of therapy. Therapy was
given at weekly or fortnightly intervals over six months, for a maximum of 22 sessions. Patients
received on average 16 sessions (range 11-22). The therapists met regularly (fortnightly to monthly)
throughout the trial for peer supervision sessions, in order to ensure that they applied the approach
consistently.
Thirteen patients commenced therapy but one dropped out after three sessions; he suffered a major
relapse after a complete change of neuroleptic in preparation for discharge from hospital. A second
person, while continuing in therapy, became suspicious of the assessor and refused to complete the
assessments. Data are therefore available on 11 completed treatment cases and seven controls. However,
the analysis included all the available data.
Briefly, the therapy consists first of a detailed and relatively lengthy assessment phase (up to five
sessions), following which an individual formulation is made. The assessment period is extensive for
262 P. A . Garety et al.
two reasons: firstly, it is important to have a thorough understanding both of the present (the person’s
current difficulties, psychotic experiences and associated beliefs, self-concept, views on diagnosis,
mood, and living circumstances) and also of the past (both the initial stages of the psychosis with its
subsequent course and the individual’s earlier history). The results of the assessment form the basis
of an individually tailored intervention, which, in consultation with the patient, determines the relative
emphasis to be given to the three treatment components. A second reason for a lengthy assessment
phase is that psychotic patients are frequently difficult to engage in any therapy and drop-out rates
can be high (see Gunderson, Frank, Katz, Vannicelli, Frosch & Knapp, 1984); we therefore use
the assessment phase as a period of engagement, in which the primary emphasis is on understanding
the person’s own perspective and developing a collaborative approach rather than on active
change.
Depending on the formulation of the case, therapy may address any or all of three major goals: ( a )
to reduce the distress and interference that arises from the experience of chronic psychotic
symptomatology; ( b ) to increase the understanding of psychotic disorders and to foster motivation to
engage in self-regulative behaviours; (t) to reduce the occurrence of dysfunctional emotions and
self-defeating behaviours arising from a sense of hopelessness, negative self-image or perceived
psychological threat. As many patients present with multiple problems, in each case a variety of dfferent
techniques may be used to address these treatment goals. The process of therapy typically involves
discussing the results of the extensive assessment with the patient and then planning a strategy for
intervention. Specific therapy techniques consist of adaptations of well-documented procedures used
in cognitive-behavioural therapies for other disorders (e.g. Williams, 1992) together with some
techniques developed specifically for psychosis. Some of the most useful procedures are described
below. (The therapy is described in detail in Fowler, Garety & Kuipers, in preparation.)

1. Cognitive behavioural coping strategies. These procedures aim to equip the patient with a set of adaptive
ways of managing the occurrence of psychotic experience. The therapist first carries out a detailed
cognitive-behavioural analysis of the situations associated with the patient’s experience of particular
distressing psychotic symptoms. For example, psychotic symptoms may be triggered by specific
situations, may interfere with a person’s ability to enter social situations or to go shopping, or may
result in severe distress while alone at home. These analyses are then discussed with the patient and
the implications for new ways in which the patient may act or think to reduce frequency of symptom
onset, or distress or disabiity in such situations are discussed. The patient is then encouraged to practise
using new coping strategies ‘in vivo’ and to experiment with a number of different strategies until a
useful coping repertoire is developed. Examples of specific coping strategies include listing rational
alternatives to paranoid ideation or learning to distract attention from hallucinations. Such approaches
have been described in more detail by Fowler et al. (1989) and by Tarrier et al. (1990, 1993).

2. Relabelling and pychoeducation. The aim of these strategies is to help the person to relabel psychotic
experiences and to suggest that such experiences are not unique, but have been described by others.
(Johnson, Ross & Mastria [1977], Kingdon & Turkington [I9911 and Valins & Nisbett [1972] have
described similar approaches.) Therapy proceeds by first eliciting specific examples of psychotic
experience and then, using careful Socratic questioning, by suggesting that there may be rational
explanations for the occurrence of such experience. This may lead to exploring the implications of the
new understanding, in particular the implications for reducing the risk of onset of psychotic experience
in the future. In this way, careful questioning may lead to the development of rationales for taking
neuroleptic medication, or adapting behavioural patterns likely to reduce the risk of relapse.

3. Goal setting and overcoming hopelessness. A number of patients describe being overwhelmed by their
life situation as a person with a chronic mental illness and have little understanding of how to help
themselves. Here the aim is to generate hope by highlighting worthwhile short-term and long-term
goals which may be achieved despite continuing disabilities. This may involve discussion of the
person’s experience of more enduring problems such as continuing cognitive deficits or the social
consequences of disability. It may be important to clarify limitations set by such disabilities. Once the
nature of the problem is clarified, proposals for the self-regulation of disabilities may be discussed.
 Cognitive behavioural therapy for psychosis 263
4. Modz3cation of delusional beliefs. There is a growing consensus on psychological approaches to modify
strongly held beliefs. (The process has been described by Chadwick & Lowe [1990], Shapiro &
Ravenette [1959] and Watts, Powell & Austin [1973].) The therapist first carefully elicits the person’s
view of the reasons for the development and maintenance of the delusional beliefs. This may involve
extensive discussion of the development of beliefs in the past. Then the therapist invites the patient
to consider alternative interpretations of specific pieces of evidence cited by the patient. More peripheral
evidence and beliefs are addressed before moving to a re-evaluation of central beliefs.

5. Modi&g dyfunctional assumptions. A number of patients with continuing psychotic symptoms may
hold dysfunctional assumptions about the self which imply worthlessness, uselessness, unlovability.
Such assumptions may be associated with self-defeating patterns of thought and behaviour. To address
such assumptions the therapist starts by attempting to clarify the nature of the assumptions held. Most
often this is done by a longitudinal assessment (see Williams, 1992), a process involving questioning
about the origins of assumptions and how they have affected the person’s life since the time they started
to the present. Once dysfunctional assumptions have been clarified, cognitive therapy procedures are
used to restructure such assumptions and develop more adaptive and positive self-appraisals.

Statistical anabsis
All routine analyses and data description were carried out using SPSS/PC (version 4.0). The analysis
of the repeated measures (up to six times, with a variable amount of missing data) was carried out
using the variance components software REML (Scottish Agricultural Statistical Services, University
of Edinburgh) or the general mixed model program 5V in BMDP PC-90. Estimates of the mean values
of patients’ symptom scores were made in REML in a way which allows for many of the potential
sources of bias arising from differential drop-out and haphazard missing values (Gornbein, Lazaro &
Little, 1992). This was particularly relevant, since it was not possible to complete six assessments on
each subject, given missed appointments and the tight time-scale of the study. The p values are for
a test of the linear trend by group interaction in a mixed model, where time and group are fixed effects
and subject is a random effect. The BMDP program was used to re-analyse selected results (the Brief
Psychiatric Rating Scale and Beck Depression Inventory scores) to check the robustness of the findings
to various model assumptions. The pre-post measures were analysed by constructing change scores
in subjects where both measures were available and then comparing the groups with t tests.

Results
Subjects
Background information on the subjects in the two groups is presented in Table 1.
They were a predominantly male sample, with lengthy psychiatric histories. Most
patients (11) in the treatment group were out-patients or day patients, as were all

Table 1. Demographic data on subjects who entered the trial

Subjects (N = 13) Controls (N = 7)
-
Variable Mean Range Mean Range
Age (years) 39.6 21-70 37.6 26-53
Duration of illness (years) 16.5 6-30 10.9 5-20
Number of admissions 2.9 1-5 2.0 1-3
Predicted IQ (NART) 108 94-125 112 98-125
Gender Male (N = 12) Male (N = 6)
Female (N = 1) Female (N = 1)
264 P. A.Garety e t al.
the controls. Two in the treatment group were in-patients. The predicted premorbid
IQ of the sample was good average, while current functioning on the WAIS-R
subtests averaged about eight points, or low average. While the groups did not differ
significantly on any of the demographic variables, there was a trend to the treatment
group having spent more months in hospital (mean = 11.5, SD = 10.8) than the
controls (mean = 4.3, SD = 2.2) [ t ( l 5 )= 1.7, p = .l) and to having spent more
months in hospital in the past five years (treatment group mean = 3.2, SD = 3.9;
controls mean = .7, SD = .8 [ t ( l 6 )= 1.6, p = .1]). Two in the therapy group and
one control were in full-time employment.
Selected aspects of the patients’ clinical condition at initial assessment are shown
in Table 2. While nearly all the patients were deluded at the initial PSE assessment,
hallucinations were less common in the treatment group. All of the clinical diagnoses
in the treatment group were of schizophrenia, barring one person with a diagnosis
of schizo-affective diorder; however, the Catego classifications based on current
mental state were more mixed: four were classified as paranoid schizophrenia, four
as paranoid psychosis, four as psychotic depression and one as ‘other psychosis’. In
the control group, all with a clinical diagnosis of schizophrenia, five were classified
as paranoid schizophrenia and two as ‘other psychosis’. Pre-treatment scores on the
Brief Psychiatric Rating Scale indicate moderate levels of symptomatology; the scale
assesses 19 aspects of mental state, each item scored on a 1-7 scale for severity. The
groups on average score as mildly depressed, with four treatment subjects and three
controls moderately to severely depressed (Beck scores greater than 20 points). All
patients were being prescribed neuroleptic medication throughout the trial. There
were no significant differences between the groups on any of the pre-treatment
clinical measures, although there was a numerically higher proportion of hallucina-
tors in the control group.

Table 2. Clinical data at initial assessment or subjects who entered the trial
Variable Therapy group (N= 13) Control group (N= 7)
Clinical diagnosis: Schizophrenia 12 Schizophrenia 7
Schizo-affective 1
PSE: one or mort current delusions rated 13 5
PSE: one or more current hallucinations 5 5
P S E Altered perception 2 3
Mean (SD) Mean (SD)
Brief Psychiatric Rating Scale 34.4 (5.6) 29.9 (6.9)
Beck Depression Inventory 18.0 (11.5) 15.9 (10.2)

Personal questionnaires
All delusions were assessed monthly for intensity of conviction, preoccupation and
subjective distress, on a 0-5 scale. Where subjects completed PQs for more than one
delusion, these scores were averaged before being entered into the group data
analysis. The mean scores for each group are represented graphically in Figs 1-3.
Whereas the REML estimate mean conviction score of the treatment group
z Mean Preoccupation Rating z Mean Conviction Rating
3 (REML Estimates) 3 (REML Estimate)
CL
P
2! 0 A N 0 P 0 a N W P UI
6 I I I I
g. 6'
3

g. 4
3
E

W P

2o
a
r,
c n v l

Q,
 P. A . Garety et al.

ITreated Gp
N = l l I
1 2 3 4 5 6

Monthly Assessments
NS
Figure 3. Delusional distress during treatment.

started at 4.4 and reduced gradually to 1.7, the control group’s score remained quite
stable throughout, starting at 3.7 and ending at 3.9 (see Table 3). This is a highly
significant difference between the groups ( p < .Ol). The group mean scores over
time are not significantly different for the personal questionnaire measures of
delusional preoccupation and distress, although other measures of preoccupation
and distress show an improvement in the treatment group (see below).

Table 3. Before and after measures of personal questionnaire delusional conviction

Therapy group Control group
Monthly
assessment Mean SD N REML est. Mean SD N REML est.
Before therapy
1 4.4 .8 12 4.4 3.7 1.1 5 3.7
During therapy
2 3.5 1.5 9 3.4 3.1 1.2 5 3.1
3 2.1 1.0 9 2.1 3.2 1.6 5 3.2
4 2.2 1.8 10 2.4 3.5 1.3 4 3.1
5 1.9 1.9 10 1.8 4.5 .6 4 4.1
After therapy
6 1.7 1.6 8 1.7 4.5 .7 2 3.9
p < .01.
Note. REML estimates: allow for bias due to drop-outs or missing values.
 Cognitive bebaviotlral therapy for psycbosis 267
Brief Psychiatric Rating Scale
The scores on the BPRS show a significant difference between the groups, the
REML estimates for the treatment group reducing from 34.4 to 28.5, while the
control group remain stable at about 30 points (starting at 29.8 and ending at 31.9;
p < .Ol) (see Table 4).

Table 4. Before and after measures o n the Brief Psychiatric Rating Scale
Treatment group Control group
Monthly
assessment Mean SD N REML est. Mean SD N REML est.
Before therapy
1 34.4 5.6 12 34.4 29.9 6.9 7 29.8
During therapy
2 32.5 7.1 9 30.9 31.7 7.0 7 31.7
3 30.3 6.4 9 30.8 31.4 7.2 7 31.4
4 29.5 6.0 10 29.2 31.6 10.0 5 30.6
5 28.4 5.1 10 28.1 32.4 9.8 5 31.4
After therapy
6 30.2 10.4 8 28.5 36.7 11.0 3 31.9
p < .01.
Note. REML estimates: allow for bias due to drop-outs or missing values.

Beck Depression Inventor_y

The REML estimates of the BDI show a small but statistically significant reduction
in depression scores for the treatment group compared with the control group
( p < .05). It is important to note here that the raw means to the left of both parts
of the table are misleading. The apparent rise to 27 points in the control group is
a statistical artifact arising from the pattern of drop-out (see Table 5).

Table 5. Before and after measures on Beck Depression Inventory

Treatment group Control group
Monthly
assessment Mean 4; SD N REML est. Mean SD N REML est.
Before therapy
1 18.0 11.5 13 18.0 15.9 10.2 7 15.9
During therapy
2 19.6 9.8 9 18.9 17.1 14.8 7 17.1
3 15.2 10.8 9 18.9 19.1 13.3 7 19.1
4 12.0 11.9 10 13.5 17.4 13.3 5 16.0
5 10.8 10.3 10 11.8 19.8 16.5 5 18.4
After therapy
6 15.7 13.0 9 15.5 27.0 15.6 3 20.5
~~~ ~~

p < .05.
Note. REML estimates: allow for bias due to drop-outs or missing values.
268 P. A . Garety e t al.
Other repeated measures
The other repeated measures did not yield statistically significant changes: these were
the Watson & Friend (1969) Social Avoidance and Distress Scale and the Hustig
& Hafner (1990) Hallucinations Scale.

Pre - and post -treatment measures

The treatment group showed improvements, compared with the controls, on the
items of the MADS which assess preoccupation with delusional beliefs and acting
on the beliefs, and on the Appraisal of Problems Questionnaire ratings of distress
and interference with normal life caused by the person’s problems (see Table 6 for
full details). Measures which did not show an improvement were the MADS items
assessing distress caused by the delusion, the Life Skills Profile, the Rosenberg Self
Esteem Questionnaire and the Insight Scale.

Table 6. Summary of measures taken only before and after therapy

Therapy group Control group
change score change score

Variable N Mean SD N Mean SD f d.f. p

MADS
Preoccupation 11 0.82 0.9 7 0.1 0.4 1.9 16 .07
Total Action 11 1.5 1.3 7 - 0.1 1.5 2.4 16 .03
Total Distress 11 1.5 2.5 7 0.7 1.4 0.7 16 .50
Appraisal of Problems
Questionnaire
Distress 11 0.8 1.2 7 -0.6 1.0 2.6 16 .02
Interference 11 0.8 0.9 7 - 0.1 0.9 2.3 16 .04
Life Skills Profile 11 2.4 0.9 6 - 0.3 7.5 0.5 15 .62
Insight Scale 11 2.8 11.8 7 2.1 1.9 0.5 16 .65
Rosenberg Self-Esteem
Questionnaire 11 -0.6 5.7 7 - 2.4 11.2 0.4 16 .66

Discussion
We have presented here the results of a small controlled trial of cognitive behaviour
therapy for psychosis. Clearly the study has important limitations. Firstly, the
patients were not randomly allocated to groups and it is possible that the referrals
received first were of patients with more amenable problems o r who were different
in some other respect. The two groups were reasonably well matched, but the
control group seemed to have more hallucinators. However, on most direct and
indirect measures of severity of illness (e.g. BPRS, BDI, PQs and time in hospital
and duration of illness) the treatment group scored at the outset as more severe,
although not significantly so. The numbers were small and the duration of therapy
 Cognitive behavioural therapy for psychosis 269
only six months, a relatively short time, given the persistence and severity of the
problems.
Despite these factors, which we predicted would limit the power of the study, we
have found that the therapy group benefited significantly in comparison to the
controls. The most remarkable finding is in the reduction of delusional conviction
in the majority of treated subjects, whose previously intensely held delusions had
for most caused considerable and long-standing distress. On certain measures we
also found reductions in distress, preoccupation and action. A further goal of the
therapy, to reduce depression and improve self-esteem, appears to show modest
benefits; in a larger study we would hope to increase effectiveness in this area. A
number of therapy patients showed an increase in their BDI scores at the
post-therapy assessment, relative to the fifth assessment; in certain cases, terminating
therapy at six months seemed premature. We plan to extend the duration of therapy
to nine to 12 months in our future trial.
It is notable that measures of social functioning, the Life Skills Profile and the
Social Avoidance and Distress Scale, showed no change. This is disappointing; it
is possible that a longer time is needed for the changes in thinking to translate into
changes of a broader social nature, or more probably that more explicit behavioural
goal setting is needed to improve these aspects of functioning. Such work may be
best conducted together with other professionals concerned with the care of the
patient, such as case managers or other workers in rehabilitation services.
Another limitation is that our assessor was not blind to the group assignment,
although she was an independent researcher not involved in any therapy. It is
possible that this may have led to some bias in assessment, although bias could have
been in either direction.
The subjects of the study were all receiving antipsychotic medication. It is
important to stress that, in contrast to cognitive therapy for neurotic disorders, we
do not purport to be treating the basic disorders of thinking that constitute
psychosis. For this reason the therapy is offered as an adjunct to medication and we
would not, at this stage, seek to consider it as an alternative approach. In two therapy
cases we found that although medication was prescribed, and the prescribing doctor
understood that the patient was taking the medication, this was not in fact so. Part
of the therapy involved offering a model of schizophrenia which provided a rationale
for medication; after taking medication, both patients then appeared to the therapist
more amenable to discussions and improved in concentration, although the
medication alone did not appear to influence their delusions.
Many patients, despite their medication, reported continuing and frequent
anomalous experiences: disturbances of perception or thinking, such as hallucina-
tions or passivity phenomena. It is our experience that when this is so, delusional
beliefs, although successfully reappraised in therapy sessions, are easily triggered on
future occasions. In line with some views about the process of cognitive therapy for
depression (e.g. Williams, 1992) we suggest that therapy provides the patient with
ways of compensating for biased thinking rather than correcting the basic underlying
deficit. In this study we were only able to investigate whether such beliefs could be
changed; the factors contributing to successful long-term maintenance of change are
clearly extremely important and should be considered in a larger study.
270 P. A . Garety e t a/.

Acknowledgement
This study was supported by grant from the Bethlem and Maudsley Research Fund.

References
Beck, A. T., Rush, A. J., Shaw, B. F. & Emery, G. (1979). Cognitive Therapy of Depression. Chichester:
Wiley.
Beck, A. T., Ward, C. H., Mendelson, M., Mock, J. & Erbaugh, J. (1961). An inventory for measuring
depression. Archives of General Psychiatry, 4, 561-571.
Bentall, R. P., Kaney, S. & Dewey, M. E. (1991). Paranoia and social reasoning: An attribution theory
analysis. British Journal of Clinical Psychology, 30, 13-23.
Breier, A. & Straws, J. S. (1983). Self control in psychotic disorders. Archives of General Psychiatry,
40, 1141-1145.
Brett-Jones, J., Garety, P. A. & Hemsley, D. (1987). Measuring delusional experiences: A method and
its application. British Journal of Clinical Psychology, 26, 257-265.
Briera, A., Schreiber, J. L., Dyder, J. & Pickard, D. (1991). NIMH longitudinal study of chronic
schizophrenics: Prognosis and predictors of outcome. Archives of General Psychiatry, 48, 239-246.
Buchanan, A., Reed, A., Wessely, S., Garety, P., Taylor, P., Grubin, D. & Dunn, G. (1993). Acting
on delusions (2): The phenomenological correlates of acting on delusions. British Journal of
Psychiatry, 163, 77-81.
Chadwick, P. & Lowe, F. (1990). The measurement and modification of delusional beliefs. Journal of
Consulting Clinical Psychology, 58, 225-232.
Curson, D. A., Barnes, T. R. E., Bamber, R. W., Platt, S. D., Hirsch, S. R. & Duffy, J. B. (1985).
Long-term depot maintenance of chronic schizophrenic outpatients. British Journal of Psychiatry, 146,
464-480.
Curson, D. A., Patel, M., Liddle, P. E. & Barnes, T. R. E. (1988). Psychiatric morbidity of a long
stay hospital population with chronic schizophrenia and implications for future community care.
British Medical Journal, 297, 819-822.
David, A. (1990). Insight and psychosis. British Journal of Psychiatry, 156, 798-808.
Fowler, D. (1992). Cognitive behavour therapy in the management of patients with schizophrenia:
Preliminary studies. In A. Werbart and J. Cullberg (Eds), Psychotherapy of Schixophrenia: Facilitating
and Obstructive Factors. Oslo: Scandinavian University Press.
Fowler, D., Garety, P. A. & Kuipers, L. (in preparation). Cognitive Behaviour Therapy for People with
Psychosis: A Clinical Handbook. Chichester: Wiley.
Fowler, D. & Morley, S. (1989). The cognitive behavioural treatment of hallucinations and delusions:
A preliminary study. Behavioural Psychotherapy, 17, 267-282. u
Garety, P. A. (1985). Delusions: Problems in definition and measurement. British Journal of Medical
Psychology, 58, 25-34.
Garety, P. A. (1992). Making sense of delusions. Psychiatry, 55, 282-291.
Gaiety, P. A. & Hemsley, D. R. (1987). Characteristics of delusional experience. European Archives of
Psychiatry 6 Neurological Science, 236, 294-298.
Garety, P. A., Hemsley, D. R. & Wessely, S. (1991). Reasoning in deluded schizophrenic and paranoid
patients: Biases in performance on a probabilistic inference task. Journal of Nentous and Mental Disease,
179, 194-201.
Gornbein, J. A., Lazaro, C. G. & Little, R. J. A. (1992). Incomplete data in repeated measures analysis.
Statistical Methods in Medical Research, 1, 275-295.
Gunderson, J. G., Frank, A. F., Katz, H. M., Vannicelli, M. L., Frosch, J. P. & Knapp, P. U. (1984).
Effects of psychotherapy in schizophrenia 11. Comparative outcomes of two forms of treatment.
Schizophrenia Bulletin, 10, 567-598.
Harrow, M., Carone, B. J. & Westermeyer, J. (1985). The course of psychosis in early phases of
schizophrenia. American Journal of Psychiatry, 142, 702-707.
Harrow, M., Rattenbury, F. & Stoll, F. (1988). Schizophrenic delusions: An analysis of their
persistence, of related premorbid ideas and of three major dimensions. In T. F. Oltmanns & B.
A. Maher (Eds), Delusional Beliefs. New York: Wiley.
 Cognitive behavioural therapy for psychosis 27 1
Hirsch, S. R. (1982). Depression revealed in schizophrenia. British Journal of Psychiatry, 140, 421-424.
Hustig, H. H. & Hafner, R. J. (1990). Persistent auditory hallucinations and their relationship to
delusions and mood. Journal of Nervous and Mental Disease, 178, 264-267.
Johnson, W. G., Ross, J. M. & Mastria, M. A. (1977). Delusional behavior: An attributional analysis
of development and modification. Journal of Abnormal Psychology, 86, 421-426.
Johnstone, E. C., Owens, D. G. C., Frith, C. D. & Leavy, J. (1991). Clinical findings: Abnormalities
of mental state and their correlates. The Northwick Park follow-up study. British Journal of
Psychiatry. 159, Supplement 13, 21-25.
Kingdon, D. G. & Turkington, D. (1991). Preliminary report: The use of cognitive behavior therapy
with a normalizing rationale in schizophrenia. Journal of Nervous and Mental Disease, 179, 207-21 1.
Nelson, H. E. (1982). The National Adult Reading Test. Windsor, Berks: NFER-NELSON.
Overall, J. E. & Gorham, D. R. (1962). The Brief Psychiatric Rating Scale. Psychological Reports, 10,
799-81 2.
Rosen, A., Hadzi-Pavlovic, D. & Parker, G. (1989). The Life Skills Profile: A measure of assessing
function and disability in schizophrenia. Schizophrenia Bulletin, 15, 325-337.
Rosenberg, M. (1965). Society and the Adolescent Self Image. Princeton, N J: Princeton University Press.
Shapiro, M. B. & Ravenette, A. T. (1959). A preliminary experiment on paranoid delusions. Journal
of Mental Science, 105, 295-312.
Tarrier, N., Beckett, R., Harwood, S., Baker, A., Yusopoff, L. & Ugarteburu, I. (1993). A trial of two
cognitive behavioural methods of treating drug-resistant residual psychotic symptoms in schizo-
phrenic patients: I Outcome. British Journal of Psychiatry, 162, 524-532.
Tarrier, N., Harwood, S., Yusopoff, L., Beckett, R. & Baker, A. (1990). Coping strategy enhancement
(CSE): A method of treating residual schizophrenic symptoms. Behavioural Psychotherapy, 18,
283-293.
Teasdale, J. D., Fennell, M. J. V., Hibbert, G. A. & Amies, P. L. (1984). Cognitive therapy for major
depressive disorder in primary care. British Journal of Psychiatry, 144, 40CM06.
Valins, S. & Nisbett, R. E. (1972). Attribution processes in the development and treatment of
emotional disorders. In E. E. Jones & D. Canouse (Eds), Attribution: Perceiving the Causes of Behavior.
New Jersey: General Learning Press.
Watson, D. & Friend, R. (1969). The measurement of social evaluative anxiety. Journal of Consulting
and Clinical Psychology, 33, 448-457.
Watts, F. N., Powell, G. E. & Austin, S . V. (1973). The modification of abnormal beliefs. British Journal
of Medical Psychology, 46, 359-363.
Wechsler, D. (1981). Wechsler Adult Intelligence Scale-Revised. New York: The Psychological Corpor-
ation.
Williams, J. M. G. (1992). The Psychological Treatment of Depression: A Guide to the Theoy and Practice
of Cognitive Behaviour Therapy. London: Routledge.
Wing, J. K., Cooper, J. E. & Sartorius, N. (1974). The Measurement and Classification .f Psychiatric
symptom^. Cambridge: Cambridge University Press.

Received 4 June 1993; revised version received 19 November 1993