Unit of Clinical Psychology
Unit of Methods and Statistics, Leiden University Institute for Psychological Research, Leiden, The Netherlands
National Suicide Research Foundation, Cork, Ireland
Unit of Clinical Psychology, Leiden University Institute for Psychological Research, and Department of Psychiatry, Leiden University Medical Centre, Leiden, The Netherlands
Correspondence: Nadja Slee, Department of Clinical, Health and Neuropsychology, Wassenaarseweg 52, PO Box 9555, 2300 RB Leiden, The Netherlands. Email: nadja.slee{at}planet.nl
None. Funding detailed in Acknowledgements.
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Self-harm by young people is occurring with increasing frequency. Conventional in-patient and out-patient treatment has yet to be proved efficacious.
Aims
To investigate the efficacy of a short cognitive–behavioural therapy intervention with 90 adolescents and adults who had recently engaged in self-harm.
Method
Participants (aged 15–35 years) were randomly assigned to treatment as usual plus the intervention, or treatment as usual only. Assessments were completed at baseline and at 3 months, 6 months and 9 months follow-up.
Results
Patients who received cognitive–behavioural therapy in addition to treatment as usual were found to have significantly greater reductions in self-harm, suicidal cognitions and symptoms of depression and anxiety, and significantly greater improvements in self-esteem and problem-solving ability, compared with the control group.
Conclusions
These findings extend the evidence that a time-limited cognitive–behavioural intervention is effective for patients with recurrent and chronic self-harm.
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Although in-patient treatment is the standard of care for people who self-harm, it has never been found efficacious in a controlled clinical trial.14 Furthermore, controlled cognitive–behavioural therapy (CBT) intervention studies for self-harm are limited and their results are inconsistent. Tyrer et al reported that brief CBT is no more effective than usual care when it comes to preventing repetition of self-harm,15 whereas Brown et al reported positive effects of cognitive therapy on suicide attempts, depression and hopelessness.16 In addition, several controlled studies have established the efficacy of dialectical behavioural therapy in reducing self-injury in (female) patients with borderline personality disorder.17 Schema-focused therapy has also been found to reduce self-harm effectively in patients with borderline personality disorder.18 Furthermore, cognitive–behavioural interventions with a problem-solving component seem to have positive effects on self-harm.19 These findings are important, given the strong association between acts of self-harm and the risk of suicide described above. In addition, given the association between negative emotions, suicidal cognitions, problem-solving deficits and self-harm, it is important to assess in more detail the impact of treatment on these correlates of self-harm.
In the study reported here the efficacy of a short, manualised cognitive–behavioural intervention for self-harm was investigated. This intervention was based on a cognitive–behavioural model of maintenance factors of self-harm.20 The model assumed that vulnerability to self-harm can be changed by changing suicidal and negative thinking and problem-solving deficits. The intervention aimed to develop cognitive and behavioural skills for coping with situations that trigger self-harm. Considering the wide range of psychiatric, psychological and social problems that patients present with, the intervention was intended to give therapists a clear framework to orient themselves within the therapy. At the same time, the intervention needed to be flexible enough to be of help to a broad range of patients, including those with high risk of repetition of self-harm and high levels of psychiatric comorbidity. The study was designed to determine the short-term and long-term efficacy of the intervention with respect to the rate of repetition of self-harm as well as emotional problems, suicidal cognitions and problem-solving deficits. It was predicted that the rate of self-harm of participants who received CBT in addition to treatment as usual (TAU) would be lower than in patients who received TAU only, and also that participants from the CBT condition would have significantly lower scores for emotional problems (depression and anxiety) and suicidal cognitions, and significantly higher scores for functional cognitions (self-esteem) and behavioural skills (problem-solving ability) following treatment, than participants from the TAU condition.
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The study was conducted at the Leiden University Medical Centre and the Rivierduinen mental health centre from March 2003 until April 2006. The initial sample consisted of 222 individuals who had visited the Leiden University Medical Centre or the local mental health centre because of self-harm. Of these 222 people, 32% (n=72) could not be reached, because the name, address or telephone number they had left was incorrect. Of the 68% (n=150) who were contacted, 12% (n=26) declined to participate and 11% (n=24) were excluded from the study. Reasons for exclusion were the index episode not being an act of self-harm (n=3), being under 15 years old (n=1), being hospitalised for an extended period because of schizophrenia or alcohol or drug misuse (n=11), being unable to converse in Dutch (n=3), having cognitive impairments (n=2) or living abroad (n=4). As a result, 100 individuals (45% of the initial sample) were invited for the baseline interview. The flow of these participants through the study is illustrated in Fig. 1. It shows that 10 people failed to meet the inclusion criteria: they were unable to converse in Dutch (n=2), had cognitive impairments (n=1) or were living outside the Leiden area (n=5). Two more persons did not want to complete the baseline interview. The 90 individuals who entered the study were randomly assigned to 12 CBT sessions in addition to TAU (n=48) or to TAU only (n=42).
![]() View larger version (14K): [in a new window] [as a PowerPoint slide] |
Fig. 1 Flow of participants through the study (CBT, cognitive–behavioural
therapy).
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Procedure
On visiting one of the participating centres, individuals who had recently
engaged in self-harm received a brochure with a complete description of the
study. In this brochure it was announced that the person would be contacted by
a member of the research team, who would provide further information on the
study and would ask if the person were interested in participating. Informed
consent was obtained from all participants, and from parents of adolescents
below the age of 16 years. After participants had given written consent they
were interviewed in their home or at the medical centre. We allowed a week to
pass between a persons index episode of self-harm and entering the
study, 2 weeks to pass between the index episode and the initial interview,
and 3 weeks between the index episode and the first session of CBT. Those who
agreed to participate and were found to be eligible for the study were
randomly assigned to 12 sessions of CBT in addition to TAU, or to TAU only.
All participants were invited for subsequent assessments 3 months, 6 months
and 9 months following the baseline interview. Like the baseline interviews,
these interviews were conducted in the participants home or at the
medical centre. The medical ethics committee of the Leiden University Medical
Centre approved all procedures.
Design
Participants were randomly assigned to 12 sessions of CBT in addition to
TAU (n=48) or to TAU only (n=42). Randomisation to treatment
was accomplished using a computer program and a random-number generator
provided by an independent investigator. Stratification was not used. Although
masked assessments were conducted at baseline, masking of follow-up
assessments was not possible because participants were asked about their use
of healthcare services at each assessment. In addition, information regarding
treatment assignment was essential to provide care for individuals who were in
crisis. The assessments were conducted by an independent member of the
research team who was not the participants therapist.
Outcome measures
The primary outcome measure of the study was the number of episodes of
self-harm in the past 3 months, which was assessed using a structured clinical
interview. Self-harm was defined as including both deliberate self-poisoning
(overdose) and
self-injury.4 An
overdose was defined as the deliberate ingestion of more than the prescribed
or recommended amount of a chemical substance with the intention of self-harm.
Patients were also asked about incidents of self-injury, which was defined as
intentional self-injury irrespective of the apparent purpose of the act, and
included cutting, scratching, punching, kicking and head-banging. In this
definition, both the original parasuicide definition of the World Health
Organization (WHO)/Euro study and that studys current nomenclature of
fatal and non-fatal suicidal behaviour are included, as well as habitual
behaviours and self-injuries with no intent to die, which the WHO/Euro study
excluded.22,23
Thus, all behaviour that was self-initiated with the intent to harm the body
(regardless of intent to die) was included.
At each of the four assessments participants were asked about the number of episodes of self-harm in the past 3 months. Other aspects of self-harm were also recorded: suicide intent, motives, the antecedent events and consequences. However, only the number of episodes of self-harm was selected as the primary outcome measure. To investigate the reliability of the assessment of the number of episodes of self-harm, the retrospective self-reports were compared with hospital records, as well as with information coming from the treatment sessions. The correlations between the three measures were high, with correlations ranging from 0.88 to 0.90. Scores of the number of episodes of self-harm in the past 3 months ranged from 0 to 25.
Secondary outcome measures assessed by patient self-report at the baseline, 3-month, 6-month and 9-month assessments included depression, anxiety, self-esteem, suicidal cognitions and problem-solving ability.
Depression
Depression was measured with the Beck Depression Inventory II
(BDI–II),24,25
a 21-question depression scale with each answer rated 0–3. Scores range
from 0 to 63. The test has high internal consistency, with
=0.91.24,26
In this study we found a reliability of
=0.93.
Anxiety
Anxiety was measured using a sub-scale of the Symptom
Checklist–90,27,28
which is a self-report clinical rating scale of psychiatric symptoms. The
anxiety sub-scale consists of ten items, assessing whether and
to what extent participants reported symptoms of anxiety. Items are measured
on a five-point Likert scale, ranging from not at all
distressing (0) to extremely distressing (4). Individual
sub-scale scores are obtained by summing the ten items (range 0–40).
Previous studies have reported alpha coefficients ranging from 0.71 to 0.91
for the anxiety sub-scale. In addition, test–retest reliabilities are
found to be good and the sub-scale has been found to show strong convergent
validity with other conceptually related
scales.28 In our
study we found a reliability of
=0.93 for the anxiety sub-scale.
Self-esteem
Self-esteem was measured with the Robson Self-Concept Questionnaire, Short
version,29 an
eight-item questionnaire dealing with attitudes and beliefs that people have
about themselves, for example, Im glad I am who I am. All
items are self-rated from 1 to 4 (strongly disagree to
strongly agree). Scores range from 8 to 32. The scale has good
validity and
reliability;29 in
our study we found a reliability of
=0.82.
Suicidal cognition
Suicidal cognitions were measured using the Suicide Cognition
Scale.11 This
comprises 20 questions about core beliefs of perceived burdensomeness
(I am a burden to my family), helplessness (no one can
help solve my problems), unlovability (I am completely unworthy
of love) and poor distress tolerance (when I get this upset, it
is unbearable), with each answer rated 1 (strongly disagree) to 5
(strongly agree). Scores on the total scale range from 20 to 100. Scores on
the perceived burdensomeness sub-scale (two items) range from 2 to 10, scores
on the helplessness sub-scale (five items) range from 5 to 25, scores on the
unlovability sub-scale (six items) range from 6 to 30 and scores on the poor
distress tolerance sub-scale (seven items) range from 7 to 35. In this study
we found alpha reliability values of 0.96 for the total scale, 0.74 for
perceived burdensomeness, 0.88 for helplessness, 0.90 for poor distress
tolerance and 0.89 for unlovability.
Problem-solving
Problem-solving ability was measured with the Coping Inventory for
Stressful Situations (CISS) sub-scale task oriented
coping.30
This sub-scale consists of 16 items scored on a five-point Likert scale,
referring to the extent to which people make use of problem-solving techniques
in the face of stress (Make an extra effort) with answers
ranging from 1 (not at all) to 5 (very strongly.
Scores range from 16 to 80. Across studies, the CISS has proved to be
reliable. The internal consistency of the sub-scales is excellent
(
>0.85).30,31
In this study we found a reliability of
=0.93.
Other measures
Demographic information was obtained, as well as information about the use
of healthcare services. Baseline characteristics also included suicide intent
and motives of the index episode of self-harm. Suicide intent was assessed
with the Suicide Intent Scale
(SIS),32 an
instrument with sound psychometric properties. The SIS has 20 items, but only
the first 15 items are used for calculating the score. Scoring for each item
ranges from 0 to 2. Items 1–9 are concerned with the act itself, items
10–15 with the thoughts and feelings associated with the act, and items
16–20 with the respondents thoughts and feelings about suicide in
the present. To assess motives for self-harm, the Reasons for Overdose Scale
was used.33 The ten
motives presented were a subset of those originally developed by Bancroft
et al,34
including wanting to die, wanting to get relief and wanting to escape.
Participants were asked to indicate the extent to which these motives were
important to them at the time of the index episode.
Psychiatric diagnosis
For screening purposes, psychiatric diagnosis was assessed using a short
structured diagnostic interview with an administration time of approximately
20–30 min, the
MINI.21 In this
study the Dutch translation of the clinician-rated version of the MINI was
used
(MINI–CR).35
Validation of the MINI–CR against the Structured Clinical Interview
DSM–III–R Patient version and the Composite International
Diagnostic Interview for ICD–10 showed good to very good kappa
values.21
Intervention
Cognitive–behavioural therapy
In addition to usual care (e.g. prescribed psychotropic medication,
psychotherapy, psychiatric hospitalisations), participants in the CBT
condition received 12 out-patient CBT sessions specifically developed for
preventing self-harm. The sessions were provided on a weekly basis or as
needed in case of crisis. Ten of the 12 sessions were given weekly; the last
two were follow-up sessions. All together, the intervention lasted
approximately 5.5 months. The central feature of this intervention was the
identification and modification of the mechanisms that maintained self-harm.
Thus, the treatment started with the assessment of the most recent episode of
self-harm (e.g. circumstances at the time of the episode, motives and reasons
for self-harm, cognitions, emotions and behaviour prior to and at the time of
the episode). The therapist and patient then investigated how emotional,
cognitive and behavioural factors played a part in the maintenance of
self-harm. Specific maintenance factors that were addressed included
dysfunctional cognitions, emotion regulation difficulties and poor
problem-solving. Near the end of therapy relapse prevention was addressed as
well. The treatment is first and foremost an individual one. However,
involvement of the partner or (non-abusive) parents in the therapeutic process
is of great importance, since these patients need the support of others to
overcome self-harm. A manual was written to standardise the intervention
(available from the authors upon request). To improve treatment compliance,
therapists played an active part in keeping patients in treatment (e.g.
calling patients to remind them of appointments).
All therapists were experienced practitioners of CBT and accustomed to working with patients who engage in self-harm. Before they took part in the research project, the therapists received 2 days of training in the standardised protocol. To maintain the integrity of treatment, the therapists followed this treatment protocol. In addition, checklists and outlines were used in every session to foster correct execution of the treatment. At monthly meetings the treatment sessions were reviewed and therapists could share their experiences with their colleagues. Issues that were discussed were reactions in the therapist elicited by episodes of self-harm (e.g. sadness, worry, aversion) or problems with treatment compliance. The average number of patients treated by each of the therapists was eight (range seven to nine).
Treatment as usual
For ethical reasons participants in both study conditions were free to
pursue any form of usual treatment they deemed warranted. We recorded three
forms of TAU: psychotropic medication, psychotherapy and psychiatric
hospitalisations. In addition, we recorded whether psychotherapy in TAU had a
focus on self-harm. However, we did not systematically record the specific
types of psychotherapy or psychotropic medication that patients in the
comparison condition received, nor did we record the specific types of
psychotherapy or psychotropic medication those in the experimental condition
received in addition to the intervention therapy. As a result, we do not know
whether the comparison group and experimental group were equivalent in this
respect. Although we did not systematically record specific types of
psychotherapy in TAU, most of the interventions involved a limited number
(2–30) of sessions of individual psychotherapy such as CBT and
interpersonal psychotherapy. Social skills training was also common,
especially among adolescents and young adults. No treatment specific to
self-harm was reported. These treatments focused instead on specific
psychiatric problems (e.g. depression) or on specific needs of the patient
(e.g. problems with housing, finances, social isolation).
Statistical procedure
The study design was constrained to a maximum of four measurements per
participant. Given this restriction, a power analysis was performed to
determine the sample size needed to detect between-group differences on the
primary outcome measure – the number of episodes of self-harm. Results
obtained with the program
PINT36 indicated
that a sample size of approximately 45 participants in each group would be
sufficient to detect a difference in average time slope between the groups of
0.40 (corresponding to a small effect size) with adequate power (0.80) and
=0.05. Socio-demographic characteristics and outcome measures of the
groups were examined using t-tests or chi-squared tests, as
appropriate. Multilevel analysis was used to analyse the development of each
outcome measure over time; this procedure is especially suited to analysing
repeated-measure data because it takes into account the dependencies among
observations nested within individuals. Another advantage of this method is
its ability to handle missing data, which is also common to the type of
longitudinal research discussed in this paper. Random coefficient models were
fitted for all outcome measures, allowing for individual variation of
intercepts and regression slopes. (In all models time was included as a
variable with values 0, 3, 6 and 9. Condition, medication use, psychotherapy
and suicidal acts were all included as dummy variables: TAU 0, CBT 1; no
medication 0, medication use 1; no psychotherapy 0, psychotherapy 1; no
suicidal act 0, suicidal act 1.) Fixed effects of time, condition and the
interaction between time and condition were tested using two-tailed
z-tests. Effects of baseline differences with regard to suicidal acts
during the past 3 months on the development of all outcome measures over time
were controlled for (suicidal acts condition time). Effects of baseline use of
psychotropic medication and psychotherapy on the development of all outcome
measures over time were also controlled for: medication
usexconditionxtime and psychotherapyxconditionxtime.
Models were fitted using MLwiN version
2.02.37 In
addition, effect sizes were calculated to facilitate comparison of improvement
in the CBT condition with improvement in the TAU condition. Effect sizes were
derived by calculating the difference of the means on the outcome variables in
CBT and TAU at the 3-month, 6-month or 9-month assessment, divided by the
pooled standard deviation (see reference
38 for the program to
calculate effect sizes). Furthermore, to give an indication of the differences
between the conditions for a given variable at baseline, 3-month, 6-month and
9-month assessments, significance levels were calculated using
t-tests or chi-squared tests.
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2=3.12, d.f.=1, n=82;
P=0.08) and trends towards more psychotherapy in the TAU group at
baseline (
2=4.74, d.f.=1, n=82; P=0.09).
Both medication use and psychotherapy at baseline were included in the
multilevel analysis models. Psychiatric hospitalisation was not included as a
covariate in the models because this had not been reported at baseline
(Table 2 and online Table DS2).
In addition, we used multilevel analysis to determine whether there was any
baseline difference between the groups on the primary and secondary outcome
measures (see condition effects in
Table 3 and online Tables DS3
and DS4). No significant group difference was found on any of these outcome
measures (Table 3 and online
Tables DS3 and DS4). The mean number of episodes of self-harm during the past
3 months as reported at baseline was 14.42 (s.d.=10.51) in CBT and 11.62
(s.d.=11.42) in TAU; score range 0–25
(Table 2 and online Table
DS2). |
View this table: [in a new window] | Table 1 Demographic characteristics of participants receiving cognitive–behavioural therapy (n=40) and treatment as usual (n=42) |
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View this table: [in a new window] | Table 2 Primary and secondary outcome measures at baseline and follow-up (n=82) |
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View this table: [in a new window] | Table 3 Multilevel analysis effects for time, condition and time x condition, and Cohens d effect sizes for differences on outcome measures between the two study groups (n=82) |
Primary and secondary outcome measures
Table 2 shows the means and
standard deviation of scores on the primary and secondary outcome measures at
baseline and at the 3-month, 6-month and 9-month assessments, including
significant group differences based on t-tests. In addition, it shows
that during the study period two persons in the TAU group died by suicide. The
online Table DS2 describes the use of healthcare services by patients in CBT
and TAU and group differences based on chi-squared tests.
Outcome of treatment at 9 months
In Table 3 (multilevel
analysis without the 8 early withdrawals, n=82), online Table DS3
(multilevel analysis with those completing the intervention, n=73)
and online Table DS4 (multilevel analysis with intent-to-treat sample, last
observation carried forward, n=90), fixed effects and corresponding
standard errors are reported for the multilevel analysis models regarding the
primary and secondary outcome measures. (In multilevel analysis
themostcommonlyusedestimationmethodismaximum likelihood. For this method it is
necessary to assume normality for the dependent variable. The distribution of
self-harm does not satisfy the normality assumption. However, all conclusions
are based on the interpretation of fixed effects. Simulation results show that
with the sample size in this study estimates of fixed effects and their
standard errors are not seriously affected by non-normality of the
residuals.39,40
Moreover, a comparison between the maximum likelihood standard errors and the
so-called robust standard errors, used as a tool to assess model
mis-specifications, showed that results for self-harm can be considered
reliable and can be interpreted correctly.) The effect of time
indicates the overall increase or decrease for each of the outcome measures.
The effect of condition indicates thedifferencebetween CBT and
TAU atbaseline. The interaction effect (timexcondition) indicates
whether there is a significant difference between CBT and TAU upon the
development of the outcome measures over time. To control for baseline
differences in suicidal acts during the past 3 months, the interaction of
suicidal actsxconditionxtime was included in the models as well.
In addition, to control for baseline differences in psychotropic medication
use and psychotherapy, the interactions of medication usexcondition time
and of psychotherapyxcondition time were included in the models. Fixed
effects were tested by two-tailed z-tests. Variance components are
omitted here because they are not the primary focus of our study.
Multilevel analysis results without the 8 participants who left the study early (n=82; Table 3) showed that overall self-harm, depression and suicidal cognitions (total scale and the sub-scales perceived burdensomeness, poor distress tolerance and unlovability) significantly decreased over time. Self-esteem was shown to increase significantly over time. No significant effect was found for condition, indicating that on average there was no significant baseline difference between the groups on all outcome measures. The fixed effects of timexcondition showed that there was a significant effect of condition upon the development (increase or decrease) of all outcome measures over time. For instance, the estimated value of –0.576 in the model for self-harm indicates that the individuals in the CBT group, on average, showed a significant difference in decrease of self-harm compared with individuals in the TAU group (Table 3). The significant timex condition effects remain with different ways of handling study withdrawals. Multilevel analysis results using the completers sample (n=73; online Table DS3) and the last observation carried forward (LOCF) method (n=90; online Table DS4) showed a slightly smaller effect for time on average, but a similar significant effect for timexcondition as multilevel analysis without the 8 early withdrawals (n=82, see Table 3). The most conservative analysis (LOCF) showed the strongest effect for CBT on self-harm (t=–2.843), whereas the more optimistic analysis without the 8 early withdrawals showed the weakest effect for CBT on self-harm (t=–2.390). However, each of the three analyses led to the same significant effect of timexcondition. Moreover, none of the effects of suicidal acts during the past 3 monthsxconditionxtime were significant, indicating that there was no effect of suicidal acts at baseline on the development of the outcome measures over time in the two conditions. In addition, none of the effects of medication usexconditionxtime was significant, indicating that there was no effect of medication use at baseline on the development of the outcome measures over time in the two conditions. Furthermore, none of the effects of psychotherapyxconditionx time was significant, indicating that there was no effect of psychotherapy at baseline on the development of the outcome measures over time in the two conditions. These interaction effects are omitted from the models. Table 3 (multilevel analysis without the 8 early withdrawals, n=82), online Table DS3 (multilevel analysis with completers, n=73) and online Table DS4 (multilevel analysis with LOCF, n=90) present the results of a simple model with only three fixed effects, which is preferable because it is easier to understand. In addition, effect sizes were calculated to facilitate comparison of improvement in the CBT condition with improvement in the TAU condition (Table 3 and online Tables DS3 and DS4). Effect sizes of 0.20 indicate small effects, effect sizes of 0.50 indicate medium effects, whereas values of 0.80 indicate large effects.41 As can be derived from Table 3 and online Tables DS3 and DS4, the effect sizes become larger during the follow-up period and at the 9-month assessment effect sizes are medium for the difference in self-harm and large to very large for the differences on all other primary and secondary outcome measures between both treatment conditions. The use of parametric statistics with skewed data (the number of episodes of self-harm) might have reduced the effect size estimates as presented in Table 3 and online Tables DS3 and DS4.
Visual inspection of means in Table 2 and effect sizes in Table 3 and online Tables DS3 and DS4 suggests a curvilinear time trend for self-harm in TAU but a linear trend for self-harm in CBT. However, the curvilinear trend did not prove to be significant. We therefore used a linear model for self-harm in CBT as well as TAU.
Use of healthcare services during the study period
Chi-squared tests were used to examine differences in the use of healthcare
services during the study period. Table
2 shows that at baseline, 43% (n=17) of the patients in
the CBT group received psychotherapy. About half of these patients preferred
to interrupt their regular psychotherapy schedule for a period of 3 months,
which was the period in which 10 out of 12 CBT sessions took place. Between
baseline and the 3-month assessment, only 21% of the patients received CBT for
self-harm and regular psychotherapy at the same time. Between the 3-month and
6-month assessments, 28% of the patients received CBT for self-harm in
addition to usual care (Table
2). After the CBT intervention, 52% (n=25) of the
patients continued or began regular psychotherapy.
Table 2 also shows that
individuals receiving CBT used significantly less psychotropic medication
between the baseline and 3-month assessments (
2=3.970, d.f.=1,
n=77; P=0.046) and between the 3-month and 6-month
assessments (
2=4.270, d.f.=1, n=74;
P=0.039), but not between the 6-month and 9-month assessments. From
baseline to the 6-month assessment the number of psychiatric hospitalisations
was lower in the CBT group (n=4) than in the TAU group
(n=13), but this difference was not significant. However, between the
6-month and 9-month assessments significantly fewer people had been
hospitalised in the CBT group compared with the TAU group (n=1
v. n=7;
2=6.488, d.f.=1, n=73;
P=0.011).
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While this study confirms prior studies showing that self-harm can be effectively treated by CBT,17,18 it is among the first to suggest that these changes can occur with a brief intervention. Furthermore, this studys findings that time-limited CBT decreases self-harm contrasts with the results reported by Tyrer et al.15 The difference in outcome could be attributed to the fact that in our study all participants who began CBT completed all sessions, a fact that probably contributed to its efficacy. The positive treatment effect on self-harm is important given the high suicide risk following self-harm.3 The suicidal process appears to have been at least partially deflected by the CBT intervention.42 It is especially important that these results are found for people with recurrent and chronic self-harm, with a high risk of repetition and high levels of psychiatric comorbidity.
Possible mechanisms: suicidal cognitions and behavioural skills deficits
The theoretical model underlying the cognitive–behavioural
intervention suggested that vulnerability to self-harm was related to
underlying suicidal cognitions and behavioural skills
deficits.20 From
this perspective, reduction in repetition of self-harm following CBT might be
seen as a consequence of the therapy reducing specific suicidal thoughts and
problem-solving deficits and increasing self-esteem. As expected, over the
course of treatment there were marked changes in suicidal cognitions as well
as in self-esteem. The significant decrease in suicidal cognitions is
especially important, since these are considered to be the main triggers of
self-harm, especially for individuals with recurrent and chronic
self-harm.11 Given
the central role of suicidal cognitions in repetition of self-harm, the CBT
aimed to increase the patients hope by systematically targeting
cognitions of perceived burdensomeness, helplessness, poor distress tolerance
and unlovability. This occurred as the therapist, while validating the
patients emotions, modelled hopefulness and the ability to improve the
current situation through the identification and modification of unhelpful
thoughts as well through the use of effective problem-solving skills.
Helping patients with their current problems was another important element of treatment, because previous research had shown that people who self-harm display poor problem-solving ability, which seems to be independent of mood,12 and relatively stable unless intervened upon.43 At the start of therapy patients commonly reported feeling overwhelmed by the problems they were facing, believing they were lacking effective problem-solving strategies. By identifying effective strategies that they already used, the idea that control was already part of their repertoire was introduced. In addition, patients were encouraged to develop and use new strategies.44 As expected, patients problem-solving skills significantly improved during treatment.
It is remarkable that effects on secondary measures – particularly depression, suicidal cognitions and problem-solving – were stronger than on the target variable self-harm (the number of episodes of self-harm in the past 3 months). Moreover, changes in these factors seemed to precede changes in self-harm. This suggests that the CBT primarily targeted depression, suicidal cognitions and problem-solving and that the specific self-harm effect (which was only apparent at the 9-month assessment) was a secondary effect. This would be consistent with the assumption that repetition of self-harm could be reduced by revising its maintenance factors.20 Given the emphasis in CBT on challenging suicidal thinking and increasing problem-solving ability, either of these aspects might be the mechanisms of change.
Unique additional effect of CBT
The trajectory for the average patient in the CBT group showed a relatively
rapid reduction on many outcome measures early in therapy and this reduction
continued as therapy progressed and during the follow-up period. However, this
rapid reduction is also found in the TAU group, as indicated by the strong
effect of time in the multilevel analysis. This effect might be explained by
the fact that people were in crisis when they entered the study; at that time
their risk of self-harm was elevated, mood was particularly low, suicidal
cognitions were persistent, and these people had great difficulty solving the
problems they were facing. It has been argued that crises are by themselves
time-limited, even in those exhibiting recurrent and chronic
self-harm.11
However, the magnitude of the interaction effects in the multilevel analysis
clearly show the unique additional effect of CBT. Furthermore, cognitions of
helplessness and problem-solving ability did not seem to change significantly
over time in the TAU condition. Therefore, it seems that CBT emphasises these
important risk factors and possible mediators of treatment effect. Targeting
both cognitions of helplessness and problem-solving difficulties might have
made the intervention especially effective.
Limitations
Despite these generally positive findings, several limitations of this
study deserve comment.
Assessment of self-harm
A primary limitation is that the instrument used to assess the number of
episodes of self-harm during the preceding 3 months does not have
well-established psychometric properties. Validated instruments that cover the
number of episodes of self-harm as well as other aspects of self-harm (e.g.
circumstances of the act, motives, intent, consequences) were not available at
the start of the project.
Duration of the follow-up period
A second limitation is the absence of an extended follow-up period; a
longer period could clarify whether the positive treatment effects persist or
even develop further over time. A follow-up period of 12 months would be
advisable, because the risk of repetition of self-harm (and completed suicide)
is at its greatest during the first 12 months following an episode of
self-harm.45
Usual treatment
A third limitation is the way in which usual treatment was specified. We
recorded three forms of such treatment: psychotropic medication, psychotherapy
and psychiatric hospitalisations. We can conclude that both conditions
received a comparable level of care within these general categories of
treatment. However, we did not record specific types of psychotherapy or
psychotropic medication in the TAU condition. Therefore, it is unclear if the
conditions were equivalent in this respect. Future studies should record
specific types of usual treatment received by people in the experimental and
comparison conditions. Furthermore, the effect of CBT was only demonstrated in
relation to TAU. Therefore, it is unclear whether the treatment effects are
attributable to specific ingredients of the therapy or to the total package of
CBT in addition to TAU. Moreover, since people in the TAU group did not always
receive psychotherapy, it is conceivable that the treatment effects in the CBT
group were non-specific. In addition, more than half of the patients in the
CBT group continued with psychotherapy or began psychotherapy after the
self-harm intervention had ended. Future research is necessary to identify
variables that mediate treatment effects (e.g. specific cognitions) and to
detect the active ingredients of the intervention therapy (e.g. identifying
and modifying suicidal
cognitions).46
Recruitment and withdrawal rates
A fourth limitation is the low recruitment rate (45%) and the relatively
high rate of withdrawal from the CBT condition (17%), in which 8 patients left
prior to treatment. However, session attendance of those who began the CBT was
high. Furthermore, other studies also report that adherence to treatment is a
well-known problem among self-harm patients, because of the severity of their
psychological distress and the wide range of problems they face (e.g. social,
financial,
housing).47
Importantly, the recruitment and withdrawal rates in this study did not exceed
rates reported in similar studies.
Treatment integrity
A fifth limitation concerns treatment integrity in the CBT condition. This
could have been more systematically assessed by rating audiotapes or
videotapes of the treatment sessions. Furthermore, the assessments were not
carried out masked to treatment group, which might have influenced
outcome.
Handling of study withdrawals
A sixth limitation is the way study withdrawals were handled. Multilevel
analysis uses all available data but assumes that withdrawals occur at random,
which is questionable in this population. As the assumption of randomness is
unlikely, we also executed and reported the results with missing data
estimated with the LOCF method (n=90). Both this analysis
(n=90) and the analysis without the 8 withdrawals (n=82) led
to a significant effect of timexcondition. A significant effect of CBT
for self-harm was also observed in the completers sample
(n=73). The true effect of the CBT is probably somewhere between the
conservative LOCF method (n=90) and the more optimistic analysis
without the 8 withdrawals (n=82). Remarkably, the LOCF method showed
the strongest effect of CBT for self-harm, which is contrary to our
expectations.
Personality disorders
A further limitation is that the presence of personality disorders was not
assessed with a structured clinical interview. The presence of borderline
personality disorder or a range of personality disorders is likely to have an
impact on treatment outcome. A previous study showed that personality
disturbance has an impact on repetition of self-harm, patients with borderline
personality disorder being most likely to repeat episodes
quickly.48
Furthermore, with the absence of data on personality disorders, it remains
unclear whether the study population has similar Axis II diagnoses to the
patients described in the studies of Tyrer et al and Linehan et
al.15,17
However, the participants in our study strongly endorsed maladaptive beliefs
associated with personality disorders, especially borderline and avoidant
beliefs (further information available from the authors), to a greater extent
than even patients with borderline personality
disorder,49 which
can be seen as an indication of the presence of personality disturbance. The
high rate of repetition of self-harm found in this study seems to confirm
this. A last limitation is that this study primarily involved young women with
Dutch nationality. This absence of diversity limits the generalisability of
our findings.
Clinical implications
In sum, our findings extend the evidence that CBT is effective in patients
with chronic and recurrent
self-harm.16,17
The results of our study are strengthened by the consistency of the results
across several outcomes. Adding this short cognitive–behavioural
intervention to usual care might provide us with an important tool to prevent
repetition of self-harm in people who are at risk. It might, for instance, be
the first intervention in a stepped-care programme, in which self-harm is
addressed first, followed by a treatment focusing on underlying personality
characteristics, such as schema-focused therapy or mentalisation-based
treatment.50,51
Replication of these findings using a longer follow-up period and more insight
into the underlying mechanisms of change is necessary.
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M. Kripalani, A. Gash, and J. Reilly Cognitive-behavioural therapy for self-harm The British Journal of Psychiatry, July 1, 2008; 193(1): 80 - 80. [Full Text] [PDF] |
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