Rep36 Understanding Personality Disorder

particularly those of generalisability of results.
On the whole, treatment outcome research in
this area has concentrated on the domains of
social functioning (such as relationships and
work) and symptoms (affect, cognition and
behaviour) and there is a need for greater
consensus from patients, therapists, and other
stakeholders about what changes are important
and can be reliably and validly measured and
achieved in therapy (Slade & Priebe, 2001). 
Effectiveness studies, where treatments are
examined in a more naturalistic setting and a
less highly selected group of patients are studied
have many advantages and can also comply with
many of the high standards set by randomised
controlled trials and the results may be more
applicable to routine clinical settings. Well-
defined study questions, adequate patient
selection criteria, clear procedures for
randomisation, and adequate concealment of
treatment allocation help eliminate potential
investigator bias in studies and improve the
internal validity of studies. There is a strong case
for effectiveness studies as the results are more
likely to be generalisable.
RCTs have an important place in evidence-
based health care and give a more definitive
answer to questions of efficacy than any other
type of study design. The fact that a therapy has
not been demonstrated to be effective in a
controlled study does not mean that it is
ineffective but we have no compelling reason to
believe that it would be effective, and
importantly, we do not know if is harmful. Many
psychological therapies, particularly cognitive
behavioural therapies, have been demonstrated
to be effective in randomised controlled trials.
There are few specific reasons why controlled
studies cannot be carried out in individuals with
personality disorder and we need to continue to
establish the evidence base for psychological
therapy at the highest level of evidence possible.