interventions. However, few replications have been done
by independent research groups, and studies have yet to
establish interventions that prevent people at risk from
making an initial suicide attempt. Findings from a meta-
of cognitive behaviour therapies for suicidal
behaviour showed a statistically significant effect of
cognitive behavioural therapy to reduce the rate of suicide
attempt; however, the investigators noted a publication
bias in this topic, with a funnel plot of published studies
centring close to zero, smaller studies reporting more
positive effect sizes, and no published study findings
showing negative effects for any intervention.
Several new interventions also offer promise. The
collaborative assessment and management of suicidality
is a clinical intervention designed to enhance the
therapeutic alliance and decrease the risk of suicidal
Safety-planning interventions, which
include the identification of warning signs, coping
strategies, and sources of support in addition to
restriction of access to lethal means, are also receiving
welcome attention.
Treatment based on mentalisation
has shown some promise to reduce self-harm in
The fact that most suicidal people do not
receive treatment, and that little evidence is available for
the effectiveness of the interventions received by those
who do, emphasises the tremendous importance of
future work to develop psychological treatments for
people at risk of suicidal behaviour. The utility of the
internet and smartphones in treatment delivery also
requires close examination.
Key directions for psychological research
Despite substantial advances in understanding of the
suicidal mind, much more psychological research is
needed (panel 3). Studies of suicide should routinely
incorporate psychological components, especially in the
case of large-scale national-linkage studies of suicide
and suicide attempts. Psychological autopsy studies, in
which information is collected about the deceased
person from several informants, have played a key part
in under­standing the risk factors for suicide.
sophisticated autopsy studies in the future should be set
up to investigate psychological factors in more detail.
Research efforts to distinguish between suicide ideators,
suicide attempters, and repeated attempters should be
prioritised, because understanding of the factors that
enable or impede behavioural enactment will inform
the development of intervention studies. Studies that
use new technologies (eg, smartphones) and real-time
data collection (eg, ecological momentary assessment)
are essential in this regard. Focus on the differential
effects of psychological factors of suicide risk as a
function of age, culture, and ethnic origin should be
increased. There is still a tendency to generalise findings
from, for example, middle adulthood to older adult and
adolescent populations. Researchers have also over-
relied on self-report observational studies; multimethod
approaches with an increased focus on basic-science
experimental research will help uncover the
mechanisms by which factors increase or reduce suicide
risk. As the specialty develops, the testing of
psychological theories of suicide risk should be the rule
rather than the exception. Such programmatic testing of
risk and protective factors will not only benefit
researchers, but also assist clinicians in the translation
of research into clinical practice.
Although the physical availability (ie, access) to
methods of suicide affects their use,
not much is known
about the psychological factors that affect selection of
one method of suicide over another. Psychological
suicidology is still dominated by research in populations
in western Europe and the USA and Canada, despite the
fact that 60% of the world’s suicides occur in Asia. The
dearth of research into protective factors also needs to be
addressed. Although the development and use of
psychological treatments has grown somewhat,
are not well supported by evidence and most people who
experience suicidal thoughts and behaviours do not seek
them out. The barriers to help-seeking and the role of
media (including social media) within the suicidal
process also remain poorly understood; although media
guidelines for the reporting of suicide exist, more
empirical evidence about which aspects of reporting are
most dangerous is needed. Finally, psychological science
has much to offer to policy planners in the development
and implementation of programmes for suicide
prevention. Promising multi­component intervention
developments have been made in recent years,
further advancement is needed to combat this devastating
public health problem.
Both authors contributed equally to the preparation of this Series paper.
Declaration of interests
We declare that we have no competing interests.
MKN received funding support from the John D and
Catherine T MacArthur Foundation.
Search strategy and selection criteria
We searched PsycINFO, PubMed, andWeb of Knowledge for
articles published between January, 2003, and January, 2014,
with the terms “suicid*”, and “psycholog* or “personality” or
“cognitive”. We used no language restrictions. We selected
key papers from the identified publications on the basis of
topic covered and quality of research. Within a topic area with
many studies, we selected a study (or studies) suggestive of
the evidence-base or included a study that described a key or
new finding. In less well researched but new topics, key
studies were selected. We supplemented these publications
with earlier landmark papers and suggestions from reviewers.
The studies covered a wide range of populations, many of
which included participants with psychiatric disorders.
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