Lithium in the episode and suicide prophylaxis and in augmenting strategies in patients with unipolar depression
Abou‑Saleh et al. Int J Bipolar Disord
Lithium in the episode and suicide prophylaxis and in augmenting strategies in patients with unipolar depression
Mohammed T. Abou‑Saleh 0 3
Bruno Müller‑Oerlinghausen 2
Alec J. Coppen 1
0 St George's, University of London , Cranmer Terrace, London SW17 0RE , UK
1 5 Walnut Close , Epsom, Surrey KT18 5JL , UK
2 Drug Commission of the German Medical Association, Freie Universität Berlin, Charité Universitäts‐Medizin , Berlin , Germany
3 St George's, University of London , Cranmer Terrace, London SW17 0RE , UK
Background: Depressive disorders are a leading cause of the global burden of disease and are associated with high recurrent often continuing morbidity and high excess mortality by suicide and cardiovascular disease. Whilst there are established, effective and cost‑ effective treatments for depression, their long‑ term management is often neglected: there is continuing controversy over the case of need for long‑ term treatment including lifelong treatment and safety issues. Objective and methods: In this narrative review, we critically examine the evidence for the effectiveness and safety of lithium salts in the long‑ term management of unipolar depression. We refer to existing recent international guidelines as well as the scientific literature selectively and against the background of our longstanding experience with patients suffering from unipolar depression who are often under treated or inappropriately treated. Results and discussion: According to many studies mostly dating back to the 1970/1980s, lithium is efficacious in the prophylaxis of unipolar depression particularly depression with melancholia and delusional depression and showing a clearly episodic course. Also the efficacy of lithium maintenance treatment following recovery by ECT has been clearly shown. Moreover, convincing evidence exists that lithium has added value and benefit for its unique anti‑ suicidal effects as well as reducing mortality by other causes. The anti‑ suicidal effect has been convincingly demonstrated in bipolar as well as in unipolar patients. Nevertheless its use in the management of patients with unipolar depression has not been properly recognized by a majority of textbooks and guidelines. Whilst it has been well considered as an effective treatment for depression that has not responded to antidepressants as an adjunct treatment, also called augmentation, it has been much less recommended for the prevention of recurrent episodes of unipolar depression. One of the reasons for this neglect is the blurring of the diagnosis “unipolar depression” by modern diagnostic tools. Lithium will hardly work in a patient with “unipolar depression spectrum disease”. Conclusions: We conclude that lithium is an effective prophylactic treatment for carefully selected patients with unipolar depression and is safe when prescribed in recommended doses/plasma lithium levels and with regular, careful monitoring. We propose that lithium prophylaxis can be indicated in patients with unipolar depression and that the occurrence of 2 episodes of depression within 5 years is a practical criterion for starting lithium prophylaxis particularly in severe depression with psychotic features and high suicidal risk. Furthermore, an indication might be considered especially in unipolar patients in whom a bipolar background is suspected. In some cases, lithium prophylaxis may be recommended after a single episode of depression that is severe with high suicidal risk and continued life‑ long.
Lithium; Long‑ term‑ prophylaxis; Unipolar depression; ECT; Antisuicidal effect; Augmentation
Background and methods
The serendipitous discovery of lithium and its
introduction to psychiatry in 1949 has provided one of the most
dramatic developments in psychiatric practice. Indeed
it has antedated the introduction of chlorpromazine in
1957 and imipramine in 1962. Moreover, its established
efficacy in the management of manic-depressive
psychosis affirmed Kraeplin’s distinction between schizophrenia
and manic-depressive psychosis and later on the
distinction between bipolar and unipolar affective disorder. Its
efficacy in the management of affective disorders has
been established by numerous high-quality controlled
studies which showed that the use of lithium substantially
reduces the morbidity and mortality of recurrent
affective disorders (Coppen 1994) including unipolar
depression (Coppen and Abou-Saleh 1983; Coppen 2000a, b;
Guzzetta et al. 2007; Bschor 2014; Lewitzka et al. 2015a).
This narrative review focuses on the use of lithium in
the management of patients with unipolar depression. It
selectively reviews the evidence for the effectiveness of
lithium as an augmentation treatment to antidepressants,
continuation medication after ECT and importantly as
prophylactic treatment in unipolar depression with
reference to its unique antisuicidal effects. As to the selected
scientific literature we are referring to, we took advantage
of the recently published evidence-based guidelines by
the World Federation of Societies of Biological Psychiatry
(WFSBP) on the maintenance treatment of major
depressive disorder (Bauer et al. 2015).
The burden of unipolar depression
Depressive disorders are a leading cause of the global
burden of disease and are associated with high recurrent
often continuing morbidity including physical
multimorbidity and high mortality by suicide and other causes.
Worldwide, it is estimated that 350 million people are
affected. Data from the Global Burden of Diseases,
Injuries, and Risk Factors Study 2010 reported that
depressive disorders accounted for 40.5% of DALYs caused by
mental and substance use disorders (Whiteford et al.
2013). The World Health Organization projections
estimate that it will be the leading cause of disease burden
worldwide by 2030. The estimated median treatment gap
for depression is 56.3% ranging from 45.4% in Europe
to 70.2% the Eastern Mediterranean Region (Kohn et al.
2004). Worldwide, depressive disorders contribute to
2.2 million excess deaths in 2010 by suicide and
comorbid disease such as cardiovascular disease (Patel et al.
2016).The WHO Mental Health Action Plan 2013–2020
aims for a 10% reduction in the suicide rate and
healthcare services need to incorporate suicide prevention
as a core component (WHO 2013). The plan advocates
the implementation of evidence-based interventions in
at risk populations including people with mood
disorders but there is no mention of the effectiveness of
lithium for the prevention of suicide. Moreover, the WHO
report on suicide prevention has not mentioned the role
of lithium among pharmacological treatments (WHO
2014). However, WHO’s Mental Health Gap Action
Programme, which was launched in 2008, includes suicide
as one of the priority conditions and provides
evidencebased technical guidance to expand service provision in
The course of unipolar depression
Unipolar depression in its classic form is an episodic
disorder (Angst et al. 1973, 1986) with a high
persisting morbidity. The first episode starts commonly
around 42 years of age and can last for a period of up
to 12 months or more. The episode will then remit and
the patient can be symptom free for a period of several
years before it is followed by a further episode in a
substantial proportion of patients. Many patients will have
multiple episodes; the length of an episode usually does
not vary but the interval between the episodes decreases.
After 3 or 4 episodes, patients can spend a considerable
proportion of their lives (on average 30%) with a
depressive episode (Coppen et al. 1971). (It should, however, be
remembered that the origin of these observations date
back to the 1960 ies/1970 ies when the Kraepelian type
of depression was much more frequently presented in
psychiatric hospitals). The population attributable risk
for suicide in mood disorders is 26% for males and 32%
for females (Li et al. 2011). In clinical populations and
by 18 months, 10% of individuals with unipolar
depression attempt suicide when ill particularly among patients
with previous attempts, female patients, those with poor
social support, and those aged 40 years or less (Holma
et al. 2014), Similar rates were observed over 5 years in
primary care (Riihimäki et al. 2015). The incidence of
suicide attempts during major depressive episodes was
21-fold and fourfold during partial remission compared
with full remission (Holma et al. 2014).
Unipolar depression is not a uniform, homogenous
entity. Particularly in recent decades, the introduction
and general use of modern diagnostic systems such as
ICD-10 or DSM -IV/5 have broadened its definition and
blurred the picture and course of formerly defined
unipolar depression favouring terms such as “spectrum
disease”, “mixed states” including a variety of psychiatric
comorbidities (Ghaemi 2008).
Furthermore, it has been shown by several researchers
that there exists a background of “bipolarity” in quite a
number of patients with severe “major depressive
disorder” or “unipolar depression” and also in “atypical
depression” and “pseudounipolars” (Marneros and Angst
2002). Particularly, those patients with early onset and a
high number of episodes in early life are at risk to convert
to bipolar disorder. (Akiskal et al. 1989, 2000; Angst et al.
2013; Lojko et al. 2015; Rihmer et al. 2016; Park and Lee
A recent review of the evidence for the mood spectrum
model in light of DSM-5 showed that the mood spectrum
model approach has demonstrated its usefulness mainly
in 3 areas: (1) Patients with the so-called “pure” unipolar
depression that might manifest hypomanic atypical and/
or sub-threshold aspects; (2) Spectrum features that are
clinically relevant, because they might manifest in waves
during the lifespan, sometimes together, sometimes
alone, sometimes reaching the severity for a full-blown
disorder, sometimes interfering with other mental
disorders or complicating the course of somatic diseases; and
(3) Features of “psychomotor disturbances”, “mixed
instability” and “suicidality” delineate subtypes of patients
characterized by the more severe forms of mood
disorders, the higher risk for psychotic symptoms, and the
lower quality of life after the remission of the
full-blownepisode (Benvenuti et al. 2015). This heterogeneity should
have considerable impact on the potential response to
antidepressants or mood stabilizers such as lithium.
The Yale family study of delusional depression (DD)
(Leckman et al. 1984; Weissman et al. 1984) supports
a relationship of DD with bipolar disorder, but not as
establishing DD as simply a subtype of bipolar disorder.
The possibility of a unique, late-onset unipolar subgroup
is suggested by the apparent bimodal distribution of the
age of onset of DD, the occurrence of a dementia-like
presentation only in the older age group and the
association of recurrence and a treatment refractory course with
older age. Another study (Coryell et al. 1986) also noted
in a group of psychotic depressives that a point of rarity
in the age distribution occurred at 50 years. The
earlyonset unipolar subgroup was characterized by an index
episode of DD in the patient’s 20 and 30 s and a recurrent
A retrospective study of phenomenology and
treatment course of delusional depression reported a high
relapse rate of unipolar DD (83.3%) (Aronson et al. 1988).
It was proposed that unipolar DD will require long-term
maintenance pharmacologic treatment, as 40.7% of the
relapses occurred during or shortly after a medication
Lithium augmentation in acute treatment
Studies including randomized double-blind trials of
lithium monotherapy for the acute treatment of
depression have not established its efficacy compared with
antidepressants (Bschor 2014). However, even with
antidepressants, the overall response rate is modest.
Lithium is able to optimize the response in hitherto
poor responders. This special use of lithium is called
Since the first report on the efficacy of lithium
augmentation treatment for depression that has not responded
to tricyclic antidepressants (Dé Montigny et al. 1981),
numerous RCTs and meta-analyses demonstrated the
efficacy of lithium augmentation. Meta-analysis by
Crossley and Bauer (2007) included 10
placebo-controlled trials showing that lithium was not only more
efficacious than placebo but had a relatively large effect size
and number-needed-to-treat of 5. Only 2 of these RCTs
were of SSRIs (Katona et al. 1995 and Baumann et al.
1996). The study by Katona and colleagues (1995) was the
largest RCT (N = 62) examining response to adjunctive
lithium inpatients receiving fluoxetine or lofepramine.
Lithium or placebo was added on a double-blind basis
for 6 weeks to the drug regime of 62 patients with major
depressive illness (in both hospital and primary care
settings) who had failed to respond to a controlled trial of
fluoxetine or lofepramine. Response was seen more
frequently in patients taking lithium than in those
remaining on antidepressant alone. Rapid response to lithium
augmentation was not consistently observed, but was
evident in those maintained on adequate plasma lithium
levels >or = 0.4 mmol/l. A recent systematic review and
meta-analysis of lithium augmentation of tricyclic and
second generation antidepressants in major depression
was published by Nelson et al. (2014). Nine trials that
included 237 patients were selected. Adjunctive lithium
was effective with TCAs (7 contrasts) and with second
generation agents (3 contrasts). Discontinuation due to
adverse events was infrequent and did not differ between
lithium and placebo. The meta-analysis was limited by
the small size and number of trials and limited data for
treatment-resistant patients. A comparison of lithium
and T(3) augmentation following two failed medication
treatments for depression in the STAR*D study showed
that remission rates with lithium and T(3) augmentation
for participants who experienced unsatisfactory results
with two prior medication treatments were modest and
did not differ significantly (Nierenberg et al. 2006).
It is concerning that despite the good evidence that
lithium augmentation is clearly effective; it is not widely
used for treatment of depression. A study of adjunctive
treatments in a Veterans Administration medical setting
found that of 53,807 depressed patients that received
adjunctive treatment because of unsatisfactory response,
49.7% received a second antidepressant and 33.1%
received an atypical antipsychotic (Valenstein et al. 2006).
Only 1106 patients (2%) received lithium augmentation
(Nelson et al. 2014). A survey of UK psychiatrists showed
that only 12% of them have used lithium augmentation
as first choice after the use of an antidepressant
(Shergill and Katona 1997). It appears as if many patients with
refractory depression are not receiving further treatment
according to rational algorithms (Bschor 2014).
A recent survey of lithium prescribing patterns for a
clinical audit of the quality of lithium monitoring,
conducted by the Prescribing Observatory for Mental Health
in the UK reported on 2776 patients with a diagnosis of
affective disorder 31% of whom had non-bipolar affective
disorder (Paton et al. 2010). Co-prescribing was common;
77% of those with non-bipolar affective disorders received
an antidepressant, prescribing that is consistent with
evidence-based treatment guidelines that may reflect difficulty
managing the symptoms of affective disorders with lithium
monotherapy. One in 10 patients of patients prescribed
lithium had a sub-therapeutic blood level (<0.4 mmol/l)
and so might have been at high risk of relapse.
A recent systematic review and network meta-analysis
of the comparative efficacy, acceptability, and tolerability
of augmentation agents in treatment-resistant
depression showed that quetiapine, aripiprazole, thyroid
hormone and lithium were significantly more effective but
less tolerable than placebo (Zhou et al. 2015). A
comprehensive meta-analysis of efficacy and safety outcomes in
short-term trials of lamotrigine compared to placebo and
other agents with antidepressant activity in patients with
unipolar and bipolar depression showed that lamotrigine
did not differ regarding efficacy on depressive symptoms,
response, or remission from lithium (Solmi et al. 2016).
Lithium as a continuation treatment following ECT
Electroconvulsive therapy (ECT) is an effective
treatment for patients with severe, psychotic and
medicationresistant depression. Although the immediate response
to ECT is good, ample evidence exists that there is a high
incidence of relapse in the months following treatment
unless antidepressants are given as continuation therapy
(Seager and Bird 1962).
In the first prospective study of lithium continuation
therapy following ECT, a group of 38 patients who had
responded to ECT were studied (Coppen et al. 1981;
AbouSaleh and Coppen 1988). The patients were randomly
allocated to receive either placebo or lithium therapy for 1
year. The patients who received lithium spent significantly
less time with a relapse (average 1.7 weeks over the year)
than the placebo group (over 7.8 weeks). The difference
was particularly marked during the second 6 months of
the study when the lithium patients spent 0.2 weeks with a
relapse compared to 5.6 weeks in the placebo group.
Lithium thus appears to be a satisfactory continuation therapy
after recovery from the acute episode. It was noted that
the efficacy of lithium continuation treatment was more
evident in the second 6 months of the trial indicating the
need for continuation treatment beyond the commonly
recommended 6 months. Further analysis of the data
suggested that lithium may be as effective in preventing a
recurrence (new episode) as continuation treatment to
prevent early relapse of the ongoing episode of depression
(Abou-Saleh 1987). The conclusion was that ECT is a very
effective form of treatment of severe depression but must
be accompanied by continuation therapy for its optimum
effect; this continuation therapy should be maintained
for up to 1 year after ECT. If the patient has had several
attacks of depression, then long-term prophylaxis must be
Another placebo-controlled trial studied the efficacy of
continuation pharmacotherapy with nortriptyline
compared with a combination of nortriptyline and lithium
in preventing post-ECT relapse over 24 weeks (Sackeim
et al. 2001). Nortriptyline-lithium combination therapy
had a marked advantage in time to relapse, superior to
both placebo and nortriptyline alone. Over the 24-week
trial, the relapse rate for placebo was 84%; for
nortriptyline, 60% and for nortriptyline-lithium, 39%. All but one
instance of relapse with nortriptyline-lithium occurred
within 5 weeks of ECT termination, while relapses
continued throughout treatment with placebo or
nortriptyline alone. Medication-resistant patients, female patients,
and those with more severe depressive symptoms
following ECT had more rapid relapses. The conclusion
was that without active continuation treatment, virtually
all remitted patients relapse within 6 months of
stopping ECT. Monotherapy with nortriptyline has limited
efficacy. The combination of nortriptyline and lithium is
more effective, but the relapse rate is still high,
particularly during the first month of continuation therapy.
A recent consideration of the evidence for the efficacy
of post-ECT lithium therapy in the prevention of relapse
concluded that, “in the main, there is strong evidence that
lithium can help prevent relapses in the first 6 months
after index ECT. However, there are several unanswered
questions about its use post-ECT, including optimal
target blood level, duration of use, and concomitant
antidepressant choice” (Rasmussen 2015). A very recently
published RCT focussed on the comparison of a
“medication only”(venlafaxine plus lithium) vs. an
“continuation ECT plus medication” group observed over 24 weeks
after an acute course of ECT. The results of the combined
group were more favourable than those of the medication
only strategy (Kellner et al. 2016).
Lithium prophylaxis in unipolar depression
The first systematic study of lithium prophylaxis in
recurrent affective illness using a “mirror” or “before and after”
design was reported by Baastrup and Schou (1967). Before
lithium treatment, the patients spent 3.88 months per
year with an affective episode and this fell to 0.27 months
per year during the period of lithium treatment. Other
investigations using a similar ‘before and after design’ also
produced similarly encouraging reports (Angst et al. 1973;
Hullin et al. 1972). There followed prospective
doubleblind placebo-controlled studies in which patients were
randomly allocated to receive either lithium or placebo
for a fixed period during which time they were regularly
assessed. Relapses were treated by conventional
antidepressant measures, but the prophylactic measures were
not changed. This enables a sensitive measure of benefit
to be obtained either in terms of the time spent with an
episode or as the “Affective Morbidity Index” (AMI). The
AMI is a composite measure both of duration and
severity of affective episodes (Coppen et al. 1973; Baethge et al.
2003), and is calculated by measuring the area under the
curve made by joining all the points representing ratings
of severity of affective disturbance at each assessment.
Such a measure is invaluable in calculating reduction of
morbidity where, as is often the case, there is not a
complete abolition of morbidity.
Coppen et al. (1971) reported a highly significant
reduction of morbidity in unipolar depressives in a
prospective double-blind placebo-controlled trial in which
patients received lithium or placebo over 27 months. The
percentage of time spent with a depressive episode was
4.7% in the lithium group and 30% in the placebo group.
The AMI was 0.12 in the lithium patients compared to
0.60 in those who received placebo. All these differences
were statistically significant. No patient in the lithium
group required ECT but almost half the patients in the
placebo group required one or more courses of ECT.
The results of the trial were updated so that they could
be examined in intent-to-treat analysis of the original
cohort using the global assessment based on a five-point
scale (Coppen 2000a, b). The subgroup of patients with
unipolar depression who were treated with lithium did
significantly better at the end of the study than the
placebo-treated patients. The results in unipolar patients
were comparable with those obtained in studies of
maintenance antidepressant treatment of depressed patients
(Kupfer et al. 1992) which are generally conducted in
patients who have responded to acute antidepressant
The first meta-analysis on the acute and long-term
effects lithium in unipolar depression found an
“impressive effect” of lithium vs. placebo in RCTs over 5 months
to 3 years and also in uncontrolled studies (Souza and
Goodwin 1991). The second systematic review of the
efficacy of lithium treatment compared to placebo in
the prevention of relapse in recurrent mood disorders
indicated that in unipolar depression, the evidence of
efficacy is less robust than in bipolar disorder (Burgess
et al. 2001). Descriptive analysis, however, showed that
assessments of general health and social functioning
generally favoured lithium. However, it should again be
emphasized that the bulk of patients selected for those
studies were recruited in the 1970 ies and early 1980 ies.
Thus, their psychopathology most likely was different
from “modern” patients with various types of “depression
The third systematic review of the efficacy of lithium
treatment compared to antidepressants in the long-term
treatment of unipolar depression was published by
Cipriani et al. (2006). Eight randomized, controlled trials
involving 475 patients were included. There was a
statistically significant difference in favour of lithium (relative
risk (RR) fixed effect 0.34, 95% Cl 0.14–0.82) which was
significantly superior to antidepressants in preventing
relapses that required admission to hospital. The authors
concluded that “there was adequate efficacy evidence
for lithium or antidepressants preventing relapse in
unipolar affective disorder depression, however their
relative efficacy was unknown. When considering lithium or
antidepressant long-term therapy, patients and clinicians
should take into account the patient’s clinical history, the
side-effects and the individual’s likely adherence to the
recommended treatment regime”.
Long-term naturalistic studies strongly supported the
effectiveness of lithium prophylaxis for unipolar
depression disorder in clinical practice.
An early study explored the response to lithium
therapy in 95 patients with unipolar depression. Response to
lithium showed a linear relationship to Newcastle Scale
scores (measure of the degree of endogeneity) in these
patients. The AMI of patients with endogenous and
psychotic depression was very low indicating an excellent
response to prophylactic lithium which was similar to
AMI of patients with bipolar disorder (Abou-Saleh and
Coppen 1983). Similar findings were reported after the
adoption of lower doses/levels of lithium in 1983
(Coppen and Abou-Saleh 1988).
Response to prophylactic lithium was studied in
relation to clinical and psychological characteristics in a
large series of patients with recurrent affective disorders
(Abou-Saleh and Coppen 1986). Unipolar patients with
more endogenous illnesses and those with pure
familial depressive disease had more favourable responses
than those with less endogenous illnesses and those
with sporadic and depression spectrum disorders. Good
responders showed generally less personality disturbance
on a variety of measures than fair-to-poor responders.
Response to lithium over the first 6 months of treatment
in unipolar illness was strongly associated with long-term
Other long-term naturalistic studies of the
effectiveness of long-term lithium prophylaxis in unipolar
depression during an average follow-up period of 6.7 years
reported a significant decline in the number of days spent
in hospital and a low AMI was observed in these carefully
monitored and documented patients from a specialized
lithium clinic, who originally most likely had been
diagnosed according to Kraepelian tradition (Baethge et al.
The meta-analysis by Kim et al. (1990) though on the
basis of a rather restricted number of patients showed
that combining lithium and imipramine leads to better
episode prevention than either lithium or imipramine
alone. Also the wfsbp-guideline (Bauer et al. 2015)
recommends a combination of lithium and antidepressant in
patients who fail to remain well on either drug alone
Indications for commencing prophylaxis
in unipolar depression
A crucial decision for the clinician is when to start
lithium prophylaxis. A detailed and profound discussion of
this topic was published by Angst (1980). He analysed
the course of the illness in 159 unipolar patients
probably diagnosed in a traditional European manner and
decided that it would be desirable to start prophylaxis if
the patients were likely to suffer 2 further episodes (in
addition to the present one) in the subsequent 5 years.
He examined numerous criteria to see which identified
those patients at risk. His conclusions were surprisingly
simple. He found that if the patient had had one episode
or more in the previous 5 years in addition to the present
one, then he was likely to have 2 further episodes in the
following 5 years. He also reported that at least 40% of
unipolar patients would require prophylactic treatment.
Of course, more than one episode in the previous 5 years
would be a strong indication for starting prophylactic
therapy. He could find no good criteria for discontinuing
lithium therapy which should be continued indefinitely
provided that patient’s adherence is satisfactory and
serious adverse drug effects do not occur.
Lithium and suicide prevention in unipolar
Whilst it is well established that recurrence of
unipolar depression can be significantly reduced by adequate
maintenance treatment, be it by antidepressants or
lithium, it is strange, therefore, that the reduction in suicide
rates over the years has been relatively modest (Coppen
2000a, b). A probable explanation of this modest
reduction is that only a proportion of patients with unipolar
depression are diagnosed, and only a proportion of those
patients are treated, mostly with antidepressants.
However, in contrast to a common belief, antidepressants
do not reduce the risk of suicide (see below). If patients
are adequately treated, however, preferably with lithium,
one can observe a significant reduction of up to 75% in
the suicide rate, as demonstrated by 18-year mortality
and suicide rate in a group of 103 patients who attended
a mood disorder clinic (Coppen and Farmer 1998). The
majority of patients had unipolar depression which was
severe and recurrent illness with a few dropouts during
the first year of treatment. The standard treatment was
sustained—release lithium given once-daily. Until 1982,
the plasma lithium concentration measured
approximately 12 h after dosage was maintained between 0.8
and 1.2 mmol/l. In 1982, the regiment was changed to
maintain patients at the plasma lithium concentration
between 0.6 and 0.8 mmol/l. Additional treatments,
including antidepressants and neuroleptics, were
administered as required.
In two other long-term follow-up studies in patients
with affective disorders, patients had been treated for at
least 1 year before recruitment and lithium levels were
carefully monitored. In the first study, the International
Group for the Study of Lithium treated Patients (IGSLI;
ref. www.igsli.org) followed up 827 patients from 4
countries who attended lithium clinics for an average 7 years
equalling 5600 patient years (Müller-Oerlinghausen et al.
1992). The overall suicide rate was 1.3 per 1000 patient
years; the Standardised Mortality Rate (all causes) was
0.89. In other words, in contrast to an expected 2–3 fold
increased all-cause mortality, the mortality of this
longterm lithium-treated patient group did not differ from
that of a matched cohort from the general population.
This mortality reducing effect was observed in the
unipolar patients as well as in those with bipolar or
schizoaffective disorder. The other study involved mood disorder
patients admitted to the main psychiatric hospital in
Gothenburg, Sweden, between 1970 and 1991 who had
received lithium for at least 1 year (Nilsson 1995). The
suicide rate was 1.5 suicides per 1000 patient years for
patients maintained on lithium treatment. For patients
who had discontinued lithium, the suicide rate was 7.1
per 1000 patient years. Combining the three studies
(11,085 patient years) yielded an unexpectedly low
average suicide rate of 1.3 per 1000 patient years. (Bauer et al.
2015; Lewitzka et al. 2015a).
These rates contrast with the reports of suicide rates
between 5.4 and 10.2 per 1000 patient years in long-term
studies of patients not given maintenance treatment
(Coppen and Farmer 1998). Furthermore, the IGSLI
studies could also prove a reduction of the otherwise
increased cardiovascular excess mortality of patients
with affective disorders (Ahrens et al. 1995).
A systematic review of randomized, controlled trials of
lithium reported that long-term lithium reduced the risk
of suicide in mood disorders by about 75% as compared
with placebo or other drugs (Cipriani et al. 2005).
An often heard argument by psychiatrists is that
allegedly the antisuicidal effect of lithium refers exclusively to
bipolar patients. However, an updated systematic review
and meta-analysis on lithium in the prevention of suicide
in mood disorders confirmed that also in unipolar
depression lithium was associated with a reduced risk of suicide
and the number of total deaths compared with placebo
(Cipriani et al. 2013). Generally lithium compared with
each active individual treatment showed superior
efficacy in reducing the risk of deliberate self harm. Lithium
tended to be generally better than the other active
comparators, with small statistical variation between the
results. The review concluded that lithium is an effective
treatment for reducing the risk of suicide in people with
mood disorders. Corresponding findings from very
carefully documented unipolar patients of a specialized
lithium clinic were reported by Guzzetta et al. (2007).
Lithium may exert its antisuicidal effects by reducing
relapse of mood disorder, but additional mechanisms
should also be considered because there is some evidence
that lithium decreases aggression and possibly
impulsivity, which might be another mechanism mediating the
antisuicidal effect (Ahrens and Müller-Oerlinghausen
Maintenance treatment with antidepressants has
been shown to be effective in terms of episode
prevention when given for periods up to 5 years (Kupfer et al.
1992). There is a limitation with antidepressants; in that
at least one-third of patients show a poor response to
them. Moreover, it has been shown in controlled
studies that antidepressants do not reduce the suicide risk in
patients with mood disorders and that in some instances
particularly the SSRIs can trigger de novo suicidal ideas
and behaviour even in patients who never before
experienced suicidal ideas (Fergusson et al. 2005; Bschor 2014;
Stübner et al. 2010; Braun et al. 2016).
Maintenance treatment for depression may be
continued for longer than 2 years if symptoms recur after
discontinuation and in patients with late onset depression
and delusional depression which is often highly recurrent
with high risk of mortality by suicide and other causes.
We refer to World Federation of Societies of Biological
Psychiatry (WFSBP) Guidelines on Maintenance
Treatment of Major Depressive that recommended
“maintenance therapy is most commonly appropriate for
recurrent patients, particularly when an episode prior to
the present one has occurred in the last 5 years or when
remission has been difficult to achieve. Maintenance
treatment for 5–10 years or even indefinitely is
recommended for those patients at greater risk, particularly
when two or three attempts to withdraw medication have
been followed by another episode within a year” (Bauer
et al. 2015).
Lithium maintenance therapy is strongly recommended
for the long-term management of selected patients with
unipolar depression since there is strong evidence for
its episode-preventing efficacy and unique anti-suicidal
effects. The WFSBP Guidelines also do recommend the
use of lithium as an effective maintenance treatment of
Lithium is an effective prophylactic treatment in selected
patients with unipolar depression in its classic form.
Most importantly, lithium is unique in being the only
medicine with proven antisuicidal effects and hence a
lethal disease is no longer lethal.
In our view, lithium prophylaxis is indicated in severe,
clearly episodic unipolar depression that failed to
respond to antidepressant medication.
We propose that in unipolar depression, the occurrence
of 2 episodes of depression within 5 years is a practical
criterion for starting lithium prophylaxis particularly in
severe depression with psychotic features high suicidal
risk and particularly in such patients in whom a
bipolar background can be suspected. It seems self-evident
that not only the subtype of depressive illness but also
the psychosocial impact of the illness on the patient and
the relatives must be adequately considered in making a
sound shared decision.
In some cases, lithium prophylaxis may be
recommended after a single episode of depression that is severe
with high suicidal risk and continued life-long with
regular and careful monitoring taking its specific profile
of adverse drug reactions under proper consideration
(Bauer and Gitlin 2016)
Lithium treatment has the advantage that it can be
easily controlled to ensure adequate dosage and
compliance and that other treatments such as antipsychotics or
antidepressants can be added for some time if needed
e.g., during break-through episodes. There is little doubt
that recurrent mood disorders are most easily and
satisfactorily treated in specialized mood disorder clinics.
It is especially important that the initial assessment of a
patient for long-term treatment be made by a specialist.
There is a need for large international RCTs
comparing the efficacy of lithium prophylaxis with other
recommended maintenance treatments of unipolar depression.
Furthermore, it would be of eminent interest whether
lithium would also possess acute anti-suicidal effects in
patients with varying psychiatric diagnoses particularly
those with unipolar depression (Lewitzka et al. 2015a, b).
In our view, the WHO should hasten to integrate
the robust evidence on lithium’s antisuicidal effect
demonstrated in various forms of affective disorder in its
mental health action plan for the worldwide prevention
In addition, there is strong evidence that lithium
augmentation is effective in the management of patients with
unipolar depression not responding to antidepressant
medication. We, therefore, propose that lithium
augmentation should be the first line treatment option among
antidepressant augmentation strategies, particularly after
two different antidepressants have been tried
unsuccessfully (Tundo et al. 2015)
Finally, lithium is also an effective continuation
treatment following ECT.
All authors participated equally in the conception and writing design of the
review. They selected and reviewed the literature and drafted the manuscript.
All authors read and approved the final manuscript.
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