Refractory depression: the addition of lithium to fluoxetine or desipramine

A History of the Pharmacological Treatment of Bipolar Disorder

In this paper, the authors review the history of the pharmacological treatment of bipolar disorder, from the first nonspecific sedative agents introduced in the 19th and early 20th century, such as solanaceae alkaloids, bromides and barbiturates, to John Cade's experiments with lithium and the beginning of the so-called "Psychopharmacological Revolution" in the 1950s. We also describe the clinical studies and development processes, enabling the therapeutic introduction of pharmacological agents currently available for the treatment of bipolar disorder in its different phases and manifestations. Those drugs include lithium salts, valproic acid, carbamazepine, new antiepileptic drugs, basically lamotrigine and atypical antipsychotic agents (olanzapine, risperidone, quetiapine, ziprasidone, aripiprazole, asenapine, cariprazine and lurasidone). Finally, the socio-sanitary implications derived from the clinical introduction of these drugs are also discussed.

If at first you don't succeed: a review of the evidence for antidepressant augmentation, combination and switching strategies

Major depressive disorder is a common and disabling illness that leads to significant reductions in quality of life and considerable cost to society. Despite numerous advances in the pharmacological treatment of depression, many patients remain ill despite initial treatment. Beyond first-line treatment, current guidelines recommend either augmentation or switching of the initial antidepressant. In this narrative review, we summarize the data from randomized controlled trials and meta-analyses in order to concisely discuss how the impact of current research can be translated into clinical practice and, ultimately, into lasting improvements in patient outcomes. The augmentation strategies reviewed are lithium, thyroid hormone, pindolol, psychostimulants and second-generation antipsychotics. The data on switching from first-line antidepressants to other antidepressants are also reviewed, and include switching within the same class, switching to other first-line antidepressant classes and switching to less commonly prescribed antidepressants. Finally, the strategy of antidepressant combinations is examined. Overall, the strength of evidence supporting a trial of augmentation or a switch to a new agent is very similar, with remission rates between 25% and 50% in both cases. Our review of the evidence suggests several conclusions. First, although it is true that adjunctive lithium and thyroid hormone have established efficacy, we can only be confident that this is true for use in combination with tricyclic antidepressants (TCAs), and the trials were done in less treatment-resistant patients than those who typically receive TCAs today. Of these two options, triiodothyronine augmentation seems to offer the best benefit/risk ratio for augmentation of modern antidepressants. After failure of a first-line selective serotonin reuptake inhibitor (SSRI), neither a switch within class nor a switch to a different class of antidepressant is unequivocally supported by the data, although switching from an SSRI to venlafaxine or mirtazapine may potentially offer greater benefits. Interestingly, switching from a newer antidepressant to a TCA after a poor response to the former is not supported by strong evidence. Of all strategies to augment response to new-generation antidepressants, quetiapine and aripiprazole are best supported by the evidence, although neither the cost effectiveness nor the longer-term benefit of these strategies has been established. The data to guide later steps in the treatment of resistant depression are sparse. Given the wide variety of options for the treatment of major depressive disorder, and the demonstrated importance of truly adequate treatment to the long-term outcomes of patients facing this illness, it is clear that further well conducted studies are needed.

Therapeutic options for treatment-resistant depression

Treatment-resistant depression (TRD) presents major challenges for both patients and clinicians. There is no universally accepted definition of TRD, but results from the US National Institute of Mental Health's (NIMH) STAR*D (Sequenced Treatment Alternatives to Relieve Depression) programme indicate that after the failure of two treatment trials, the chances of remission decrease significantly. Several pharmacological and nonpharmacological treatments for TRD may be considered when optimized (adequate dose and duration) therapy has not produced a successful outcome and a patient is classified as resistant to treatment. Nonpharmacological strategies include psychotherapy (often in conjunction with pharmacotherapy), electroconvulsive therapy and vagus nerve stimulation. The US FDA recently approved vagus nerve stimulation as adjunctive therapy (after four prior treatment failures); however, its benefits are seen only after prolonged (up to 1 year) use. Other nonpharmacological options, such as repetitive transcranial stimulation, deep brain stimulation or psychosurgery, remain experimental and are not widely available. Pharmacological treatments of TRD can be grouped in two main categories: 'switching' or 'combining'. In the first, treatment is switched within and between classes of compounds. The benefits of switching include avoidance of polypharmacy, a narrower range of treatment-emergent adverse events and lower costs. An inherent disadvantage of any switching strategy is that partial treatment responses resulting from the initial treatment might be lost by its discontinuation in favour of another medication trial. Monotherapy switches have also been shown to have limited effectiveness in achieving remission. The advantage of combination strategies is the potential to build upon achieved improvements; they are generally recommended if partial response was achieved with the current treatment trial. Various non-antidepressant augmenting agents, such as lithium and thyroid hormones, are well studied, although not commonly used. There is also evidence of efficacy and increasing use of atypical antipsychotics in combination with antidepressants, for example, olanzapine in combination with fluoxetine (OFC) or augmentation with aripiprazole. The disadvantages of a combination strategy include multiple medications, a broader range of treatment-emergent adverse events and higher costs. Several experimental pharmaceutical treatment alternatives for TRD are also being explored in combination with antidepressants or as monotherapy. These less studied alternative compounds include pindolol, inositol, CNS stimulants, hormones, herbal supplements, omega-3 fatty acids, S-adenosyl-L-methionine, folic acid, lamotrigine, modafinil, riluzole and topiramate. In summary, despite an increasing variety of choices for the treatment of TRD, this condition remains universally undefined and represents an area of unmet medical need. There are few known approved pharmacological agents for TRD (aripiprazole and OFC) and overall outcomes remain poor. This might be an indication that depression itself is a heterogeneous condition with a great diversity of pathologies, highlighting the need for careful evaluation of individuals with depressive symptoms who are unresponsive to treatment. Clearly, more research is needed to provide clinicians with better guidance in making those treatment decisions--especially in light of accumulating evidence that the longer patients are unsuccessfully treated, the worse their long-term prognosis tends to be.

Therapeutic alternatives for difficult-to-treat depression: a narrative review of the state of the evidence

Despite the large number of depressed patients who do not respond to first-line antidepressants, the evidence base of alternate strategies is quite thin. In this article, a simple 5-stage system for categorizing treatment-resistant depression (TRD) is described and the evidence pertaining to the major strategies currently utilized is summarized using four grades, ranging from D (case reports only) to A (multiple positive placebo-controlled trials). It is concluded that the level of evidence supporting many of the contemporary strategies used for TRD (eg, combinations of antidepressants and augmentation with medications such as pindolol, buspirone, or modafinil) is scanty at best. Even the fundamental question concerning "to augment or to switch" is not answerable with available data. It is noted that the best-documented treatments (ie, lithium augmentation, switching to a monoamine oxidase inhibitor, and electroconvulsive therapy) are among the least utilized. This state of affairs will improve with completion of the studies of Systematic Treatment Alternatives to Relieve Depression, a large multicenter study of difficult-to-treat depression funded by the National Institute of Mental Health. There is a need for greater collaboration among academicians and organizations, such as the American Psychiatric Association, the National Institute of Mental Health, and the pharmaceutical industry, to ensure that sufficient research is conducted so that clinician's choices for patients with TRD can be guided by empirical evidence.

Lithium augmentation in venlafaxine non-responders: an open study

Thirteen major depressive patients not responding to a 4-week venlafaxine 300 mg treatment were eligible for a 4-week open trial of lithium addition. Two patients had to stop lithium for a possible moderate serotonin syndrome and five patients became responders, including one dramatic response and two semi-rapid responses.

Background and rationale for the sequenced treatment alternatives to relieve depression (STAR*D) study

Sequenced Treatment Alternatives to Relieve Depression (STAR*D) attempts to fill in major clinical information gaps and to evaluate the theoretical principles and clinical beliefs that currently guide pharmacotherapy of major depressive disorder. The study is conducted in representative participant groups and settings using clinical management tools that easily can be applied in daily practice. Outcomes include clinical outcomes and health care utilization and cost estimates. Research findings should be immediately applicable to, and easily implemented in, the daily primary and specialty care practices. This article provides the overall rationale for STAR*D and details the rationale for key design, measurement, and analytic features of the study.

Double-blind study of high-dose fluoxetine versus lithium or desipramine augmentation of fluoxetine in partial responders and nonresponders to fluoxetine

In a previous study, of 41 depressed patients who had not responded to fluoxetine 20 mg/day, 53% were treated with high-dose fluoxetine (40-60 mg/ day) and responded (i.e., their 17-item Hamilton Rating Scale for Depression [HAM-D-17] score was <7) versus 29% and 25% of patients treated with fluoxetine plus lithium (300-600 mg/day) or fluoxetine plus desipramine (25-50 mg/day), respectively. We wanted to assess whether these findings could be replicated in a larger sample of depressed outpatients. We identified 101 outpatients with major depressive disorder (52 men and 49 women; mean age, 41.6 + 10.6 years) who were either partial responders (n = 49) or nonresponders (n = 52) to 8 weeks of treatment with fluoxetine 20 mg/ day. These patients were randomized to 4 weeks of double-blind treatment with high-dose fluoxetine (40-60 mg/day), fluoxetine plus lithium (300-600 mg/day), or fluoxetine plus desipramine (25-50 mg/day). In the overall group of patients (N = 101), there was no significant difference in response rates across the three treatment groups (high-dose fluoxetine, 42.4%; fluoxetine plus desipramine, 29.4%; fluoxetine plus lithium, 23.5%). Dropout rates were also comparable, ranging from 9.1% (high-dose fluoxetine) to 14.7% (fluoxetine plus desipramine and fluoxetine plus lithium). There were also no significant differences in response rates across the three treatment groups among partial responders (high-dose fluoxetine, 50.0%; fluoxetine plus desipramine, 33.3%; fluoxetine plus lithium, 33.3%) and nonresponders (high-dose fluoxetine, 35.3%; fluoxetine plus desipramine, 26.3%; fluoxetine plus lithium, 12.5%). At the end of the study, the mean lithium level was 0.37 + 0.15 mEq/L (n = 27; range, 0.1-0.8 mEq/L) among lithium-treated patients, and the mean desipramine level was 104.7 + 58.8 ng/mL (n = 22; range, 25-257 ng/mL). There were no significant relationships between lithium or desipramine blood levels and degree of improvement (as measured by the change in HAM-D-17 score). We found no significant differences in efficacy among these three treatment strategies among patients who had failed to respond adequately to 8 weeks of treatment with fluoxetine 20 mg/day, although the high-fluoxetine group was associated with nonsignificantly higher response rates in both partial responders and nonresponders.

Effect of subchronic lithium treatment on citalopram-induced increases in extracellular concentrations of serotonin in the medial prefrontal cortex

We investigated the effect of citalopram [a selective serotonin (5-HT) reuptake inhibitor; SSRI] and MKC-242 (a selective 5-HT1A agonist), following treatment with subchronic lithium (p.o., 1 week) on extracellular 5-HT concentrations in the medial prefrontal cortex (mPFC). Acute treatment with citalopram (3 and 30 mg/kg) led to significant increases in extracellular 5-HT concentrations. The subchronic lithium group showed significantly higher basal levels of extracellular 5-HT than normal diet controls. Acute citalopram (3 and 30 mg/kg) treatment together with subchronic lithium treatment showed significant increases in the extracellular 5-HT concentrations, compared with citalopram treatment alone. Acute MKC-242 (1 mg/kg) treatment showed significant decreases in extracellular 5-HT concentrations, in both the normal diet and lithium diet groups to the same extent. The addition of lithium did not change the effect of the 5-HT1A agonist on extracellular 5-HT concentrations. This study suggests that lithium augmentation of the antidepressant effect of SSRI is mediated by the additional increases in extracellular 5-HT concentrations following the co-administrations of lithium and SSRI.

Antidepressant augmentation and combinations

A significant proportion of patients with MDD are treatment resistant or only partial responders to adequate therapy with a single agent. In this situation, one must consider augmentation with another agent. Lithium and thyroid augmentation have been investigated for many years. In a meta-analysis of double-blind studies involving augmentation with lithium or placebo after nonresponse to conventional antidepressants, lithium augmentation was concluded to be the first-line therapy for depressed patients who failed to respond to monotherapy. One important study reported no significant difference in response rates between T3 and lithium as augmentation agents in patients who had failed to respond to TCAs. Very few controlled, double-blind trials show consistently positive results for the other augmentation strategies, although some open-labeled trials and case reports are promising. Additional placebo-controlled, double-blind studies are needed to assess the efficacy and tolerability of all of these agents, especially in combination with the newer classes of antidepressants.

Depressive breakthrough

Controlled studies of continuation and maintenance pharmacotherapy have consistently shown the advantage of drug therapy over placebo for the prevention of relapses and recurrences, particularly when antidepressant medications are maintained at the full dose required initially to establish remission. Nevertheless, controlled and observational studies indicate substantial rates of relapse and recurrence despite long-term treatment. Although depressive breakthrough is a common clinical problem, few uncontrolled studies and no controlled trials are available on management of depressive breakthrough. Three principal pharmacologic strategies seem to be (1) increasing dose, (2) adding another agent, and (3) switching antidepressants. Controlled studies of long-term treatment are needed to identify the optimal nature and sequence of approaches for re-emergent depression and to determine what symptom severity and duration should prompt the initiation of treatment.

Ongoing lithium treatment prevents relapse after total sleep deprivation

Forty bipolar depressed inpatients underwent three consecutive cycles of total sleep deprivation (TSD). At the beginning of the study, 20 patients were free of psychotropic drugs and 20 had been receiving lithium medication for at least 6 months. Mood was rated on the Hamilton Rating Scale for Depression before and after TSD; perceived mood changes during treatment were evaluated with self-administered visual analog scales. Patients undergoing long-term lithium treatment showed a significantly better response to TSD as rated on both scales: 13 of 20 patients (vs. 2 of 20 patients without lithium) showed a sustained response during a follow-up period of 3 months. This preliminary evidence of a positive interaction of TSD and long-term lithium treatment could be explained by a synergistic effect of both treatments on brain serotonergic function, possibly via a desensitization of 5-hydroxytryptamine-1A inhibitory autoreceptors.

Risk of adverse events with the use of augmentation therapy for the treatment of resistant depression

Augmentation therapy is used for those situations where a patient's depression is either treatment-resistant, or partially and/or insufficiently responsive to treatment. It also may be used to attempt to induce a more rapid treatment response. Using drugs together may increase the risk of adverse effects, through potentiation of existing adverse effects or alterations in plasma concentrations of the drug. It is important that clinicians are aware of potential risks of augmentation therapy. Lithium augmentation of a tricyclic antidepressant is relatively well tolerated and the dangers are no greater than using these medications on their own. There are also no reports of serious adverse events when lithium is added to a monoamine oxidase inhibitor. With lithium augmentation of selective serotonin (5-hydroxytryptamine; 5-HT) reuptake inhibitor (SSRI) therapy there have been case reports of the development of a central serotonin syndrome, and thus caution must exercised. A serious concern when using a tricyclic antidepressant to augment an SSRI is the effect of the SSRI on the cytochrome P450 system and the resulting significant increase in tricyclic antidepressant blood concentrations. Augmentation with thyroid hormones appears to be well tolerated and effective. Case reports and open studies indicate that augmentation with buspirone and the psychostimulants, carbamazepine and valproic acid (valproate sodium) is effective and results in minimal adverse effects. However, there is no empirical evidence supporting these results. Recent work supports the tolerability and efficacy of pindolol augmentation. Considerable caution should be exercised when combining psychotropic drugs. The practitioner should only do so with a full knowledge of the compounds involved and their pharmacological properties.

Modification of the Clinical Global Impressions (CGI) Scale for use in bipolar illness (BP): the CGI-BP

The Clinical Global Impressions Scale (CGI) was modified specifically for use in assessing global illness severity and change in patients with bipolar disorder. Criticisms of the original CGI were addressed by correcting inconsistencies in scaling, identifying time frames for comparison, clarifying definitions of illness severity and change, and separating out assessment of treatment side effects from illness improvement during treatment. A Detailed User's Guide was developed to train clinicians in the use of the new CGI-Bipolar Version (CGI-BP) for rating severity of manic and depressive episodes and the degree of change from the immediately preceding phase and from the worst phase of illness. The revised scale and manual provide a focused set of instructions to facilitate the reliability of these ratings of mania, depression, and overall bipolar illness during treatment of an acute episode or in longer-term illness prophylaxis. Interrater reliability of the scale was demonstrated in preliminary analyses. Thus, the modified CGI-BP is anticipated to be more useful than the original CGI in studies of bipolar disorder.

Fluoxetine tenth anniversary update: the progress continues

This tenth anniversary review/update of fluoxetine concentrates on the past 5 years of its clinical application. The mechanism of action of fluoxetine; its metabolism; its efficacy in patients with various diagnostic subgroups of depression, patients with coincident medical disease, children and adolescents with depression, patients with eating disorders, and patients with obsessive-compulsive disorder (OCD); its long-term (maintenance) efficacy; its side effects and toxicity; and pharmacoeconomic considerations are reviewed. Pharmacotherapy is currently the only proven method for treating major depressive disorder that is applicable to all levels of severity of major depressive illness. Since its introduction 10 years ago, fluoxetine has been available to psychiatrists, primary care physicians, and other nonpsychiatric physicians as full-dose effective pharmacotherapy for patients with depression. Fluoxetine has been widely prescribed by physicians knowledgeable in pharmacology and in the treatment of depression because of its proven efficacy (ie, equal to that of tricyclic antidepressants [TCAs]), its ease of administration (with full therapeutic dosing usually starting from day 1), its generally benign side-effect profile, its remarkable safety in over-dose, and its proven effectiveness in the most common depressed patient population--anxious, agitated, depressed patients--as well as in patients with various subtypes and severities of depression. In more recent years it has also proved effective in the treatment of bulimia, an entity for which only limited or inadequate treatment options had been previously available. In OCD, fluoxetine, with its more acceptable side-effect profile and greater ease of dosing, presents a favorable alternative to previous drug therapy and is useful in treating both obsessions and compulsions. Fluoxetine is currently recognized among clinicians as efficacious in treating anxiety disorders and is being used successfully in special depressed populations such as patients with medical comorbidity, elderly patients, adolescents, and children. Rapid discontinuation or missed doses of short-half-life selective serotonin reuptake inhibitors, TCAs, and heterocyclic antidepressants are associated with withdrawal symptoms of a somatic and psychological nature, which cannot only be disruptive, but can also be suggestive of relapse or recurrence of depression. In striking contrast to these short-half-life antidepressants, fluoxetine is rarely associated with such sequelae on sudden discontinuation or missed doses. This preventive effect against withdrawal symptoms on discontinuation of fluoxetine is attributed to the unique extended half-life of this antidepressant. Current studies show that the overall increased effectiveness of fluoxetine in treating depression compensates for its higher cost, compared with older drugs, by reducing the need for physician contact because of increased compliance and less need of titration, and by reducing premature patient discontinuation, thereby yielding fewer relapses, less recurrence, and less reutilization of mental health services.

A review of the use of augmentation therapy for the treatment of resistant depression: implications for the clinician

OBJECTIVE

To critically review the literature on augmentation therapy in resistant depression in order to assist the clinician to make a reasoned choice. Augmentation therapy is defined as the addition of a second agent to an existing antidepressant regimen with the aim of achieving improved clinical response.

METHOD

The available literature which related specifically to currently popular augmentation strategies in treatment resistant depression for the past 20 years was examined. The scientific evidence supporting the efficacy of these regimens and their safety was reviewed.

RESULTS

Considerable research on lithium augmentation has been undertaken, and on triiodothyronine augmentation to a lesser degree. A number of other drugs have been trialed as augmentation agents with claims of success; however, most of the evidence supporting these agents is anecdotal and in the form of case reports. There are very few well-performed double-blind placebo-controlled studies of augmentation therapy.

CONCLUSIONS

Because of possible complex pharmacodynamic and pharmacokinetic interactions, augmentation therapy is not without its potential complications. Lithium augmentation of tricyclic antidepressants can be recommended as a safe and effective strategy and there is a body of scientific evidence supporting the addition of T3 as an effective augmentation agent. Recent research with pindolol augmentation of selective serotonin re-uptake inhibitors (SSRIs) is encouraging, but these findings require replication. There is no empirical evidence supporting buspirone, carbamazepine, sodium valproate, methylphenidate or amphetamine as effective augmentation agents, or that adding a tricyclic to a SSRI has usefulness in relieving depressive symptoms. There is a need for considerable research in this area, with more prospective well-controlled placebo studies.

Selective serotonin reuptake inhibitor-induced serotonin syndrome: review

The selective pharmacology of the selective serotonin reuptake inhibitors (SSRIs) results in a lower potential for pharmacodynamic drug interactions relative to other antidepressants such as the tricyclic antidepressants (TCAs) and monoamine oxidase inhibitors (MAOIs). However, the SSRIs have been implicated in the development of the serotonin syndrome--a potentially life-threatening complication of treatment with psychotropic drugs. The syndrome is produced most often by the concurrent use of two or more drugs that enhance central nervous system serotonin activity and often goes unrecognized because of the varied and nonspecific nature of its clinical features. The serotonin syndrome is characterized by alterations in cognition (disorientation, confusion), behavior (agitation, restlessness), autonomic nervous system function (fever, shivering, diaphoresis, diarrhea), and neuromuscular (ataxia, hyperreflexia, myoclonus) activity. The difference between this syndrome and the occurrence of adverse effects caused by serotonin reuptake inhibitors alone is the clustering of the signs and symptoms, their severity, and their duration. There are important pharmacokinetic interactions between SSRIs and other serotonergic drugs due principally to their effects on the cytochrome P450(CYP) isoenzymes, the potential for which varies widely amongst the SSRI group, which may increase the likelihood of a pharmacodynamic interaction. The exceptionally long washout period required after fluoxetine discontinuation may cause additional problems and/or inconvenience. Patients with serotonin syndrome usually respond to discontinuation of drug therapy and supportive care alone, but they may also require treatment with antiserotonergic agent such as cyproheptadine, methysergide, and/or propranolol. To reduce the occurrence, morbidity, and mortality of the serotonin syndrome, it must be both prevented by prudent pharmacotherapy and given prompt recognition when it is present.

Heat intolerance induced by antidepressants

A case in which prescription medications induced heat intolerance which led to heat stroke is presented. A subject who suffered from depression and was treated with fluoxetine HCL (prozac) and lithium carbonate was engaged in mild intermittent work for 4 hours under hot/dry climatic conditions (Ta = 37 degrees C, rh = 15%). The subject lost consciousness, was hyperthermic and suffered from disseminated intravascular coagulation. A year later residual cerebellar symptoms were still evident and severe atrophy of the cerebellar tissue was demonstrated in a CT scan. It is suggested that drug-induced heat intolerance was the predisposing factor that reduced the patient ability to sustain exercise-heat stress, and under the favorable environmental circumstances led to excessive heat accumulation which ultimately caused heat stroke. This is the first description, to our knowledge, of heat intolerance of a patient treated by a combination of fluoxetine and lithium carbonate.

Concurrent treatment of nonresistant major depression with desipramine and lithium: a double-blind, placebo-controlled study

The objective of this study was to compare the onset, rate of antidepressant (AD) response, and treatment outcome of depressed patients treated for 5 weeks with either the concomitant administration of the tricyclic AD desipramine (DMI) and lithium carbonate (Li) or with DMI alone. In this double-blind, placebo-controlled study, 31 nonpsychotic, mild to moderately depressed outpatients (DSM-III-R unipolar or bipolar major depression) were randomly assigned to 5 weeks of treatment with DMI plus Li (N = 16) or DMI plus placebo (N = 15). Drug dosages were adjusted to achieve therapeutic plasma levels. Clinical state was rated weekly by the Hamilton Rating Scale for Depression, the Clinical Global Impression Scale, a Visual Analogue Self-Report Scale, and an adverse-effect form. Twenty-seven patients completed the study, 12 in the DMI-Li group and 15 in the DMI-placebo group. Four patients dropped out due to adverse events, all from the DMI-Li group. Both groups responded well to treatment, without a significant difference between them in the rate of response of final outcome. Sixty-seven percent (10/15) of the patients taking DMI only and 75% (9/12) of the patients taking DMI plus Li met our response criteria. The combination of DMI and Li was associated with significantly more adverse effects than DMI alone. Concurrent treatment with Li did not demonstrate an enhancement of either DMI's efficacy or its onset of action in these patients, suggesting that this strategy may not confer any additional benefit compared with DMI alone in mild to moderately depressed patients who are not preselected for nonresponse to an AD during their current depressive episode.

Predicting outcome of lithium added to antidepressants in resistant depression

This study was conducted to assess the predictive value of different variables including the response to dexamethasone suppression test (DST), in 105 patients with resistant depression after the addition of lithium (600 to 800 mg/day) for 4 weeks to antidepressant medication. Clinical remission was observed in 57 patients and no improvement in 48. A dramatic and rapid relief of depression occurred in 12 patients. Variables with significant or marginally significant differences between responders and non-responders were included in a stepwise logistic regression model. Weight loss (P = 0.0013) and depressive psychomotor activity (P = 0.045) in the Newcastle diagnostic index (NDI) scale, and overall score of the Hamilton Rating Scale for Depression (HRSD) before adding the lithium (P = 0.0039) were significantly associated with clinical remission. The difference in post-DST cortisol plasma levels between both groups was marginally significant. The logistic equation resulted in a sensitivity of 78% and a specificity of 65% and total correct classification of the lithium-added response of 72%. The clinical profile of patients who improve with the addition of lithium may include significant weight loss, psychomotor retardation and possibly, poor control of cortisol secretion. Partial remission before adding lithium as well as endogenomorphic traits according to NDI may also be considered additional criteria for response.

Fluoxetine augmentation in bipolar disorder patients on maintenance lithium treatment

Lithium augmentation during long-term treatment with antidepressants has long been considered an effective therapeutic strategy in the treatment of depressive syndromes. This paper deals with an 'opposite' strategy, i.e. the use of serotonin reuptake inhibitors (SRIs) during maintenance lithium treatment in bipolar disorder (BP) patients who may present a breakthrough depressive syndrome. The study involved 26 patients on maintenance lithium treatment for a mean of 38 months (mean serum lithium level=0.57 mEq/l). Mean fluoxetine dose was 29.3 mg/day for a mean period of 7.36 weeks. Median HDRS scores before and after fluoxetine augmentation were 14 and 6, respectively. The results provide evidence for the efficacy of fluoxetine augmentation in the treatment of breakthrough depressions occurring in bipolar disorder patients during maintenance lithium treatment. The neuropharmacological explanation of the augmentation is not yet well understood, but it is conceivable that the improvement of the depressive symptoms may be related to the increase in serotonergic function provided by combination of the two treatments.

A double-blind, placebo-controlled study of citalopram with and without lithium in the treatment of therapy-resistant depressive patients: a clinical, pharmacokinetic, and pharmacogenetic investigation

Sixty-nine depressive patients (DSM III criteria: 296.2, 296.3, 296.5, 300.4) were treated with 40 to 60 mg citalopram (CIT) daily for 4 weeks. Among them, 45 responded to treatment (improvement > 50% on the 21-item Hamilton Rating Scale for Depression [HAM-D]) and continued their treatment for another week before being released from the study. The 24 nonresponders were randomized and comedicated under double-blind conditions with lithium carbonate (Li) (2 x 400 mg/day) (CIT-Li group) or with placebo (CIT-Pl group) from days 29 to 35. For days 36 to 42, the patients of both subgroups were treated openly with Li (800 mg/day) in addition to the ongoing CIT treatment. On day 35, 6 of 10 patients responded to the CIT-Li combination, whereas 2 of 14 patients only responded to the CIT-Pl combination. This group difference reached significance (p < 0.05) on day 35 with lower HAM-D total scores in the CIT-Li group. No evidence was seen of a pharmacokinetic interaction between CIT and Li, and this combination was well tolerated. Patients were phenotyped with dextromethorphan and mephenytoin at baseline and at day 28. As evaluated at baseline, three patients (responders) were poor metabolizers of dextromethorphan and six patients (three responders and three nonresponders) of mephenytoin. On day 28, the ratio CIT/N-desmethylCIT (DCIT) in plasma was significantly higher in poor than in extensive metabolizers of mephenytoin (p = 0.0001), and there was a significant positive correlation between the metabolic ratio of dextromethorphan and the ratio DCIT/N-didesmethylCIT in plasma (p < 0.001). These findings illustrate the role of CYP2D6 and CYP2C19 in the metabolism of CIT. It can be concluded that Li addition to CIT is effective in patients not responding to CIT alone without any evidence of an accentuation or provocation of adverse events.

Adverse events and tolerability of the combination of fluoxetine/lithium compared with fluoxetine

Data from an intensive observational drug utilization study were analyzed to determine whether patients who received the combination of fluoxetine and lithium had more and different adverse events as compared with those receiving fluoxetine alone. In a matched cohort control design, we compared 110 patients per group. Results showed no significant difference in side effects between groups. Also, the incidence of "serotonergic" adverse events showed no significant differences between groups during the 7-week study period. In conclusion, the results show that the combination of fluoxetine/lithium is generally well tolerated in spite of a somewhat increased rate of minor side effects.

Additive effects of lithium and antidepressants in the forced swimming test: further evidence for involvement of the serotoninergic system

In the mouse forced swimming test (FST) pretreatment with a subactive dose of lithium (1 mEq/kg), given IP 45 min before the test, facilitated the antidepressant activity of iprindole, fluoxetine, and moclobemide (given IP 30 min before the test). These antidepressants (ADS) were not active alone in the FST in this study. Moreover, when subactive lithium was combined with a wide range of ADS, each given at subactive doses, those ADS with serotoninergic properties (e.g. imipramine, citalopram, paroxetine, fluoxetine, trazodone, mianserin, and moclobemide) significantly reduced immobility times. ADS acting primarily on noradrenaline (NA) or dopamine (DA) systems (desipramine, maprotiline, viloxazine, and bupropion) did not significantly decrease immobility when given in combination with lithium. This was also the case for RO 16 6491 [a reversible, B specific monoamine oxidase inhibitor (MAOI)], nialamide, and pargyline (both irreversible, mixed MAOIs). The anti-immobility effect of iprindole in combination with lithium suggests either a direct or indirect action on the serotonin (5HT) system by this ADS whose mechanism of action remains obscure. These results, using an animal behavioral model of depression and combining our present knowledge of the acute action of various ADS, support the hypothesis that the potentiation by lithium of ADS is via direct 5HT mechanisms, indirectly via a NA/5HT link, and/or by second messenger systems. Lithium may also facilitate the expression of antidepressant activity of ADS not active by themselves in the FST.

Treatment-resistant depression: a critique of current approaches

The clinical and research literature on "treatment-resistant depression" is sampled and reviewed. Major conceptual and methodological inadequacies are identified in this literature. The main conceptual problem consists of a confounding of syndrome description with clinicians' treatment-outcome expectations. Methodological problems include: (a) the failure to adequately conceptualise and/or specifically define treatments; (b) the extreme variety of treatments evaluated in the absence of methodological controls; (c) inadequate sampling procedures; (d) the heterogeneity of the patient samples; (e) the bias in favour of reporting positive results; (f) the misrepresentation of outcome in published reports; and (g) the neglect of considering spontaneous remission as a viable alternative explanation. It is recommended that research attention be refocused on defining the characteristics of the depressed person who does not respond to standard anti-depressant therapies, as a precursor to identifying a specific therapy.

Lithium augmentation in sertraline-resistant depression: a preliminary dose-response study

Eleven patients with DSM-III-R major depression who were treatment-resistant to sertraline were allocated for lithium augmentation therapy. In conjunction with their sertraline, 6 received lithium carbonate 400 mg at night and 5 received 800 mg at night. A total of 7 patients responded within 1 week. The degree of response was not related to the serum lithium level. Patients with lithium levels as low as 0.3 mEq/l responded. No significant side effects were reported.

Lithium. Current status in psychiatric disorders

Lithium is the recommended treatment for the prophylaxis of bipolar affective disorder. The drug is also effective in the prophylactic treatment of recurrent unipolar depression, although many psychiatrists prefer to use antidepressant drugs for this indication. The efficacy of lithium is well established in the short term treatment of mania, although neuroleptic drugs are required at the start of treatment for more severely disturbed patients. Lithium augmentation of antidepressant drugs is increasingly popular for the treatment of resistant depression. It is now common practice to maintain serum lithium concentrations in the range 0.5 to 0.8 mmol/L, which is generally as effective as higher concentrations while reducing the incidence of adverse effects and intoxication. Some individuals may nevertheless require higher serum concentrations. Most adverse effects such as tremor and gastrointestinal upset are usually minor and often transient. There is no good evidence of nephrotoxicity with long term treatment, but persistent polyuria can occur. Hypothyroidism, with or without goitre, can occur uncommonly during long term lithium therapy. Prescribers should be alert to, and patients should be educated about, the predisposing factors and early symptoms relating to lithium intoxication. Specialist mood disorder clinics can facilitate safer and more effective lithium treatment.

Fluoxetine: adverse effects and drug-drug interactions

This overview summarizes the major and minor side effects and drug interactions of fluoxetine. The adverse reactions include the "serotonin syndrome", cardiovascular complications, extrapyramidal side effects such as akathisia, dyskinesias, and parkinsonian-like syndromes and an apparently increased risk of suicidality. Fluoxetine-induced mania and hypomania, seizures and sexual disorders are evaluated along with minor symptoms of allergic reactions, stuttering, hematological changes, psoriasis, and inappropriate secretion of the antidiuretic hormone. The major fluoxetine-drug interactions involve the amino acids L-dopa and L-tryptophan, anorexiants, anticonvulsants, antidepressants, anxiolytics, calcium channel blockers, cyproheptadine, lithium salts, and drugs of abuse. The underlying mechanism and the paradoxical effects of fluoxetine are addressed.