Melancholic features and response to lithium prophylaxis in mood disorders

Chronic Lithium Treatment Affects Anxious Behaviors and theExpression of Serotonergic Genes in Midbrain Raphe Nuclei of Defeated Male Mice

There is experimental evidence that chronic social defeat stress is accompanied by the development of an anxiety, development of a depression-like state, and downregulation of serotonergic genes in midbrain raphe nuclei of male mice. Our study was aimed at investigating the effects of chronic lithium chloride (LiCl) administration on anxiety behavior and the expression of serotonergic genes in midbrain raphe nuclei of the affected mice. A pronounced anxiety-like state in male mice was induced by chronic social defeat stress in daily agonistic interactions. After 6 days of this stress, defeated mice were chronically treated with saline or LiCl (100 mg/kg, i.p., 2 weeks) during the continuing agonistic interactions. Anxiety was assessed by behavioral tests. RT-PCR was used to determine Tph2, Htr1a, Htr5b, and Slc6a4 mRNA expression. The results revealed anxiolytic-like effects of LiCl on social communication in the partition test and anxiogenic-like effects in both elevated plus-maze and social interaction tests. Chronic LiCl treatment upregulated serotonergic genes in midbrain raphe nuclei. Thus, LiCl effects depend on the treatment mode, psycho-emotional state of the animal, and experimental context (tests). It is assumed that increased expression of serotonergic genes is accompanied by serotonergic system activation and, as a side effect, by higher anxiety.

A systematic review and meta-analysis of clinical predictors of lithium response in bipolar disorder

OBJECTIVE

To determine clinical predictors of lithium response in bipolar disorder.

METHODS

Systematic review of studies examining clinical predictors of lithium response was conducted. Meta-analyses were performed when ≥2 studies examined the same potential predictor.

RESULTS

A total of 71 studies, including over 12 000 patients, identified six predictors of good response: mania-depression-interval sequence [odds ratio (OR): 4.27; 95% CI: 2.61, 6.97; P < 0.001], absence of rapid cycling (OR for rapid cycling: 0.30; 95% CI: 0.17, 0.53; P < 0.001), absence of psychotic symptoms (OR for psychotic symptoms: 0.52; 95% CI: 0.34, 0.79; P = 0.002), family history of bipolar disorder (OR: 1.61; 95% CI: 1.03, 2.52; P = 0.036), shorter prelithium illness duration [standardised mean difference (SMD): -0.26; 95% CI: -0.41, -0.12; P < 0.001] and later age of onset (SMD: 0.17; 95% CI: 0.02, 0.36; P = 0.029). Additionally, higher body mass index was associated with poor response in two studies (SMD: -0.61; 95% CI: -0.90, -0.32; P < 0.001). There was weak evidence for number of episodes prior to lithium treatment (SMD: -0.42; 95% CI: -0.84, -0.01; P = 0.046), number of hospitalisations before lithium (SMD: -0.40; 95% CI: -0.81, 0.01; P = 0.055) and family history of lithium response (OR: 10.28; 95% CI: 0.66, 161.26; P = 0.097).

CONCLUSIONS

The relative importance of these clinical characteristics should be interpreted with caution because of potential biases and confounding.

Differential response to lithium between melancholic and non-melancholic unipolar depression

The purpose of this report was to review the evidence regarding the differential response to lithium treatment between patients with unipolar melancholic and non-melancholic depression. Three studies suggest that the prophylactic effect of lithium in maintenance treatment may be greater in melancholic depression. Another study reported that melancholic symptoms, such as weight loss and psychomotor disturbances, predict a better response to lithium augmentation. These preliminary data suggest that the response to lithium may be greater in melancholic than in non-melancholic depression, which could be the focus of further research.

Common genetic, clinical, demographic and psychosocial predictors of response to pharmacotherapy in mood and anxiety disorders

The aim of this study is to summarize available knowledge about common genetic, clinical, demographic and psychosocial predictors of response to pharmacotherapy in mood and anxiety disorders. A literature search was carried out by using MEDLINE and references of selected articles. The search included articles published up to March 2008. The main genetic finding concerns the serotonin transporter gene promoter polymorphisms, the long variant of which seems to be related to a positive response to therapy in mood disorders and could also have a role in the treatment of anxiety disorders. Among other predictors, the main factors common to both classes of disorder are comorbid axis II disorders and early onset of illness, which are related to a worse response to therapy and concomitant good physical conditions, absence of earlier treatments, early administration and response to therapies, and higher self- directedness, which is related to a better outcome. Many common predictors have been identified and these seem to be related to features covering the totality of patients that go beyond specific characteristics of single disorders. Possible limitations and suggestions for future research based on a more integrated vision of human complexity are discussed.

Further evidence for a possible association between serotonin transporter gene and lithium prophylaxis in mood disorders

We previously reported an association between the functional polymorphism in the upstream regulatory region of the serotonin transporter gene (SERTPR) and the prophylactic efficacy of lithium in a sample of 201 Italian subjects affected by Mood disorders. The aim of the present study was to replicate analyses on an independent sample. In total, 83 subjects affected by Bipolar disorder were recruited in the Mood Disorders Clinic of the Eginition Hospital of the Athens University, Medical School Department of Psychiatry. All patients were administered with lithium as prophylactic therapy and they were prospectively observed for at least 3 years. Subjects were typed for their SERTPR variant using polymerase chain reaction techniques. SERTPR variants were associated with lithium outcome among those subjects who had few manic episodes before lithium treatment and, as a trend, among subjects who received a high daily dose of lithium (> or =1200 mg/die). In both cases, subjects with the l/l variant showed a higher probability to develop an illness episode within 3 years of prophylactic treatment with lithium. The present study confirmed our previous observation of a better response of SERTPR*l/s carriers, but could not confirm a poor efficacy in subjects with the SERTPR*s/s genotype. Notwithstanding the conflicting results, SERTPR variants are a possible liability factor for lithium long-term efficacy in mood disorders. Further studies on independent and large samples are required to determine the reliability and direction of the possible association between SERTPR variants and lithium outcome.

Predicting response to lithium in mood disorders: role of genetic polymorphisms

Lithium is considered to be the first choice mood stabilizer in recurrent mood disorders. Its widespread and large-scale use is the result of its proven efficacy. In spite of this fact, patients have been observed to show a variable response to lithium treatment: in some cases it is completely effective in preventing manic or depressive relapses, while in other cases it appears to show no influence on the disease course. The possible definition of a genetic liability profile for adverse effects and efficacy will be of great help, as lithium therapy needs at least 6 months to be effective in stabilizing mood disorders. During the last few years, a number of groups have reported possible liability genes. Lithium long-term prophylactic efficacy has been associated with serotonin transporter protein, tryptophan hydroxylase and inositol polyphosphate 1-phosphatase variants. A number of other candidate genes and anonymous markers did not yield positive associations. Therefore, even if some positive results have been reported, no unequivocal susceptibility gene for lithium efficacy has been identified. Although the available data may not currently allow a meaningful prediction of lithium response, future research is aimed at the development of individualized treament of mood disorders, including the possibility of 'pharmacological genetic counseling'.

Prophylaxis latency and outcome in bipolar disorders

OBJECTIVE

To analyze new and reviewed findings to evaluate relations between treatment response and latency from onset of bipolar disorder (BD) to the start of mood-stabilizer prophylaxis.

METHOD

We analyzed our own new data and added findings from research reports identified by computerized searching.

RESULTS

We found 11 relevant studies, involving 1485 adult patients diagnosed primarily with BD. Reported latency to prophylaxis averaged 9.6 years (SD 1.3), and follow-up in treatment averaged 5.4 years (SD 3.1). Greater illness intensity and shorter treatment latency were closely associated, resulting in a greater apparent reduction in morbidity with earlier treatment. However, this finding was not sustained after correction for pretreatment morbidity, and treatment latency did not predict morbidity during treatment. Therefore, assessments based on improvement with treatment, or without correction for pretreatment morbidity, can be misleading.

CONCLUSIONS

Available evidence does not support the proposal that delayed prophylaxis may limit response to prophylactic treatment in BD and related disorders.

The effect of lithium in bipolar disorder: a review of recent research evidence

Recently published clinical research on lithium is briefly reviewed. The antimanic effect of lithium is supported by recent evidence. It is confirmed that a drastic reduction of affective morbidity is very frequent in bipolar patients receiving lithium prophylaxis regularly for several years, but that the impact of prophylaxis on the course of bipolar disorder is significantly limited by the high drop-out rate. Lithium does seem to be efficacious also in bipolar disorder with mood-incongruent psychotic features or with rapid cycling. The effect of lithium prophylaxis does not seem to decrease over time, at least in the large majority of patients. The recurrence risk is increased in the months following lithium discontinuation. Lithium seems to exert an antisuicidal effect in bipolar patients.

Treatment-latency and previous episodes: relationships to pretreatment morbidity and response to maintenance treatment in bipolar I and II disorders

OBJECTIVE

To clarify relationships of treatment delay and pretreatment episode count with pretreatment morbidity and responses to maintenance treatments in bipolar disorders.

METHODS

In 450 DSM-IV bipolar I (n = 293) or II (n = 157) patients (280 women, 170 men), we evaluated correlations of latency from illness-onset to starting maintenance treatment and pretreatment episode counts with pretreatment morbidity and treatment response. We considered morbidity measures before and during treatment, and their differences.

RESULTS

Latency averaged 7.8 years, with 9.0 episodes per patient, before various maintenance treatments started. Morbidity (percentage of time-ill, episodes per year, first wellness-interval, or proportion of subjects hospitalized or having no recurrences) during maintenance treatment averaging 4.2 years was unrelated to treatment latency or pretreatment episode count. However, pretreatment morbidity was greater with shorter latency, resulting in larger relative reduction of morbidity after earlier treatment.

CONCLUSIONS

Greater treatment latency and pretreatment episode count were not followed by greater morbidity during treatment, although longer delay yielded smaller during-versus-before treatment reduction in morbidity. Predictions that longer treatment delay or more pretreatment episodes lead to poorer responses to various maintenance treatments in bipolar I or II disorder were not supported.

Seasonal variations of lithium plasma levels

The aim of this study was to investigate the seasonal time course of lithium blood levels. We analyzed lithium plasma and red blood cell (RBC) levels in 186 subjects affected by bipolar (n=134) and major depressive (n=52) disorder, with stable oral dosage, followed in our lithium clinic for an average of 36 months. We observed a significant elevation of lithium plasma levels in summer with a more marked variation among early-onset subjects, bipolar subtype, and females. Lithium levels in plasma peaked in summer, and levels in RBC showed a trend in the same direction. Possible stratification factors such as presence of affected relatives or psychotic features did not significantly influence results. In conclusion, we observed a significant variation of lithium plasma levels according to seasons. If confirmed, this finding could have both clinical and research implications.

Behavioral effects of novel enterosorbent Noolit on mice with mixed depression/anxiety-like state

The aim of this work was to examine the behavioral effects of a novel lithium-based enterosorbent, Noolit (665 mg/kg), on male mice with mixed depression/anxiety-like state evoked by exposure to repeated social defeats in daily agonistic confrontations. The lithium component allows Noolit to be used as a psychotropic drug. Two experiments are described, in which the therapeutic and preventative effects of chronic Noolit treatment were examined. Response to Noolit was assessed in the plus maze, open field, partition test, and Porsolt's test. In both experiments, Noolit produced obvious anxiolytic and antidepressant effects. Treatment with Noolit fully restored some behavioral parameters in the plus maze and open field in depressed mice and prevented depression that would otherwise have developed. It has been suggested that enterosorbent Noolit can be a potent drug for the treatment of mixed anxiety/depression pathologies and for prevention of mood disorders.

Serotonin transporter gene associated with lithium prophylaxis in mood disorders

The aim of this study was to investigate the possible association between the functional polymorphism in the upstream regulatory region of the serotonin transporter gene (5-HTTLPR) and the prophylactic efficacy of lithium in mood disorders. Two hundred and one subjects affected by bipolar (n = 167) and major depressive (n = 34) disorder were followed prospectively for an average of 58.2 months and were typed for their 5-HTTLPR variant using polymerase chain reaction techniques. 5-HTTLPR variants were associated with lithium outcome (F = 5.35; df = 2,198; P = 0.005). Subjects with the s/s variant showed a worse response compared to both l/s and l/l variants. Consideration of possible stratification effects such as sex, polarity, age at onset, duration of lithium treatment and previous episodes did not influence the observed association. 5-HTTLPR variants may be a possible influencing factor for the prophylactic efficacy of lithium in mood disorders.

Lithium long-term treatment in mood disorders: clinical and genetic predictors

Lithium is the most widely used long-term treatment for recurrent mood disorders. Despite its proven efficacy, patients show a variable response, ranging from complete efficacy to no influence at all. This paper reviews possible predictors of response focusing on molecular genetic studies. The functional polymorphism in the upstream regulatory region of the serotonin transporter gene (5-HTTLPR) has been associated with lithium long-term efficacy in two independent studies, marginal associations have been reported for tryptophan hydroxylase and inositol polyphosphate 1-phosphatase (INPP1). A number of other candidate genes and anonymous markers did not yield positive associations. Therefore, even though some positive results have been reported, no unequivocal susceptibility gene for lithium efficacy has been identified.