CSF inositol does not predict antidepressant response to inositol. Short communication

Complementary and alternative therapies as add-on to pharmacotherapy for mood and anxiety disorders: a systematic review

BACKGROUND

Depressed and anxious patients often combine complementary and alternative medicine (CAM) therapies with conventional pharmacotherapy to self-treat symptoms. The benefits and risks of such combination strategies have not been fully evaluated. This paper evaluates the risk-benefit profile of CAM augmentation to antidepressants in affective conditions.

METHODS

PubMed was searched for all available clinical reports published in English up to December 2012. Data were evaluated based on graded levels of evidence for efficacy and safety.

RESULTS

Generally, the evidence base is significantly larger for depression than for anxiety disorder. In unipolar depression, there is Level 2 evidence for adjunctive sleep deprivation (SD) and Free and Easy Wanderer Plus (FEWP), and Level 3 for exercise, yoga, light therapy (LT), omega-3 fatty acids, S-adenosylmethionine and tryptophan. In bipolar depression, there is Level 1 evidence for adjunctive omega-3s, Level 2 for SD, and Level 3 for LT and FEWP. In anxiety conditions, exercise augmentation has Level 3 support in generalized anxiety disorder and panic disorder. Though mostly well-tolerated, these therapies can only be recommended as third-line interventions due to the quality of available evidence.

LIMITATIONS

Overall, the literature is limited. Studies often had methodological weaknesses, with little information on long-term use and on potential drug-CAM interactions. Many CAM studies were not published in English.

CONCLUSIONS

While several CAM therapies show some evidence of benefit as augmentation in depressive disorders, such evidence is largely lacking in anxiety disorders. The general dearth of adequate safety and tolerability data encourages caution in clinical use.

Second-tier natural antidepressants: review and critique

The use of Complementary and Alternative Medicine (CAM) for physical and mental problems has increased significantly in the US over the past two decades, and depression is one of the leading indications for the use of CAM. This article reviews some of the lesser-known natural products with potential psychiatric applications that are starting to emerge with some scientific and clinical evidence and may constitute a next wave of natural antidepressants: Rhodiola rosea, chromium, 5-Hydroxytryptophan (5-HTP) and inositol. Background information, efficacy data, proposed mechanisms of action, recommended doses, side effects, and precautions are reviewed. We found some encouraging data for the use of these natural products in specific populations of depressed patients. R. rosea is an adaptogen plant that can be especially helpful in treating asthenic or lethargic depression, and may be combined with conventional antidepressants to alleviate some of their common side effects. Chromium has a beneficial effect on eating-related atypical symptoms of depression, and may be a valuable agent in treating atypical depression and seasonal affective disorder. Inositol may be useful in the treatment of bipolar depression when combined with mood stabilizers. Evidence for the clinical efficacy of 5-HTP is also promising but still preliminary. Although more well-designed and larger controlled studies are needed before any substantive conclusions can be drawn, the available evidence is compelling and these natural products deserve further investigation as a possibly significant addition to the antidepressant armamentarium.

Alternative treatments in pediatric bipolar disorder

There has been growing interest in the use of complementary and alternative treatments in pediatric bipolar disorder (BPD). There are limited data, however, regarding the safety and efficacy of these treatments. This article discusses select complementary and alternative treatments that have been considered for use in pediatric BPD and/or depression, including omega-3-fatty acids, inositol, St. John's wort, SAMe, melatonin, lecithin, and acupuncture. Background information, reference to available adult and pediatric data, proposed mechanisms of action, dosing, side effects, and precautions of these treatments are included. Across the board, more research is necessary and warranted regarding the long-term safety and efficacy of available complementary and alternative treatments for the management of pediatric BPD.

Inositol depletion: a good or bad outcome of valproate treatment?

Bipolar affective disorder is a severe and chronic disabling illness affecting 1.5% of the general population. Lithium, valproate and other mood stabilizers are used to treat bipolar disorder; however, these are ineffective for, and not tolerated by, a significant percentage of patients, underscoring the urgent need for better medications. Although not universally accepted, the inositol-depletion hypothesis is one of the main hypotheses suggested to explain the therapeutic mechanism of mood-stabilizing drugs. This paper reviews the relevance of the inositol-depletion hypothesis, paying special attention to the inhibition of inositol de novo synthesis by valproate. It also discusses inositol supplementation as a treatment strategy for multiple neurological disorders, including prophylactic use against valproate-induced neural tube defects.

Inositol augmentation of lithium or valproate for bipolar depression

OBJECTIVE

Despite promising new therapies, bipolar depression remains difficult to treat. Up to half of patients do not respond adequately to currently approved treatments. This study evaluated the efficacy of adjunctive inositol for bipolar depression.

METHODS

Seventeen participants with DSM-IV criteria for bipolar depression and a 17-item Hamilton Rating Scale for Depression (HRSD) > or =15 on proven therapeutic levels of lithium or valproate for >2 weeks were randomized to receive double-blind inositol or placebo for 6 weeks. At the end of double-blind treatment, subjects were eligible for an 8-week open-label trial of inositol.

RESULTS

Response was defined a priori as >50% reduction in the HRSD and a Clinical Global Impression of 1-2. Four of nine subjects (44%) on inositol and zero of eight subjects on placebo met response criteria (p = 0.053). There was no difference between groups in the average change score for the HRSD or Young Mania Rating Scale (YMRS). Response to inositol was highly variable. Of nine subjects randomized to inositol, two had >50% worsening in HRSD scores at the end of treatment, three had no change and four had >50% improvement. Those who had worsening in depressive symptoms on inositol had significantly higher scores at baseline on the YMRS total score and irritability, disruptive/aggressive behavior and unkempt appearance items.

CONCLUSIONS

There was a trend for more subjects on inositol to show improvement in bipolar depression symptoms, but, on average, inositol was not more effective than placebo as an adjunct for bipolar depression. Baseline levels of anger or hostility may be predictive of clinical response to inositol.

An exploratory approach to the serotonergic hypothesis of depression: bridging the synaptic gap

In this exploratory review, we attempt to integrate pre and post synaptic theories of the biochemical basis of depression--in particular with regard to 5-HT. We will be providing evidence that in major depressive disorder, there is a continuity of dysfunction of neural function, i.e. pre and post synaptic serotonergic symptoms are affected. Furthermore, we will also be providing the implications of this approach for normal treatments for depressive disorder.

The effects of inositol treatment in animal models of psychiatric disorders

Clinical trials indicate that inositol may be effective in the treatment of patients with depression, panic disorder and obsessive compulsive disorder (OCD), but not in the treatment of patients with schizophrenia, Alzheimer's disease, ADHD or autism. This spectrum of clinical action parallels that of serotonin selective reuptake inhibitors (SSRIs), but inositol is a precursor in the phosphatidylinositol cycle, a second messenger system distal to the receptor for 5HT-2. To study its mechanism of therapeutic action there is a need to test inositol's activity in animal models of psychopathology. In rats, chronic inositol was demonstrated to increase activity levels, reduce immobility time in the forced swim test and in the reserpine-induced hypoactivity models of depression, and reduce anxiety-like behaviors in the elevated plus-maze. The reduction in anxiety-like behaviors appears to be related to baseline levels of activity. Inositol treatment was not observed to have any effect on amphetamine-induced hyperactivity, apomorphine-induced stereotypy, or on the performance of memory tasks by monkeys. Clinical controlled trials of inositol in patients with depression, panic disorder, and OCD were small, and positive psychoactive effects in animals clearly strengthen the case for further clinical trials and potential for general therapeutic use in humans.

Increased cerebrospinal fluid glutamine levels in depressed patients

BACKGROUND

There is increasing evidence for an association between alterations of brain glutamatergic neurotransmission and the pathophysiology of affective disorders.

METHODS

We studied the association between cerebrospinal fluid (CSF) metabolites, including glutamine, in unipolar and bipolar depressed patients versus control subjects using a proton magnetic resonance spectroscopy technique. Cerebrospinal fluid samples were obtained from 18 hospitalized patients with acute unmedicated severe depression without medical problems and compared with those of 22 control subjects.

RESULTS

Compared with the control group, the depressed patient group had significantly higher CSF glutamine concentrations, which correlated positively with CSF magnesium levels.

CONCLUSIONS

These findings suggest an abnormality of the brain glial-neuronal glutamine/glutamate cycle associated with N-methyl-D-aspartate receptor systems in patients with depression.

Inositol as an add-on treatment for bipolar depression

OBJECTIVE

Inositol is a constituent of the intracellular phosphatidyl inositol (PI) second messenger system, which is linked to various neurotransmitter receptors. Inositol crosses the blood-brain barrier in pharmacological doses, and has shown efficacy in a small double-blind study of unipolar depression. This pilot study evaluated its potential efficacy and safety in bipolar depression.

METHODS

Twenty-four consenting adult men and women with DSM-IV bipolar depression (bipolar I = 21; bipolar II = 3) were randomly assigned to receive either 12 g of inositol or D-glucose as placebo for 6 weeks. Efficacy and safety ratings were done weekly. Thymoleptic medications (lithium, valproate, carbamazepine) in stable doses and at therapeutic levels at study entry were continued unchanged.

RESULTS

Two subjects receiving placebo dropped out early due to worsening or non-adherence to the protocol. Among the 22 subjects who completed the trial, six (50%) of the inositol-treated subjects responded with a 50% or greater decrease in the baseline Hamilton Depression Rating Scale (HAM-D) score and a Clinical Global Improvement (CGI) scale score change of 'much' or 'very much' improved, as compared to three (30%) subjects assigned to placebo, a statistically nonsignificant difference. On the Montgomery-Asberg Depression Rating Scale (MADRS), eight (67%) of twelve inositol-treated subjects had a 50% or greater decrease in the baseline MADRS scores compared to four (33%) of twelve subjects assigned to placebo (p = 0.10). Inositol was well tolerated with minimal side effects, and thymoleptic blood levels were unaltered.

CONCLUSIONS

These pilot data suggest a controlled study with an adequate sample size, and the appropriate rating scale may demonstrate efficacy for inositol in bipolar depression. The tolerability and the 'natural substance' aspect of inositol may be particularly appealing to subjects with bipolar depression.

Reduced glutamate in the anterior cingulate cortex in depression: an in vivo proton magnetic resonance spectroscopy study

BACKGROUND

Functional imaging studies suggest a specific role of the anterior brain regions in the pathogenesis of major depression. The aim of this study was to evaluate possible neurochemical alterations in the frontomesial cortex in patients with major depressive episode using in vivo proton magnetic resonance spectroscopy ((1)H-MRS).

METHODS

Single voxel (1)H-MRS was performed in 19 patients with major depressive episodes and 18 age-matched healthy controls within the anterior cingulate cortex and the parietal white matter. Absolute concentrations were estimated for N-acetyl-aspartate, choline-containing compounds, total creatine, myo-inositol, unresolved glutamate and glutamine (Glx) and glutamate alone (Glu). Voxel composition was analyzed by image segmentation into cerebrospinal fluid (CSF), grey and white matter.

RESULTS

MANOVA test for Glx and Glu using age, percent CSF and percent grey matter contribution as covariates yielded a significant group effect within the anterior cingulate due to decrease of Glx in patients (-10.4%, p =.013). Considering only severely depressed patients, both Glx and Glu (-14.3%, p =.03) showed a significant decrease. There was no significant group effect for the neuronal marker NAA, creatine, choline or myo-inositol in either localization.

CONCLUSIONS

This study suggests a possible role of altered glutamatergic neurotransmission within the anterior cingulate in the pathogenesis of mood disorders. The otherwise unremarkable findings of major brain metabolites confirms lack of neurodegenerative or membrane metabolic changes in major depression.

Epi-inositol and inositol depletion: two new treatment approaches in affective disorder

Inositol is a simple polyol precursor in a second messenger system important in brain myo-insitol, the natural isomer, which has been found to be therapeutically effective in depression, panic disorder, and obsessive-compulsive disorder in double-blind controlled trials. Recently, epi-inositol, an unnatural stereoisomer of myo-inositol, was found to have effects similar to those of myo-inositol to reverse lithium-pilocarpine seizures. We measured the behavior of rats in an elevated plus maze model of anxiety after chronic treatment of 11 daily intraperitoneal injections of epi-inositol, myo-inositol, or control solution. Epi-inositol reduced anxiety levels of rats compared with controls, and its effect was stronger than that of myo- inositol. Lithium has been hypothesized to alleviate mania by reducing brain inositol levels. Inositol in brain derives from the second messenger cycle, from new synthesis, or from diet via transport across the blood brain barrier. Because the first two are inhibited by lithium, we propose that an inositol-free diet will augment lithium action in mania by enhancing restriction of inositol.

Cerebrospinal fluid inositol monophosphatase: elevated activity in depression and neuroleptic-treated schizophrenia

BACKGROUND

Inositol monophosphatase (IMPase) is a key enzyme in the regulation of the activity of the phosphatidyl inositol (PI) signaling pathway. This enzyme is also found in the cerebrospinal fluid (CSF), where it may prove useful as a marker of dysfunctional PI signal transduction.

METHODS

IMPase activity was measured in lumbar CSF of depressed and neuroleptic-treated schizophrenic patients. In addition, and to gain an insight into the factors that influence the levels of CSF IMPase, enzyme activity was measured in subgroups of schizophrenic patients treated for 3-7 days with lithium or 7 days with inositol.

RESULTS

CSF IMPase activity was significantly increased by 88% in depressed and by 172% in schizophrenic patients relative to control subjects. Lithium produced a marked increase in CSF IMPase activity in the group as a whole, and this group effect could be more specifically attributed to 3 of the 8 individuals in whom enzyme activity increased by over 300%. On the other hand, inositol had no effect on CSF IMPase activity.

CONCLUSIONS

In the absence of a clear relationship between CSF IMPase activity and neuronal PI signaling pathways it is not possible to correlate these changes with altered neuronal function. Nevertheless, increased CSF IMPase activity in depression and schizophrenia may be a marker of the pathophysiological processes underlying these disorders. Moreover, the large lithium-induced increase in IMPase activity seen in a subgroup of schizophrenic subjects suggests a differential regulation of CSF enzyme activity in these patients.