Mitochondrial DNA content and oxidation in bipolar disorder and its role across brain regions.

The underlying pathology of bipolar disorder remains unknown, though evidence is accumulating to support a role of mitochondrial dysfunction. In this study, we aim to investigate electron transport chain complex I subunit NDUFS7 protein expression; mtDNA content; common deletion; and oxidation in the Broadmann area 24 (BA24), cerebellum, hippocampus, and prefrontal cortex from patients with bipolar disorder, schizophrenia, and non-psychiatric controls. Here, we demonstrate no changes in NDUFS7 in BA24, cerebellum or hippocampus, increases in mtDNA content in hippocampus of patients with bipolar disorder, and decreases in mtDNA oxidation in patients with bipolar disorder and schizophrenia, respectively. Paired analysis between BA24 and cerebellum reveal increases within NDUFS7 levels and mtDNA content in cerebellum of patients with bipolar disorder or schizophrenia. We found a positive correlation between NDUFS7 and mtDNA content (ND4 and ND5) when combining brain regions. Our study supports the involvement of mitochondrial dysfunction in bipolar disorder and schizophrenia.

Optimal duration of risperidone or olanzapine adjunctive therapy to mood stabilizer following remission of a manic episode: A CANMAT randomized double-blind trial.

Atypical antipsychotic adjunctive therapy to lithium or valproate is effective in treating acute mania. Although continuation of atypical antipsychotic adjunctive therapy after mania remission reduces relapse of mood episodes, the optimal duration is unknown. As many atypical antipsychotics cause weight gain and metabolic syndrome, they should not be continued unless the benefits outweigh the risks. This 52-week double-blind placebo-controlled trial recruited patients with bipolar I disorder (n=159) who recently remitted from a manic episode during treatment with risperidone or olanzapine adjunctive therapy to lithium or valproate. Patients were randomized to one of three conditions: discontinuation of risperidone or olanzapine and substitution with placebo at (i) entry ('0-weeks' group) or (ii) at 24 weeks after entry ('24-weeks' group) or (iii) continuation of risperidone or olanzapine for the full duration of the study ('52-weeks' group). The primary outcome measure was time to relapse of any mood episode. Compared with the 0-weeks group, the time to any mood episode was significantly longer in the 24-weeks group (hazard ratio (HR) 0.53; 95% confidence interval (CI): 0.33, 0.86) and nearly so in the 52-weeks group (HR: 0.63; 95% CI: 0.39, 1.02). The relapse rate was similar in the 52-weeks group compared with the 24-weeks group (HR: 1.18; 95% CI: 0.71, 1.99); however, sub-group analysis showed discordant results between the two antipsychotics (HR: 0.48, 95% CI: 0.17; 1.32 olanzapine patients; HR: 1.85, 95% CI: 1.00, 3.41 risperidone patients). Average weight gain was 3.2 kg in the 52-weeks group compared with a weight loss of 0.2 kg in the 0-weeks and 0.1 kg in the 24-weeks groups. These findings suggest that risperidone or olanzapine adjunctive therapy for 24 weeks is beneficial but continuation of risperidone beyond this period does not reduce the risk of relapse. Whether continuation of olanzapine beyond this period reduces relapse risk remains unclear but the potential benefit needs to be weighed against an increased risk of weight gain.

Low rate of prenatal diagnosis among neonates with critical aortic stenosis: insight into the natural history in utero.

OBJECTIVES: To better understand the natural history and spectrum of fetal aortic stenosis (AS), we aimed to (1) determine the prenatal diagnosis rate of neonates with critical AS and a biventricular (BV) outcome, and (2) describe the findings at fetal echocardiography in patients diagnosed prenatally. METHODS: A multicenter, retrospective study was performed on neonates who presented with critical AS and who were discharged with a BV outcome from 2000 to 2013. The prenatal diagnosis rate was compared with that reported for hypoplastic left heart syndrome (HLHS). We reviewed fetal echocardiographic findings in patients who were diagnosed prenatally. RESULTS: In only 10 (8.5%) of 117 neonates with critical AS and a BV outcome was the diagnosis made prenatally, a rate significantly lower than that for HLHS in the contemporary era (82%; P < 0.0001). Of the 10 patients diagnosed prenatally, all had developed left ventricular dysfunction by a median gestational age of 33 (range, 28-35) weeks. When present, Doppler abnormalities such as retrograde flow in the aortic arch (n = 2), monophasic mitral inflow (n = 3) and left-to-right flow across the foramen ovale (n = 8) developed late in gestation (median 33 weeks). CONCLUSION: The prenatal diagnosis rate of critical AS and a BV outcome among neonates is very low, probably owing to a relatively normal four-chamber view in mid-gestation with development of significant obstruction in the third trimester. The natural history contrasts with that of severe mid-gestation AS with evolving HLHS and suggests that the gestational timing of development of significant AS has an important impact on subsequent left-heart growth in utero.

Elevated serum measures of lipid peroxidation and abnormal prefrontal white matter in euthymic bipolar adults: toward peripheral biomarkers of bipolar disorder.

Diffusion tensor imaging (DTI) studies consistently reported abnormalities in fractional anisotropy (FA) and radial diffusivity (RD), measures of the integrity of white matter (WM), in bipolar disorder (BD), that may reflect underlying pathophysiologic processes. There is, however, a pressing need to identify peripheral measures that are related to these WM measures, to help identify easily obtainable peripheral biomarkers of BD. Given the high lipid content of axonal membranes and myelin sheaths, and that elevated serum levels of lipid peroxidation are reported in BD, these serum measures may be promising peripheral biomarkers of underlying WM abnormalities in BD. We used DTI and probabilistic tractography to compare FA and RD in ten prefrontal-centered WM tracts, 8 of which are consistently shown to have abnormal FA (and/or RD) in BD, and also examined serum lipid peroxidation (lipid hydroperoxides, LPH and 4-hydroxy-2-nonenal, 4-HNE), in 24 currently euthymic BD adults (BDE) and 19 age- and gender-matched healthy adults (CONT). There was a significant effect of group upon FA in these a priori WM tracts (BDECONT: F[1,41]=10.3; P=0.003), and a significant between-group difference in LPH (BDE>CONT: t[40]=2.4; P=0.022), but not in 4-HNE. Multivariate multiple regression analyses revealed that LPH variance explained, respectively, 59 and 51% of the variance of FA and RD across all study participants. This is the first study to examine relationships between measures of WM integrity and peripheral measures of lipid peroxidation. Our findings suggest that serum LPH may be useful in the development of a clinically relevant, yet easily obtainable and inexpensive, peripheral biomarkers of BD.

Neuroprotective effect of lithium on hippocampal volumes in bipolar disorder independent of long-term treatment response.

BACKGROUND: Neuroimaging studies have demonstrated an association between lithium (Li) treatment and brain structure in human subjects. A crucial unresolved question is whether this association reflects direct neurochemical effects of Li or indirect effects secondary to treatment or prevention of episodes of bipolar disorder (BD). METHOD: To address this knowledge gap, we compared manually traced hippocampal volumes in 37 BD patients with at least 2 years of Li treatment (Li group), 19 BD patients with <3 months of lifetime Li exposure over 2 years ago (non-Li group) and 50 healthy controls. All BD participants were followed prospectively and had at least 10 years of illness and a minimum of five episodes. We established illness course and long-term treatment response to Li using National Institute of Mental Health (NIMH) life charts. RESULTS: The non-Li group had smaller hippocampal volumes than the controls or the Li group (F 2,102 = 4.97, p = 0.009). However, the time spent in a mood episode on the current mood stabilizer was more than three times longer in the Li than in the non-Li group (t(51) = 2.00, p = 0.05). Even Li-treated patients with BD episodes while on Li had hippocampal volumes comparable to healthy controls and significantly larger than non-Li patients (t(43) = 2.62, corrected p = 0.02). CONCLUSIONS: Our findings support the neuroprotective effects of Li. The association between Li treatment and hippocampal volume seems to be independent of long-term treatment response and occurred even in subjects with episodes of BD while on Li. Consequently, these effects of Li on brain structure may generalize to patients with neuropsychiatric illnesses other than BD.

Decreased mRNA expression of uncoupling protein 2, a mitochondrial proton transporter, in post-mortem prefrontal cortex from patients with bipolar disorder and schizophrenia.

Although the neurobiological basis of bipolar disorder (BD) remains unknown, mitochondrial dysfunction, oxidative stress and oxidative cell damage have been identified in this disease. Uncoupling proteins (UCP) are proton carriers located in the inner membrane of the mitochondria involved in controlling the production of mitochondrial reactive oxygen species (ROS). Therefore, in this study we wished to investigate the involvement of UCP in BD. We analyzed the RNA and protein levels of UCP2 in the dorsolateral prefrontal cortex (DLPFC) of subjects with BD and schizophrenia (SCZ) and assessed the potential relationship between the antioxidant superoxide dismutase (SOD1 and SOD2) and UCP2 in the same region. Our results showed a downregulation of UCP2 mRNA levels in the DLPFC of subjects with BD and SCZ. There were no differences in UCP2 protein, SOD1 and SOD2 levels between patients and controls. Although more studies are necessary, our results suggest that UCP2 is not been used as a compensatory mechanism to oppose the higher levels of oxidative stress found in BD and SCZ.

Lithium treatment prevents stress-induced dendritic remodeling in the rodent amygdala.

Amygdala function is altered in patients with bipolar disorder (BD), but may be normalized by treatment with mood stabilizers. Lithium remains the most effective mood stabilizing therapy for BD, but the relevance of its neuroprotective effects in pre-clinical studies to clinical outcomes is unknown, and the targeting of amygdalar neurons by therapeutic interventions for BD has not yet been examined. Chronic stress in rodents increases activation of the amygdala and induces dendritic hypertrophy, thus providing a quantifiable marker of neuronal structural pathology that may be reversed by lithium treatment. Rats underwent restraint stress for 21 days, with or without concurrent administration of lithium in their diet. The overall length and complexity of neuronal dendritic arbors of principal pyramidal neurons in the basolateral amygdala were quantified using Golgi-Cox impregnation and three-dimensional neuron tracing. Lithium treatment prevented stress-induced increases in dendritic branching of amygdalar pyramidal neurons by reducing total dendritic length (18.0%; P=0.006) and the number of dendritic branch points (21.0%; P=0.02). Despite its protective effect when administered during stress, lithium did not alter amygdalar dendritic morphology when administered to non-stressed control rats. Our results demonstrate that lithium attenuates structural remodeling in the amygdala during stress, but has contrasting effects on neuronal morphology under pathological versus healthy conditions. This may reflect an ability of lithium to stabilize excitatory neurotransmission in the amygdala of individuals with BD, reducing the need for compensatory adjustments of dendritic architecture.

The effect of mood stabilizer lithium on expression and activity of glutathione s-transferase isoenzymes.

Chronic treatment with the mood stabilizer lithium is required to generate its mood stabilizing effect in the treatment of bipolar disorder. Our recent studies have shown that chronic lithium treatment increases mRNA and protein levels of the cytosolic glutathione s-transferase (GST) M1 isoenzyme. Cytosolic GST encompasses a family of detoxification enzymes that include four main classes: alpha (A), mu (M), pi (P) and theta (T). The purpose of this study is to examine the effect of lithium on GST isoenzymes that are expressed in brain, and determine the role of GST in the neuroprotective effects of lithium against oxidative stress. We found in primary cultured rat cerebral cortical cells that chronic lithium treatment not only increased GST M1 mRNA levels, but also increased GST M3, M5 and A4 mRNA levels. Chronic lithium treatment increased GST enzyme activity when 1-chloro-2, 4-dinitrobenzene and 4-hydroxynonenal were used as substrates. In addition, we found that chronic lithium treatment inhibited reactive oxygen metabolite H(2)O(2)-induced cell death and DNA fragmentation in primary cultured rat cerebral cortical cells, while GST inhibitor ethacrynic acid reduced the neuroprotective effect of lithium against H(2)O(2)-induced cell death and DNA fragmentation. Since GST conjugates glutathione, the major antioxidant in brain, with a variety of oxidized products to form nontoxic products, and plays an important role in cellular protection against oxidative stress, our findings suggest that lithium selectively targets GST isoenzymes in order to produce neuroprotective effects against oxidative stress.

Role of glutathione in neuroprotective effects of mood stabilizing drugs lithium and valproate.

Mood stabilizing drugs lithium and valproate are the most commonly used treatments for bipolar disorder. Previous studies in our laboratory indicate that chronic treatment with lithium and valproate inhibits oxidative damage in primary cultured rat cerebral cortical cells. Glutathione, as the major antioxidant in the brain, plays a key role in defending against oxidative damage. The purpose of this study was to determine the role of glutathione in the neuroprotective effects of lithium and valproate against oxidative damage. We found that chronic treatment with lithium and valproate inhibited reactive oxygen metabolite H(2)O(2)-induced cell death in primary cultured rat cerebral cortical cells, while buthionine sulfoximine, an inhibitor of glutathione rate-limiting synthesis enzyme glutamate-cysteine ligase, reduced the neuroprotective effect of lithium and valproate against H(2)O(2)-induced cell death. Further, we found that chronic treatment with lithium and valproate increased glutathione levels in primary cultured rat cerebral cortical cells and that the effects of lithium and valproate on glutathione levels were dose-dependent in human neuroblastoma SH-SY5Y cells. Chronic treatment with lithium and valproate also increased the expression of glutamate-cysteine ligase in both rat cerebral cortical cells and SH-SY5Y cells. In addition, chronic treatment with other mood stabilizing drugs lamotrigine and carbamazepine, but not antidepressants desipramine and fluoxetine, increased both glutathione levels and the expression of glutamate-cysteine ligase in SH-SY5Y cells. These results suggest that glutathione plays an important role in the neuroprotective effects of lithium and valproate, and that glutathione may be a common target for mood stabilizing drugs.

Effects of restraint stress on the expression of proteins involved in synaptic vesicle exocytosis in the hippocampus.

Chronic restraint stress has been associated with induction of morphological changes in the hippocampus. Postsynaptically, these changes include decreased length and branching of apical dendrites from CA3 pyramidal neurons, while presynaptically, depletion and clustering of synaptic vesicles have been observed. However, the molecular correlates of these changes remain poorly defined; while some studies have identified changes in the levels of some presynaptic proteins, none have assessed the coordinate expression of components of the membrane fusion complex, including synaptobrevin, syntaxin, and synaptosomal-associated protein 25 kDa, and their major regulatory molecules synaptotagmin, synaptophysin, and synapsin. Therefore, we undertook to assess the immunoreactivity of these proteins in hippocampal slices obtained from rats subjected to either acute (one 6 h session) or chronic (21 days at 6 h per day) of restraint stress. Specifically, we observed a significant increase in synaptobrevin immunoreactivity in the inner molecular layer of the dentate gyrus (54.2%; P=0.005), the stratum radiatum in the CA1 subfield (55.5%; P=0.007), and a region including the stratum lucidum and the proximal portion of the stratum radiatum in the CA3 subfield (52.7%; P=0.002); we also observed a trend toward increased synaptophysin levels in the stratum lucidum/radiatum of the CA3 subfield (8.0%; P=0.051) following chronic, but not acute, restraint stress. In that synaptobrevin has been associated with replenishment of the "readily-releasable" pool of synaptic vesicles and the efficiency of neurotransmitter release, the present results suggest that stress-induced changes in synaptobrevin may at least in part underlie the previously observed changes in synaptic and neuronal morphology.

One-year outcome with antidepressant--treatment of bipolar depression.

OBJECTIVE: To examine the risk of relapse into mania or depression with varying duration of antidepressant treatment in a cohort of 59 patients with bipolar disorder. METHOD: An open naturalistic evaluation using life charting methods of patients with 1 year follow-up, who responded to antidepressant treatment and who then less or more than 6 months of antidepressant treatment. RESULTS: Patients who received more than 6 months of antidepressant treatment were less likely to relapse into depression at follow-up of 1 year. There was no difference in relapse rates for mania in the different antidepressant treatment duration groups. Gender and bipolar subtype did not significantly affect relapse rates for depression or mania. CONCLUSION: Our data, taken with other studies, suggest that the duration of optimal antidepressant treatment in bipolar disorder must be further evaluated.

Differential display polymerase chain reaction reveals increased expression of striatal rat glia-derived nexin following chronic clozapine treatment.

Clozapine is considered a prototype of the 'so-called' atypical antipsychotic drug class. It has affinity for a broad range of receptors and, in comparison to typical antipsychotic drugs, produces less extrapyramidal side effects. However, its mechanism of action remains unclear. Differential display polymerase chain reaction (ddPCR) was implemented in this study to contribute to the current understanding of this mechanism at the genetic level and to identify novel genes regulated by clozapine. This technique generated approximately 2400 gene sequences that were analyzed for differential gene expression following protracted clozapine treatment. One of these sequences, originally termed Clozapine Regulated Gene (CRG), was shown to be significantly upregulated following the treatment. Northern hybridization confirmation of this finding revealed that chronic clozapine administration caused a five-fold increase in CRG mRNA. Elongation of the 5'- and 3'-ends of CRG indicated that the fragment was in fact rat glia-derived nexin mRNA. Western blotting demonstrated that levels of the mRNA's associated protein also increased comparably (three-fold) following chronic treatment with the antipsychotic drug. This study presents a possible neuroprotective role of nexin in clozapine treatment, particularly in the prevention of neuronal proteolytic degradation, since nexin has been shown to be a protease inhibitor.

Implications of the neuroprotective effects of lithium for the treatment of bipolar and neurodegenerative disorders.

Bipolar disorder is increasingly recognized as an illness that may progress to impairment in neurocognitive functioning and cell loss in cortical and limbic brain regions. Glutamatergic damage and/or damage due to high glucocorticoid levels that inhibit adult neurogenesis are likely contributing mechanisms. Drug treatments with possible neuroprotective effects are becoming increasingly important both clinically and as research tools. Mood stabilizing drugs and lithium in particular may act to prevent neuronal damage and tissue loss that may occur in the brain of patients with bipolar disorders. Lithium has been shown to exert neuroprotective effects in vitro and to stimulate neurogenesis in the hippocampus. Animal studies have demonstrated pharmacological effects of lithium suggestive of its role in neuroprotection, which range from reducing excitotoxicity through increased glutamate uptake, to regulation of a number of signal transduction intermediates such as myo-inositol, protein kinase C, phosphotidylinositol-3 kinase (PI-3K)/protein kinase B (Akt), ras-mitogen-activated protein kinase (MAPK), glycogen synthase kinase (GSK)-3alpha and -3beta and calcium. It remains to be established whether lithium treatment protects against possible cell damage in the same manner as it protects against recurrences of the illness. We propose to examine the effect of long-term lithium treatment on neurocognitive functioning of bipolar patients and the use of lithium in the treatment of chronic neuropsychiatric disorders.

Attenuation of N-methyl-D-aspartate-mediated cytoplasmic vacuolization in primary rat hippocampal neurons by mood stabilizers.

Recent post-mortem and brain imaging studies suggest that decreased neuronal and glial densities may account for cell loss in vulnerable brain regions such as the hippocampus and the frontal cortex in patients with bipolar disorder. Investigations into the mechanisms of action of mood stabilizers suggest that these drugs may regulate the expression of neuroprotective genes and protect against excitotoxicity. In this study, we characterized the ultrastructural appearance of rat hippocampal neurons pretreated with mood stabilizers and then exposed to the glutamate receptor agonist N-methyl-D-aspartate. Using transmission electron microscopy we found that rat hippocampal neurons exposed to 0.5 mM N-methyl-D-aspartate for 10 min produced more cytoplasmic vacuolization than in control neurons. Chronic treatment with mood stabilizers, lithium, valproate or carbamazepine for 7 days at therapeutically relevant concentrations fully attenuated N-methyl-D-aspartate-mediated cytoplasmic vacuolization. These results suggest that inhibition of neurotoxicity may be involved in the action of mood stabilizers.

Valproate inhibits oxidative damage to lipid and protein in primary cultured rat cerebrocortical cells.

Valproate is often prescribed as a long-term therapeutic mood stabilizing agent for individuals with bipolar disorder. Although research suggests that this drug may produce a neuroprotective effect, its neuroprotective mechanism is not yet clear. The purpose of this study was to determine if valproate provides a neuroprotective effect against damage caused by oxidative stress in primary cultured rat cerebral cortical cells. We found that chronic treatment with valproate at therapeutically relevant concentrations for 7 days inhibited lipid peroxidation and protein oxidation induced by treatment with 0.25 mM oxidant FeCl(3) for 90 min, indicating that valproate inhibits oxidative damage to lipid and protein. Our results suggest that chronic treatment with valproate may protect neuronal cells from damage caused by oxidative stress and that neuroprotection from oxidative damages may be involved in the mechanism of action of valproate. Supporting this possibility are recent findings that chronic treatment with valproate increased the expression of endoplasmic reticulum stress protein GRP78 and antiapoptotic factor bcl-2 in rat cerebral cortex. Since GRP78 binds Ca(2+) and folds damaged protein, bcl-2 stabilizes mitochondrial transmembrane potential and inhibits cytochrome C release, and both GRP78 and bcl-2 have been shown to inhibit oxyradical accumulation, together these findings indicate that valproate may target one or more of these processes in order to produce neuroprotective effects.

Induction of mania and cycle acceleration in bipolar disorder: effect of different classes of antidepressant.

OBJECTIVE: To assess the effect of different antidepressants on induction of mania and cycle acceleration, commonly accepted unwanted effects of antidepressant treatment for acute bipolar depression. There is, however, the suggestion that certain classes of antidepressants may be less likely than others to cause these unwanted effects. METHOD: We conducted a prospective, open, naturalistic, life charting study to assess the occurrence of onset of mania and cycle acceleration attributable to two antidepressant classes: selective serotonin reuptake inhibitors (SSRIs) and bupropion. RESULTS: No difference was found between the two drug classes for either antidepressant-induced mania or cycle acceleration. Antidepressant-induced mania was much more likely to occur in bipolar I rather than bipolar II patients. The overall occurrence of induction of mania and cycle acceleration was low across antidepressant classes. CONCLUSION: These findings suggest that there is probably no difference in the risk of antidepressant-induced mania or cycle acceleration across commonly used classes of antidepressants for the treatment of bipolar depression.

Antidepressant and benzodiazepine for major depression.

BACKGROUND: Anxiety frequently coexists with depression. Adding benzodiazepines to antidepressants is commonly used to treat people with depression, although there has been no convincing evidence to show that such a combination is more effective than antidepressants alone and that there are suggestions that benzodiazepines may lose their efficacy with long-term administration and that their chronic use carries risks of dependence. OBJECTIVES: To determine whether, among adult patients with major depression, adding benzodiazepines to antidepressants brings about any benefit in terms of symptomatic recovery or side-effects in the short term (less than 8 weeks) and long term (more than 2 months), in comparison with treatment by antidepressants alone. SEARCH STRATEGY: We searched MEDLINE (1972 to September 1997), EMBASE (1980 to September 1997), International Pharmaceutical Abstracts (1972 to September 1997), Biological Abstracts (1984 to September 1997), LILACS (1980 to September 1997), PsycLIT (1974 to September 1997), the Cochrane Library (issue 3, 1997) and the trial register of the Cochrane Depression, Anxiety and Neurosis Group (last searched March 1999), combined with hand searching, reference searching, SciSearch and personal contacts. SELECTION CRITERIA: All randomised controlled trials that compared combined antidepressant-benzodiazepine treatment with antidepressant alone for adult patients with major depression. Exclusion criteria are: antidepressant dosage lower than 100 mg of imipramine or its equivalent daily and duration of trial shorter than four weeks. DATA COLLECTION AND ANALYSIS: Two reviewers independently assessed the eligibility and quality of the studies. Two reviewers independently extracted the data. Standardized weighted mean differences and relative risks were estimated with random effects model. The dropouts were assigned the least favourable outcome. Two sensitivity analyses examined the effect of this assumption as well as the effect of including medium quality studies. Three a priori subgroup analyses were performed with regard to the patients with or without comorbid anxiety and with regard to the type. MAIN RESULTS: Aggregating nine studies with a total of 679 patients, the combination therapy group was less likely to drop out than the antidepressant alone group (relative risk 0.63, 95% confidence interval 0.49 to 0.81). The intention-to-treat analysis (with people dropping out assigned the least favourable outcome) showed that the combination group was more likely to show improvement in their depression (defined as 50% or greater reduction in the depression scale from baseline) (relative risk 1.63, 95% confidence interval 1.18 to 2.27 at one week and relative risk 1.38, 95% confidence interval 1.15 to 1.66 at four weeks). The difference was no longer significant at six to eight weeks. None of the included RCTs lasted longer than eight weeks. The patients allocated to the combination therapy were less likely to drop out from the treatment due to side effects than those receiving antidepressants alone (relative risk 0.53, 95% confidence interval 0.32 to 0.86). However, these two groups of patients were equally likely to report at least one side effect (relative risk 0.99, 95% confidence interval 0.92 to 1.07). REVIEWER'S CONCLUSIONS: The potential benefits of adding a benzodiazepine to an antidepressant must be balanced judiciously against possible harms including development of dependence and accident proneness, on the one hand, and against continued suffering following no response and drop-out, on the other.

Recollection memory deficits in patients with major depressive disorder predicted by past depressions but not current mood state or treatment status.

BACKGROUND: Neuropsychological studies have suggested that memory systems reliant on medial temporal lobe structures are impaired in patients with depression. There is less data regarding whether this impairment is specific to recollection memory systems, and whether clinical features predict impairment. This study sought to address these issues. METHOD: A computerized process-dissociation memory task was utilized to dissociate recollection and habit memory in 40 patients with past or current major depression and 40 age, sex and IQ matched non-psychiatric control subjects. The Cognitive Failures Questionnaire was used to assess patients' perceptions of day-to-day memory failures. RESULTS: Patients had impaired recollection memory (t = 4.7, P < 0.001), but no impairment in habit memory when compared to controls. Recollection memory performance was not predicted by indices of current mood state, but was predicted by self-assessments of impairment (beta = -0.33; P = 0.008) and past number of depressions (beta = -0.41; P = 0.001). There was no evidence that standard therapy with antidepressant medication either improved or worsened memory performance. CONCLUSIONS: The results confirm that patients with multiple past depressions have reduced function on recollection memory tasks, but not on habit memory performance. The memory deficits were independent of current mood state but related to past course of illness and significant enough that patients detected impairment in day-to-day memory function.