Subcortical brain alterations in major depressive disorder: findings from the ENIGMA Major Depressive Disorder working group.

The pattern of structural brain alterations associated with major depressive disorder (MDD) remains unresolved. This is in part due to small sample sizes of neuroimaging studies resulting in limited statistical power, disease heterogeneity and the complex interactions between clinical characteristics and brain morphology. To address this, we meta-analyzed three-dimensional brain magnetic resonance imaging data from 1728 MDD patients and 7199 controls from 15 research samples worldwide, to identify subcortical brain volumes that robustly discriminate MDD patients from healthy controls. Relative to controls, patients had significantly lower hippocampal volumes (Cohen's d=-0.14, % difference=-1.24). This effect was driven by patients with recurrent MDD (Cohen's d=-0.17, % difference=-1.44), and we detected no differences between first episode patients and controls. Age of onset ⩽21 was associated with a smaller hippocampus (Cohen's d=-0.20, % difference=-1.85) and a trend toward smaller amygdala (Cohen's d=-0.11, % difference=-1.23) and larger lateral ventricles (Cohen's d=0.12, % difference=5.11). Symptom severity at study inclusion was not associated with any regional brain volumes. Sample characteristics such as mean age, proportion of antidepressant users and proportion of remitted patients, and methodological characteristics did not significantly moderate alterations in brain volumes in MDD. Samples with a higher proportion of antipsychotic medication users showed larger caudate volumes in MDD patients compared with controls. This currently largest worldwide effort to identify subcortical brain alterations showed robust smaller hippocampal volumes in MDD patients, moderated by age of onset and first episode versus recurrent episode status.

Does non-pharmacological therapy for antenatal depression reduce risks for the infant?

Depression during pregnancy has been associated with an increased risk of adverse outcomes for the infant such as preterm birth. These risks are not reduced with pharmacological treatment, but the effect of non-pharmacological therapies is unknown. We performed a systematic review to assess the risk of adverse perinatal outcomes in non-pharmacologically treated depressed women compared to non-depressed women. We found no studies that met our inclusion criteria, highlighting a critical need for research on this topic.

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.

Theory of mind performance in women with posttraumatic stress disorder related to childhood abuse.

OBJECTIVE: Key questions remain unaddressed concerning the nature of interpersonal functioning in trauma survivors, including the ability to understand and interpret other people's thoughts and feelings. Here, we investigate theory of mind (ToM) performance of women with PTSD related to childhood abuse in comparison to healthy controls. METHOD: Participants completed two ToM tasks, the Interpersonal Perception Task-15 (IPT-15) and the Reading the Mind in the Eyes Task - Revised (RMET). RESULTS: Relative to controls, women with a history of childhood trauma had difficulty recognizing familial relationships depicted in the IPT-15 (P = 0.005). No other category of the IPT-15 showed significant group differences. In addition, while healthy women displayed faster RMET reaction times to emotionally valenced mental states (positive: P = 0.003; negative: P = 0.016) compared with neutral mental states, the PTSD group showed similar reaction times across all valences. The presence of dissociative symptoms (e.g., disengagement, amnesia, identity dissociation) was strongly associated with hindered accuracy of complex mental state identification and altered perception of kinship interactions. CONCLUSION: Women with PTSD stemming from childhood trauma show changes in ToM abilities particularly those often involved in the interpretation of family interactions. In addition, individuals with PTSD showed slower reaction times during the recognition of complex mental states from emotionally salient facial/eye expressions in comparison with healthy subjects.

The hippocampus in major depression: evidence for the convergence of the bench and bedside in psychiatric research?

Major depressive disorder (MDD) has until recently been conceptualized as an episodic disorder associated with 'chemical imbalances' but no permanent brain changes. Evidence has emerged in the past decade that MDD is associated with small hippocampal volumes. This paper reviews the clinical and biological correlates of small hippocampal volumes based on literature searches of PubMed and EMBASE and discusses the ways in which these data force a re-conceptualization of MDD. Preclinical data describe the molecular and cellular effects of chronic stress and antidepressant treatment on the hippocampus, providing plausible mechanisms through which MDD might be associated with small hippocampal volumes. Small hippocampal volumes are associated with poor clinical outcome and may be a mechanism through which MDD appears to be a risk factor for Alzheimer's disease. The pathways through which stress may be linked to MDD, the emergence of chronicity or treatment resistance in MDD and the association between MDD and memory problems may be at least partially understood by dissecting the association with depression and changes in the hippocampus. MDD must be re-conceived as a complex illness, associated with persistent morphological brain changes that are detectable before illness onset and which may be modified by clinical and treatment variables.

Pavlovian conditioning of rat mucosal mast cells to secrete rat mast cell protease II.

Antigen (egg albumin) injections, which stimulate mucosal mast cells to secrete mediators, were paired with an audiovisual cue. After reexposure to the audiovisual cue, a mediator (rat mast cell protease II) was measured with a sensitive and specific assay. Animals reexposed to only the audiovisual cue released a quantity of protease not significantly different from animals reexposed to both the cue and the antigen; these groups released significantly more protease than animals that had received the cue and antigen in a noncontingent manner. The results support a role for the central nervous system as a functional effector of mast cell function in the allergic state.

Cognitive dysfunction associated with metabolic syndrome.

Metabolic syndrome which includes visceral obesity, elevated triglycerides, elevated fasting blood sugar, high blood pressure and a decrease in high-density lipoprotein cholesterol levels comprises the most common chronic physical illnesses in modern society. Components of the metabolic syndrome play a role in the pathogenesis of a plethora of medical illnesses. Evidence has emerged highlighting the detrimental effects of metabolic syndrome and its constituent features on the cognitive aspects of neurological function. The precise mechanisms underlying this association are not known but a combination of neuroanatomical changes and neuroendocrine consequences of somatic dysregulation may be relevant. As the population ages and the prevalence of metabolic syndrome increases, it is important that this clinically relevant association be recognized.

Influence of birth cohort on age of onset cluster analysis in bipolar I disorder.

PURPOSE: Two common approaches to identify subgroups of patients with bipolar disorder are clustering methodology (mixture analysis) based on the age of onset, and a birth cohort analysis. This study investigates if a birth cohort effect will influence the results of clustering on the age of onset, using a large, international database. METHODS: The database includes 4037 patients with a diagnosis of bipolar I disorder, previously collected at 36 collection sites in 23 countries. Generalized estimating equations (GEE) were used to adjust the data for country median age, and in some models, birth cohort. Model-based clustering (mixture analysis) was then performed on the age of onset data using the residuals. Clinical variables in subgroups were compared. RESULTS: There was a strong birth cohort effect. Without adjusting for the birth cohort, three subgroups were found by clustering. After adjusting for the birth cohort or when considering only those born after 1959, two subgroups were found. With results of either two or three subgroups, the youngest subgroup was more likely to have a family history of mood disorders and a first episode with depressed polarity. However, without adjusting for birth cohort (three subgroups), family history and polarity of the first episode could not be distinguished between the middle and oldest subgroups. CONCLUSION: These results using international data confirm prior findings using single country data, that there are subgroups of bipolar I disorder based on the age of onset, and that there is a birth cohort effect. Including the birth cohort adjustment altered the number and characteristics of subgroups detected when clustering by age of onset. Further investigation is needed to determine if combining both approaches will identify subgroups that are more useful for research.

Does a combination regimen of thyroxine (T4) and 3,5,3'-triiodothyronine improve depressive symptoms better than T4 alone in patients with hypothyroidism? Results of a double-blind, randomized, controlled trial.

Some hypothyroid patients receiving levothyroxine replacement therapy complain of depressive symptoms despite normal TSH measurements. It is not known whether adding T(3) can reverse such symptoms. We randomized 40 individuals with depressive symptoms who were taking a stable dose of levothyroxine for treatment of hypothyroidism (excluding those who underwent thyroidectomy or radioactive iodine ablation of the thyroid) to receive T(4) plus placebo or the combination of T(4) plus T(3) in a double-blind manner for 15 wk. Participants receiving combination therapy had their prestudy dose of T(4) dropped by 50%, and T(3) was started at a dose of 12.5 micro g, twice daily. T(4) and T(3) doses were adjusted to keep goal TSH concentrations within the normal range. Compared with the group taking T(4) alone, the group taking both T(4) plus T(3) did not report any improvement in self-rated mood and well-being scores that included all subscales of the Symptom Check-List-90, the Comprehensive Epidemiological Screen for Depression, and the Multiple Outcome Study (P > 0.05 for all indexes). In conclusion, the current data do not support the routine use of combined T(3) and T(4) therapy in hypothyroid patients with depressive symptoms.

Increased hippocampal BDNF immunoreactivity in subjects treated with antidepressant medication.

BACKGROUND: The cAMP signaling pathway, and its downstream neurotrophic factor BDNF, are major targets of antidepressant medications. Abnormalities in this pathway have previously been reported in postmortem brain of subjects with mood disorders. This study was designed to test whether the diagnosis of a mood disorder, or treatment with an antidepressant or mood stabilizer was associated with changes in hippocampal BDNF in postmortem brain. METHODS: Frozen postmortem anterior hippocampus sections were obtained from the Stanley Foundation Neuropathology Consortium. Tissue from subjects with major depression, bipolar disorder, schizophrenia and nonpsychiatric control subjects were stained for BDNF using immunohistochemistry. RESULTS: Increased BDNF expression was found in dentate gyrus, hilus and supragranular regions in subjects treated with antidepressant medications at the time of death, compared with antidepressant-untreated subjects. Furthermore, there was a trend toward increased BDNF expression in hilar and supragranular regions in depressed subjects treated with antidepressants, compared with the subjects not on these medications at the time of death. CONCLUSIONS: These findings are consistent with recent studies measuring CREB levels in this same subject sample, and support current animal and cellular models of antidepressant function.

Double-blind comparison of addition of a second mood stabilizer versus an antidepressant to an initial mood stabilizer for treatment of patients with bipolar depression.

OBJECTIVE: This study's purpose was to clarify the appropriate treatment of bipolar depression by comparing the addition of an antidepressant versus a second mood stabilizer for inpatients being treated with lithium carbonate or divalproex sodium. METHOD: Twenty-seven patients were randomly assigned to groups that received double-blind treatment with paroxetine or a second mood stabilizer (lithium carbonate or divalproex sodium) for 6 weeks. RESULTS: Both groups showed significant improvement in depressive symptoms during the 6-week trial. There were significantly more noncompleters in the group being treated with the two mood stabilizers than in the group being treated with a mood stabilizer and paroxetine. CONCLUSIONS: Both treatments appeared to be effective; however, the addition of an antidepressant may have greater clinical utility in the treatment of bipolar depression.

Increased temporal cortex ER stress proteins in depressed subjects who died by suicide.

Regulation of ER stress proteins, such as the 78-kilodalton glucose regulated protein (GRP78) by chronic treatment with mood stabilizing drugs suggests that this family of proteins may be involved in the pathophysiology of mood disorders. Indeed, increased levels of GRP78, GRP94, and calreticulin, a third member of the ER stress protein family, were found in temporal cortex of subjects with major depressive disorder who died by suicide compared with controls and subjects who died by other means. No such differences were found in subjects with other psychiatric disorders such as bipolar disorder or schizophrenia. These data suggest a potential role for ER stress proteins in severe depression that merits further study.

Late-onset Tay-Sachs disease presenting as catatonic schizophrenia: diagnostic and treatment issues.

BACKGROUND: It is not commonly appreciated that patients with hexosaminidase A deficiency (Tay-Sachs disease) can first present in adulthood with psychiatric illness. METHOD: A 17-year-old non-Jewish male patient was referred with a history of treatment-resistant catatonic schizophrenia. We uncovered coexistent neurologic abnormalities and evidence of cognitive decline. Metabolic screening revealed a severe deficiency of beta-hexosaminidase A. We reviewed the literature on late-onset gangliosidosis with attention to (1) the nature of the associated psychiatric and neurologic abnormalities and (2) the treatment of psychosis in these patients. RESULTS: The patient's catatonia responded promptly to benzodiazepine therapy. Treatment with neuroleptic medication resulted in the rapid development of neuroleptic malignant syndrome. The patient was thereafter maintained on lorazepam with resolution of his acute psychiatric disturbances and unexpected improvement in his neurologic status. CONCLUSION: Patients with hexosaminidase deficiency may first present in adolescence or adulthood with psychiatric illness, particularly schizophrenic-like psychosis. The presence of speech disturbance, gait abnormalities, movement disorders, and cognitive decline may indicate an underlying metabolic disorder. The use of traditional neuroleptics to treat the psychosis in such individuals may produce an unacceptably high risk/benefit ratio. Benzodiazepines may ameliorate the psychiatric and neurologic abnormalities in these patients.

Conditional immunomodulation following training with cyclophosphamide.

In 5 experiments, paired-group rats received a conditional stimulus (CS) paired with the immunosuppressive drug cyclophosphamide (CY). In Experiments 1-3, the CS was saccharin (SAC). Consistent with previous reports, these rats acquired a SAC aversion. However, there was no evidence of conditional immunosuppression. Rather, when reexposed to SAC in conjunction with an antigenic challenge, paired-group rats evidenced hemagglutination antibody titers similar to those seen in rats that never received the immunosuppressant. That is, the usual effect of CY in compromising immunological functioning was attenuated or eliminated by the CY-paired flavor. The findings of Experiments 1-3 were confirmed in Experiments 4-5, which used nongustatory CSs. Both audiovisual (noise and flashing-light) and pharmacological (pentobarbital) cues were also effective signals for CY injection. Following pairing with CY, these cues protected animals from the immunosuppressive effects of the drug.

Performance of heterozygous brain-derived neurotrophic factor knockout mice on behavioral analogues of anxiety, nociception, and depression.

Evidence suggests that brain-derived neurotrophic factor (BDNF) may be important in the pathophysiology of depression, in addition to its role as a neurotrophic factor for sensory neurons. The authors conducted a series of experiments examining the behavioral profile of BDNF heterozygous knockout and wild-type mice. The heterozygous and wild-type mice did not differ on measures of activity, exploration, or hedonic sensitivity, or in the forced swim test. When assessed in the learned helplessness paradigm, heterozygous mice were slower to escape after training than were wild-type mice (p = .02). This effect may be accounted for by the fact that these mice demonstrate a reduced sensitivity to centrally mediated pain, apparent on the hot plate and Formalin injection tests of nociception. Overall, heterozygous mice were not more likely to display anxious or depressive-like behaviors and, consequently, may not constitute a murine model of genetic vulnerability to mood and anxiety disorders.

Pre-drug cues modulate morphine tolerance, striatal c-Fos, and AP-1 DNA binding.

To evaluate the molecular mechanisms that mediate the effect of learning on morphine tolerance in rats, we examined striatal c-Fos, and c-Jun protein expression, and AP-1 DNA binding. Morphine paired with a conditioned stimulus (CS) led to analgesic tolerance in the presence of the CS. Rats receiving morphine unpaired with the CS displayed significantly less tolerance than paired morphine animals. Striatal c-Fos protein levels and AP-1 DNA binding activity were increased in rats receiving paired morphine compared with rats that did not receive morphine but not in rats receiving morphine without the CS. No differences were found in c-Jun levels. These results suggest that Pavlovian conditioning may account, in part, for the molecular mechanisms associated with morphine tolerance.

Increased hippocampal supragranular Timm staining in subjects with bipolar disorder.

Biochemical and structural abnormalities have been reported in hippocampus of subjects with mood disorders. This study examined the organization of mossy fibers in anterior hippocampus of subjects obtained from the Stanley Neuropathology Consortium. Frozen postmortem hippocampal sections from subjects with major depression, bipolar disorder, schizophrenia and non-psychiatric controls were stained using the Neo-Timm procedure, which selectively stains mossy fibers. Increased Timm staining in the supragranular layer was found in subjects with bipolar disorder relative to control subjects. These results are suggestive of neuronal sprouting in hippocampus of subjects with bipolar disorder. There were no significant associations between supragranular Timm staining and suicide, length illness or drug treatment at the time of death.

Abnormalities in the cAMP signaling pathway in post-mortem brain tissue from the Stanley Neuropathology Consortium.

There is an established relationship between the monoaminergic neurotransmitter system and mood disorders. In an attempt to define further the pathophysiology of mood disorders, research is focussing on intracellular second messenger systems, including cyclic adenosine 3',5'-monophosphate (cAMP) and the polyphosphoinositol generated second messengers. The availability of tissue from the Stanley Foundation Neuropathology Consortium has offered us the opportunity to make a number of observations with respect to these second messenger systems in tissue from patients with major depressive disorder and bipolar affective disorder. There is evidence that antidepressants stimulate components of the cAMP pathway in patients with depression while mood stabilizers blunt the same pathway in patients with bipolar disorder. Furthermore, downstream targets of this pathway appear to be altered in patients with mood disorders. The relations between changes in second messenger systems, gene transcription, and clinical effects of current therapeutic regimens has implications for development of novel treatments of mood disorders.

Levels of functioning and well-being in recovered psychotic versus nonpsychotic mania.

The aim of the study was to compare psychotic and nonpsychotic bipolar patients on demographic and outcome measures. Sixty two patients with bipolar disorder were divided into groups on the basis of psychosis during an index episode of mania. Groups were compared on demographic, clinical and outcome measures. Psychotic patients were more symptomatic during the index episode, but they did not differ from nonpsychotic patients on ratings of function and well being when euthymic. Psychosis occurring within the context of an exacerbation of mania does not seem to predict a poorer outcome when patients return to the euthymic state. A limitation of the present study is that it involves short-term outcome, but the data can be used to inform patients and family about the possibility of full recovery even in the psychotic form of mania.

Gabapentin as an adjunctive treatment in bipolar disorder.

OBJECTIVE: To evaluate the efficacy of gabapentin as an adjunctive treatment for bipolar disorder in both depressed and manic phases. METHOD: Thirty seven patients with bipolar type I or II with or without a rapid cycling course were openly treated with gabapentin added to current treatment for up to six months. Mood symptoms were rated weekly for 12 weeks then monthly for 3 months utilizing the HamD and YMS. RESULTS: Participants experienced a significant reduction in both depressive and manic symptoms. CONCLUSIONS: These findings are consistent with others in establishing the efficacy of gabapentin in both phases of bipolar disorder. LIMITATIONS: Small sample size and the use of an open uncontrolled design limit interpretation of results.