ABSTRACT
BACKGROUND: Many patients with post-traumatic stress disorder (PTSD) experience dissociative symptoms. The question of whether these dissociative symptoms negatively influence the effectiveness of psychotherapy for PTSD is unresolved. AIMS: To determine the influence of dissociative symptoms on psychotherapy outcome in PTSD. METHOD: We conducted a systematic search in Cochrane, Embase, PILOTS, PsycINFO, PubMed and Web of Science for relevant clinical trials. A random-effects meta-analysis examined the impact of dissociation on psychotherapy outcome in PTSD (pre-registered at Prospero CRD42018086575). RESULTS: Twenty-one trials (of which nine were randomised controlled trials) with 1714 patients were included. Pre-treatment dissociation was not related to treatment effectiveness in patients with PTSD (Pearson's correlation coefficient 0.04, 95% CI -0.04 to 0.13). Between-study heterogeneity was high but was not explained by moderators such as trauma focus of the psychotherapy or risk of bias score. There was no indication for publication bias. CONCLUSIONS: We found no evidence that dissociation moderates the effectiveness of psychotherapy for PTSD. The quality of some of the included studies was relatively low, emphasising the need for high-quality clinical trials in patients with PTSD. The results suggest that pre-treatment dissociation does not determine psychotherapy outcome in PTSD.
ABSTRACT
BACKGROUND: Meta-analyses have established a high prevalence of childhood maltreatment (CM) in patients with eating disorders (EDs) relative to the general population. Whether the prevalence of CM in EDs is also high relative to that in other mental disorders has not yet been established through meta-analyses nor to what extent CM affects defining features of EDs, such as number of binge/purge episodes or age at onset. Our aim is to provide meta-analyses on the associations between exposure to CM (i.e. emotional, physical and sexual abuse) on the occurrence of all types of EDs and its defining features. METHOD: Systematic review and meta-analyses. Databases were searched until 4 June 2016. RESULTS: CM prevalence was high in each type of ED (total N = 13 059, prevalence rates 21-59%) relative to healthy (N = 15 092, prevalence rates 1-35%) and psychiatric (N = 7736, prevalence rates 5-46%) control groups. ED patients reporting CM were more likely to be diagnosed with a co-morbid psychiatric disorder [odds ratios (ORs) range 1.41-2.46, p < 0.05] and to be suicidal (OR 2.07, p < 0.001) relative to ED subjects who were not exposed to CM. ED subjects exposed to CM also reported an earlier age at ED onset [effect size (Hedges' g) = -0.32, p < 0.05], to suffer a more severe form of the illness (g = 0.29, p < 0.05), and to binge-purge (g = 0.31, p < 0.001) more often compared to ED patients who did not report any CM. CONCLUSION: CM, regardless of type, is associated with the presence of all types of ED and with severity parameters that characterize these illnesses in a dose dependent manner.
ABSTRACT
BACKGROUND: Women are believed to be more vulnerable to develop a depression or depressive symptoms during the perimenopause. Estimates from individual studies are heterogeneous and hence true risk estimate is unknown. OBJECTIVE: This study investigated the risk on clinical depression and depressive symptoms during the perimenopause when compared to other female hormonal stages. METHODS: We performed a meta-analysis of 11 studies identified in Pubmed, Web of Science and the Cochrane library (up to July 2015). Studies were included when the perimenopause was defined according the criteria of Stages of Reproductive Aging Workshop (STRAW). The outcome measures were Odds Ratio's (OR) on depression diagnosis and depressive symptoms and standardized mean difference (Hedges's g) in depression scores during each menopausal stage. RESULTS: The odds to develop a depression were not significantly higher during the perimenopause than in the premenopause (OR=1.78 95% CI=0.99-3.2; p=0.054). A higher risk was found on depressive symptoms during the perimenopause as compared to the premenopause (OR=2.0, 95% CI=1.48-2.71; p<0.001) but not compared to the postmenopause (OR=1.07, 95% CI=0.737-1.571; p=0.70). There was a higher symptom severity of depression in the perimenopause when compared to the premenopause (Hedges's g=0.44, 95% CI=0.11-0.73, p=0.007). The odds on vasomotor symptoms and depression were 2.25 (95% CI=1.14-3.35; p<0.001) during the perimenopause. LIMITATIONS: Time interval in measuring the depressive symptoms was different in studies. Menopausal symptoms possibly may have confounded our results by increasing the scores on depression questionnaires. Publication bias needs to be considered. CONCLUSION: The perimenopause is a phase in which women are particular vulnerable to develop depressive symptoms and have higher symptom severity compared to the premenopause. There are indications that vasomotor symptoms are positively related to depressive symptoms during menopausal transition.
Subject(s)
Depression/diagnosis , Perimenopause/psychology , Postmenopause/psychology , Premenopause/psychology , HumansABSTRACT
In the forced swim test (FST) rodents progressively show increased episodes of immobility if immersed in a beaker with water from where escape is not possible. In this test, a compound qualifies as a potential antidepressant if it prevents or delays the transition to this passive (energy conserving) behavioural style. In the past decade however the switch from active to passive "coping" was used increasingly to describe the phenotype of an animal that has been exposed to a stressful history and/or genetic modification. A PubMed analysis revealed that in a rapidly increasing number of papers (currently more than 2,000) stress-related immobility in the FST is labeled as a depression-like phenotype. In this contribution we will examine the different phases of information processing during coping with the forced swim stressor. For this purpose we focus on the action of corticosterone that is mediated by the closely related mineralocorticoid receptors (MR) and glucocorticoid receptors (GR) in the limbic brain. The evidence available suggests a model in which we propose that the limbic MR-mediated response selection operates in complementary fashion with dopaminergic accumbens/prefrontal executive functions to regulate the transition between active and passive coping styles. Upon rescue from the beaker the preferred, mostly passive, coping style is stored in the memory via a GR-dependent action in the hippocampal dentate gyrus. It is concluded that the rodent's behavioural response to a forced swim stressor does not reflect depression. Rather the forced swim experience provides a unique paradigm to investigate the mechanistic underpinning of stress coping and adaptation.
Subject(s)
Adaptation, Psychological/physiology , Brain/physiopathology , Receptors, Glucocorticoid/physiology , Receptors, Mineralocorticoid/physiology , Stress, Psychological/physiopathology , Stress, Psychological/psychology , Animals , Behavior, Animal , Brain/metabolism , Glucocorticoids/physiology , Limbic System/metabolism , Limbic System/physiopathology , Mice , Rats , Receptors, Glucocorticoid/metabolism , Receptors, Mineralocorticoid/metabolism , Stress, Psychological/metabolism , SwimmingABSTRACT
BACKGROUND: The neurotrophic hypothesis of depression postulates that neuronal plasticity is a key factor in the development of depression and in the clinical response to antidepressants. Brain-derived neurotrophic factor (BDNF) is an important protein in this process. AIM: To provide a survey of the current scientific view regarding the neurotrophic hypothesis of depression. METHOD: We studied the literature using PubMed. RESULTS: The serum bdnf level was found to be consistently lower in depressed patients compared to healthy controls. In short open-label antidepressant treatment trials the bdnf levels were found to be higher post-treatment than pre-treatment. Longitudinal analysis of a large naturalistic cohort study revealed that it was more likely that bdnf serum levels were lower as a result of depression than that they represented an etiological factor for the illness. CONCLUSION: These findings show that the neurotrophic hypothesis of depression is more complex than previously assumed. Animal studies have shown a correlation between stress, diminished bdnf expression in the brain and depressive-like behavior. Studies in humans, on the other hand, particularly those with a longitudinal design, suggest that the decrease in serum bdnf is a consequence of the depression rather than vice versa. This is in sharp contrast to the original assumptions of the neurotrophic hypothesis.
Subject(s)
Brain-Derived Neurotrophic Factor/blood , Depressive Disorder, Major/blood , Antidepressive Agents/therapeutic use , Depressive Disorder, Major/drug therapy , HumansABSTRACT
Emerging data suggest that Electro-Convulsive Treatment (ECT) may reduce depressive symptoms by increasing the expression of Brain-Derived Neurotrophic Factor (BDNF). Yet, conflicting findings have been reported. For this reason we performed a systematic review and meta-analysis of the preclinical and clinical literature on the association between ECT treatment (ECS in animals) and changes in BDNF concentrations and their effect on behavior. In addition, regional brain expression of BDNF in mouse and human brains were compared using Allen Brain Atlas. ECS, over sham, increased BDNF mRNA and protein in animal brain (effect size [Hedge's g]: 0.38-0.54; 258 effect-size estimates, N = 4,284) but not in serum (g = 0.06, 95% CI = -0.05-0.17). In humans, plasma but not serum BDNF increased following ECT (g = 0.72 vs. g = 0.14; 23 effect sizes, n = 281). The gradient of the BDNF increment in animal brains corresponded to the gradient of the BDNF gene expression according to the Allen brain atlas. Effect-size estimates were larger following more ECT sessions in animals (r = 0.37, P < .0001) and in humans (r = 0.55; P = 0.05). There were some indications that the increase in BDNF expression was associated with behavioral changes in rodents, but not in humans. We conclude that ECS in rodents and ECT in humans increase BDNF concentrations but this is not consistently associated with changes in behavior.
Subject(s)
Behavior, Animal , Brain-Derived Neurotrophic Factor/biosynthesis , Depression , Gene Expression Regulation , RNA, Messenger/biosynthesis , Animals , Depression/metabolism , Depression/physiopathology , Depression/therapy , Electric Stimulation Therapy , Humans , MiceABSTRACT
BACKGROUND: Women are believed to be more vulnerable to depression during the perimenopause than during the premenopausal period. In clinical practice little attention has been given to the relationship between the menopause and depression. AIM: To provide an overview of the literature on the relationship between the perimenopause and the development of depression and to analyse the relationship between hormonal fluctuations and depression. METHOD: We consulted the databases of PubMed, Web of Science and the Cochrane library, searching for epidemiologic studies on perimenopausal depression. We selected 22 studies relating to the prevalence of and the risk of depression during perimenopause. RESULTS: Most of the 22 epidemiological studies selected suggest that the chances of developing depression during the perimenopause are higher than during during the premenopausal period. We found no unambiguous correlation between the fluctuation of hormones (e.g. oestrogen) and depression. A possible reason for this finding is that it is difficult to measure these hormones accurately. CONCLUSION: The chances of developing depression seem to be higher during the perimenopause than during the premenopause. The difficulty in measuring the fluctuations of female hormones during the perimenopausal stage may be the reason why no correlation between depression and the fluctuations of hormones has yet been unambiguously established. Future studies and meta-analysis could provide a more accurate estimate of the risk of developing depression during the perimenopause and could give detailed information about the relationship between hormonal factors and perimenopausal depression.
Subject(s)
Depressive Disorder/blood , Depressive Disorder/etiology , Perimenopause/psychology , Adult , Estradiol/blood , Female , Humans , Luteinizing Hormone/blood , Middle AgedABSTRACT
One of the leading neurobiological hypotheses on depression states that decreased expression of brain-derived neurotrophic factor (BDNF) contributes to depression. This is supported by consistent findings of low serum BDNF levels in depressed patients compared with non-depressed controls. Whereas it has been generally assumed that this is a state characteristic of depression, strong inferences about state or trait effects require a longitudinal study design. To investigate the longitudinal association between serum BDNF and depression, we measured serum BDNF, (current and past) depression status, use of antidepressants, and all potential covariates at baseline and after 2 years in 1751 individuals, consisting of patients with an incident (n=153), remitted (n=420) and persistent depression (n=310) and non-depressed controls (n=868). We analyzed change/differences in serum BDNF across these four groups with analyses of covariance adjusted for covariates and baseline BDNF value, together with the effects of starting and stopping antidepressant treatment. Our analyses revealed a significant difference for the depression course groups (P=0.007). Compared with non-depressed controls, persistently depressed and remitted patients had a steeper decrease of BDNF levels over time (-1.33 (P=0.001) and -0.97 ng ml(-1) (P=0.011), respectively), whereas BDNF reductions in patients with incident depression were similar to those in healthy controls. Initiation or discontinuation of antidepressants was not associated with BDNF change (P=0.72). These findings suggest that BDNF not only contributes to depression, but that depression in turn may also contribute to low BDNF.
Subject(s)
Brain-Derived Neurotrophic Factor/blood , Depression/blood , Adult , Antidepressive Agents/therapeutic use , Child , Child Abuse/psychology , Chronic Disease , Depression/classification , Depression/drug therapy , Female , Humans , Longitudinal Studies , Male , Middle Aged , Psychiatric Status Rating Scales , Retrospective Studies , Statistics, NonparametricABSTRACT
It has been postulated that schizophrenia (SZ) is related to a lower expression of brain-derived neurotrophic factor (BDNF). In the past few years, an increasing number of divergent clinical studies assessing BDNF in serum and plasma have been published. It is now possible to verify the relationship between BDNF levels and severity of symptoms in SZ as well as the effects of antipsychotic drugs on BDNF using meta-analysis. The aims of this study were to verify if peripheral BDNF is decreased in SZ, whether its levels are correlated with positive and negative symptomatology and if BDNF levels change after antipsychotic treatment. This report consists of two distinct meta-analyses of peripheral BDNF in SZ including a total of 41 studies and more than 7000 participants: (1) peripheral BDNF levels in serum and plasma were moderately reduced in SZ compared with controls. Notably, this decrease was accentuated with the disease duration. However, the extent of peripheral BDNF level decrease did not correlate with the severity of positive and negative symptoms. (2) In plasma, but not serum, peripheral BDNF levels are consistently increased after antipsychotic treatment irrespective of the patient's response to medication. In conclusion, there is compelling evidence that there are decreased levels of peripheral BDNF in SZ, in parallel to previously described reduced cerebral BDNF expression. It remains unclear whether these systemic changes are causally related to the development of SZ or if they are merely a pathologic epiphenomenon.
Subject(s)
Antipsychotic Agents/therapeutic use , Brain-Derived Neurotrophic Factor/blood , Schizophrenia/blood , Schizophrenia/drug therapy , Adult , Biomarkers/blood , Case-Control Studies , Female , Humans , Male , Middle Aged , Young AdultABSTRACT
OBJECTIVES: Low serum BDNF levels have been found in depressed patients. No study has systematically investigated whether individual symptoms or symptom profiles within a depressed population contribute to low BDNF levels found in depressed subjects. METHODS: All 1070 patients with a past 6-month diagnosis of major depressive disorder from the Netherlands Study of Depression and Anxiety (NESDA) were included. Composite International Diagnostic Interview (CIDI) and Inventory of Depressive Symptoms (IDS) items were tested individually in separate multiple regression analyses with serum BDNF level as the dependent and the CIDI or IDS item as independent variable. Subsequently, we compared BDNF levels between patients with seasonal affective disorder (based on the Seasonal Pattern Assessment Questionnaire) and melancholic depression, atypical depression and moderate depression (based on a latent class analysis). All analyses were adjusted for confounders. RESULTS: Only one item was significantly associated with serum BDNF levels, namely the CIDI item "loss of interest" (ß = 0.14; P < 0.01). Counterintuitively the presence of this symptom was associated with higher BDNF levels. Other items and the comparison between different types of depression did not reveal significant differences. CONCLUSIONS: Decreased serum BDNF levels in depression cannot be attributed to a specific symptom or symptom cluster.
Subject(s)
Brain-Derived Neurotrophic Factor/blood , Depression/blood , Depressive Disorder, Major/blood , Depressive Disorder/blood , Adult , Depression/physiopathology , Depressive Disorder/physiopathology , Depressive Disorder, Major/physiopathology , Female , Humans , Male , Middle Aged , NetherlandsABSTRACT
Meta-analyses, published in 2008-2010, have confirmed abnormally low serum brain-derived neurotrophic factor (BDNF) concentrations in depressed patients and normalization of this by antidepressant treatment. These findings are believed to reflect peripheral manifestations of the neurotrophin hypothesis, which states that depression is secondary to an altered expression of BDNF in the brain. Since the publication of these meta-analyses, the field has seen a huge increase in studies on these topics. This motivated us to update the evidence on the aforementioned associations and, in addition, to compile the data on serum BDNF concentrations in relation to the symptom severity of depression. Using a manifold of data as compared with earlier meta-analyses, we find low serum BDNF concentrations in 2384 antidepressant-free depressed patients relative to 2982 healthy controls and to 1249 antidepressant-treated depressed patients (Cohen's d=-0.71 and -0.56, P-values <0.0000001). When publication bias is accounted for, these effect-sizes become substantially smaller (d=-0.47 and -0.34, respectively, P-values<0.0001). We detect between-study heterogeneity in outcomes for which only year of publication and sample size are significant moderators, with more recent papers and larger samples sizes in general being associated with smaller between-group differences. Finally, the aggregated data negate consistent associations between serum BDNF concentrations and the symptom severity of depression. Our findings corroborate the claim that altered serum BDNF concentrations are peripheral manifestations of depression. However, here we highlight that the evidence for this claim is slimmer as was initially thought and amidst a lot of noise.
Subject(s)
Brain-Derived Neurotrophic Factor/blood , Depression/blood , Antidepressive Agents/therapeutic use , Biomarkers/blood , Case-Control Studies , Depression/drug therapy , Humans , Psychiatric Status Rating Scales , Publication Bias/statistics & numerical dataABSTRACT
The val(66)met polymorphism on the BDNF gene has been reported to explain individual differences in hippocampal volume and memory-related activity. These findings, however, have not been replicated consistently and no studies to date controlled for the potentially confounding impact of early life stress, such as childhood abuse, and psychiatric status. Using structural and functional MRI, we therefore investigated in 126 depressed and/or anxious patients and 31 healthy control subjects the effects of val(66)met on hippocampal volume and encoding activity of neutral, positive and negative words, while taking into account childhood abuse and psychiatric status. Our results show slightly lower hippocampal volumes in carriers of a met allele (n=54) relative to val/val homozygotes (n=103) (P=0.02, effect size (Cohen's d)=0.37), which appeared to be independent of childhood abuse and psychiatric status. For hippocampal encoding activity, we found a val(66)met-word valence interaction (P=0.02) such that carriers of a met allele showed increased levels of activation in response to negative words relative to activation in the neutral word condition and relative to val/val homozygotes. This, however, was only evident in the absence of childhood abuse, as abused val/val homozygotes showed hippocampal encoding activity for negative words that was comparable to that of carriers of a met allele. Neither psychiatric status nor memory accuracy did account for these associations. In conclusion, BDNF val(66)met has a significant impact on hippocampal volume independently of childhood abuse and psychiatric status. Furthermore, early adverse experiences such as childhood abuse account for individual differences in hippocampal encoding activity of negative stimuli but this effect manifests differently as a function of val(66)met.
Subject(s)
Anxiety Disorders/genetics , Brain-Derived Neurotrophic Factor/genetics , Depressive Disorder/genetics , Emotions/physiology , Hippocampus/pathology , Hippocampus/physiopathology , Mental Recall/physiology , Polymorphism, Genetic/genetics , Adult , Arousal/genetics , Arousal/physiology , Child , Child Abuse/psychology , Echo-Planar Imaging , Female , Genetic Carrier Screening , Homozygote , Humans , Image Interpretation, Computer-Assisted , Individuality , Life Change Events , Magnetic Resonance Imaging , Male , Middle Aged , Organ Size/genetics , Organ Size/physiology , Reference Values , Verbal Learning/physiologyABSTRACT
Recent evidence supports 'the neurotrophin hypothesis of depression' in its prediction that brain-derived neurotrophic factor (BDNF) is involved in depression. However, some key questions remain unanswered, including whether abnormalities in BDNF persist beyond the clinical state of depression, whether BDNF levels are related to the clinical features of depression and whether distinct antidepressants affect BDNF levels equally. We addressed these questions and investigated serum BDNF levels in 962 depressed patients, 700 fully remitted persons (≥6 months) and 382 healthy controls. We found serum BDNF levels to be low in antidepressant-free depressed patients relative to controls (P=0.007) and to depressed patients who were treated with an antidepressant (P=0.001). BDNF levels of fully remitted persons (whether unmedicated or treated with an antidepressant) were comparable to those of controls. Analyzing the sample of antidepressant-free depressed patients showed that BDNF levels were unrelated to the core clinical features of depression such as its severity or first versus a recurrent episode. The antidepressant associated upregulation of serum BDNF in depressed patients was confined to selective serotonin reuptake inhibitors (SSRIs) (P=0.003) and St John's wort (P=0.03). Our results suggest that low serum levels of BDNF are a state abnormality that is evident during depression and normalizes during remission. Increases in serum levels of BDNF during antidepressant treatment appear to be confined to some antidepressants and do not parallel clinical characteristics, such as the severity of depressive symptoms.
Subject(s)
Brain-Derived Neurotrophic Factor/blood , Depressive Disorder, Major/blood , Hypericum , Phytotherapy , Plant Extracts/therapeutic use , Adult , Antidepressive Agents, Tricyclic/pharmacology , Antidepressive Agents, Tricyclic/therapeutic use , Anxiety Disorders/blood , Anxiety Disorders/drug therapy , Biomarkers , Convalescence , Depressive Disorder, Major/drug therapy , Drug Monitoring , Female , Humans , Male , Middle Aged , Models, Neurological , Models, Psychological , Plant Extracts/pharmacology , Recurrence , Selective Serotonin Reuptake Inhibitors/pharmacology , Selective Serotonin Reuptake Inhibitors/therapeutic use , Severity of Illness IndexABSTRACT
BACKGROUND: Brain-derived neurotrophic factor (BDNF) belongs to the neurotrophin family of growth factors and affects the survival and plasticity of neurons in the adult central nervous system. The high correlation between cortical and serum BDNF levels has led to many human studies on BDNF levels in various populations, however knowledge about determinants that influence BDNF is lacking. AIMS: To gain insight into the factors that influence BDNF levels in humans. METHODS: In 1168 people aged 18 through 65, free of antidepressants and current psychiatric disease, from the Netherlands study of depression and anxiety four categories of determinants (sampling, sociodemographics, lifestyle indicators and diseases) were measured as well as BDNF level. We used univariate analyses as well as multivariate linear regression analyses in particular to determine which of the possible determinants significantly influenced serum BDNF levels. RESULTS: The mean BDNF level was 8.98ng/ml (SD 3.1ng/ml) with a range from 1.56ng/ml through 18.50ng/ml. Our final multivariate regression analysis revealed that a non-fasting state of blood draw (ß=-.067; p=.019), later measurement (ß=-.065; p=.022), longer sample storage (ß=-.082; p=.004) and being a binge drinker (ß=-.063; p=.035) all resulted in attenuated BDNF levels. This was in contrast to smoking (ß=.098; p=.001) and living in an urban area (ß=.109; p<.001), which resulted in increased BDNF levels. Moreover we found that older subjects also had higher BDNF levels, but this only applied to women (ß=.226; p<.001). CONCLUSIONS: Future studies on serum levels of BDNF in humans should correct for the time of blood withdrawal, storage, urbanicity, age, sex, smoking status and food and alcohol intake.