Response rate and subjective memory after electroconvulsive therapy in depressive disorders with psychiatric comorbidity

Who is at risk of long-term subjective memory impairment after electroconvulsive therapy?

BACKGROUND

Electroconvulsive therapy (ECT) is an effective treatment for depression with potential transient cognitive side effects. However, subjective memory impairment can extend over a long period after ECT.

OBJECTIVES

This study aimed to assess potential risk factors for long-term subjective memory impairment 6 months after ECT and to explore if the associations are mediated by depressive symptoms.

METHODS

This registry-based study used the Swedish National Quality Register for ECT and other national registers. Long-term subjective memory worsening was defined as a minimum 2-step worsening on the memory item from the comprehensive psychopathological rating scale (CPRS-M) from before ECT to 6 months after ECT. Changes on the scale were also analyzed in continuous models. Statistical methods used were logistic regression and linear regression analyses in univariable and multivariable models.

RESULTS

The study population consisted of 1498 patients. Subjective memory worsening occurred in 25.2 % of the population. Long-term subjective memory worsening was associated with more depressive symptoms and lower education levels. No association could be found related to ECT technical factors. The associations between age and psychiatric comorbidities with subjective memory worsening were mediated by depressive symptoms.

CONCLUSION

Patients can be informed that depressive symptoms are one of the biggest contributing factors to long-term subjective memory impairment after ECT. A successful treatment is therefore important to minimize the long-term experience of memory deficits. The number of sessions or ECT technical factors do not seem to be associated with long-term subjective memory impairment.

Comparative efficacy of multiple non-invasive brain stimulation to treat major depressive disorder in older patients: A systematic review and network meta-analysis study based on randomized controlled trials

BACKGROUND

Major depressive disorder (MDD) is prevalent among older patients and is frequently associated with cognitive decline and a reduced quality of life. Non-invasive brain stimulation (NIBS) techniques show promise for treating MDD, but their comparative efficacy and safety older populations remain unclear. This study aimed to compare the efficacy and cognitive effects of various NIBS techniques in treating MDD in older patients.

METHODS

We searched the PubMed, EMBASE, Cochrane Library, and Web of Science core databases from inception to March 2024. Seventeen randomized controlled trials (RCTs) were included.

RESULTS

Surfaces under the cumulative ranking curve (SUCRA) values were used to rank the interventions. The SUCRA rankings for the Hamilton Depression Rating Scale (HDRS) outcomes indicated that repetitive transcranial magnetic stimulation (rTMS) (89.0 %) had the highest efficacy, followed by transcranial direct current stimulation (tDCS) (68.7 %). rTMS demonstrated significantly superior efficacy compared with bilateral electroconvulsive therapy (BL ECT) and right unilateral electroconvulsive therapy (RUL ECT). Theta burst stimulation (TBS) had the highest response rate (69.6 %), followed by rTMS (61.8 %). Based on the Mini-Mental State Examination, rTMS (86.4 %) ranked the highest, with RUL ECT showing significantly better outcomes than BL ECT.

CONCLUSION

NIBS, particularly rTMS and TBS, may offer effective treatment options for older patients with MDD. Further research with larger sample sizes and longer follow-up periods is required to validate these findings and inform clinical practice.

A Retrospective Analysis of the Impact of Electroconvulsive Therapy on Anxiety Symptoms in Patients With Treatment-Resistant Depression

BACKGROUND

Electroconvulsive therapy (ECT) is an effective treatment for treatment-resistant depression (TRD). There are limited data on the improvement of anxiety symptoms in patients receiving ECT for TRD.

OBJECTIVE

The aim of the study was to examine the extent to which anxiety symptom severity improves, relative to improvements in depressive symptoms, in TRD patients receiving an acute course of ECT.

METHODS

A retrospective chart review of 117 TRD patients who received an acute ECT course in a naturalistic outpatient setting was conducted. Symptomatic response was measured using the Beck Depression Inventory II and Generalized Anxiety Disorder 7 Scale. Two generalized estimating equation models assessed the degree of change in anxious symptoms relative to the change in depressive symptoms.

RESULTS

Both depression (-0.09, P < 0.001) and anxiety (-0.08, P < 0.001) improved after ECT treatment, with a greater standardized decrease for symptoms of depression. Higher levels of anxiety over the treatment (-0.42, P < 0.001) were associated with smaller antidepressant improvements.

CONCLUSIONS

ECT may improve symptoms of anxiety in patients with TRD. Anxiety symptoms show a favorable trajectory of improvement, though to a lesser extent, relative to changes in symptoms of depression. Higher symptoms of anxiety throughout the treatment course may be a negative predictor of antidepressant response in ECT.

Investigating Anxiety's Impact on Seizure Quality in Electroconvulsive Therapy: A Prospective Observational Study

BACKGROUND

Electroconvulsive therapy (ECT) is a medical procedure for treating severe depression and other mental health disorders, with anesthesia management being crucial for patient safety. Despite extensive research on factors influencing seizure quality during ECT, the impact of pre-ECT anxiety remains insufficiently explored.

METHODS

This prospective observational study aimed to investigate the influence of pre-ECT anxiety, as measured by the Amsterdam Preoperative Anxiety and Information Scale, on electroencephalogram ictal characteristics during ECT and to explore anesthesia-related factors that may enhance seizure quality.

RESULTS

A total of 38 patients participated in 168 documented ECT sessions over a 2-month period. Data analysis revealed a significant association between higher levels of pre-ECT anxiety, lidocaine doses exceeding 0.36 mg/kg, and decreased seizure quality during ECT sessions.

CONCLUSION

These findings suggest an association between pre-ECT anxiety, lidocaine dosage, and decreased seizure quality during ECT. Further research, including interventional studies, is required to better understand the causal factors.

Allopregnanolone and progesterone in relation to a single electroconvulsive therapy seizure and subsequent clinical outcome: an observational cohort study

BACKGROUND

Electroconvulsive therapy (ECT) is an important treatment for several severe psychiatric conditions, yet its precise mechanism of action remains unknown. Increased inhibition in the brain after ECT seizures, mediated by γ-aminobutyric acid (GABA), has been linked to clinical effectiveness. Case series on epileptic patients report a postictal serum concentration increase of the GABAA receptor agonist allopregnanolone. Serum allopregnanolone remains unchanged after a full ECT series, but possible transient effects directly after a single ECT seizure remain unexplored. The primary aim was to measure serum concentrations of allopregnanolone and its substrate progesterone after one ECT seizure. Secondary aims were to examine whether concentrations at baseline, or postictal changes, either correlate with seizure generalization or predict clinical outcome ratings after ECT.

METHODS

A total of 130 participants (18-85 years) were included. Generalization parameters comprised peak ictal heart rate, electroencephalographic (EEG) seizure duration, and prolactin increase. Outcome measures were ratings of clinical global improvement, perceived health status and subjective memory impairment. Non-parametric tests were used for group comparisons and correlations. The prediction analyses were conducted with binary logistic and simple linear regression analyses.

RESULTS

Allopregnanolone and progesterone remained unchanged and correlated neither with seizure generalization nor with clinical outcome. In men (n = 50), progesterone increased and allopregnanolone change correlated negatively with EEG seizure duration. In a subgroup analysis (n = 62), higher baseline allopregnanolone and progesterone correlated with postictal EEG suppression.

CONCLUSIONS

ECT seizures have different physiologic effects than generalized seizures in epilepsy. Progesterone might have implications for psychiatric illness in men.

Childhood maltreatment and outcomes following electroconvulsive therapy in adults with depression

OBJECTIVE

Childhood maltreatment is associated with less favourable treatment outcomes with pharmacotherapy and psychotherapy for depression. It is unknown whether this increased risk of treatment resistance in maltreated individuals extends to electroconvulsive therapy (ECT).

METHODS

This retrospective cohort study included 501 consecutive adult referrals for an acute course of twice-weekly ECT for unipolar or bipolar depression at an academic inpatient centre in Ireland between 2016 and 2024. Retrospectively reported physical and sexual childhood maltreatment were assessed on hospital admission. Response was defined as a score of 1 or 2 and remission was defined as a score of 1 on the Clinical Global Impression - Improvement scale 1-3 days after final ECT session. Logistic regression analyses were used to examine the associations between childhood maltreatment and ECT nonresponse and nonremission, adjusting for covariates. Mediation analyses were conducted to explore the role of psychiatric comorbidities, persistent depressive symptoms lasting 2 years or more in the current episode, and baseline depression severity.

RESULTS

Compared to the group with no childhood maltreatment, the childhood maltreatment group had similar odds of ECT nonresponse (adjusted odds ratio = 1.47, 95% CI = 0.85-2.53) but significantly elevated odds of ECT nonremission (adjusted odds ratio = 3.75, 95% CI = 1.80-7.81). In a mediation analysis, presence of persistent depressive symptoms mediated 7.4% of the total effect of childhood maltreatment on ECT nonremission.

CONCLUSION

Individuals with exposure to childhood maltreatment may be less likely to achieve full remission following a course of ECT.

Efficacy of Esketamine among patients with treatment resistant depression in a 'real world' health-care setting in Israel

One in five people will likely suffer from major depressive disorder (MDD) during their life. Thirty percent of those with MDD will experience Treatment Resistant Depression (TRD), which is characterized by a failure to respond to two adequately administered trials of antidepressants. Esketamine is a rapidly acting intranasal antidepressant. Present-day Esketamine research has limited data in real-world populations. This study aimed to assess Esketamine treatment in a real-world community-based population. This naturalistic retrospective study included 94 individuals age 18 and above diagnosed with TRD, treated with Esketamine in an outpatient setting. The treatment was given in a single clinic, from January 2021 to January 2023, following approval of the Institutional Internal Review Board. The treatment included an acute phase (biweekly treatment, continuing 4-8 weeks), followed by a maintenance phase (once a week to once a month, for 6-12 months). Dosing ranged from 28 mg to 84 mg. Demographic and clinical data were retrospectively gathered. Depressive symptoms were assessed using the Quick Inventory of Depressive Symptomatology, at baseline and during each treatment phase. All patients completed the acute phase. About 60% completed the maintenance phase. Linear improvement of depressive symptoms was revealed in both phases. A sub-analysis of patients with comorbid personality disorder revealed a similar improvement pattern in the acute phase with milder improvement during the maintenance phase, compared to the other patients. This study supports the use of Esketamine for TRD, including patients with comorbid personality disorder and previous electroconvulsive therapy.

Assessment of memory deficits in psychiatric disorders: A systematic literature review

Memory deficits are observed across psychiatric disorders ranging from the prodrome of psychosis to common mental disorders such as anxiety, depression, and dissociative disorders. Memory deficits among patients recovering from psychiatric disorders could be directly related to the primary illness or secondary to the adverse effect of a treatment such as Electroconvulsive Therapy (ECT). The trouble in the meaningful integration of working-memory and episodic memory is the most commonly affected domain that requires routine assessments. An update on the recent trends of methods of assessment of memory deficits is the first step towards understanding and correcting these deficits to target optimum recovery. A systematic literature search was conducted from October 2018 to October 2022 to review the recent methods of assessment of memory deficits in psychiatric disorders. The definition of 'Memory deficit' was operationalized as 'selective processes of memory, commonly required for activities of daily living, and affected among psychiatric disorders resulting in subjective distress and dysfunction'. We included 110 studies, most of them being conducted in western countries on patients with schizophrenia. Other disorders included dementia and mild cognitive impairment. Brief Assessment of Cognition in Schizophrenia, Cambridge Automated Neuropsychological Test Battery, California Verbal Learning Test, Trail Making Test Part A and B, Rey Auditory Verbal Learning Test, Wechsler Memory Scale, Wechsler Adults Intelligence Scale-IV were the most common neuropsychological assessments used. Mini-Mental State Examination and Montreal Cognitive Assessment were the most common bedside assessment tools used while Squire Subjective Memory Questionnaire was commonly used to measure ECT-related memory deficits. The review highlights the recent developments in the field of assessment of memory deficits in psychiatric disorders. Findings recommend and emphasize routine assessment of memory deficits among psychiatric disorders in developing countries especially severe mental illnesses. It remains interesting to see the role of standardized assessments in diagnostic systems given more than a decade of research on memory deficits in psychiatric disorders.

Outcomes of electroconvulsive therapy in patients with depressive symptoms with versus without comorbid personality disorders/traits: A systematic review and meta-analysis

AIMS

To assess electroconvulsive therapy (ECT) outcomes in patients affected by depressive symptoms with versus without additional comorbid personality disorders/traits.

METHODS

We identified observational studies investigating ECT clinical outcomes in patients affected by depressive symptoms with versus without comorbid personality disorders/traits in Embase/Medline in 11/2022. Our protocol was registered with PROSPERO (CRD42023390833). Study quality was evaluated using the Newcastle-Ottawa-Scale. Our primary outcomes were ECT response and remission rates. Meta-regression analyses included effects of in/outpatient percentages, age, number of ECT sessions, and electrode placement; subgroup analyses included the assessment methods for personality disorders/traits. We performed sensitivity analyses after excluding poor-quality studies.

RESULTS

A total of 20 studies (n = 11,390) were included in our analysis. Patients with comorbid personality disorders/traits had lower remission rates (OR = 0.42, 95% CI = 0.31, 0.58, p < 0.001) with substantial heterogeneity (I2  = 93.0%) as well as lower response rates (OR = 0.35, 95% CI = 0.24, 0.51, n = 5129, p < 0.001) with substantial heterogeneity (I2  = 93.0%) compared with patients without comorbid personality disorders/traits. Relapse rates were higher in patients with versus without comorbid personality disorders/traits (OR = 3.23, 95% CI = 1.40, 7.45, k = 4, n = 239, p = 0.006) with moderate heterogeneity (I2  = 75.0%) and post-ECT memory impairment was more frequent in patients with versus without comorbid personality disorders/traits (OR = 1.41, 95% CI = 1.36, 1.46, k = 4, n = 471, p < 0.001) with minimal heterogeneity (I2  = 0.0%). Dropout rates were higher in patients with versus without comorbid personality disorders/traits (OR = 1.58, 95% CI = 1.13, 2.21, k = 3, n = 6145, p = 0.008).

CONCLUSIONS

Patients with comorbid personality disorders/traits treated with ECT are reported to have lower response and remission rates and higher rates of side effects and relapse rates compared with patients without personality disorders/traits.

Ketamine or ECT? What Have We Learned From the KetECT and ELEKT-D Trials?

1. Two recent clinical trials, KetECT and ELEKT-D, compared the effectiveness of ketamine and electroconvulsive therapy (ECT) for major depressive disorder. Notably, these trials reported marked differences in ECT's clinical outcomes of, with remission rates of 63% for KetECT and a strikingly lower rate of 22% for ELEKT-D, while the remission rates for ketamine were 46% and 38%, respectively. Considering that the primary objective of both trials was to compare the standard treatment (ECT) with an experimental intervention (ketamine), it is crucial to highlight the pronounced disparities in ECT's clinical outcomes. This article offers a comprehensive comparison of these trials while also exploring how patient characteristics, treatment protocols, and study designs may contribute to such pronounced outcome discrepancies. These differences highlight the heterogeneous nature of depression and underscore the need for personalized treatments. These studies also provide valuable insights into identifying the most suitable candidates for ketamine and ECT.

Changes in self-reported suicidal ideation during treatment with electroconvulsive therapy: A retrospective cohort study

OBJECTIVE

Suicidal ideation (SI) is common in patients with depressive symptoms, who are the most common recipients of electroconvulsive therapy (ECT). We sought to quantify changes in self-reported SI occurring during treatment with ECT, and to identify factors associated with persistence of SI in patients beginning treatment with SI.

METHOD

Retrospective, single-center cohort study of patients receiving ECT and who self-reported symptoms using Quick Inventory of Depressive Symptomatology (QIDS) prior to ECT and after treatment #5 or #10. Changes in QIDS-reported SI over the course of ECT were calculated, and logistic regression models were performed to assess factors associated with reporting SI at the end of treatment.

RESULTS

2554 provided baseline and follow-up SI scores, of whom, 1931 (75.6%) endorsed SI at baseline. There was a reduction in SI with ECT treatment (McNemar's test; df = 1, Χ2  = 803.7; p < 0.001), and in adjusted models 64.0% of individuals with baseline SI reported resolution of SI with ECT treatment, while 3.3% without baseline SI reported SI at the end of treatment. Higher baseline SI severity and outpatient treatment were associated with a higher odds of persistent SI among individuals beginning treatment with SI.

CONCLUSION

Electroconvulsive therapy treatment was associated with reductions in self-reported SI. These results support the use of ECT in the treatment of patients with SI, but further research is needed to determine the effects of ECT on suicidal behavior.

Effects of Anesthesia Changes During Maintenance ECT: A Longitudinal Comparison of Seizure Quality Under Anesthesia Using Propofol/Esketamine Versus Methohexital

INTRODUCTION

The effectiveness of ECT relies on the induction of a generalized cerebral seizure. Among others, seizure quality (SQ) is potentially influenced by the anesthetic drug used. Commonly used anesthetics comprise barbiturates, etomidate, propofol, and esketamine, with different characteristics and impacts on seizure parameters. So far, no studies have compared the influence of methohexital vs. a combination of propofol/esketamine on established SQ parameters.

METHODS

This retrospective longitudinal study compared eight established SQ parameters (PSI, ASEI, MSC, midictal amplitude, motor and electroencephalography (EEG) seizure duration, concordance, PHR) before and after the change from propofol/esketamine to methohexital in 34 patients under maintenance ECT. Each patient contributed four measurements, two before and two after the anesthesia change. Anesthesia dose, stimulus dose, electrode placement, and concomitant medication remained unchanged throughout the analyzed treatments.

RESULTS

Under methohexital (M=88.97 mg), ASEI (p=0.039 to 0.013) and midictal amplitude (p=0.022 to<0.001) were significantly lower, whereas seizure duration (motor and EEG) was significantly longer when compared to propofol/esketamine (M=64.26 mg/51.18 mg; p=0.012 to<0.001). PSI, MSC, seizure concordance, and PHR were not affected by the anesthetic used.

DISCUSSION

Although to what extent these parameters correlate with the therapeutic effectiveness remains ambiguous, a decision for or against a particular anesthetic could be considered if a specific SQ parameter needs optimization. However, no general superiority for one specific substance or combination was found in this study. In the next step, anesthetic effects on treatment response and tolerability should be focused on.

Sex-specifics of ECT outcome

OBJECTIVE

Electroconvulsive therapy (ECT) is the most effective treatment for patients with severe major depressive disorder (MDD). Given the known sex differences in MDD, improved knowledge may provide more sex-specific recommendations in clinical guidelines and improve outcome. In the present study we examine sex differences in ECT outcome and its predictors.

METHODS

Clinical data from 20 independent sites participating in the Global ECT-MRI Research Collaboration (GEMRIC) were obtained for analysis, totaling 500 patients with MDD (58.6 % women) with a mean age of 54.8 years. Severity of depression before and after ECT was assessed with validated depression scales. Remission was defined as a HAM-D score of 7 points or below after ECT. Variables associated with remission were selected based on literature (i.e. depression severity at baseline, age, duration of index episode, and presence of psychotic symptoms).

RESULTS

Remission rates of ECT were independent of sex, 48.0 % in women and 45.7 % in men (X²(1) = 0.2, p = 0.70). In the logistic regression analyses, a shorter index duration was identified as a sex-specific predictor for ECT outcome in women (X²(1) = 7.05, p = 0.01). The corresponding predictive margins did show overlapping confidence intervals for men and women.

CONCLUSION

The evidence provided by our study suggests that ECT as a biological treatment for MDD is equally effective in women and men. A shorter duration of index episode was an additional sex- specific predictor for remission in women. Future research should establish whether the confidence intervals for the corresponding predictive margins are overlapping, as we find, or not.

Response to electroconvulsive therapy in treatment-resistant depression: nationwide observational follow-up study

BACKGROUND

Previous studies have not investigated response rates after electroconvulsive therapy (ECT) in patients with non-psychotic treatment-resistant depression (TRD).

AIMS

To assess and compare the response rate of ECT for patients with TRD and non-TRD, in a large and clinically representative patient sample.

METHOD

Patients aged ≥18 years, who were treated for a unipolar, non-psychotic depressive episode with at least one ECT session as part of a first-time, index ECT series between 1 January 2011 and 31 December 2017 were included from the Swedish National Quality Register for ECT. Patients who had initiated a third consecutive trial of antidepressants or add-on medications before start of ECT were classified as having TRD. Patients not meeting criteria for TRD were classified as non-TRD. The main outcome was response to ECT according to the Clinical Global Impressions - Improvement Scale (CGI-I), scored as 1 or 2 ('very much' or 'much improved' after ECT, respectively). Logistic regression was used to compare outcome measures between TRD and non-TRD, adjusting for potential confounders.

RESULTS

A total of 4244 patients were included. Of these, 1121 patients had TRD and 3123 patients had non-TRD. The CGI-I response rate was 65.9% in the TRD group compared with 75.9% in the non-TRD group (adjusted odds ratio 0.64, 95% CI 0.54-0.75). Older age and more severe depression were predictors of response in patients with TRD.

CONCLUSIONS

A clear majority of patients with TRD, as well as patients with non-TRD, responded to ECT, although the response rate was somewhat lower for TRD.

Trajectories of Efficacy and Cognitive Function During Electroconvulsive Therapy Course in Young Adults with Treatment-Resistant Depression

Objective

Little is known about the effectiveness and cognitive side-effects of electroconvulsive therapy (ECT) in young adults with treatment-resistant depression (TRD). The primary aim of this prospective longitudinal observational trial was to examine the clinical features and cognitive outcomes of young adults with TRD undergoing ECT.

Methods

Changes in depressive symptoms and objective and subjective cognitive function were assessed using repeated evaluation at baseline, after each ECT session, and at one-month follow-up using the Montgomery-Äsberg Depression Rating Scale (MADRS) and the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), Forward Digital Span Test (FDST), and part of the Columbia Subjective Side Effects Schedule.

Results

Of 41 inpatients, 35 (85.4%) and 12 (29.3%) met the criteria for response and remission after ECT, respectively. The greatest clinical improvements occurred during the first 3-4 ECT sessions. While 34 patients reported subjective cognitive impairment increased with ECT, immediate and delayed memory (RBANS) significantly increased after ECT, consistent with FDST results. Objective cognition significantly improved during follow-up, but subjective cognition remained impaired.

Conclusion

ECT is effective in young adults with TRD. Although subjective cognitive impairment increased during treatment, objective cognitive impairments were not observed.

Can electrical interventions be helpful in treating mood disorders in patients diagnosed with personality disorders? Case report and literature review

Introduction: The main indication for electrical interventions remains mood disorders. Depressive disorders have high comorbidity, which is one factor in poorer remission and higher suicide risk. Borderline personality disorder is characterized by a variety of psychopathology, in particular the presence of mood swings, impulsive behaviour, and difficulties in maintaining stable interpersonal relationships. An extremely serious clinical problem is the occurrence of episodes of self-harm and suicidal behaviour in these patients. Comorbidity in affective disorders increases the risk of suicide and also reduces the likelihood of achieving symptomatic remission.

Material and methods: A case report of a patient with a major depressive episode and suicidal tendencies with coexisting borderline personality disorder who received electrical treatments with good results is presented and literature from the last 10 years is reviewed using the keywords: borderline personality disorder, depression, electroconvulsive therapy, suicide.

Results: The results of several studies indicate that electrical treatments are partially effective in patients suffering from depressive disorders and borderline personality disorder.

Conclusions: The case of the patient described, as well as data from the literature, suggest that further research is needed into the use of electrical interventions in patients with mood disorders and comorbidity, and their use may be considered in them as a potentially good therapeutic method. The use of ECT in a patient with comorbid personality disorder reflects an individualized treatment approach; however, there is a need for further research in this area, especially in the context of long-term treatment effects.

Antidepressant treatment outcomes in patients with and without comorbid physical or psychiatric disorders: A systematic review and meta-analysis

BACKGROUND

Many patients with major depressive disorder (MDD) experience substantial impairment despite the availability of efficacious treatments. We performed a systematic review and meta-analysis to compare antidepressant outcomes in MDD with or without physical or psychiatric comorbidities.

METHODS

Pubmed, EMBASE, and PsycInfo were searched up to May 14th, 2020 using keywords including MDD, antidepressant, medication, and comorbid. 1915 studies were reviewed. Studies that performed a direct and quantitative comparison of antidepressant effect in patients with MDD with or without comorbidities were included. Study characteristics and primary outcomes were extracted. Continuous and dichotomous variables were considered using standardized mean difference (SMD). Heterogeneity was measured using χ² and I² tests. Risk of bias was assessed using Cochrane Risk of Bias tool and NIH Quality Assessment Tool.

RESULTS

26 studies met selection criteria. Studies of physical (6 studies; I² = 57.69%, p = 0.04) and psychiatric comorbidities (20 studies; I² = 75.75%, p < 0.001) were heterogeneous. When compared to patients with MDD without comorbidities, those with physical (SMD = -0.19, 95% CI: -0.30 to -0.08, p = 0.001; 1910 and 2905 patients with or without comorbidities) or psychiatric comorbidities (SMD = -0.20, 95% CI: -0.31 to -0.095, p < 0.001; 4308 and 6867 patients with or without comorbidities) had worse antidepressant outcomes.

LIMITATIONS

Our limitations included aggregating the comorbidities into physical and psychiatric comorbidities and the high heterogeneity of the studies.

CONCLUSIONS

Our review provides updated evidence demonstrating that patients with MDD and physical or psychiatric comorbidities experience worse antidepressant outcomes.