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Electroconvulsive Therapy (ECT) & Long-Term Cognitive Effects in Major Depression (2023 Review)

Electroconvulsive therapy (ECT) has long been a controversial yet potent treatment for major depressive disorder (MDD), particularly in cases resistant to conventional therapies.

Despite its effectiveness, the long-term cognitive effects of ECT have been a subject of intense debate.

A recent meta-analysis offers new insights into these cognitive changes, shedding light on the nuances of ECT’s impact on cognitive functions and the effectiveness of cognitive assessment tools.


  • Long-Term Cognitive Changes: This meta-analysis provides evidence of both detrimental and beneficial cognitive changes in MDD patients post-ECT.
  • Innovative Assessment Tool: The Electroconvulsive Therapy Cognitive Assessment (ECCA) emerges as a more sensitive tool compared to conventional instruments like MMSE or MoCA.
  • Sub-Dimensional Variations: Different cognitive sub-dimensions such as memory, attention, and executive function exhibit varied responses to ECT.
  • Clinical Implications: These findings are crucial for formulating international clinical guidelines and advancing the therapeutic approach to MDD.

Source: Psychiatry Research (2023)

Electroconvulsive Therapy (ECT): The Basics

Electroconvulsive Therapy (ECT) is one of the most intriguing and controversial treatments in psychiatry.

While highly effective for certain mental health conditions, particularly major depressive disorder (MDD), its use often raises concerns regarding its impact on cognitive functions.

ECT involves delivering controlled electric currents through the brain while the patient is under general anesthesia.

This electrical stimulation induces brief, controlled seizures, which are believed to produce therapeutic effects.

Mechanisms of Action

The exact mechanisms by which ECT exerts its effects remain not fully understood. However, several hypotheses have been proposed:

  • Neurotransmitter Changes: ECT appears to alter neurotransmitter levels, such as serotonin, dopamine, and norepinephrine, which play key roles in mood regulation.
  • Neuroplasticity: ECT may promote neuroplasticity, the brain’s ability to form new neural connections, potentially reversing the effects of chronic stress or depression.
  • Neuroendocrine Regulation: ECT can influence the hypothalamic-pituitary-adrenal (HPA) axis, which may be dysregulated in severe depression.
  • Anti-inflammatory Effects: ECT might reduce neuroinflammation, which is increasingly linked to depressive disorders.

ECT & Cognitive Effects (Long-Term)

Electroconvulsive therapy (ECT) has been a cornerstone in the treatment of severe psychiatric conditions, particularly major depressive disorder (MDD).

Despite its efficacy in alleviating depressive symptoms, the cognitive side effects of ECT have been a subject of ongoing research and debate.

Recent meta-analyses have brought to light the nuanced and varied long-term cognitive impacts of ECT, providing a more detailed understanding of its effects on different cognitive domains.

1. Learning Abilities (Decline)

One of the most significant findings from recent studies is the decline in learning abilities following ECT.

This decline indicates a potential impact on specific brain regions and neural pathways that are crucial in the process of acquiring and retaining new information.

  • Hippocampal Function: The hippocampus plays a vital role in the formation of new memories and learning. ECT-induced seizures might temporarily disrupt hippocampal function, leading to difficulties in learning new information.
  • Neurotrophic Factors: ECT can alter levels of neurotrophic factors like BDNF (Brain-Derived Neurotrophic Factor), which are essential for neuroplasticity and cognitive functions. Fluctuations in these factors post-ECT could affect learning capabilities.
  • Synaptic Plasticity: ECT induces widespread changes in synaptic plasticity. While this can be beneficial for mood regulation, it might also temporarily hinder the synaptic mechanisms involved in learning processes.

2. Executive Function & Processing Speed (Enhancement)

Contrary to the decline in learning abilities, studies have shown improvements in executive functions and processing speed in patients post-ECT.

These improvements offer an intriguing insight into the selective cognitive effects of ECT.

  • Frontal Lobe Activation: The frontal lobes, responsible for executive functions, may experience increased activation or improved connectivity post-ECT. This could enhance abilities such as problem-solving, decision-making, and planning.
  • Neurogenesis & Neuroplasticity: ECT promotes neurogenesis (the formation of new neurons) and enhances neuroplasticity in certain brain regions. These changes can lead to improvements in cognitive processing speed and executive functioning.
  • Reduction in Depressive Symptoms: The alleviation of depressive symptoms itself can lead to improvements in cognitive functions. Depression is often associated with impaired executive function and processing speed, and its treatment can reverse these deficits.

Evidence Review Findings: ETC & Cognitive Changes (2023)

By utilizing a robust meta-analytical framework, a review highlighted the differential impacts of ECT across various cognitive domains.

It also underscored the role of the Electroconvulsive Therapy Cognitive Assessment (ECCA) in detecting these changes with greater specificity and sensitivity compared to traditional tools like MMSE and MoCA.

ECCA (Assessment Tool) is Better

  • Finding: ECCA demonstrated a significant sensitivity (SMD = -0.94, 95% CI [-1.33, -0.54], p < 0.00001) in identifying cognitive impairments post-ECT, outperforming conventional instruments such as MMSE and MoCA.
  • Discussion: This result suggests that ECCA’s design, possibly with its nuanced focus on ECT-specific cognitive changes, offers a more refined lens through which the subtle yet significant cognitive shifts can be detected and assessed.

Cognitive Domain-Specific Impacts

  • Learning Abilities: The study revealed a notable decline in learning abilities post-ECT (SMD = -0.37, 95% CI [-0.55, -0.18], p < 0.0001), indicating that ECT’s impact is particularly pronounced in the domain of acquiring new information.
  • Executive Function & Processing Speed: Conversely, improvements were observed in executive function and processing speed (SMD = 0.52, 95% CI [0.29, 0.74], p < 0.00001), suggesting that some cognitive functions might benefit from the neurobiological effects induced by ECT.
  • Memory, Attention, Language, Spatial Perception, and Orientation: These domains showed no significant detriments, challenging the commonly held belief that ECT broadly impairs cognitive functions. The nuanced findings indicate a complex interplay between ECT and various cognitive processes, with certain areas remaining stable or even improving.

Differential Cognitive Impacts

  • The mixed outcomes across cognitive domains reflect the complex and heterogeneous nature of ECT’s cognitive effects. The decline in learning abilities juxtaposed with improvements in executive function and processing speed underscores the need for a more nuanced understanding of ECT’s neurocognitive outcomes.
  • The stability in memory, attention, language, spatial perception, and orientation suggests that ECT, when administered and monitored carefully, does not universally impair cognitive functions. This finding is critical for mitigating concerns regarding ECT’s cognitive safety profile and supports its continued use in clinical practice under appropriate oversight.
  • The substantial improvement in executive functions and processing speed post-ECT could indicate neuroplastic changes or neurogenesis induced by ECT, which might enhance certain neural pathways or networks involved in these cognitive processes.

Long-Term Cognitive Effects of ETC in MDD (2023 Review)

Qinghua Guo et al. investigated the long-term cognitive effects of Electroconvulsive Therapy (ECT) in patients with Major Depressive Disorder (MDD).

The objectives included evaluating the effectiveness of the Electroconvulsive Therapy Cognitive Assessment (ECCA) compared to traditional tools like MMSE and MoCA, exploring the overall cognitive changes following ECT, and examining variations within different cognitive subdimensions.


  • The study followed the PRISMA guidelines and was registered on PROSPERO (CRD42023439259).
  • A comprehensive literature search was conducted across multiple databases including PubMed, Cochrane Library, Web of Science, Embase, SCOPUS, PsycINFO, CINAHL Plus, and OpenGrey up until June 2023.
  • The review included 10 studies: five randomized controlled trials (RCTs) and five quasi-experimental studies, involving 868 individuals diagnosed with MDD.
  • The study employed subgroup analyses and meta-analyses, examining various cognitive domains using tools like ECCA, MMSE, MoCA, and others specific to different cognitive functions.


  • The meta-analysis indicated that the debate on ECT-induced long-term cognitive impairment is largely due to the lack of specificity and sensitivity of conventional assessment instruments like MMSE or MoCA.
  • The ECCA was found to be more effective (SMD = -0.94, 95% CI [-1.33, -0.54], p < 0.00001) in assessing long-term cognitive impairment in MDD patients post-ECT.
  • The study revealed a decline in learning abilities (SMD = -0.37, 95% CI [-0.55, -0.18], p < 0.0001) but no significant detriments in memory, attention, language, spatial perception, and orientation.
  • Notably, improvements in executive function and processing speed (SMD = 0.52, 95% CI [0.29, 0.74], p < 0.00001) were observed among MDD patients post-ECT.


  • The ECCA showed higher sensitivity compared to MMSE or MoCA, but there is a potential risk of false-positive results.
  • The limited number of studies using ECCA restricted further stratification and subgroup analyses.
  • The study recommends further research to validate these findings across a broader range of assessment tools and clinical settings to strengthen the conclusions and provide a more comprehensive understanding.

Specific Cognitive Functions & ETC: Potential Effects

Electroconvulsive therapy (ECT) can have varied impacts on different cognitive functions.

While ECT is an effective treatment for certain psychiatric disorders, it’s important to be aware of the potential cognitive side effects.


  • Short-term Memory: Patients often experience difficulties with recent memories, like forgetting recent events or conversations.
  • Long-term Memory: In some cases, there can be a loss of older memories, although this is less common than short-term memory impairment.
  • Anterograde Memory: Difficulty in forming new memories immediately following ECT sessions.

Executive Functioning

This includes higher-level cognitive processes such as planning, organizing, abstract thinking, problem-solving, and executing complex tasks.

Some patients may experience challenges in these areas post-ECT.

  • Attention & Concentration: Patients might find it hard to focus their attention, stay on task, or may be easily distracted. This can impact their ability to perform daily activities that require sustained concentration.
  • Processing Speed: The speed at which the brain processes information can be slowed down. This may affect how quickly a person can understand and respond to information.
  • Verbal Fluency & Language Skills: Difficulties may arise in finding the right words, forming coherent sentences, or understanding complex language. However, these are typically less common.
  • Visuospatial Abilities: This refers to the capacity to understand and remember the spatial relationships between objects. Some individuals may experience a decline in these skills, affecting their navigation or interaction with the physical environment.
  • Motor Skills & Coordination: Though less common, there can be impacts on fine motor skills, coordination, and dexterity post-ECT.
  • Learning Abilities: As previously mentioned, learning new information can be particularly challenging following ECT. This can be a temporary effect but might be distressing for patients.
  • Orientation: In rare cases, patients might experience disorientation to time, place, or person immediately following an ECT session, though this is usually short-lived.
  • Emotional Processing: Some patients may find changes in their ability to process emotions or might experience a blunting of emotional responses.
  • It’s important to note that these cognitive side effects vary widely among individuals.

Most are temporary and tend to resolve within a few weeks post-ECT.

However, some patients might experience more prolonged cognitive issues.

The severity and duration of these side effects can depend on various factors, including: the individual’s baseline cognitive function, the number and frequency of ECT sessions, and the specific ECT technique used (such as electrode placement and electrical dosage).

Monitoring and addressing these cognitive changes is an essential component of post-ECT care.

Strategies to Minimize & Manage Cognitive Deficits from Electroconvulsive Therapy (ECT)

Electroconvulsive therapy (ECT) is an effective treatment for certain psychiatric disorders, but it can be associated with cognitive side effects.

It’s crucial to implement strategies both to reduce the risk of these deficits and to manage them if they occur.

Modified ECT Techniques

  • Right Unilateral Electrode Placement: It’s generally less cognitively impairing than bilateral placement.
  • Ultrabrief Pulse Width: Using ultrabrief pulse ECT can minimize cognitive side effects compared to standard pulse widths.
  • Lower Electrical Dosage: Adjusting the electrical dosage to the minimum effective level can reduce cognitive impacts.

Pre-ECT Cognitive Assessment: Conduct thorough cognitive evaluations before starting ECT to establish a baseline, which helps in identifying any changes post-treatment.

Patient Education & Informed Consent: Informing patients about potential cognitive side effects ensures they are making an informed decision and can prepare for possible outcomes.

Individualized Treatment Planning: Tailoring the frequency and total number of ECT sessions to the individual’s needs and response can help in reducing cognitive side effects.

Monitoring During Treatment: Regular cognitive assessments during the ECT course can help in early detection of cognitive impairments, allowing for timely adjustments in treatment.

Cognitive Rehabilitation

  • Cognitive Exercises: Engaging in activities and exercises designed to improve memory, attention, and executive functions.
  • Neuropsychological Rehabilitation: Targeted therapies to address specific cognitive deficits.

Medications: Certain medications, such as cholinesterase inhibitors or NMDA receptor antagonists, might be considered to alleviate cognitive symptoms.

Supportive Therapies

  • Psychotherapy: Techniques like cognitive-behavioral therapy (CBT) can help patients develop strategies to cope with and compensate for cognitive changes.
  • Occupational Therapy: To assist in adapting to cognitive changes in daily life activities.

Lifestyle Modifications

  • Physical Exercise: Regular physical activity has been shown to promote brain health and cognitive functioning.
  • Healthy Diet: Nutritional interventions can support cognitive health.
  • Mental Stimulation: Engaging in intellectually stimulating activities (e.g., reading, puzzles) can help maintain cognitive functions.

Patient & Family Education: Educating the patient and their family about cognitive side effects, coping strategies, and the recovery process is essential for managing expectations and improving outcomes.

Follow-Up & Monitoring: Continuous monitoring of cognitive function post-ECT is crucial for early identification and management of persistent cognitive deficits.

Support Groups & Counseling: Joining support groups and counseling can provide emotional support and practical advice for dealing with cognitive changes.

Environmental Modifications: Simplifying and structuring the patient’s environment can help in reducing confusion and stress, thereby supporting cognitive recovery.

Mindfulness & Stress Reduction Techniques: Practices like meditation and mindfulness can be beneficial in managing cognitive and emotional challenges post-ECT.

What are some clinical takeaways from the review? (ETC & Cognition)

The study’s findings have several important clinical implications that can guide practitioners in the management of patients undergoing ECT for Major Depressive Disorder (MDD):

  1. Adoption of ECCA: Clinicians should consider incorporating the Electroconvulsive Therapy Cognitive Assessment (ECCA) into their post-ECT evaluation protocols. Its superior sensitivity to cognitive changes offers a more accurate assessment, enabling tailored patient care.
  2. Individualized Patient Monitoring: The differential impact of ECT on various cognitive domains underscores the importance of individualized monitoring. Patients may exhibit distinct cognitive trajectories post-ECT, necessitating personalized intervention strategies.
  3. Educational Initiatives: Educating patients and families about potential cognitive changes post-ECT is crucial. Understanding these effects can help set realistic expectations and foster strategies for coping with cognitive changes.
  4. Cognitive Rehabilitation: The study highlights the potential for cognitive rehabilitation in areas adversely affected by ECT, such as learning abilities. Rehabilitation programs should be considered an integral part of post-ECT care.
  5. Research & Development: The findings emphasize the need for ongoing research into developing and validating cognitive assessment tools. Future studies should aim to broaden the spectrum of sensitive instruments available for post-ECT cognitive evaluation.
  6. Guideline Formulation: The evidence presented can inform the development of international clinical guidelines, advocating for the integration of sensitive cognitive assessments like ECCA. Such guidelines can standardize care and ensure that cognitive impacts are adequately addressed in the therapeutic regimen for MDD.

Conclusion: Electroconvulsive Therapy & Cognition

This comprehensive review underscores the nuanced cognitive landscape following Electroconvulsive Therapy (ECT) in patients with Major Depressive Disorder (MDD), revealing both the strengths and limitations of current cognitive assessment tools.

The Electroconvulsive Therapy Cognitive Assessment (ECCA) emerged as a notably more sensitive instrument than traditional tools like MMSE and MoCA, particularly in detecting subtle changes in learning abilities and executive function.

The findings advocate for a reevaluation of cognitive assessment practices post-ECT, emphasizing the need for instruments that can accurately reflect the complex cognitive outcomes.

This research contributes significantly to the academic discourse, paving the way for enhanced clinical guidelines that could profoundly influence therapeutic approaches in MDD treatment.

It also calls for further research to validate these findings across a broader spectrum of assessment tools and clinical settings.

Ultimately, this study marks a critical step towards refining our understanding and management of cognitive changes associated with ECT.


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