Clarification Regarding Study Type: Observational

This study is a prospective, non-interventional observational study. The decision to administer Electroconvulsive Therapy (ECT) and the selection of the anesthetic agent (ketamine + propofol or propofol alone) are made entirely by the treating psychiatrist as part of routine clinical practice, independent of and prior to any research-related activities. Participants are not assigned to anesthetic groups by the investigators; rather, they are observed and grouped according to the anesthetic regimen already determined by their clinical team based on standard medical care. The investigators do not intervene in, alter, or influence the treatment process in any way. Data collection consists solely of administering validated psychiatric rating scales at predefined time points to monitor naturally occurring clinical outcomes. Therefore, this study meets the definition of an observational study as outlined in the Protocol Registration Data Element Definitions: participants receive interventions as part of routine medical care, and the researcher studies the effect of the intervention without assigning it.

Summary of the Study

This research project, titled "A Prospective Observational Study of Suicidal Ideation, Dissociative Symptoms, and Treatment Response in Psychiatric Patients Receiving Electroconvulsive Therapy (ECT)", aims to investigate clinical outcomes associated with different anesthetic agents used during ECT in patients diagnosed with Major Depressive Disorder (MDD) or Bipolar Depression. As these disorders constitute some of the most disabling psychiatric conditions globally, effective and timely treatment remains critical. Despite the widespread use of antidepressant medications, a substantial proportion of patients-particularly those classified under Treatment-Resistant Depression (TRD)-fail to achieve adequate remission. For such individuals, ECT continues to be one of the most reliable and evidence-based therapeutic options.

The study focuses on how anesthetic choice during ECT influences three key clinical parameters:

Depression severity, Suicidal ideation, and Dissociative symptoms. Ketamine, an NMDA receptor antagonist, has gained particular interest due to its rapid antidepressant properties and unique neurobiological profile. It has shown promise in reducing depressive symptoms more quickly than traditional anesthetic agents, although it may also trigger transient dissociative experiences. In contrast, propofol-another commonly used anesthetic during ECT-has more neutral sedative characteristics and lacks the rapid antidepressant effects attributed to ketamine. Understanding how these anesthetics influence clinical trajectories during ECT may help optimize treatment approaches for complex depressive disorders.

This non-interventional, prospective observational study will include 65 patients aged 18-65, all of whom meet DSM-5 criteria for MDD or Bipolar Disorder in a depressive episode and have an established clinical indication for ECT. Participants will be assigned naturally, based on clinical practice, to one of two groups:

Ketamine + Propofol anesthesia group (n=30) Propofol-only anesthesia group (n=35)

Researchers will not intervene in the anesthesia selection process. Instead, they will observe and measure clinical progress using validated psychiatric assessment tools:

Montgomery-Åsberg Depression Rating Scale (MADRS) for depression severity, Beck Suicidal Ideation Scale (BSI) for suicidal thoughts and planning, and Clinician-Administered Dissociative States Scale (CADSS) for dissociative symptoms such as depersonalization, derealization, and amnesia.

Assessments will be conducted at four time points to monitor the evolution of symptoms during treatment:

Before initiation of ECT, After the first ECT session, After the third ECT session, At the completion of the full ECT course. By comparing these clinical measurements across different anesthetic groups, the research seeks to determine whether ketamine offers measurable advantages in terms of speed of antidepressant response, reduction in suicidal thoughts, or increase in dissociative phenomena, compared with propofol. Prior studies have suggested that ketamine may produce faster mood improvement, especially in TRD, but may also lead to short-term cognitive and perceptual disturbances. This study will contribute real-world data from a psychiatric inpatient population undergoing standardized ECT procedures.

The expected outcome is a clearer understanding of how anesthetic choice influences the clinical course of patients undergoing ECT for depressive disorders. Such knowledge has the potential to guide personalized treatment strategies, optimize patient safety, and improve outcomes for individuals who have not responded to standard pharmacological interventions. Additionally, identifying dissociative responses linked specifically to ketamine may help clarify whi

Inclusion Criteria:

1. Diagnosed with depression or bipolar depression according to DSM-5
2. Having an indication for ECT (Electroconvulsive Therapy)

Exclusion Criteria:

1. Mental limitations such as intellectual disability
2. Refusal to undergo ECT
3. Patients not suitable for general anesthesia
4. Substance use disorder
5. Alcohol dependence

Being an inpatient at Pamukkale University Faculty of Medicine, Department of Mental Health and Diseases Hospital