Use of Ketamine to Enhance Electroconvulsive Therapy (ECT) in Depression

• Hamilton Rating Scale for Depression-24 (HRSD24) [ Time Frame: Change from beginning of ECT treatment to end; on average 3 weeks ] [ Designated as safety issue: No ]
  The HDRS-24 is used to rate depressive symptoms. This instrument is considered one of the "gold standard" clinician-rated instruments for depressive symptoms. We have established procedures for the maintenance of inter-rater reliability.
  
  

• Quick Inventory of Depressive Symptomatology, Self Report (QIDS-SR) [ Time Frame: Change from beginning of ECT treatment to end; on average 3 weeks ] [ Designated as safety issue: No ]
  The QIDS-SR is a 16-item self-rated instrument designed to assess the severity of depressive symptoms present in the past seven days (Rush et al 2003). The 16 items cover the nine symptom domains of major depression, and are rated on a scale of 0-3. Total score ranges from 0 to 27, with ranges of 0-5 (normal), 6-10 (mild), 11-15 (moderate), 16-20 (moderate to severe), and 21+ (severe).
  
  
• Brief Psychiatric Rating Scale (BPRS) [ Time Frame: Change from beginning of ECT treatment to end; on average 3 weeks ] [ Designated as safety issue: Yes ]
  The BPRS is used to assess acute behavioral changes during the infusions. Four key BPRS items for the positive (+) symptoms of psychosis will be used: conceptual disorganization, hallucinatory behavior, suspiciousness, and unusual thought content. Three items representing the negative (-) symptoms of psychosis will also be used: blunted affect, emotional withdrawal, and motor retardation.
  
  
• Patient Rated Inventory of Side Effects (PRISE) [ Time Frame: Change from beginning of ECT treatment to end; on average 3 weeks ] [ Designated as safety issue: Yes ]
  The PRISE assesses the presence of treatment side effects in nine organ/function systems (gastrointestinal, nervous system, heart, eyes/ears, skin, genital/urinary, sleep, sexual functioning, and other). Each system will score 0 to 2 based on the severity of the complaints (0 = no side effect, 1 = tolerable side effect, 2 = distressing side effect) and the total score is calculated.
  
  
• Autobiographical Memory Interview (AMI) [ Time Frame: Change from beginning of ECT treatment to end; on average 3 weeks ] [ Designated as safety issue: Yes ]
  
• Clinician-Administered Dissociative States Scale (CADSS) [ Time Frame: Change from beginning of ECT treatment to end; on average 3 weeks ] [ Designated as safety issue: Yes ]
  The CADSS is used to measure dissociative effects during the infusions. The scale includes 19 questions and 8 observer ratings scored from 0 (not at all) to 4 (extremely). The CADSS measures impairment in body perception, environmental perception, time perception, memory impairment, and feelings of unreality.
  
  
• The Rey Auditory Verbal Learning Test (AVLT) [ Time Frame: Change from beginning of ECT treatment to end; on average 3 weeks ] [ Designated as safety issue: Yes ]
  This scale is brief and easy to administer and has been well-validated. Equivalent alternate forms are available
  
  

Electroconvulsive therapy (ECT) is one of the most robust antidepressant treatments available. However, there is the potential for significant acute and longer term adverse cognitive effects with ECT and the antidepressant response requires multiple treatment sessions, increasing risk of adverse effects. Further, antidepressant response to ECT is often less than maximal and relapse is common. Growing preclinical and clinical evidence of the rapid-acting antidepressant properties of the anesthetic agent ketamine suggests the use of ketamine anesthesia as a strategy to increase rate of response and shorten treatment course in the administration of ECT. In addition, preclinical and clinical evidence suggests the potential of ketamine to decrease the adverse cognitive effects associated with ECT.

The investigators propose a pilot study to measure both acute therapeutic efficacy and cognitive side effects of ECT using ketamine compared to methohexital in depressed patients. The investigators will also explore other parameters of ECT such as seizure duration and morphology, as well as hemodynamic and behavioral changes.