Cognitive and Psychophysiological Effects of Delta-9-Tetrahydrocannabinol in Bipolar Disorder

Cognitive and Psychophysiological Effects of Delta-9-Tetrahydrocannabinol in Bipolar Disorder

The overarching goal of this study is to characterize the acute cognitive and psychophysiological effects of the main psychoactive constituent of cannabis, 9-delta-tetrahydrocannabinol (THC) in individuals with euthymic bipolar disorder (BD), and to begin probing the mechanisms that may underlie its effects in this illness.

This study is expected to contribute to a better characterization of specific effects of THC in individuals with BD compared to healthy controls (HC).

To compare the dose related acute effects of inhaled THC, administered through a vaporizer over approximately 20 minutes, between HC and euthymic BD individuals (referred to as eBD) on a range of subjective and objective parameters as described below:

Primary Aims:

• Verbal memory, measured by a modified computer version of the Rey Auditory Verbal Learning Test (RAVLT) and/or the CogState battery, administered while EEG data is collected.
• Executive functioning measured by the CogState battery and/or Trails Making Test-Part B.

Secondary Aims:

• Attention, measured by the Continuous Performance Test-Identical Pairs (CPT-IP).
• Working memory, measured by the Wechsler Memory Scale-3 Letter-Number Sequencing.
• Mood, measured by the Profile of Mood States (POMS).
• Psychotic-type experiences, measured by the Psychotomimetic States Inventory (PSI) and/or the Clinician Administered Dissociative Symptoms Scale (CADSS).
• Anxiety symptoms, measured by the Visual Analog Scale for Anxiety (VAS-A).
• Impulsivity, measured by the Balloon Analogue Risk Task (BART).

Exploratory aims:

•Serum prolactin, serum ACTH, serum cortisol and serum endocannabinoid levels.

Inclusion Criteria for individuals with Bipolar Disorder (BD)

1. Men and women aged 18-55 years (extremes included).
2. Able to provide informed consent in English.
3. A diagnosis of BD type I or BD type II and good physical health.
4. Current euthymic state for at least 4 weeks.

Inclusion Criteria for Healthy Control (HC) individuals:

1. Men and women aged approximately 18-55 years (extremes included).
2. Able to provide informed consent in English.
3. No psychiatric diagnoses and in good physical health.

General exclusion criteria:

1. Cannabis naïve
2. Unwillingness to remain alcohol-free, cannabis-free for at least 1 week (in infrequent cannabis users) prior to each test day.
3. Evidence of a hearing deficit.
4. IQ less than 80.
5. Positive pregnancy test, lactation, and refusal to practice birth control.