Selegiline and Reward Processing

There has been growing interest in the relationship between reward processing and clinical symptoms of depression such as anhedonia (loss of interest and response to pleasurable activities).

The aim of the study is to investigate the acute effects of a single dose of selegiline (an irreversible monoamine oxidase B inhibitor) on reward and emotional processing in healthy volunteers.

There has been growing interest in the relationship between reward processing and clinical symptoms of depression such as anhedonia (loss of interest and response to pleasurable activities). Studies in animals have suggested that the neurotransmitter, dopamine, plays a key role in reward processing. This has given rise to the suggestion that in depression, decrements in dopamine activity lead to impaired reward processing which cause symptoms such as anhedonia and low motivation.

Research in humans into dopamine and reward is limited by suitable pharmacological means to manipulate dopamine activity safely and effectively.

To our knowledge, no previous research has studied the effects of acute administration of the licensed drug, selegiline, on reward and emotional processing. However, a single dose of selegiline effectively inhibits monoamine oxidase B (MAO-B), which should lead to increased dopamine availability in the CNS. Therefore, selegiline may be a useful tool to explore the effect of modifying dopamine availability on reward processing. Acquiring such knowledge through this study could assist in the clinical use of MAO-B inhibition as a target to ameliorate symptoms such as anhedonia as well as increasing our general understanding of reward processing in healthy individuals.

The aim of this study is to explore the effects of acute administration of a standard (10mg) dose of selegiline on reward and emotional processing versus a placebo, in healthy volunteers. At this dose selegiline only has an -MAO-B function therefore the specific impact of MAO-B blockade on reward and emotional processing can be explored.

Research Question: What effect will the administration of a single dose of selegiline have on reward and emotional processing in healthy volunteers?

Eligibility Criteria:
Inclusion Criteria:

* 18-40 years of age
* Able to give informed consent for study participation
* Sufficient fluency in English to understand and complete the neuropsychological tasks

Exclusion Criteria:

* Current usage of other regular medication (including the contraceptive pill, the Depo-Provera injection or the progesterone implant, and hormone replacement therapy)
* Any past or current Axis 1 DSM-IV psychiatric disorder
* Significant medical condition
* Pulse \< 60 beats per minute at baseline screening
* Current or past gastro-intestinal disorder or irritable bowel syndrome
* Current pregnancy or breastfeeding
* Known lactate deficiency or any other problem absorbing lactose, galactose or glucose
* Current or past history of drug or alcohol dependency
* Participation in a psychological or medical study involving the use of medication within the last 3 months
* Previous participation in a study using the same, or similar, emotional processing tasks
* Smoker \> 5 cigarettes per day
* Typically drinks \> 6 caffeinated drinks per day