None listed
Conditions
Brief summary
‘Anxiety disorders’ diagnosis is currently based on clinical symptom check lists and there are no biological markers to diagnose specific syndromal causes. We have described a detailed theory of the brain systems controlling anxiolytic-insensitive threat-avoidance and anxiolytic-sensitive threat-approach. This new biomarker should allow division of untreated ‘anxiety’ patients, with superficially similar clusters of symptoms, into distinct high scoring (syndromal) and low scoring groups with different treatment-responses. This would be the first theoretically-derived biomarker for any mental disorder and should: 1) predict treatment efficacy better than current symptom-based diagnoses; 2) provide a human single dose test of novel anxiolytics; 3) provide a starting point for developing biomarkers for other ‘anxiety’ syndromes; and so, 4) greatly improve treatment outcomes and cost-effectiveness. Our previous work has shown that single doses of 3 types of anxiolytic drug all reduce goal-conflict-specific rhythmicity (GCSR) in a stop signal task despite sharing only anxiolytic and not panicolytic or antidepressant or other actions. Preliminary results indicate that this action is also seen in a variant of the stop signal task with targeted rather than speeded responses; but drug action has not been tested in the choice tasks, involving monetary gain and loss, in which GCSR was originally demonstrated and from which the money-free variant was developed. Generality of the results has also not been extended to other doses of the original anxiolytic drugs or to drugs with broader actions on panic and depression that share a capacity to reduce clinical anxiety. There are several objectives in the proposed randomized double blind parallel group studies: -To evaluate the dose-response relationship for drugs already known to affect an EEG biomarker of an anxiety-related process. -To evaluate the generalisation of effect on the EEG biomarker of the anxiety-related process to drugs with broader anxiolytic-antipanic-antidepressant-antipsychotic actions. -To evaluate the dose-response relationship of anxiolytic drugs on behaviour and potential EEG biomarkers in behavioural tasks involving explicit approach-avoidance conflict generated by gain and loss of money.
Interventions
Single doses of one of the following anxiolytic medications: buspirone 5, 10 or 15mg, citalopram 10mg, clonidine 75mcg, pregabalin 25, 75 or 100mg, triazolam 0.125, 0.25 or 0.5mg, promethazine 10mg, quetiapine 25mg, venlafaxine 75mg. All medications will be encapsulated (i.e.administered as an oral capsule) to assist with blinding. Dosing will be directly observed by study staff.
Sponsors
University of Otago
Study design
Allocation
Randomised controlled trial
Intervention model
Parallel
Primary purpose
Treatment
Masking
Blinded (masking used) (Subject, Caregiver, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
All
Age
18 Years to 65 Years
Healthy volunteers
Yes
Inclusion criteria
1. Capable of understanding and signing an informed consent. 2. Aged 18-65 years on the day of consent. 3. Good general health.
Exclusion criteria
1. Females who are or intend to become pregnant, or are lactating. 2. Participants who, in the opinion of the investigator, do not understand the information and procedures of the study, or would not be compliant with them (in particular the study restrictions and risks involved). 3. Any participant for whom the investigator believes, for any reason, that participation would not be an acceptable risk. 4. Regular use of any drug that alters mood or is used to treat mental disorder, including daily use of alcohol or use of alcohol within 24 hours prior to testing. 5. Subjects with a prior history of seizures; susceptibility to photosensitivity; or a history of allergic skin reactions.
Outcome results
None listed