Tryptophan depletion in patients with Selective Serotonin Reuptake Inhibitor (SSRI)-remitted anxiety disorders
| ISRCTN | ISRCTN01523262 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN01523262 |
| Protocol serial number | RA/4/1/1193, ACTRN12609000170224 |
| Sponsor | Raine Medical Research Foundation (Australia) |
| Funder | Raine Priming Grant 2005-6. |
- Submission date
- 15/04/2005
- Registration date
- 10/05/2005
- Last edited
- 12/01/2021
- Recruitment status
- No longer recruiting
- Overall study status
- Completed
- Condition category
- Mental and Behavioural Disorders
Plain English summary of protocol
Not provided at time of registration
Contact information
Scientific
School of Psychiatry and Clinical Neurosciences (M521)
Queen Elizabeth II Medical Centre
Nedlands
Perth
6009
Australia
| Phone | +61 (0)8 93462393 |
|---|---|
| sean@cyllene.uwa.edu.au |
Study information
| Primary study design | Interventional |
|---|---|
| Study design | Randomised controlled trial |
| Secondary study design | Randomised controlled trial |
| Scientific title | Tryptophan depletion in patients with Selective Serotonin Reuptake Inhibitor (SSRI)-remitted anxiety disorders |
| Study objectives | Primary hypotheses: 1. Tryptophan depletion (TD) will cause transient symptom relapse in SSRI-remitted GAD patients, but only when challenged with the 7.5% CO2 provocation paradigm (Study 2) 2. OCD patients well on SSRIs will not relapse spontaneously when undergoing TD but will suffer a significant worsening of anxiety when exposed to a personalised phobic stimulus (Study 1) Secondary hypotheses: 1. TD will have a greater impact upon women than men, according to primary outcome measures 2. Women will experience more nausea on the occasion that they have the tryptophan-restored (control) drink than on the tryptophan-depleted occasion 3. Transient depressive symptoms will be seen in subjects with a past history of depressive illness, despite the absence of a current or recent diagnosis of a depressive disorder |
| Ethics approval(s) | Not provided at time of registration |
| Health condition(s) or problem(s) studied | Obsessive-compulsive disorder (OCD); Generalised anxiety disorder (GAD). |
| Intervention | 1. Tryptophan depletion (double-blind crossover) vs tryptophan restored intervention 2. Disorder specific provocation, viz: a. 20 min 7.5% CO2 inhalation or air (GAD) b. Exposure to a known anxiogenic stimulus (OCD) |
| Intervention type | Other |
| Primary outcome measure(s) |
Study 1: Visual Analogue Scales (VAS), The Spielberger State Anxiety Inventory (STAI), tryptophan levels, c. Profile of Mood States (POMS), Yale-Brown Obsessive Compulsive Scale (Y-BOCS) |
| Key secondary outcome measure(s) |
Beck Depression Inventory (BDI), Blood pressure/heart rate data, Swedish universities Scales of Personality (SSP). |
| Completion date | 31/12/2006 |
Eligibility
| Participant type(s) | Patient |
|---|---|
| Age group | Adult |
| Lower age limit | 18 Years |
| Upper age limit | 65 Years |
| Sex | All |
| Target sample size at registration | 28 |
| Total final enrolment | 12 |
| Key inclusion criteria | Study 1: Primary diagnosis of obsessive-compulsive disorder (OCD), currently remitted with SSRI therapy Study 2: Primary diagnosis of generalised anxiety disorder (GAD), currently remitted with SSRI therapy Aged 18-65 Able and willing to give informed consent prior to participation |
| Key exclusion criteria | 1. No significant co-morbid anxiety disorder or other psychiatric disorder including alcohol or drug dependence 2. No major depressive episode with past 6 months 3. No significant other illness 4. No significant other medication therapy 5. No psychological therapy applied this episode |
| Date of first enrolment | 01/07/2005 |
| Date of final enrolment | 31/12/2006 |
Locations
Countries of recruitment
- Australia
Study participating centre
6009
Australia
Results and Publications
| Individual participant data (IPD) Intention to share | No |
|---|---|
| IPD sharing plan summary | Not provided at time of registration |
| IPD sharing plan |
Study outputs
| Output type | Details | Date created | Date added | Peer reviewed? | Patient-facing? |
|---|---|---|---|---|---|
| Results article | results | 01/02/2010 | 12/01/2021 | Yes | No |
Editorial Notes
12/01/2021: The following changes have been made:
1. Publication reference added.
2. The final enrolment number has been added from the reference.
3. The ANZCTR number has been added.
