Study 1: Brain imaging study using MRI’s of patients with HPPD and people without HPPD
This study serves to help understand the neurological pathways that are affected by HPPD, giving further insight into the condition.
Study 2: Pupil dilation test
Dr. Abraham noticed that patients suffering from HPPD seem to have more dilated pupils than people without HPPD. This is a symptom of a hyper-aroused autonomic system. A simple test measuring the size of patient’s pupils in controlled lighting conditions would test this hypothesis.
Study 3: PPI (pre pulse inhibition)
When people have a pre-warning on a sound they are less likely to be startled, however in patients with schizophrenia the pre-pulse does not seem to affect the startle response. This is thought to be related to the dopinergic system, other conditions such as ADHD, OCD and Tourette’s also show reduced PPI. Dr. Abraham’s hypothesis is that patients suffering from HPPD may have reduced PPI, suggesting that the pathway causing the condition may be similar (but less pronounced) to schizophrenia.
Study 4: CFF and dark adaption
Dr. Abraham has stated that people with HPPD have very bad impairment in night vision. This test would serve to understand how badly the individual’s vision is impaired in the absence of natural light.
Study 5: Genetic vulnerability
Dr. Abraham has applied for funding for this study 3 times. He believes there are a distinct set of specific genetic vulnerabilities in patients suffering from HPPD. Dr. Abraham is happy to share the information on the various genes that he thinks are relevant to the problem. If a genetic study is indeed to be conducted, it would be prudent to do this in conjunction with study 6 (below), to see if genetics could be used as a tool to predict the onset and duration of HPPD.
Study 6: Recovery rate
The study would investigate what percentage of people with HPPD will eventually recover. From Dr. Abraham’s observations, those who do recover, do so within 5 years. Around 50% of people who suffer from HPPD will recover. He suggested that it may be possible to do this study using surveys, as well as other special and validated ways of testing to ensure that the findings are comprehensive. These tests would include having face to face interviews. Interviewing people twice by two different interviewers to make sure responses match and also using various other techniques.
Questions to include:
- What initiated your HPPD?
- How long ago did you first experience HPPD?
- Have you symptoms changed since you first experienced it?
- Have you experienced any psychiatric co-morbidities?
- Does the intensity of your HPPD vary and what causes variations in intensity?
- Does anxiety influence symptoms?
Study 7: Open-label study on the effectiveness of treatments for HPPD
Select drug treatments that are thought to improve HPPD symptoms and do a cross over study using questionnaires to measure the effectiveness of each treatment and any associated side effects. Treatments to test include:
Treatments to test include:
- Clonidine – Which is an alpha 2 agonist
- Phosphatidylcholine – It helps with fatty acid metabolism and improves nerve cell integrity
- Methyl folate – This is the active form of folate and ¼ of depressed people lack the enzyme that converts folate to its active form.
Study 8: Anxiety study
Many people suffering from HPPD comment that anxiety intensifies the HPPD itself. It is possible to test this theory and to establish if anxiety is indeed a trigger for more intense symptoms. A study must be designed to understand any correlations that exist between anxiety and HPPD. If anxiety is a trigger, than ways of reducing anxiety could be determined as a means of treatment. This includes meditation, yoga, and maybe other forms of exercise. Dr. Abraham emphasized that meditation has been shown to significantly reduce anxiety.