How does taking Ritalin affect depersonalization-derealization disorder patients?

California State University Northridge
La Crescenta, California
DOI: 10.18258/11943
Raised of $370 Goal
Funded on 3/01/19
Successfully Funded
  • $380
  • 102%
  • Funded
    on 3/01/19




Aim 1: To examine DPDR reduction following prescribed methylphenidate use. Participants will take methylphenidate as prescribed and report levels of dissociation using the Cambridge Depersonalisation Scale (CDS) before administration, at peak action, and 6 hours post-administration.

Hypothesis 1a. In the treatment group, DPDR symptoms will be reduced at peak action compared to pre-test.

Hypothesis 1b. In the treatment group, DPDR symptoms will increase at follow-up, compared to peak action.

Hypothesis 1c. In the control group, DPDR symptoms will not change.

Aim 2: To examine the impact of self-reported anxiety on DPDR amelioration.  

Hypothesis 2. In the treatment group only, anxiety will moderate the association between methylphenidate and DPDR symptom reduction. Individuals with higher anxiety will report less efficacy, as methylphenidate’s mechanism of action involves inhibiting reuptake of dopamine and norepinephrine (Kuczenski & Segal, 1997) and may exacerbate DPDR symptoms among anxious individuals.

Aim 3: To examine the impact of co-morbid ADHD on DPDR amelioration.

Hypothesis 3. In the treatment group only, ADHD will moderate the association between methylphenidate and DPDR symptom reduction. Individuals with higher ADHD symptoms will report greater efficacy, as methylphenidate activates impaired frontal circuits, and may potentially dampen overactive activity in the parietal lobe.


The proposed project is a mixed between/within subjects design in which individuals will be recruited from Amazon MTurk. Power analyses suggest the minimum sample size to detect the expected effects is N = 165. Therefore, 180 will be collected to account for potential missing data (treatment group = 90 currently taking Methylphenidate as prescribed; control group = 90 endorsing ADHD but not taking stimulant medication). This design will ensure symptom changes observed with medication activity are not better accounted for by natural diurnal rhythms. Methylphenidate dosage will be statistically controlled. The sample size will ensure a range of DPDR symptom levels across which effects can be compared.


Participants will be recruited using Amazon MTurk and will answer the State Trait Anxiety Inventory, Adult ADHD Self-Report Scale, and Cambridge Depersonalization Scale (CDS) before taking methylphenidate, at approximate peak concentration, and post-metabolism (along with a control group with unmedicated ADHD who will also respond at these times). The CDS screens for derealization and depersonalization and is well-suited to the momentary experience of DPDR. The STAI and ASRS will be included because we hypothesize that comorbid anxiety and ADHD symptoms will moderate the response between methylphenidate and DPDR symptom amelioration.

Participants will be pre-screened for the period of time having taken methylphenidate, prescribed dosage, and time of day taken. To distract from the true purpose, participants will be informed that the purpose of the study is to “assess the effectiveness of ADHD medication”. Participants will take the CDS, State Trait Anxiety Inventory (STAI), and (Adult ADHD Self-Report Scale) ASRS at three time points: baseline (prior to ingestion), at peak medication action (2 hours post ingestion) and after drug metabolism (6 hours post ingestion).

The CDS is valid, reliable, and well-correlated with the depersonalization subscale of the Dissociative Experiences Scale (DES). The CDS’s questions are more suited to the momentary assessment of symptoms (e.g. “What I see looks ‘flat’ or ‘lifeless’, as if I were looking at a picture”) than the DES (e.g. “Some people are told that they sometimes do not recognize friends or family members. Select a number to show what percentage of the time this happens to you”) and is sufficient for assessing DPDR specifically. At peak concentration (based on participants’ responses about time of ingestion), participants will be prompted by email to re-take these three questionnaires and reminded to answer them based on their experience at that moment. There will be a twenty-minute window of time during which the questionnaires will be available. At follow-up, participants will again take the questionnaires.


The greatest challenge is that because individuals are prescribed varying dosages, it is possible that individuals with differing sensitivities and metabolisms will receive variable relief from DPDR symptoms. However, we are optimistic that this should not pose a significant threat, as dosage is expected to be calibrated to each individual by his/her prescriber.

Pre Analysis Plan

We plan to employ a series of mixed factorial ANOVAs to test our hypothesis.


This project has not yet shared any protocols.