Clinical trial NCT03825627: From Attention to Behavior: Increasing Behavioral Inhibition
Official title: From Attention to Behavior: Increasing Behavioral Inhibition Through Transcranial Direct Current Stimulation in Pedophilia
Study type: INTERVENTIONAL
Overall status: UNKNOWN
Phase: NA
Conditions: Pedophilia
Lead sponsor: University of Zurich
Sponsor class: OTHER
First posted: 2019-01-31
Enrollment: 76
Sex: MALE
Minimum age (years): 18
Maximum age (years): 65
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: This project will investigate if transcranial direct current stimulation can be used as treatment for Pedophilia. Treatment efficacy will be evaluated with behavioral tasks and the recording of eye-movement.

Detailed description: Pedophilia is an important motivation for sexual offenses involving children, including child pornography and sexual contacts with children (henceforth, pedosexual behavior). Indeed, approximately half of individuals convicted for sexual offenses against children have a Pedophilic disorder and offenders with a Pedophilic disorder are much more likely to sexually reoffend.

A promising line of research has examined the neurocognitive basis of pedophilia. Pedophilic individuals display altered activity in the dorsolateral prefrontal cortex (dlPFC) when attending to child-related stimuli. This brain area is involved in the cognitive control of sexual arousal. Transcranial Direct Current Stimulation (tDCS) has been examined as a non-invasive method to increase activity in the dlPCF, ultimately increasing inhibitory control over impulses. Accumulating evidence also shows that individuals have an attentional bias towards sexually preferred stimuli. These attentional processes can be investigated by recording eye movements. Early automatic eye movements are particularly relevant in discriminating individuals with pedophilia from those without pedophilia.

The proposed study will examine the effects of tDCS over the dlPFC of pedophilic individuals and healthy controls, while they complete a task requiring controlled attention to virtual (computer-generated) images of children and adults. In two separate sessions, participants will be randomly assigned to an active and a placebo (sham) tDCS condition. Eye movements will be recorded during the task.

The investigators expect to observe a conflict between automatic and controlled attention when participants are presented with their sexually preferred stimuli. Specifically, the investigators expect pedophiles to show an attentional bias towards virtual child stimuli. The investigators predict that the attentional conflict will be reduced when tDCS is applied, compared to the sham condition. If the attentional bias is a key cognitive feature of sexual interest, the investigators expect to measure changes in reported or indirectly assessed sexual preferences.

Eligibility criteria: Inclusion Criteria:

Patients

* Diagnosed with pedophilia (further psychiatric illnesses possible)
* Sufficient German language skills

Controls:

* Not diagnosed with Pedophilia (or other psychiatric illnesses)
* Sufficient German language skills

Exclusion Criteria:

Patients

* Prior head injury with loss of consciousness for at least 5 min
* Neurological diagnosis (including epilepsy) or prior medical conditions with possible central nervous system sequelae
* Metallic implants inside the brain or any electrical medical device (e.g. pacemaker) in the body
* Visual or hearing impairment, to the extent that it interferes with task instructions

Current medication in patients (antiandrogenic medication among the pedophilic subjects, in particular) will be recorded and acknowledged as a covariate.

Controls

* Prior head injury with loss of consciousness for at least 5 min
* Neurological diagnosis (including epilepsy) or prior medical conditions with possible central nervous system sequelae
* Metallic implants inside the brain or any electrical medical device (e.g. pacemaker) in the body
* Visual or hearing impairment, to the extent that it interferes with task instructions
* Current or previous pedophilic sexual interest

For both groups further exclusion (prematurely) will occur if initial data shows that participants don't comply with instructions or if questionnaires hint toward a lack of sexual interest in general.

Primary outcomes:
measure: Entry Time
timeFrame: Through study completion, an average of 10 months. The outcome measure is not an event but a performance measure recorded for every participant in every session.
measure: differential AAT index (∆RT)
timeFrame: Through study completion, an average of 10 months. The outcome measure is not an event but a performance measure recorded for every participant in every session.
Secondary outcomes:
Other outcomes:
Locations:
city: Zürich
country: Switzerland
facility: Psychiatrische Universitätsklinik Zürich
Study officials:
affiliation: University Hospital of Psychiatry Zurich, Department of Forensic Psychiatry
name: Nathalie Brackmann, Dr.
role: PRINCIPAL_INVESTIGATOR
References:
citation: Dombert B, Mokros A, Bruckner E, Schlegl V, Antfolk J, Backstrom A, Zappala A, Osterheider M, Santtila P. The virtual people set: developing computer-generated stimuli for the assessment of pedophilic sexual interest. Sex Abuse. 2013 Dec;25(6):557-82. doi: 10.1177/1079063212469062. Epub 2013 Jan 7.
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citation: Fromberger P, Jordan K, Steinkrauss H, von Herder J, Witzel J, Stolpmann G, Kroner-Herwig B, Muller JL. Diagnostic accuracy of eye movements in assessing pedophilia. J Sex Med. 2012 Jul;9(7):1868-82. doi: 10.1111/j.1743-6109.2012.02754.x. Epub 2012 Apr 30.
citation: Oberlader VA, Ettinger U, Banse R, Schmidt AF. Development of a Cued Pro- and Antisaccade Paradigm: An Indirect Measure to Explore Automatic Components of Sexual Interest. Arch Sex Behav. 2017 Nov;46(8):2377-2388. doi: 10.1007/s10508-016-0839-7. Epub 2016 Oct 17.
citation: Phaf RH, Mohr SE, Rotteveel M, Wicherts JM. Approach, avoidance, and affect: a meta-analysis of approach-avoidance tendencies in manual reaction time tasks. Front Psychol. 2014 May 8;5:378. doi: 10.3389/fpsyg.2014.00378. eCollection 2014.
citation: Poeppl TB, Nitschke J, Santtila P, Schecklmann M, Langguth B, Greenlee MW, Osterheider M, Mokros A. Association between brain structure and phenotypic characteristics in pedophilia. J Psychiatr Res. 2013 May;47(5):678-85. doi: 10.1016/j.jpsychires.2013.01.003. Epub 2013 Feb 9.
citation: Weidacker K, Kargel C, Massau C, Weiss S, Kneer J, Krueger THC, Schiffer B. Approach and Avoidance Tendencies Toward Picture Stimuli of (Pre-)Pubescent Children and Adults: An Investigation in Pedophilic and Nonpedophilic Samples. Sex Abuse. 2018 Oct;30(7):781-802. doi: 10.1177/1079063217697134. Epub 2017 Mar 20.