The additive effect of biofeedback to regular aggression regulation treatment in a forensic outpatient population.

Aggressive behaviour is causing a wide range of problems for victims, offenders
and the society. Given the current trend to prefer outpatient interventions
over residential treatment, and the high treatment drop-out rates in forensic
populations, further improvement of the effectiveness of forensic outpatient
treatment methods is needed. It is know that forensic patients often lack
insight in and attention to their emotions and associated physiological cues
(Robertson, Daffern & Bucks, 2014). Their limited capability to timely detect
(in particular slowly) rising arousal levels, increases the chance of
*suddenly* occurring aggressive outbursts. This stresses the importance of
teaching patients to pay attention to their physical sensations as components
of anger; necessary skills on the pathway to gain more control and practice
behavioural alternatives (Novaco, 2007). In this, biofeedback * informing users
about their physiological state based on heart rate or skin conductance * is a
promising intervention. According to researchers (Lisetti & Nasoz, 2004; Yucha
& Montgomery, 2008) providing psychiatric patients with information about their
physiology can be a helpful tool to signal heightened arousal in response to
emotional events. In forensic psychiatry, real-time biofeedback can possibly
help patients with problematic aggressive behaviour to signal heightened
arousal in an early stage. By strengthening physiological awareness and
supporting use of prevention skills, we suppose that biofeedback can aid to
reduce aggressive behaviour.

This research project is divided into two projects. The first part of the study
(Study 1) aims to find an answer to the question whether and to what extent
biofeedback is a user-friendly and feasible intervention. In the main study
(Study 2), we investigate whether the addition of real-time biofeedback to
regular aggression regulation treatment is effective in improving insight into
his/her physiological condition and contributes to improving aggression and
emotion regulation skills, for the individual patient.

First, we will conduct a pilot study (Study 1) with 10 patients to test the
user-friendliness and feasibility of the intervention, on the basis of which
the biofeedback application will be further developed for use in the main
study. In the main study, the effectiveness of the intervention will be
investigated using a Single Case Experimental Design (SCED). We will use a
multiple baseline design (MBD), make comparisons within the participant (in
different phases) and between the participants. Replication takes place within
the experiment: a baseline phase ("control condition", registration only) is
followed by an intervention phase ("experimental phase", where biofeedback and
registration is used) and a new baseline phase ("follow-up", registration
only); a so-called ABA design. The baseline phase takes +/- 1 week (depending
on randomization), the intervention phase 2 weeks and the follow-up period 1
week. The entire study takes approximately 4 weeks per test subject. During
these weeks, the client answers a few questions about tension and aggression on
a daily basis, using EMA methodology. Furthermore, a pre-measurement (T0) and a
post-measurement (T1) are performed before and after this 4-week period; a
follow-up measurement (Tf) takes place after 1 month.

Aggression regulation treatment (ART), is an individually oriented treatment
protocol, based on cognitive behavioural techniques and elements of Aggression
Replacement Training (Goldstein, Glick & Gibbs, 1998). The treatment protocol
consists of four standard treatment modules and several optional modules that
can be added to meet the need of the patient.

The intervention concerns an 'add-on' to this aggression regulation treatment.
Participating clients will receive a biofeedback system for a period of 4 weeks
(and actively use it during the 2-week intervention phase). The biofeedback
system consists of a combination of a smartwatch (Moto 360 2nd Gen) and
smartphone (Moto G with Android 6.0.1 operating system) with Sense
It!-application. The Moto 360 2nd Gen is a wristband equipped with a
photoplethysmography (PPG) sensor, by which Blood Volume Pulse (BVP) can be
measured and heart rate can be derived. The Sense It!-app is a mobile
application developed by researchers of the University of Twente in cooperation
with Scelta, an expert centre treating patients with personality disorders
(Derks, De Visser, Bohlmeijer & Noordzij, 2017). This app uses a baseline
measurement in rest, computing both mean heart rate and standard deviation, to
establish five different zones of heart rate (one to five standard deviations
above baseline). Important to note is that the application is correcting for
movement by using an algorithm; this construct is called added heart rate
(Myrtek, Aschenbrenner & Brügner, 2005; Yang, Jia, Liu & Sun, 2017). Patients
will get a simple notification of significant heightened physiological arousal
when their heart rate is four or five standard deviations above their personal
baseline in rest. The patient is then asked to register what he/she is doing,
or what is going on, and can act to intervene accordingly.

In Study 2 subjects will be asked to use the biofeedback system for four weeks.
They will be asked daily to answer a number of questions using the EMA method,
via the mobile system. Other data will be collected in three face-to-face
appointments during the duration of 2 to 3 months. The duration of the
measurement moments varies between +/- 90 minutes (T0 and T1) and +/- 45
minutes (Tf). At the follow-up measurement moment (Tf), it is also possible to
take the measurement by telephone if the subject prefers it. We do not foresee
any risks for the participating test subjects.