Event-related potentials in trauma-affected refugees

Hanieh Meteran, Bob Oranje, Birte Glenthøj, Erik Vindbjerg,

Jessica Carlsson, MD, PhD,

Competence Centre for Transcultural

Psychiatry (CTP)

Today

• Background:

• What are event-related potentials (ERPs)?

• What is sensory gating?

• Why this study?

• Aims

• Methods:

• How did we do it?

• Results:

• What did we find?

• Reflections

Background:What are event-related potentials (ERPs)?

• EEG measured brain response

• Electrophysiological response to a stimulus (sensory,

cognitive or motor event)

• A noninvasive way of evaluating brain functioning

Background:What are event-related potentials?

Background:What is sensory gating?

• Important function in healthy brain to sort out

”irrelevant” information

avoid overload

psychosis / psychopathology

• Habituation necessary to avoid overload

Background:Testing sensory gating

Prepulse inhibition (PPI)

• A weak prestimulus 30-500 ms before a startling stimulus

• Reduces/gates the amplitude of startle response

• Deficits in schizophrenia spectrum

P50 sensory gating

• Two accoustic clicks in rapid succesion (500 ms apart)

• In healthy subjects potential to the second click is

reduced/gated

• Reduced in schizophrenia

Habituation

• Habituation when repeated trials

Background:Why this study?

Evidence of abnormalities in cognitive and information processing in

PTSD accumulating over the years

Far from being well-characterized

Impaired P50 gating?

References:Javanbakht et al. ,Biol. Mood Anxiety Disord. 2011, Karl et al., Biol. Psychol. 2006

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Aims

By means of electroencephalography (EEG)

1. To investigate information processing in trauma-

affected refugees with PTSD using PPI and P50

2. To study a possible association with symptom severity.

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Methods:Where and How?

• CTP a specialised out-patient facility

• Target group at CTP trauma-affected refugees with mental

health problems

• Cross-sectional study

• 25 trauma-affected refugees with PTSD from CTP

• 20 healthy refugee controls

PTSD group

Inclusion criteria

• Being a refugee or family-reunified to a refugee

• Being >= 18 years

• Speaking Danish, English, Arabic, Farsi, or Bosnian

• Fulfilling the criteria for the PTSD diagnosis according to the

ICD-10 and DSM-5 research criteria

• Legally competent to provide informed consent

PTSD group

Exclusion criteria

• Having an ICD-10 F2x (schizophrenia, schizotypal and

delusional disorders) or bipolar diagnosis

• Having neurological disorders, substance abuse or

dependency according to the ICD-10 criteria

Control group

• Healthy refugee controls

• Recruited from the community through network/advertisement

Inclusion criteria

• Matching participants on age (+/- 5 years), gender, country of

origin,

• Speaking Danish, English, Arabic, Farsi or Bosnian

• Legally competent to provide informed consent

Exclusion criteria

• Same as for the PTSD group

• Having any current psychiatric illness

Day 1 at CTP

• Clinician-administered interviews

1. CAPS (Clinician-Administered PTSD scale)

2. CGI (Clinical Global Impression)

3. SCAN (Schedules for Clinical Assessment in

Neuropsychiatry)

• Self-administered questionnaires

1. LEC (Life Event Checklist)

2. HTQ (Harvard Trauma Questionnaire)

Day 2 at Center for CSN Research (CNSR):

• Psychophysiological assessment

1. Hearing test (5 min)

2. Prepulse inhibition (PPI) of the startle reflex

(25 min) paradigm

3. P50 suppression (21 min) paradigm

4. Selective attention (13 min) paradigm

5. Mismatch negativity (12 min) paradigm

Preliminary research findings

Total

(n=45)

PTSD

(n=25)

Control

(n=20)

N (%) N (%) N (%)

Male 24 (53%) 13 (52%) 11 (55%)

Country of origin

Iran 12 (27%) 6 (24%) 6 (30%)

Afghanistan 12 (27%) 7 (28%) 5 (25%)

Iraq 10 (22%) 5 (20%) 5 (25%)

Torture 14 (31%) 11 (44%) 3 (15%)

Prison 13 (29%) 9 (36%) 4 (20%)

Having lived in war 44 (98%) 25 (100%) 19 (95%)

Soldier 11 (24%) 7 (28%) 4 (20%)

Salary/ grant 20 (44%) 3 (12%) 17( 85%)

PTSD (ICD-10) 25 (56%) 25 (100%) 0 (0%)

Comorbid

depression

20 (44%) 20 (80%) 0 (0%)

Mean Mean Mean

Age 46.0 46.4 45.5

Years in Denmark 18.3 15.0 22.4

Results

• No significant differences between patients and controls

in either PPI or P50 suppression

• Patients do not show habituation, where controls do

Reflections…

• Even in this ”raw” small sample a difference was found

• Look further into consequences and association with

symptoms

• New interventions?

Thank you for your attention!

Thanks to all participants!

CTP-NET.DK

PsykiatriHREGION