Attention Control Training Clinic will consist of:

• 6 sessions in the clinic lasting approximately 10 minutes each.
• Each session will consist of 128 presentations of pairs of neutral and threatening stimuli, followed by the presentation of a response cue (right or left arrow to be clicked on a computer keyboard).

Attention Control Training Web-delivery will consist of:

• 6 sessions lasting approximately 10 minutes each logged into via the internet from the participants' home.
• Each session will consist of 128 presentations of pairs of neutral and threatening stimuli, followed by the presentation of a response cue (right or left arrow to be clicked on a computer keyboard).
• Ideally participants will complete 2 sessions per week, allowing them to complete the trial in less than one month's time

• 6 sessions in the clinic of a presumably inactive neutral-neutral stimuli intervention lasting approximately 10 minutes each.
• Each session will consist of 128 presentations of pairs of faces, followed by the presentation of a response cue (right or left arrow to be clicked on a computer keyboard).

(Note that those receiving this arm, are invited to repeat the attention control training web-delivery arm at the end of their participation).

Attention control training teaches participants that the emotional salience of cues (i.e., threatening or neutral) is not related to successful completion of the computerized response task, and thus, teaches participants to ignore irrelevant threat-related contingencies (Badura-Brack et al., 2015).

Structured diagnostic interview for PTSD