This clinical study will examine the efficacy of a novel intervention aimed at improving Regulatory Selection Flexibility and PTSD symptoms among adult individuals with PTSD symptoms, compared to a tight active control group.

Regulatory Selection Flexibility is defined as the ability to select regulatory strategies according to differing situational demands (i.e., regulatory selection flexibility rule; distraction for high intensity vs reappraisal in low intensity). The main questions it aims to answer are: [1] Can PTSD individuals improve Regulatory Selection Flexibility [2] Does improved Regulatory Selection Flexibility associate to reduction in PTSD symptoms? Participants will be randomly assigned to either a Flexibility Training or a closely matched Active regulatory selection Control Training group. Participants in both groups will receive a novel online bi weekly seven session intervention which is matched on all aspects of the intervention except for the flexibility rule as follows, the intervention consists of three modules: (a) Psychoeducation; both groups receive information on regulatory strategies (distraction and reappraisal). The test group includes explicit psychoeducation on appropriate strategy selection according to the regulatory selection flexibility rule. (b) Computerized Regulatory Selection Task; both groups are exposed to high and low negative intensity emotional words and are asked to select a regulatory strategy. Only the test group receives the flexibility rule and its application via feedback. (c) Two homework task for between sessions. Both groups are instructed to choose two daily events and report which regulatory strategy they chose and implemented. The test group is instructed to choose a high and low intensity event and implement flexible selection. Each session begins with a brief overview on their home task, followed by corrective feedback in test group when necessary.

Primary outcome measures were acquired via the computerized assessment of Regulatory Selection Flexibility Paradigm and clinical questioners for PTSD symptoms pre, immediately post and at 3-month post intervention follow up.

To examine the efficacy of the regulatory selection intervention and its clinical effects, according to a-priori power analysis and expected drop out of 20%, 80 participants that meet me PTSD cutoff will be enrolled and randomly assigned to one of two conditions: Experimental group (Regulatory Selection Flexibility Training) or active control (Regulatory Selection without Flexibility Training).

Following intervention, the investigators expect that (a) Both groups will show PTSD symptom reduction. (b) That relative to the active control group, the experimental group will show improvement in regulatory selection flexibility pre-to-post intervention, and (c) That relative to the active control group, the experimental group will show greater reduction in PTSD symptoms.

Inclusion Criteria:

• native Hebrew speakers
• age between 18 - 65
• normal or corrected to normal vision
• computer and internet access
• fulfill screening criteria of DSM-V for PTSD

Exclusion Criteria:

• Complex PTSD
• Psychotic disorders
• substance dependence or abuse other than nicotine
• Neurological condition
• suicidal ideation or attempt
• change in psychotherapy or pharmacological treatment in the past 3 months.
• Diagnosed/suspected personality Disorder
• Cognitive impairments