Preliminary studies to development of the programs Before the development of protocol of the current treatment programs, the investigators reviewed related literature and published a systematic review about the related factors for PTG in women with breast cancer. After obtaining the ethical approval the study coordinator interviewed with eight women via telephone to explore the experiences of women with breast cancer. The investigators determined the needs and possible challenges of the illness. Besides, previous similar treatment programs were examined in detail. Later, the investigator developed the study protocol with the supervisor and send the content of the treatment programs to five specialists who have MD in clinical psychology and got feedback and the investigators revisited final version of the treatment programs.

In brief, the research hypotheses are 1) both online group therapy for PTG and online support groups will show better PTG levels and rumination scores, and other secondary measurements (such as psychological distress, heart rate variability, disclosure of distress) than wait-list control. 2) Participants who in online group therapy for PTG will improve better PTG and rumination scores, and secondary measurements' scores compared with the participants in online support groups. 3) The benefits of the treatment programs will be endured for 1-month follow-up measure.

Procedure Ethical approval: This study was approved by the institutional review board of Eskisehir Osmangazi University. All study participants gave written informed consent. Announcements will be posted in various departments of the hospital to participate in the research. First of all, volunteer participants will be assessed through the phone and informed about the research process. If they agree to participate, the investigators will organize a detailed interview. In this interview one of the researchers of the study who is a psychiatrist will apply SCID to eliminate the other possible mental disorder. Patients who meet the criteria will be informed about the group and informed consent forms will be obtained. Before beginning of the treatment program, baseline measurement and ECG Holter measurement will be scheduled by the telephone. After completing baseline measurement, the participants will then be randomly allocated to one of the three groups.

The online treatment programs will be delivered to groups of 6-8 participants by a psychologist and psychiatrist (therapist and co-therapist), eight weekly online sessions. Online sessions will be delivered through an online video-conferencing software (ZOOM). Sample size is determined by g-power analysis. For three-arm randomized controlled trial we plan to recruit at least 51 participants (each group should have at least 17 participants). Before the beginning of the study, the participants will be informed about online video-conferencing platform. The investigators will send a video about the use of platform and also step by step user manual. Each participant in treatment programs should join at least six sessions. If the participants could not complete six sessions, the investigators will admit them drop-out (This information will be declared during the interviews and written informed consent). The investigators will use SPSS 23.0 Package Program for Social Sciences. The descriptive analysis will be performed for frequencies of socio-demographics and clinical information such as cancer stage, treatments. To test the hypothesis, the investigators will conduct a repeated measure ANOVA. The investigators will employ intention to treat and as treated analysis.