Observer-report instrument to assess the severity of depression (symptom areas: apparent sadness, inner tension, reduced sleep, reduced appetite, concentration difficulties, lassitude, inability to feel, pessimistic thoughts, suicidal thoughts) on a 7-point Likert scale with 6 representing highest severity. In the applied MADRS+ version, three items assessing helplessness, hopelessness and worthlessness are added. Hence, the total score of MADRS+ ranges from 0 - 71 with higher values indicating more severe depression.

Self-report questionnaire to assess general psychopathological symptom severity in nine different symptom dimensions (somatization, obsessive-compulsive, interpersonal sensitivity, depression, anxiety, hostility, phobic anxiety, paranoid ideation, psychoticism, general severity score) on a scale from 0 to 4 with 4 representing more severe symptoms. A global indicator is the General Severity Index (GSI) which will be used as a total score here. The GSI is given by the mean of all subscales and ranges from 0 (low general symptom severity) to 4 (high severity).

Self-report questionnaire for the assessment of various mental health conditions (factors are somatic, anxiety and depression symptom scales), responses are given on a scale from 0 to 2 (with 2 representing higher symptom severity)

Self-report measure for the assessment of personality dysfunction in three domains (identity, defense, reality-testing)

self-report of post-traumatic stress symptoms with the three subdomains intrusions, avoidance and over-arousal; a scoring scheme with intervals of 0 (not at all), 1 (rarely), 3 (sometimes), and 5 (often) is used to reflect frequency of symptoms over the past week. Subscales are analyzed by summing up all responses of items that belong to one subscale. Intrusion and hyperarousal range between 0 - 35 and avoidance ranges between 0 - 40, with higher values indicating more severe intrusion/ hyperarousal/ avoidance.

self-report to assess perceived social support on the four scales emotional and practical support, social integration, and social stress. Additional scales are reciprocity, availability of a trusted person, satisfaction with social support. Contains 54 items; responses are given on a 5-point Likert scale. Patients indicate their level of agreement with a presented statement from 0 (totally disagreed) to 4 (totally agreed). The total range is from 0 to 216 with higher values representing higher perceived and received social support.

self-report to assess intensity of dysfunctional expectations (regarding social rejection/ support, mood regulation and the ability to perform). The DES consists of 25 items. Responses are given on a 5-point Likert-scale where patients express their agreement with a given statement (1= I don't agree to 5= I agree). The total score varies between 0 and 125 with higher values indicating higher intensity of dysfunctional expectations.

self-report to assess the flexibility and adaptiveness of emotion regulation. The DERS consists of 36 items. Responses are given on a 5-point Likert-scale where patients indicate how often the following statements apply to them (1= almost never (0-10%) to 5= almost always (91-100%). The total score varies between 0 and 180 with higher scores suggesting greater problems with emotion regulation.

self-report to assess individual's attachment style on the subscales closeness, trust and anxiety; on a scale from 1 (not at all true) to 5 (very true). There are 15 items in total with 5 belonging to each subscale. Higher values reflect higher comfort with closeness or depending on others or concern about abandonment.

self-report to assess six components of self-compassion (self-kindness, self-judgement, common humanity, isolation, mindfulness, over-identification). Response format ist a 5-point Likert-type scale ranging from 1 (almost never) to 5 (almost always). Total scores can range between 0 and 60 with higher values representing higher levels of self-compassion.

observer-rated questionnaire designed to measure distinctive internal reactions, referred to as impact messages, that interactants experience to the full range of interpersonal behaviours indexed along the circumplex of the interpersonal circle with the 2 dimensions dominance-submissiveness and friendliness-hostility. Messages are rated on a scale from 0 (not at all) to 4 (very much). The total score of each subscale is considered for analysis.

observer-rated questionnaire to measure quality of life and functioning, framed as skill deficits in 12 areas (e.g. skill to adapt to rules and routines, professional and non-professional skills, assertiveness, endurance etc.) Skill deficits are assessed using a response scale from 0 (no skill deficits) to 4 (complete absence of skill)

self-rated questionnaire to measure health-related quality of life. Health is assessed using 5 dimensions: mobility, self-care, usual activities, pain/ discomfort, anxiety/ depression. For each dimensions, participants can select one option out of 5 that describes them best.

self-rated questionnaire to assess euthymia. It contains 10 items which assess factors of general mood, energy and coping with stressors. Responses are given by selecting (True/ False) for a specific statement. The total range of the ES is from 0 to 10 with 10 indicating higher prevalence of euthymia.

Self-rated questionnaire administered to patients (WAI-C) and therapists (WAI-T) to assess the quality of the working alliance based on Bordin's pan theoretical concept via 3 subscales (12 items each): a)goals: agreement about the goals of therapy; b)tasks: agreement about the tasks of therapy, c)bond: bond between therapist and patient. Responses are given on a 7-point Likert scale (1= totally disagree, 7= totally agree). Mean scores are analysed for all 3 subscales and on an overall level, with higher values indicating higher satisfaction with the therapeutic alliance.

Patient expectations of alliance are assessed via an adapted form of the WAI-SR (WAI-expected; WAI-e) prior to the start of therapy at an initial assessment (T0). The instructions are altered by adding the following sentence: "Since you have not yet received any therapy through this study, we ask you to think about what you expect from the therapy in answering the following questions."

observer-rated questionnaire to measure functioning in 9 descriptors (work, law, social (family and friends), judgement, thinking, mood, anxiety, hallucinations, suicidal ideation). Each descriptor has a 9-point range from 0 (most severe) to 90 (least severe)

The PATHEV is a questionnaire measuring patient expectations on three scales: (1) hope of improvement, (2) fear of change, and (3) suitability (Schulte, 2005). It consists of 11 items and is rated on a 5-point Likert scale. The instrument has shown acceptable to good reliability (Cronbachs Alpha 0.73- 0.89). Construct validity of the scales has been demonstrated via three studies.

Patient expectations of alliance were assessed by an adapted form of the WAI-SR (WAI-expected, WAI-e).

The instructions were altered by adding the following sentence: "Since you have not yet received any therapy through this study, we ask you to think about what you expect from the therapy in answering the following questions."

To assess dispositional empathic traits, a shortened and validated German version of the interpersonal reactivity index (IRI) self-report survey is used (Davis, 1980; German Version: Paulus, 2009). The questionnaire measures the four domains (1.) perspective-taking, (2.) empathic concern, (3.) personal distress, and (4.) fantasy with four items per subscale.

A self-constructed questionnaire concerning patients' fit, acceptance and satisfaction is used to evaluate the CBASPersonalized inpatient treatment. Patients are asked to evaluate the therapy components individually according to these three criteria. All items were answered on a 6-level Likert scale.

It will be examined whether the effectiveness of CBASPersonalized can be explained by an improvement of interpersonal problems in CBASP. The IIP is a self-rated questionnaire to assess a variety of interpersonal problems.

Patients' perceived general self-efficacy is assessed using the 10-items version of the SWE. Items are rated on a 4-piont Likert-scale. Total score can be interpreted using age and gender specific standard scores.

The questionnaire measures naturalness of a videoconference therapy by the percentage of agreement (0-100%) with eight statements. The original version shows preliminary validation (α =.84). For this study, the English version was translated into German.

This 21 items questionnaire examines the participant's satisfaction with a therapeutic session and can be divided into four subscales (depth, smoothness, positivity, arousal). Items are rated on a seven-point Likert scale ranging from for example 1 to 7. The questionnaire shows high internal consistency.

This self-report-questionnaire is a "quick and dirty" method which outlines the usability of a system in percentage terms. The German version of the 10-item-inventory was adapted to the videoconference setting of the study as recommended by the author. A five point Likert scale ranging from 1 to 5 is used to rate the items. The high economy and validity of the SUS justify its use in the present study (Brooke, 1986).

The CSQ-I consists of 8 items measuring global satisfaction with online interventions. Items are rated on a 4-point Likert-scale. Good construct validity and high internal consistency has been shown in one study.

Therapeutic alliance in the guided online aftercare is measured using the WAI-I, which is an adapted version of the WAI-SR focusing on guided internet interventions. Twelve items rated on are 5-piont Likert-scale are divided into three subscales (bond, goal, task). The questionnaire which is shows adequate internal consistency and external validity in one study so far.

A self-constructed questionnaire with 16 items concerning patients' acceptance (4 items; e.g. "I find the use of CBASPersonalized@home following the inpatient treatment useful"), fit (3 items; e.g. "I have the feeling that CBASPersonalized@home was exactly right for me and my problems") and subjective effectiveness (9 items; e.g. " Through CBASPersonalized@home I have a better understanding of the views and feelings of other people.") is used to evaluate the online continuation program CBASPersonalized@home. All items were answered on a 6-level Likert scale.

Patients' usage behavior is assessed with five additional items which are answered categorially.