Objective There are reasons to suggest that the therapist effect lies at the intersection between psychotherapists' professional and personal functioning. The current study investigated if and how the interplay between therapists' (n = 70) professional self‐reports (e.g., of their difficulties in practice in the form of ‘professional self‐doubt’ and coping strategies when faced with difficulties) and presumably more global, personal self‐concepts, not restricted to the professional treatment setting (i.e., the level of self‐affiliation measured by the Structural Analysis of Social Behaviour (SASB) Intrex, Benjamin, ), relate to patient (n = 255) outcome in public outpatient care. Method Multilevel growth curve analyses were performed on patient interpersonal and symptomatic distress rated at pre‐, post‐ and three times during follow‐up to examine whether change in patient outcome was influenced by the interaction between their therapists' level of ‘professional self‐doubt’ and self‐affiliation as well as between their therapists' use of coping when faced with difficulties, and the interaction between type of coping strategies and self‐affiliation. Results A significant interaction between therapist ‘professional self‐doubt’ (PSD) and self‐affiliation on change in interpersonal distress was observed. Therapists who reported higher PSD seemed to evoke more change if they also had a self‐affiliative introject. Therapists' use of coping strategies also affected therapeutic outcome, but therapists' self‐affiliation was not a moderator in the interplay between therapist coping and patient outcome. Conclusion A tentative take‐home message from this study could be: ‘Love yourself as a person, doubt yourself as a therapist’. Copyright © 2015 John Wiley & Sons, Ltd. Key Practitioner Messages The findings of this study suggest that the nature of therapists' self‐concepts as a person and as a therapist influences their patients' change in psychotherapy. These self‐concept states are presumably communicated through the therapists' in‐session behaviour. The study noted that a combination of self‐doubt as a therapist with a high degree of self‐affiliation as a person is particularly fruitful, while the combination of little professional self‐doubt and much positive self‐affiliation is not. This finding, reflected in the study title, ‘Love yourself as a person, doubt yourself as a therapist’, indicates that exaggerated self‐confidence does not create a healthy therapeutic attitude. Therapist way of coping with difficulties in practice seems to influence patient outcome. Constructive coping characterized by dealing actively with a clinical problem, in terms of exercising reflexive control, seeking consultation and problem‐solving together with the patient seems to help patients while coping by avoiding the problem, withdrawing from therapeutic engagement or acting out one's frustrations in the therapeutic relationship is associated with less patient change.