Epistemic injustice	Epistemic injustice occurs when a person's capacity as a giver of knowledge is wrongfully denied (Fricker, 2007). This denial can manifest in two ways, which are relevant for mental health researchers and practitioners (Kidd et al., 2022): Testimonial injustice: when a person's credibility or authority is challenged because of prejudice (including assumptions of irrationality linked with mental health diagnoses), so that the person is not believed or trusted. Hermeneutical injustice: when someone is rendered unable to understand or express some important aspect of their own experience due to the person belonging to a stigmatised and vulnerable group.
Phenomenological psychopathology	Emerging from the philosophical tradition of phenomenology, phenomenological psychopathology is an interdisciplinary research programme that aims to describe and classify experiential alterations in mental disorders (i.e., characteristic features of the experience and expression of mental disorders). Phenomenological investigations usually go beyond both ‘objective’ symptoms and narrative descriptions, to explore the existential structures (and alterations thereof) that give formal coherence and meaning to our experience of world. These may include selfhood, embodiment, temporality, spatiality, affectivity, understanding, intersubjectivity, etc. (Broome et al., 2012; Fernandez and Køster, 2019; Køster and Fernandez, 2021).
Phenomenological interviews	There are a number of semi-structured psychometric checklists, inspired by phenomenology, designed to examine anomalies of various dimensions of experience: the Examination of Anomalous Self-Experience (EASE) by Parnas et al. (2005); the Examination of Anomalous World Experience (EAWE) by Sass et al. (2017), the Examination of Anomalous Fantasy and Imagination (EAFI) by Rasmussen et al. (2018). For an overview see Sholokhova (2022). Phenomenological methods are also widely used in qualitative research (e.g., Giorgi, 2009; Smith et al., 2022).
Self-disturbance	Disturbance or instability of the basic self (aka minimal self or ipseity) can manifest in a variety of anomalous subjective experiences. The term ‘basic self’ refers, in this context, to the pre-reflective and immediate awareness of being the subject of one's own experiences, thoughts and actions (Nelson et al., 2014).
Subjectivity	The ongoing first-personal manifestation of experiential life as immediate consciousness of action, experience and thought. In phenomenology, this refers to the person's experience of various aspects of their self (e.g., sense of agency and embodiment) and their lived world (e.g., space, time, intersubjectivity and atmosphere) and represents the implicit foundational background against which our experience of the world is constituted.