Psychotherapists draw on various theoretical approaches to address the mental health issues with which they work. However, this poses at least two problems: that what is called 'mind' is not a homogeneous, clear, and explicit construct in each current and that each conception of 'the mental' implies a particular episteme of such phenomena. This article seeks to address such problems; therefore, it aims to delimit and epistemologically analyze the tacit construct of mind present in the fundamental psychotherapeutic currents. Through an exploratory-descriptive qualitative approach, a hermeneutical-analogical analysis is carried out in which the mental construct of each current is delimited and then analyzed under the eaves of a series of epistemological paradigms. The conception of the mind is heterogeneous and presents various epistemological assumptions associated with each current: psychodynamic (rationalism/phenomenology), cognitive-behavioral (empiricism/positivism -rationalism/constructiveness), humanistic (critical theory/constructiveness), and systemic (constructive/rationalism). The mind construct is not transversal or objective, but relative to each psychotherapeutic current, with particular and diverse epistemological assumptions that condition the way in which mental phenomena are known. Finally, we reflect on the implications of the results in psychotherapeutic praxis.