Power relations are a structural characteristic of all social relationships, organisational systems and societies as a whole (Proctor, 2002; Dalal, 2003). Certain identities are accorded different powers and status depending on who they are as people (societal, personal and historic power) and the position they hold within a hierarchical institution or work setting (role-power; authority). In medicine, doctors (because of their education, training, experience and expertise) have the authority to diagnose and treat those they deem to be ill, with clear boundaries, systems of accountability and opportunities for others to challenge those decisions if there are breaches of a doctor's defined roles. Less obvious perhaps is the societal, personal and historic powers exerted (often unwittingly) by doctors’ values, biases and assumptions about their patients, since subjectivity is part of the clinical task. These informal values and systemic biases are not easy to identify, not necessarily limited by any formal boundaries and have no regulated system of accountability, leaving their influence to the discretion of each individual clinician. This source of influence and power is of particular significance in psychiatry, where diagnosis and treatment are determined not by an objective measurement or scientific test or biomarker, but rather by professional judgements that make positive and creative use of subjectivity (Loring & Powell, 1988; Fernando, 2010).

Psychiatry is firmly located within medical systems of authority, developed (at least initially) within Western (Euro–American, industrialised and high-income) countries and cultures; within these cultures, doctors were allocated the authority to name problematic thoughts, feelings and behaviours as illness of the mind (see Chapter 14, this volume). However, aspects of these problematic thoughts, feelings and behaviours are culturally determined and they may fall outside psychiatry's Eurocentric frame of reference. They may, however, be acceptable within their relevant cultural contexts. In such situations, misunderstandings can easily occur when psychiatrists (wittingly or unwittingly) use not only authority but also power in a way that is at least partially determined by their personal values and biases to inform diagnosis, risk assessment, treatment and management (Loring & Powell, 1988).