Talking about his most unconventional plays, Attempts on Her Life (1997) and Fewer Emergencies (2005), British playwright Martin Crimp recently said that "in this second kind of writing, the dramatic space is a mental space, not a physical one." Picking up on this expression, I propose to look at the main characteristics of a ‘theatre of the mental space’ which, since Samuel Beckett, delves into individual psychological complexes, traumas, neuroses, and even psychiatric disorders from alternating and often marginalized points of view through the use of hypersubjective figures and indistinct voices instead of traditional, defined characters. In Crimp’s Attempts on Her Life, the suicide character of Anne who, in scenario 11, "quite clearly should’ve been admitted […] to a psychiatric unit […] where she could receive treatment," is used as a means to explore the secret fears and obsessions that filter through the voices of anonymous and undefined characters who comment upon her life and death. Sarah Kane's last two pieces, Crave (1998) and 4.48 Psychosis (2000) show a similar, converging evolution of her dramatic writing towards what could be termed a "psychopoetics of the stage," this time using a first-person perspective. More broadly, the construction of dramatic spaces which are no longer physical but psychological and which investigate either specific "mentalities" (Crimp) or the mind as a dramatic world in itself seems to characterize a specific turn in contemporary theatre. Through new, unconventional forms of dialogue, monologue, and narration, these stylised explorations of our "dramas-in-the-head" form what could be labelled ‘In-Your-Head’ theatre, as opposed to the "In-Yer-Face" theatre (Aleks Sierz) which characterized the British stage of the 1990s. In addition to Crimp’s and Kane’s plays under the influence of Samuel Beckett’s theatre, I propose to see how other British playwrights such as Harold Pinter, Caryl Churchill, and debbie tucker green also evoke the tortuous and haunted mindscapes of vanishing subjects, leading to a "trauma-poetics." Using works by literary critic Les Esslin on the "empty figure on the empty stage" in Beckett’s theatre, French philosopher and psychoanalyst Anne Dufourmantelle on women and sacrifice, Professor Elisabeth Angel-Perez on Trauma Drama in contemporary British theatre and Gilles Fauconnier and Mark Turner’s Mental Space Theory, I look at how such plays renew the forms of a "psychiatric realism" on the contemporary British stage (Christina Wald). By exploring the mind and psyche as they constitute a major terrain of investigation at the beginning of the twenty-first century, as shown by the development of neuroscience and cognitive science, these theatres of the mental space reflect on urgent philosophical, ethical and societal questions on subjectivity and the self around the idea that "part of modern identity is to live inside our heads" (Crimp).