NMDA receptor inhibitory peptides for use in treatment of anxiety disorders

An agent which inhibits the specific binding of PSD95 to an NMDA receptor for use in treating or effecting prophylaxis of a patient having or at risk of developing symptoms of an anxiety disorder, the agent comprising an active peptide having an amino acid sequence comprising [E / D / N / Q] - [S / T] - [D / E / Q / N] - [V / L] (SEQ ID NO: 1).