This document discusses topics related to mental health nursing including classifications of mental disorders, defense mechanisms, and maladaptive behaviors. It provides details on ICD-10 classification codes for mental disorders ranging from organic mental disorders to personality disorders. It defines common defense mechanisms such as repression, denial, displacement, rationalization, compensation, and projection. It also defines maladaptive behaviors as those that make it difficult to adapt to new circumstances and may develop after life changes, illness, or trauma. Stress and crisis are also briefly discussed.