1. The major classes of mental health disorders include neurodevelopmental disorders, schizophrenia spectrum and other psychotic disorders, bipolar and related disorders, depressive disorders, anxiety disorders, obsessive-compulsive and related disorders, trauma- and stressor-related disorders, dissociative disorders, somatic symptom and related disorders, feeding and eating disorders, sleep-wake disorders, sexual dysfunctions, gender dysphoria, disruptive, impulse-control, and conduct disorders, substance-related and addictive disorders, neurocognitive disorders, and personality disorders. 2. Organic mental health disorders are referred to as such because they are caused by a physical disease or injury affecting the brain. This means there is an identifiable biological or physiological cause, such as a brain tumor, infection, head trauma, stroke, or substance abuse, that directly leads to the mental health symptoms.