Source [[Book - Psychopathology Foundations for a Contemporary Understanding]] # Chapter 4 - Biological Bases of Psychopathology. Robert F. Smith - Just talked about the complexity of the brain, and don't exactly know how meds work on those receptors and effects. - Biologically, what causes a psychological disorder? There is no single answer to this question. The old notion that behavior is determined both by heredity and environment is still true, but we can now add some detail to that statement, and the contributions of environment are becoming better understood. Certainly a few specific disorders, such as Huntington’s disease, can be directly inherited. In many other cases, chemicals such as alcohol, drugs, or stress hormones may alter the expression of genes, thus altering brain and behavioral development. In still other cases, the sensory stimuli and thoughts which an individual processes during early development sculpt the growth of those brain systems which interpret those kinds of stimuli, and this can lead to more complex development of systems stimulated during brain growth, and less complete development of systems deprived of normal stimulation. While the processes which produce psychopathology may be complex, a better understanding of the biological bases of psychopathology increases our ability to understand, prevent, and treat such disorders.