Final answer:
Mental illnesses are categorized as disorders characterized by emotional disturbances that can affect various aspects of life, including physical and social functions. They are diagnosed based on criteria set by the DSM, which is continuously updated to reflect the latest understanding of these disorders.
Step-by-step explanation:
The class of disorders marked by emotional disturbances that can disrupt physical, perceptual, social, and thought processes is known as mental illnesses. Mental illnesses are a range of nervous system disorders leading to significant distress or impairment in thinking, mood, or relating with other people. These can include schizophrenia, major depression, bipolar disorder, anxiety disorders and phobias, post-traumatic stress disorders, and obsessive-compulsive disorder (OCD), among others. Such disorders are severe enough to potentially hamper an individual's ability to carry out daily activities and tasks, with substantial impacts on their overall quality of life.
To diagnose and classify mental health conditions and personality disorders, the American Psychiatric Association publishes the Diagnostic and Statistical Manual of Mental Disorders (DSM). Over time, the DSM has evolved with each new edition reflecting greater understanding of these conditions. Personality disorders involve enduring, inflexible patterns of behavior that are considered abnormal in society but may seem normal to the individuals affected. As the field of mental health evolves, so does the understanding and classification of these disorders.
Moreover, the manual distinguishes between medically explained physical symptoms and those associated with psychophysiological disorders, where psychological factors significantly influence or exacerbate physical symptoms. Understanding these complexities is crucial in the effective treatment and management of these conditions.