Final answer:
The definition of a psychological disorder used to be based on 'deviant' behavior or thoughts, but after ~1980, the definition shifted to 'maladaptive' behavior or thoughts. This change is reflected in the updates to the DSM, showcasing the evolving understanding of mental health disorders focusing on individual impairment and well-being.
Step-by-step explanation:
The definition of a psychological disorder has evolved over time. Prior to around 1980, psychological disorders were often defined by thoughts or behavior that were considered "deviant", meaning they deviated from societal norms.
After the 1980s, the focus shifted to thoughts or behavior that were seen as "maladaptive", which are not just at odds with societal norms, but also are detrimental to the individual's well-being or ability to function in daily life.
Diagnostic and Statistical Manual of Mental Disorders (DSM), which is published by the American Psychiatry Association (APA), frequently updates its criteria to reflect these evolving definitions. Such changes are indicative of the ongoing debates and research into classifying and treating mental health conditions.
In conclusion, the term that replaces "deviant" in the definition of psychological disorders after ~1980 is "maladaptive". This change reflects a more nuanced understanding of mental health that recognizes the impact of disorders on an individual's functionality, beyond just their deviation from societal expectations.