Final answer:
Psychological Theories of drug use focus on an individual's personality and psychopathology to explain substance abuse as maladaptive behavior, differentiating from sociological theories that look at external societal factors.
Step-by-step explanation:
Psychological Theories as they relate to drug use behavior can be defined by examining the individual's personality and psychopathology to explain drug abuse and addiction. Unlike sociological theories that look outward at social structures, psychological theories are inward-looking, focusing on mental health, emotional processes, and individual mentality in relation to substance use. According to these theories, drug abuse is often viewed as maladaptive behavior influenced by an individual’s psychological state, rather than by social or environmental factors alone.