The term "psychologist" can refer to individuals with different levels of education and training, so whether they are called a "doctor" depends on their qualifications and credentials.
Psychologist: A psychologist is a professional who studies human behavior and mental processes. They can hold a doctoral degree (Ph.D., Psy.D., or Ed.D.) in psychology or a related field. However, not all psychologists have earned a doctorate. Some may have master's degrees (M.A. or M.S.) or bachelor's degrees (B.A. or B.S.) in psychology. Psychologists with a doctorate are typically referred to as "doctor" because they have earned a doctoral degree.
Clinical Psychologist: A clinical psychologist is a type of psychologist who specializes in diagnosing and treating mental health disorders and emotional difficulties. Clinical psychologists usually have a doctoral degree (Ph.D. or Psy.D.) in clinical psychology and are licensed to practice psychotherapy and counseling. They are commonly addressed as "doctor."
Psychiatrist: A psychiatrist is a medical doctor (M.D. or D.O.) who specializes in mental health and can diagnose and treat mental disorders. They can prescribe medication and use other medical interventions in addition to psychotherapy. Since psychiatrists have a medical degree, they are always referred to as "doctor."
In summary, if a psychologist holds a doctoral degree, they are often addressed as "doctor." However, if they have a master's or bachelor's degree, they may not use the title "doctor." On the other hand, psychiatrists, who are medical doctors, are always addressed as "doctor."