Psychologists  are practiced on mental disorder by counselling and other psychological tools such as hypnotherapy,CBT ,behavior therapy,solution focused therapies ,integrative and multi modal therapies  etc Psychologist has a master degree in psychology can practice without medication. 
In psychological  counselling,psychologist working on diagnose , evaluate, and treating client for mental, educational, behavioral, sensitive emotional, and developmental disorders. There are branches of   types of psychologists, including clinical psychologists, counseling psychologists, schooling psychologists, Industrial psychologist psychologists, and Many  more. .

Details explanation of types of psychologist in psychology field

Clinical psychologists

A Clinical Psychologist is a  licensed mental health professional, generally with a Ph.D. in the area of Psychology, who specializes and train in the diagnosis, evaluation, and treatment of mental health-related problems and mental disorders. Clinical training ready or prepares a psychologist to treat adults and children either individually, as part of a family unit, and/or as part of a couple or other group. Psychologists also conduct and handle cognitive, academic, and personality testing, and, in the case of a forensic psychologist prepare for and participate in expert witness testimony.

Counseling psychologists

Counseling Psychology refers to a generalist health service (HSP) specialty in professional psychology that uses a deep or broad range of culturally-sensitive practices and culturally informed to help people improve their well-being, prevent and alleviate distress and resolve crises, maladjustment, and increase their ability to function better in their lives.

As per the report, Counseling is one of the oldest disciplines in professional psychology & hypnotherapy, originating in 1900 (Society for Counseling Psychology, n.d.). Although we typically think of psychologists as working with mental illness, early counseling psychologists worked primarily with mentally healthy individuals or people, providing vocational guidance and life advice.

School psychologists

Mental health issues are quite pervasive or spreading, among students in the contemporary age. Revolutions in the education system and the advancement of educational practices have increased the competition level. Students find it challenging to keep up with the frequently changing practices and can succumb or go under the peer pressure caused by them. This peer pressure can also cause many negative impacts on the mental health of students. They feel stressed, anxiety-ridden, and in severe cases, depressed.

School psychologists help students maximize or increase their education through an understanding of their psychological needs.

Developmental psychologists

Developmental psychology is a scientific approach that aims or goals to explain change, growth, and consistency though the lifespan. Developmental psychology looks at how feelings, thinking, and behavior change throughout a person’s life.

Developmental psychologists study a deep or wide range of theoretical areas, such as social, emotional, biological, and cognitive processes. Empirical and provisional research in this area tends to be dominated by psychologists from Western cultures such as North America and Europe, although during the 1980s Japanese researchers began making a valid contribution to the field.

Top 8 responsibilities of a psychologist

• Perform psychological assessments, evaluation, and testing.
• Provide diagnosis based on assessments, testing, and evaluation
• Collaborate with staff, faculty, and other professionals to provide the best care possible
• Provide referrals when needed or necessary for additional care, evaluation, or treatment
• Coordinate with case managers and psychologist about care
• Complete all necessary clinical documentation in an accurate or correct and timely manner
• Develop or improve and recommend treatment plans based on patient needs and diagnosis
• Ensure all services are completed according to relevant ethical and professional standards of care

History of Psychology

According to the report Psychology is defined as “the scientific study of behavior and mental processes”. Philosophical interest in the human mind and behavior dates back to the ancient civilizations of Egypt, Greece, Persia, China, and India.
Psychology as a field of experimental study began in 1854 in Leipzig, Germany when Gustav Fechner created the first theory of how judgments about sensory experiences are made or build and how to experiment on them. Fechner’s theory admitted and recognized today as Signal Detection Theory foreshadowed the development of statistical theories of comparative judgment and thousands of experiments based on his ideas (Link, S. W. Psychological Science, 1995). Later, in 1879, Wilhelm Wundt founded in Leipzig, Germany, the first Psychological laboratory dedicated exclusively to psychological research. Wundt was also the first person to refer to himself as a psychologist. A notable precursor of Wundt was Ferdinand Ueberwasser (1752-1812) who designated himself Professor of Empirical Psychology and Logic in 1783 and gave lectures on empirical psychology at the Old University of Munster, Germany. Other important early contributors to the field include Hermann Ebbinghaus (a pioneer in the study of memory), William James (the American father of pragmatism), and Ivan Pavlov (who developed the procedures associated with classical conditioning).