The human services field is a broad professional category that includes counseling, psychology, psychiatry and social work. Professionals in this field work to improve the functioning and well-being of their clients. They often often assist people with depression and other types of psychiatric and mental health disorders, working in settings like mental health clinics, hospitals, private practices and community services agencies.

Counselors

Counselors, including substance abuse counselors and marriage and family therapists, provide mental health services to millions of people in the United States, according to the American Counseling Association. And despite the term, people with depression, as well as couples, seek assistance from marriage and family therapists.They help people by conducting assessments, counseling people, couples and groups, and implementing different therapeutic interventions, like cognitive-behavioral therapy. Counselors have at least a master's degree in counseling or marriage and family therapy and a state license to practice. They usually work in private practice, mental health clinics or other similar settings. As of May 2010, counselors and marriage and family therapists earned an average yearly salary of $39,710, according to the Bureau of Labor Statistics, or BLS.

Psychiatrists

Psychiatrists are medical doctors who specialize in treating psychiatric and mental health disorders, like depression, with medication and psychotherapy. Depression is believed to be caused, in part, by biochemical changes and reduced levels of neurotransmitters like serotonin. It often cannot be treated by talk therapy alone, especially in moderate to severe cases, and may require medication. Psychiatrists prescribe medications like antidepressants and mood stabilizers to help people feel better. In most states, psychiatrists are the only licensed mental health providers who can prescribe medication, according to WebMD. Many psychiatrists work in private practices, but some also work in hospitals and mental health clinics. As of May 2012, psychiatrists earned an average yearly salary of $177,520, according to the BLS.

Clinical Social Workers

Clinical social workers are the largest providers of mental health services in the U.S., reports the National Association of Social Workers. Like counselors, clinical social workers help people with depression and their families by providing assessments and talk therapy. They must have at least a master's degree in social work and a state license to practice. Clinical social workers are employed in private practice, mental health clinics, hospitals and other similar settings. While counselors and social workers might seem to be the same, they have some significant differences in outlook and treatment approach. The main difference is that unlike counselors, clinical social workers may provide a professional diagnosis for depression and other mood disorders, says the New York State chapter of the NASW. As of May 2010, social workers earned an average yearly salary of $42,480, according to the BLS.

Psychologists

Psychologists, like counselors and social workers, also provide assessments, counseling and talk therapy to people who have depression and their families. Like social workers, they are qualified to diagnose depression and other mood disorders. But psychologists must have a doctoral degree in psychology -- either a doctor of psychology, or a doctor of philosophy in psychology, and a state license to practice. In addition to diagnosis, assessment and psychotherapy, psychologists offer psychological testing and evaluations for depression. Psychologists in New Mexico and Louisiana may also prescribe medication like antidepressants, reports the American Psychological Association. Psychologists often work in private practice, mental health clinics, hospitals, community services agencies and other similar settings. As of May 2010, psychologists earned an average yearly salary of $68,640, according to the BLS.