A history behind the Counselling position
A counsellor was a position aboard Starfleet vessels and installations, usually held by a senior Starfleet officer with training in psychology. Qualified psychiatrists served aboard Starship’s during the 23rd century. (TOS: "Where No Man Has Gone Before", "Dagger of the Mind") Occasionally, the role of chief medical officer and counsellor were combined in the 23rd century, with medical officers also having expertise in space psychology; an example of this is Doctor Leonard McCoy. (TOS: "Court Martial").
By the mid-24th century, Starship and Starbase crews included a counsellor, who was responsible for the mental well-being of the crew and civilian staff. The position was considered vital enough that it warranted inclusion in the senior staff of the Federation flagship; in that instance at least, the ship's counsellor also had a diplomatic role, advising the captain in First Contact and other situations. At the captain's discretion, the ship's counsellor may be allowed to wear something other than their normal Starfleet uniform. This was the case with Deanna Troi, the ship's counsellor on the USS Enterprise-D, who preferred to wear colourful, casual clothing while on duty. Troi elected to wear a standard uniform permanently after being told to do so by Captain Edward Jellico. (TNG: "Chain of Command, Part I") Some Starfleet officers, such as Captain Lisa Cusak and Chief Miles O'Brien, disliked the concept of a designated ship's counsellor, preferring to seek advice about their problems from friends. (DS9:"The Sound of Her Voice")
In an early draft of TNG: "Relics", Counsellor Troi explained that the responsibility of a ship's counsellor was to take care of the emotional well-being of a ship's crew and guests. Starfleet began assigning counsellors to Starship’s in the 2330s, after they realized that the pressures of extended space travel could result in psychological problems that would require professional care. In brief the counsellor is in charge of making sure of the crews' mental health and well being. If that means just listening to the worries, concerns and/or advising when needed. Offering an unbiased opinion and compassion. Offering outlets for healthy anger management and in other areas as needed. Helping with the moral of the crew is also a key part of a Counsellor’s job.
As with the chief medical officer, the ship's counsellor has the power to relieve other officers and crew members of duty if he or she feels that their patient is suffering from a condition that may hinder their ability to perform their duties effectively. Counsellors are part of the medical department and report to the chief medical offer. While not required to have other areas of medical expertise it is helpful for a counsellor to have some idea of how to assist in areas other then mental health.
USS Tomcat Medical Department