Holo-addiction
Holo-addiction, also known as holodiction, was a psychological disorder in which a person preferred the fictional world of the holodeck to the real world. The addiction functioned as an escape mechanism, symptomatic of deeper psychological problems.

Lieutenant Reginald Barclay suffered from holo-addiction when he was assigned to the  in 2366, which was cured when he started to make real friends. () He had a relapse in 2376, after he had left the Enterprise, when he re-created the  and its crew. After he succeeded in contacting the real Voyager, he recovered, and began dating a woman named Hope. ()

While conducting research on Human interactions in 2378, Seven of Nine began to experience a form of holo-addiction, causing her to be absent from her post on several key occasions. When confronted by Captain Janeway about it, Janeway noted that she logged 49 hours in Holodeck 2 in a six-day period of time. In response to the confrontation, Seven falsely stated that she was "running a simulation of a new gravimetric array" she had been developing. ()

Psychological conditions