Mood swing
A mood swing was a sudden change in one's emotions. Mood swings often accompanied pregnancy. (, , )

In 2151, Doctor Phlox warned a pregnant  that he could begin to experience, among other symptoms, mood swings. ()

In 2370, while investigating Daniel Kwan's suicide, Deanna Troi asked Maddy Calloway if the lieutenant was prone to mood swings or depression. She replied that he wasn't, adding that he was sensitive to the moods of others. ()

In 2372, Miles O'Brien complained that his wife Keiko O'Brien continued to participate in dangerous activities despite being pregnant with their son, noting that "It's as if I have to remind her that she's pregnant." Jadzia Dax then quipped, "Yeah, I guess the extra weight, the morning sickness, the mood swings, the medical examinations, they aren't reminders enough." ()

In 2375, Jean-Luc Picard ordered a jak'tahla-stricken Worf to report if he experienced any severe mood swings. ()

In 2377, when a pregnant B'Elanna Torres expressed her desire that her and Tom Paris' baby be less Klingon in appearance, Paris reminded her that The Doctor had said she would experience mood swings. Torres found his attribution of her concerns to raging hormones to be dismissive of her feelings. ()

See also
 Bipolar personality disorder

External link

Psychological conditions