Instagram therapists are the new Instagram poets, in a way — only instead of posting free verse in typewriter font, they deal in pithy pronouncements about embracing imperfection, self-care, “growth mindset,” mothering oneself, impostor syndrome and trauma. The digital words of accounts like @thefatsextherapist, @nedratawwab and @the.holistic.psychologist are meant to encapsulate the “aha” moment of a therapy session. The best part? There’s no bill afterward.

Ms. Olivera, 33, started her account, @lisaoliveratherapy, in November 2017 while transitioning to private-practice work from community mental health. She thought Instagram could be a good way for new clients to find her. In the last two years, she has gained 161,000 followers — more than double that of Bill de Blasio, the New York City mayor and Democratic presidential candidate.

Ms. Olivera was something of a pioneer. “I started it on a whim, not sure what it would look like or where it would go. There weren’t many therapists on Instagram at that time,” she said. “It was inspiring to see how many people were wanting to learn more about emotional health and look internally and do the work inside themselves, even if they weren’t able to access therapy.”

Allyson Dinneen, 54, is a marriage and family therapist in Great Barrington, Mass. Online, she is @notesfromyourtherapist, posting handwritten advice on scraps of paper for 130,000 followers. Like Ms. Olivera, Ms. Dinneen opened her account in late 2017 while starting her private practice. She wanted a way to have an impact on more than one person at a time.

“The internet is filled with directives: ‘Do this, do that, stop doing this, do that.’ That’s hard for people to take in,” she said. “I’m coming from my own experience, and people feel more open to taking in what they need.”