Yes, this is true.
According to Realsimple.com, Tomeka McGee-Holloway and Bethany Cook, both Doctors of Psychology, claim that having one or more hobbies can improve a person’s mental health, and have an increasing number of benefits when self-confidence is gained through the hobbies.
Tomeka McGee-Holloway believes that engaging in activities can reduce cortisol that causes stress, and it is encouraging self-care and self-love. Furthermore, Bethany Cook also points out that having hobbies brings people joy and maintains good mental health.
Research studies conducted by Utah State University also state that the benefits of having hobbies are to reduce stress and anxiety, enhance well-being, and improve mental health. Hobbies during spare time, such as doing something creative or enjoyable like sports, arts, or traveling, can be meaningful to people. Having hobbies has lots of benefits to people.
Having Hobbies Can Boost Your Mental Health, Here's How (realsimple.com)
How Hobbies Improve Mental Health | USU