The BBC has an article about a study with dolphins
A University of Leicester team tested
the effect of regular swimming
sessions with dolphins on 15 depressed
people in a study carried out in
They found that symptoms improved more
among this group than among another 15
who swam in the same area - but did
not interact with dolphins.
All the volunteers who took part in
the trial stopped taking
antidepressant drugs or undergoing
psychotherapy at least four weeks
Two weeks later, both groups showed
improved mental health, but especially
so among patients who had been
swimming with the dolphins.
And here is a study about how a cat improved depressive symptoms in elderly people
28 subjects with chronic
age-related disabilities living in a
nursing home ... were assigned to
a pet-therapy intervention group.
Results showed that patients with
animal interaction had improved
depressive symptoms and a significant
decrease in blood pressure values.
This study is about animal-assisted therapy in adult college students
[The study] investigated the effects of
animal-assisted therapy (A-AT) on
self-reported depression in 44 college
Results confirmed the positive
influence of A-AT in this cohort.
Here is a study about "The Effects of Animal-Assisted Therapy on Anxiety Ratings of Hospitalized Psychiatric Patients"
This study examined whether a session
of animal-assisted therapy reduced the
anxiety levels of hospitalized
psychiatric patients and whether any
differences in reductions in anxiety
were associated with patients'
It was concluded:
Animal-assisted therapy was associated
with reduced state anxiety levels for
hospitalized patients with a variety
of psychiatric diagnoses, while a
routine therapeutic recreation session
was associated with reduced levels
only for patients with mood disorders.