Horticultural therapy: a pilot study on modulating cortisol levels and indices of substance craving, posttraumatic stress disorder, depression, and quality of life in veterans

Altern Ther Health Med. Jul-Aug 2015;21(4):36-41.


Context: Horticultural therapy (HT) is a subgroup of occupational therapy (OT). Both HT and OT have been successful as adjunctive treatment modalities in substance abuse treatment. Studies have indicated that gardening promotes neuroendocrine and affective restoration from stress.

Objectives: The study intended to assess the effect of HT versus nonhorticultural OT on cortisol levels, depression, symptoms of posttraumatic stress disorder (PTSD), alcohol cravings, and quality of life.

Methods: The research team designed a randomized pilot study.

Setting: The study was open for participation from July 2012-October 2012. It took place during multiple occurrences of a 28-d treatment programs for substance use disorder at a Veterans Affairs medical center. Participants • Participants were 49 veterans, averaging 46.4 y old (SD = 11.9); the dropout rate was 37%.

Intervention: Participants were randomly assigned to the HT or the OT group. They attended supervised HT and OT groups 5 h/d for 3 wk. Outcome Measures • Pre- and posttreatment, participants completed the Quality of Life Enjoyment and Satisfaction Questionnaire-Short Form (Q-LES-Q-SF), the Alcohol Craving Questionnaire (ACQ-NOW), the Posttraumatic Stress Disorder Checklist Civilian Version (PCLC), and the Center for Epidemiologic Studies Depression Scale (CES-D). Salivary cortisol samples were taken at wk 1, 2, and 3.

Results: A repeated measures analysis of variance (ANOVA) (F2,20 = 0.878) revealed that the HT performed was associated with a 12% reduction in salivary cortisol levels from wk 1 to wk 3, but the difference was not statistically significant (P = .43). Separate 1-way analyses of covariance (ANCOVAs) revealed no statistically significant differences in the self-administered tests, although both the Q-LES-Q-SF and CES-D showed a trend toward improving quality of life and depressive symptoms in the HT group compared with the OT group. Additional analysis of the nonbiologic tests suggests that most participants in the HT and OT had some benefit from the programmed activities.

Conclusions: The trends suggest that HT may modulate stress in veterans, as evidenced by decreased cortisol levels and depressive symptoms, and may improve quality of life more than the programs in which the OT group participated. Further investigation with larger samples, including a nontreatment control group, is needed to determine whether the observed trends are treatment effects or due to abstinence.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Analysis of Variance
  • Craving / physiology*
  • Depression / metabolism
  • Depression / therapy*
  • Female
  • Horticultural Therapy / methods*
  • Humans
  • Hydrocortisone / metabolism*
  • Male
  • Middle Aged
  • Occupational Therapy
  • Pilot Projects
  • Quality of Life / psychology*
  • Saliva / metabolism
  • Stress Disorders, Post-Traumatic / metabolism
  • Stress Disorders, Post-Traumatic / therapy*
  • Veterans*


  • Hydrocortisone