Mental health concerns are the leading cause of disability-adjusted life years worldwide.1-2 This means that psychological concerns, including anxiety, depression and post-traumatic stress disorder (PTSD), are responsible for the greatest amount of years lost due to poor health, disability, and early death. If you think those statistics are grim, it doesn’t stop there.

One out of every three people with depressive disorders will not experience remission from their mental health concerns, even after trying up to four different antidepressants.3 Now, what does this tell us? It tells us that while we can’t deny the fact that medication has its place and is helping people, there are others for whom it simply isn’t as effective. Because mental health concerns play such an important role in reducing productivity and diminishing the potential of many brilliant men and women today, it’s important for us to explore stand-alone and adjunctive therapies that may enhance the effectiveness of medication and/or be beneficial in improving overall mental wellbeing.

Could nutritional deficiencies be contributing to my poor mental health?

Because many micronutrients have anti-inflammatory and antioxidant properties, adequate amounts of these micronutrients help support optimal mental and physical wellbeing. Nutritional deficiencies are strongly associated with and may contribute to poor mental health.

Vitamin E and Depression

For example, vitamin E, which plays a significant role as an antioxidant within the body, has been found to be lower in depressed individuals than in healthy individuals.4 This is significant because one theory regarding how depression comes about is that it occurs when there is an imbalance between antioxidants and pro-oxidants. Pro-oxidants are chemicals that cause oxidative stress within the body by creating what’s known as reactive oxygen species or by blocking our antioxidant systems.

In order to maintain a healthy balance of antioxidants to pro-oxidants, it’s important for depressed individuals to eat an antioxidant-rich diet. To put it simply, this means a diet that is rich in plant-based foods because berries and other fruits, nuts, and vegetables contain significantly more antioxidants than most sources of dairy, poultry, and other meat.5

Folate and Mood

Vitamin B9, also known as folate, is another micronutrient that has an important effect on mood. Researchers in one study wanted to learn more about the relationship between folate and illness, so they took three groups of people—a group that was depressed, a group that had a psychiatric concern that did not include depression, and a group that had a physical health concern—and hospitalized them.6 While hospitalized, they were not given any medications or supplements and they all ate the same diet. At the end of the study, the group that was depressed had significantly lower levels of folate than the individuals in the other two groups. Researchers concluded that this research suggested that there may be a subcategory of depression that is actually caused by folate deficiency.

Here’s another important piece of information about folate: people with low folate levels are more likely to have melancholic depression and significantly less likely to have a positive result when taking the antidepressant fluoxetine (brand name Prozac).7 This is likely because folate has its own antidepressant effects and because adequate folate levels are important in order for antidepressants to be most effective.

Now it is worth mentioning here that there’s an important difference between folic acid, which is the synthetic form of the vitamin, and folate, which is the form our bodies use. For many people, consuming folic acid such as from fortified grains or from supplements isn’t a problem, but some people have a variant of a gene that produces an enzyme called methyltetrahydrofolate reductase (MTHFR) that results in them not being able to efficiently convert the synthetic folic acid to the form that our bodies can use. For these individuals, it’s important to avoid folic acid and get plenty of naturally occurring folate. Green leafy vegetables are an excellent source of folate.

Can an animal help my mental health?

In recent years, research has been shining more light on the therapeutic value of animals in addressing mental health concerns like anxiety, depression, PTSD, and substance abuse disorder.

In order to understand the research concerning the effects of animals on human mental health, there are two terms that you need to understand—animal-assisted therapy (AAT) and companion animals. Research that is conducted in a formal setting, such as in a residential treatment center or another institution, typically involves animal-assisted therapy. The animals involved in these studies are typically brought in (or in some cases, the participants are brought to the animals) and then the researchers draw conclusions by observing participants as they interact with the animals. They also draw conclusions by surveying participants before and afterward. Studies that mention companion animals tend to involve people who have animals as pets. These animals aren’t brought in temporarily; they’re typically already a part of the participants’ daily lives. Most of the research focuses on AAT, but there is also a small number of quality studies on companion animals.

Here are the details of a study that used AAT: A study was conducted on veterans who had been diagnosed with PTSD and/or traumatic brain injury and were participating in intensive outpatient programs to address related concerns. Study participants were permitted to engage in equine-assisted activities and therapies, a type of AAT. At the end of the study, participants reported that engaging with the horses helped them with emotional rehabilitation and benefitted their mental health by fostering interpersonal relationships.8 They also reported a great overall experience—they had a good time—and this had positive effects on their mental health as well.

Another AAT-based study looked at the effects of dogs on individuals diagnosed with one or more mental health concern(s) and a substance abuse disorder. Researchers who conducted this study concluded that dogs can capture attention and improve patient motivation, cooperation, and involvement in therapy. At the end of the study, participants reported improvement in their daily skills, resulting in improved quality of life. They also reported decreased impulsiveness and reported feeling that their participation in the AAT enabled them to regain self-control.9

In addition to AAT, simply having a pet appears to provide owners with mental health benefits. These benefits include more than simply companionship. In a study that included U.S. military veterans with PTSD between the ages of 34 and 67, the study subjects reported feeling calmer, and feeling less lonely, depressed, and worried about their families’ safety since adopting their dogs.10At the end of the study, researchers concluded that living with a dog as a companion may help alleviate psychiatric concerns, such as the symptoms of PTSD seen in U.S. military veterans.

A study that involved seriously mentally ill individuals, participants reported that their pets provided emotional support and improved their mental wellbeing in a number of ways. This included providing connections that could assist them in developing stronger social bonds with other humans, serving as “family” in the absence of or in addition to human family members, supporting their independence, and strengthening their sense of empowerment.11

In other studies, people reported that companion animals seemed to know when their owners were down and they were able to provide them with practical emotional support in those times. If you have a pet, you may identify with this sentiment: some owners reported that their pets “know” when to provide them with support and when to refrain from doing so.12

During anxiety attacks in the middle of the night, one participant’s companion dog would come to her, lick her face, and keep her company for the remainder of the night. She stated that this action immediately helped her acute symptoms of anxiety to resolve.13

Regardless of whether it’s in the context of animal-assisted therapy or companion animals, animals have been demonstrated in scientific literature to have positive effects on the mental health of their owners and those who interact with them. The interesting thing about this phenomenon is that, while some do receive special training, the animals don’t necessarily have to have special training to bring about this result. In fact, many of them don’t. By simply engaging with animals, many humans have reported improvements in mental health concerns like anxiety, depression, PTSD, and even substance abuse disorder. They’ve reported improvements in emotional wellbeing and they’ve stated that their lives have been enriched as a result.


In conclusion, because mental health concerns are responsible for the greatest amount of years lost due to poor health, disability, and early death globally, it’s important for us to research stand-alone and adjunctive therapies that can result in improved quality of life and mental/emotional wellbeing for individuals diagnosed with these conditions.

Nutritional insufficiencies or deficiencies have the potential to contribute to poor mental health. Low vitamin E levels and low folate levels have both been associated with symptoms of depression. Therefore, it is important for individuals with depressive symptoms to ensure that they consume a wide variety of plant-based foods, since they are rich in antioxidants, and foods that are high in folate, such as green leafy vegetables.

Animal-assisted therapy and simply having a pet can also have important benefits on mental health. Research supports the role of animals in helping to improve mental and overall wellbeing in individuals with diagnosed mental health concerns, including anxiety, depression, bipolar disorder, schizophrenia, and PTSD, in individuals with substance abuse disorder, and in individuals with dual diagnoses.


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  3. Rush AJ, Trivedi MH, Wisniewski SR, et al. Acute and longer-term outcomes in depressed outpatients requiring one or several treatment steps: a STAR*D report. Am J Psychiatry. 2006;163(11):1905-17. doi:10.1176/ajp.2006.163.11.1905
  4. Owen, A., Batterham, M., Probst, Y. et al. Low plasma vitamin E levels in major depression: diet or disease? Eur J Clin Nutr. 2005;59:304-6.
  5. Carlsen MH, Halvorsen BL, Holte K, et al. The total antioxidant content of more than 3100 foods, beverages, spices, herbs and supplements used worldwide. Nutr J. 2010;9:3. doi:10.1186/1475-2891-9-3
  6. Ghadirian A, Ananth J, Engelsmann F. Folic acid deficiency in depression. Psychosomatics. 1980;21:926-9. 10.1016/S0033-3182(80)73586-7.
  7. Fava M, Borus JS, Alpert JE, et al. Folate, vitamin B12, and homocysteine in major depressive disorder. Am J Psychiatry. 1997;154(3):426-8.
  8. Sylvia L, West E, Blackburn A, et al. Acceptability of an adjunct equine-assisted activities and therapies program for veterans with posttraumatic stress disorder and/or traumatic brain injury. Journal of Integrative Medicine. 2020. 10.1016/j.joim.2020.01.005.
  9. Monfort Montolio M, Sancho-Pelluz J. Animal-Assisted Therapy in the Residential Treatment of Dual Pathology. Int J Environ Res Public Health. 2019;17(1). pii: E120.
  10. Stern SL, Donahue DA, Allison S, et al. Potential benefits of canine companionship for military veterans with posttraumatic stress disorder (PTSD). Society & Animals: Journal of Human-Animal Studies. 2013;21(6), 568–81.
  11. Wisdom JP, Saedi GA, Green CA. Another breed of “service” animals: STARS study findings about pet ownership and recovery from serious mental illness. Am J Orthopsychiatry. 2009;79(3):430–6. doi:10.1037/a0016812
  12. Bystrom KM, Persson CA. The meaning of companion animals for children and adolescents with autism: the parents’ perspective. Anthrozoös. 2015;28(2):263–75. doi: 10.1080/08927936.2015.11435401.
  13. Pehle MA. Healing relationships with companion dogs in the therapeutic process: An exploratory qualitative study. California Institute of Integral Studies; 2010. p.3365.


Dr. Janelle Louis, ND

Dr. Janelle Louis, ND
Dr. Janelle Louis is a licensed naturopathic doctor who specializes in helping people with childhood trauma overcome the chronic health concerns they are at increased risk for developing, including mental health conditions, reproductive concerns, autoimmune diseases, and metabolic syndrome. Dr. Louis is committed to ensuring that her patients live their healthiest lives in the present in spite of their difficult pasts.