Introduction

Acceptance and use of complementary and integrative medicine (CIM) therapies is growing, especially among the Baby Boomers cohort born in 1946–1964, and later birth cohorts [1]. CIM has been widely used in many different cultures dating back to the eighteenth century, starting with homeopathy and ancient healing traditions, such as Traditional Oriental Medicine (TOM) (e.g., Traditional Chinese Medicine (TCM), acupuncture, shiatsu, and reiki), Indian systems of healthcare (e.g., Ayurveda and yoga), and Native American healing practices (e.g., Sweat Lodge and Talking Circles). All integrative practices share the belief that wellbeing is a state of balance in the spheres encompassing the spiritual, physical, and mental/emotional functioning that can be achieved by leading a balanced healthy lifestyle ensured by proper nutrition, exercise, sleep habits, and the ability to regulate stress response via meditation or other mind-body practices. Because CIM is often considered to be a natural and safer option compared to conventional medicine in addressing common health conditions, these interventions are rapidly gaining popularity in the USA [1, 2]. Many of these practices fall into the category of lifestyle medicine where individuals are empowered to make healthier choices in diet, exercise, sleep, and stress management. Lifestyle medicine is a new emerging field of integrative medicine that offers relatively simple and often low-cost solutions to treatment and prevention of aging-related mental and physical disorders. Lifestyle interventions include, but are not limited to nutrition and the use of supplements, aerobic and mindful physical exercise, stress reduction, intermittent fasting, and smoking cessation [3]. In cases of mind-body practices, individuals go through training to develop life-long skills for self-regulation in face of adversity and stress, and health promoting practices that improve immune functioning that is especially important during the COVID-19 pandemic (e.g., by practicing basic hygiene, improving sleep quality, diet that includes rainbow-colored fruit and vegetables, proper exercise routine, stress reduction including meditation and yoga). The COVID-19 pandemic highlighted the general importance of health-promoting practices.

Although the terms, “alternative,” “complementary,” and “integrative” are often used interchangeably, the National Center for Complementary and Integrative Health (NCCIH) defines these terms as follows: “alternative” medicine refers to a set of practices of medicine (e.g., traditional, oriental, mind-body, etc.) without sufficient evidence base that is used in place of conventional medicine, whereas “complementary” medicine refers to non-mainstream practice that is used together with conventional medicine. “Integrative” medicine refers to the use of conventional and complementary approaches in a coordinated way targeting specific disorders or underlying neurobiological processes (e.g., inflammation). CIM emphasizes a holistic, patient-focused approach to healthcare and wellness targeting the whole person rather than one organ system. Historically, these practices are oriented toward harmonious rebalancing of mind, body, and spirit. The NCCIH identified three categories for complementary and integrative approaches: (1) natural products (herbal medicines, botanicals, vitamins, minerals, probiotics, and other dietary supplements); (2) mind and body practices (massage therapy, meditation, yoga, acupuncture, chiropractic/osteopathic manipulation, hypnotherapy, tai chi, qigong, healing touch, and relaxation exercises); (3) other complementary approaches (indigenous healing practices, Chinese medicine, Ayurvedic medicine, homeopathy, and naturopathy).

Unfortunately, CIM is rarely included in the healthcare systems on the large scale with the exception of a few modalities (i.e., acupuncture and chiropractic care) due to the lack of reimbursement by the US medical insurances, and remain unaffordable for many older adults living on a limited income [4]. Billions of dollars are spent out of pocket per year on a poorly regulated large health-promotion industry with unvalidated health outcome claims and with limited evidence and can be confusing to navigate for the consumers, and especially for older adults. In this review, we focus on the most popular CIM modalities with the strongest evidence, including diet and mind-body therapies used for commonly occurring mood, anxiety, and cognitive disorders.

Complementary and integrative medicine use in the USA

In a joint survey conducted by the American Association of Retired People (AARP) and the NCCIH, the use of CIM was reported to be have increased rapidly, exceeding a prevalence of 53% among those aged 50 years and above [5]. Previously, studies had shown that older adults were more likely to use prayer for health and spiritual practices than younger adults, and were less likely to use other forms of CIM [6]. However, a recent study comparing the Baby Boomers cohort (1946–1964) to the pre-boomer cohort (those born prior to 1946) demonstrated that a higher proportion of Baby Boomers used CIM (27.7%) than pre-boomers (16.4%). [6]

Aging is associated with chronic mental, cognitive, and physical conditions. The use of CIM offers less invasive, more cost-effective, culturally acceptable, and scalable therapies [7]. There has been a robust increase in use of yoga, tai chi, and qigong from 2002 to 2017 (5.8 to 14.5%, respectively) by the general population typically for stress, anxiety, and depression [8]. Therefore, clinicians treating older adults need to be informed of the efficacy and potential side effects of various CIM therapies to better assist their patients in making healthcare decisions.

Diet and use of nutritional and herbal supplements

Several lines of investigation have pursued the role of diet and nutrition in management of mental disorders. These include targeting increased oxidative stress and inflammation, reduced essential nutrients in psychotic and mood disorders, and gut microbiome dysfunction, all of which have been linked to mental disorders. Over a half of all US adults take some form of nutritional supplements. Older adults age 70 and older suffering from disorders, such as stroke, cancer, obesity, breathing problems, and arthritis are more likely to use herbal and nutritional supplements [9]. Despite the popular belief that natural supplements are safer, their use can be associated with important adverse effects and supplement/herb-drug interactions, which is only minimally regulated by the Food and Drug Administration (FDA). Additionally, excessive consumption of certain supplements may be harmful, under-reported in the consumer reports or media, and under-appreciated by patients and healthcare providers [10].

The emerging field of nutritional psychiatry focuses on the consequences and associations between what you eat, how you feel, and ultimately, how you behave. The focus shifts from single nutrients or supplements to a comprehensive, cohesive, and scientifically rigorous evidence base to support a shift in thinking about the role of diet and nutrition in mental health [11]. The studies of the impact of diet on symptoms of depression, anxiety, and cognitive decline are summarized in Table 1. In particular, the Mediterranean diet gained attention after a large, multicenter, randomized controlled “the PREDIMED” study [12, 13] showed that adherence to a Mediterranean diet can be a primary prevention strategy for cardiovascular disease. The Mediterranean diet consists of plentiful use of olive oil; high consumption of fruit, vegetables, legumes, cereals, and nuts; regular, but moderate intake of wine (especially red wine) with meals; moderate consumption of fish, seafood, fermented dairy products (yogurt and cheese), poultry, and eggs; and limited consumption of red and processed meats and sweets. Additionally, there are emerging observational studies examining the impact of green tea on cognition and aging with promising results [14].

Table 1 Study characteristics of diet and supplements
Full size table

Mood and anxiety disorders

Two RCTs, one by Jacka et al. [15] and Parletta et al. [16], found significant improvement in depression with Mediterranean diet interventions in adults compared to social support controls. Jacka and colleagues [15] found that the dietary support group demonstrated significantly greater improvement between baseline and 12 week MADRS scores compared to social support alone, while Parletta and colleagues [16] found a greater reduction in depression (p = 0.03) and improved mental health quality of life (QoL) scores (p = 0.04) at 3 months with sustained effects at 6-month follow-up with Mediterranean and fish oil supplementation compared to social support alone. Similarly, a cross-sectional, observational study in older adults suggested that adherence to a Mediterranean diet lead to less depressive symptoms [17]. A more recent, large RCT by Ghosh et al. [18] showed a strong relationship between a Mediterranean diet and promotion of overall healthier aging through changes in gut microbiota. Another observational cohort study by Cherian et al. [19] examined the relationship between Mediterranean-Dietary Approaches to Stop Hypertension (DASH) diet on depression in older adults, demonstrating adherence to the Mediterranean-DASH diet associated with lower rates of depression while Western diets had a positive association with depression.

Cognition

Beyond mood effects, the Mediterranean diet has also shown to be beneficial for cognition. One of the first randomized control trials examining dietary pattern on global cognitive function by Martínez-Lapiscina and colleagues [12] demonstrated nutritional intervention with the Mediterranean diet supplemented with either extra virgin olive oil (EVOO) or mixed nuts is associated with improved global cognition, independent of potential confounders such as age, family history of cognitive impairment or dementia, apolipoprotein E (ApoE) genotype, education, physical activity, vascular risk factors, and energy intake. Similarly, a prospective study by Morris and colleagues [20] examined three dietary patterns (Mediterranean diet, the DASH diet, and the Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) diet) and showed that high adherence to all three diets may reduce Alzheimer’s disease (AD) risk, with moderate adherence to the MIND diet also decreasing AD risk. Similar to the Mediterranean diet, the DASH diet specifies a high consumption of plant-based foods but also limits the intake of saturated and total fat, cholesterol, and sodium; it was initially developed to target hypertension and cardiovascular risk factors. The MIND diet emphasizes natural plant-based foods as well as consumption of berries and green leafy vegetables while limiting animal foods and saturated fats [21]. More recently, a large meta-analysis by Loughrey et al. [22•] included 15 cohort studies, with 2 RCTs revealing a significant association between the Mediterranean diet and improvement in episodic memory (p = 0.03) and global cognition (p < 0.001), but not working memory (p = 0.93) or semantic memory (p = 0.28). [22•] Another recent observational study by D’Amico and colleagues demonstrated that a higher adherence to a Mediterranean diet is associated with lower perceived stress and executive dysfunction [23].

Unlike supplements where the data has been less consistent, certain dietary patterns have shown stronger, reproducible evidence to support mental health. It is likely that a combination of emphasizing foods that contain multiple beneficial nutrients, as well as reduction in saturated and unsaturated fats, has a stronger, combined effect on mental disorders than single supplementation alone.

Use of nutritional and herbal supplements

Along with regular food consumption, nutrients can also be consumed in herbal and nutritional supplement form that is the most popular form of complementary therapy in older adults. Only a few supplements used for mood and cognitive disorders have robust research evidence of efficacy and safety. There have been several approaches to recent clinical research regarding mental disorders and diet and nutrition. These include targeting increased oxidative stress and inflammation, reduced essential nutrients in psychotic and mood disorders, and gut microbiome dysfunction, all which have been linked to mental disorders [3]. Many nutritional supplements have been studied for their potential role as neuroprotective interventions in AD and cognitive disorders in older age. Some of the more popular supplements marketed for memory enhancement are fish oils (omega-3 fatty acids), B vitamins (e.g., folate, B6, and B12), and Ginkgo biloba extract [24]. The studies of the impact of supplements on symptoms of depression, anxiety, and cognitive decline are summarized in Table 1.

Vitamins

Although antioxidant compounds such as vitamins A, C, and E have a role in regulation of oxidative stress, a pathway linked with neurodegeneration and cognitive decline, the use of vitamin E has not been found to have a significant effect on progression from MCI to dementia and/or AD, or on cognitive function at intervention completion [25]. Similarly, low folate and B vitamin status is linked to cognitive dysfunction during the aging process and better cognitive performances have been associated with higher intakes of B vitamins. Although B vitamin supplementation (folic acid, vitamin B6, and B12 combination) have resulted in reduced rates of brain atrophy in MCI, findings are mixed with meta-analyses of clinical trial data reporting no significant effect of B vitamins on cognitive function [25]. A more recent meta-analysis of B vitamin supplementation for depression and anxiety showed some benefit from stress but no significant effect on depression or anxiety [26]. Lower levels of vitamin D have been observed in populations suffering from depressive disorders. However, in a recent RCT, supplementation with 1200 IU/day vitamin D for 12 months had no effect on depressive symptoms and physical functioning in older persons with relatively low vitamin D status, clinically relevant depressive symptoms, and poor physical functioning [27]. Similarly, another recent review indicated contradictory information between vitamin D for treatment of depressive symptoms [28]. Similarly, although human studies strongly support a correlation between low levels of circulating 25-hydroxyvitamin D (25(OH)D) and cognitive impairment or dementia in aging populations, prior clinical interventional studies have failed to associate increased 25(OH)D levels with improved cognitive outcomes. [29]

Omega-3 fatty acids, which include eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and alpha linolenic acid (ALA), have been extensively studied over the past two decades. However, results are mixed likely due to heterogeneity among studies regarding omega-3 preparations, doses, and study design since there are inconsistencies in administering EPA or a combination of EPA and DHA, mostly as an adjunct therapy for unipolar depression but also as monotherapy [30]. In addition to depression and anxiety, fish oil’s PUFAs have also been associated with promoting cognitive function, primarily as a result of their anti-inflammatory properties. Additionally, n-3 fatty acids, particularly DHA, are a key component of neuronal membranes in the brain, influencing neurogenesis and neuronal function [31•]. In a recent Cochrane review by Burckhardt et al. [31•] looking at the effects of omega-3 fatty acids for the treatment of dementia, three comparable randomized, placebo-controlled trials investigating omega-3 PUFA supplements in 632 participants with mild to moderate AD over 6, 12, and 18 months were examined. However, there was no evidence of a benefit from omega-3 PUFAs on cognitive function when measured at 6 months with the Alzheimer’s Disease Assessment Scale-Cognitive subscale or Mini-Mental State Examination or on activities of daily living. [31•]

S-adenosylmethionine (SAMe), an endogenous, intracellular amino acid metabolite and enzyme co-substrate involved in multiple crucial biochemical pathways, including biosynthesis of hormones and neurotransmitters, has been implicated in depression and cognition. Additionally, deficiencies of folate and vitamin B12, necessary co-factors in the synthesis of SAMe, may account for decreased SAMe levels, especially in patients with depression and dementia. A recent Cochrane review by Galizia et al. [32] and recent review by Sharma et al. [33•] looked at over 50 clinical trials in the USA and Europe examining SAMe in the treatment of depressive disorders with some encouraging evidence of efficacy and safety of SAMe as a monotherapy when compared to placebo as well as antidepressant augmentation. SAMe also had a much more favorable side effect profile and minimal drug-drug interactions. However, the data remains largely inconclusive given the overall power was low to modest and results need further investigation to establish stronger evidence [32, 33•].

Gingko biloba has been studied in cognitive cohorts with mixed results. In a systemic review and meta-analysis by Yang et al. [34], 21 trials were found examining the effects of Ginkgo biloba on cognition. They concluded that when compared with treatment as usual alone, Ginkgo biloba in combination with treatment as usual was superior in improving Mini-Mental State Examination (MMSE) scores at 24 weeks for patients with Alzheimer’s disease (p < 0.0001) and mild cognitive impairment (p < 0.00001), and Activity of Daily Living (ADL) scores at 24 weeks for Alzheimer’s disease (p = 0.0002). However, when compared with placebo or conventional medicine in individual trials, Ginkgo biloba demonstrated similar but inconsistent findings. It is important to note that Ginkgo biloba can increase risk of bleeding when combined with warfarin due to inhibition of platelet-activating factor (PAF), raise blood pressure when combined with a thiazide diuretic, and increase risk of coma when combined with trazodone [35].

St. John’s Wort

There are over 40 published clinical trials of St. John’s wort (Hypericum perforatum (SJW), including many comparisons with tricyclic antidepressants (TCAs) and selective serotonin reuptake inhibitors (SSRIs) that have been published over the past decade [30]. A Cochrane review by Linde et al. [36] examined 29 trials including 5489 patients; 18 trials compared SJW with placebo, and 17 compared it with standard antidepressants. Results showed heterogeneity, but overall, SJW was found to be superior in efficacy to placebo and equivalent to standard antidepressants, with better tolerability. A meta-analysis Ng et al. [37] of 27 clinical trials with a total of 3808 patients were reviewed, comparing the use of St John’s wort and SSRI. In patients with depression, St John’s wort demonstrated comparable response (p < 0.001) and remission (p < 0.001) rate, and significantly lower discontinuation/dropout (p < 0.001) rate compared to standard SSRIs. The evidence thus far supports SJW for treatment of depressive disorders, although it may be less effective in chronic and/or severe depression. However, it is important to note that SJW can induce P-glycoprotein and/or cytochrome P450 (CYP) enzymes (particularly CYP 3A4) by SJW due to numerous reports indicating the possibility of important interactions with prescribed drugs. SJW has been shown to lower the plasma concentration (and/or the pharmacological effect) of a number of drugs including alprazolam, amitriptyline, cyclosporine, digoxin, fexofenadine, indinavir, irinotecan, methadone, nevirapine, simvastatin, tacrolimus, theophylline, warfarin, phenprocoumon, and oral contraceptives, as well as cause serotonin syndrome when combined with serotonin reuptake inhibitor, antidepressants (e.g., sertaline, paroxetine, nefazodone), or buspirone [35].

Valerian root (Valeriana officinalis) is the most commonly used herbal supplement for sedation and anxiolysis and has been used worldwide for over 1000 years and may function similarly to benzodiazepines or barbiturates, with GABA-ergic activity [30, 38]. One RCT involving 36 patients with generalized anxiety disorder was a 4-week pilot study of valerian, diazepam and placebo, but no significant differences between the valerian and placebo groups or valerian and diazepam groups were found in HAM-A total scores [39].

A small number of studies examined the use of herbs and supplements in anxiety disorders. However, in a recent study looking to identify herbals showing interaction with the GABA system, in addition to human clinical trials, ten herbals were identified: kava, valerian, pennywort, hops, chamomile, Ginkgo biloba, passionflower, ashwagandha, skullcap, and lemon balm. Collectively, the literature reveals preclinical and clinical evidence for various herbals modulating GABA-pathways, with comparative anxiolytic effect to the current array of pharmaceuticals, along with good safety and tolerability profiles [40]. In particular, there is some data to support the effectiveness of kava compared popular supplements like St. John’s wort, valerian, and omega-3 fatty acids for anxiety [41]. Although side effects for these supplements are minimal, Kava can increase “off” periods in Parkinson patients taking levodopa and can cause a semi-comatose state when given concomitantly with alprazolam [35].

Mind-body therapies

Mind-body therapies (MBTs) are also rising in popularity according to the 2017 National Health Survey with the 5–10% increased use of yoga, meditation and chiropractic care in the last 5 years [42•]. A growing body of research evidence supports the use of MBTs (including meditation, yoga, tai chi, and qigong) as minimally invasive, cost-effective approaches for the management of stress, late-life mood, and cognitive disorders. In contrast to pharmacological approaches, MBTs aim to teach patients life-long skills that may continue to confer benefits long after formal training has ended. Continued research in this area will promote the integration of MBTs into mainstream clinical practice and help to alleviate the increased chronic health burden of an aging population. Existing evidence suggests that, on average, both meditative movement (e.g., yoga) and multicomponent mindfulness-based interventions (e.g., mindfulness-based cognitive therapy (MBCT) and mindfulness-based relapse prevention (MBRP)) can be as effective as other active treatments for disorders such as major depression, anxiety, and substance use disorder. Results of studies with healthy adults suggest that multicomponent interventions such as mindfulness-based stress reduction (MBSR) have potential to increase empathy, self-control, self-compassion, relationship quality, and spirituality, as well as decrease rumination. Research has also begun to evaluate the neurobiological mechanisms, by which meditative therapies enhance resilience to mental health disorders, and several promising mechanistic domains (neural, hormonal, immune, cellular, and cardiovascular) have been identified [43]. Mindfulness-based treatment protocols are usually brief (typically eight in-person individual or group sessions), multi-component interventions incorporating both education and practice. Two of the most commonly available and widely studied forms in research are MBSR and MBCT [43]. Yoga therapy is also becoming very popular especially among younger adults [42•]. We have previously published the results of the randomized clinical trials documenting the effects of yoga, tai chi, and meditation in older adults with depression and cognitive decline identifying therapeutic benefits for mood, anxiety, resilience, and cognition, accompanied by physiological anti-inflamatory effects, as well as improved brain neuroplasticity and connectivity [44,45,46,47,48,49,50,51,52]. The studies of the impact of mind-body therapies on symptoms of depression, anxiety, and cognitive decline are summarized in Table 2.

Table 2 Study characteristics of MBTs
Full size table

Mood disorders

The most recent meta-analysis of 11 RCTs with 12 MBT treatment arms found that mindfulness-based interventions (MBIs) showed significant improvement in depressive symptom severity compared to control groups at post-MBI assessment. However, the effect was not significant at the end of the follow-up and endpoint assessment period [43]. Another meta-analysis of 12 RCTs of mindfulness-based interventions for individuals with a current depressive or anxiety disorder found that mindfulness-based interventions significantly decreased primary symptom severity compared to a mixed control group including both active (e.g., cognitive behavior therapy, psychoeducation) and inactive (e.g., treatment as usual) control conditions but this positive effect also appeared limited to post-MBI assessment but not at the end of follow-up period [43]. Another meta-analysis on individual patient data from 9 RCTs examined the efficacy of MBCT compared with usual care and other active treatments (including antidepressants) in treating adults with recurrent depression [53]. Results indicated that patients who received MBCT had a reduced risk of relapse within a 60-week follow-up period compared with those who did not. Individuals with more severe depression pre-treatment experienced greater benefits with of MBCT compared to controls. Another meta-analysis investigated the efficacy of mindfulness-based therapies on clinical vs. sub-clinical depression. Both pre-post studies and waitlist-controlled studies indicated a significant effect of mindfulness-based therapies targeting depressive symptoms [54]. Overall, there is consistent evidence demonstrating short and likely longer-term positive effects of mindfulness-based therapies on depression.

Anxiety disorders

Khoury and colleagues [55] investigated the efficacy of various standardized multicomponent mindfulness-based therapies (e.g., MBSR, MBCT) on clinical and sub-clinical anxiety [55]. Waitlist-controlled studies indicated a significant effect of mindfulness-based therapies targeting anxiety symptoms. Using the State-Trait Anxiety Inventory (STAI), sub-clinical anxiety was significantly reduced at post-treatment and follow-up. A moderate clinical baseline level of anxiety was reduced to a sub-clinical level post-treatment and to a mild level at follow-up. A high clinical baseline level of anxiety was reduced to moderate levels at both post-treatment and follow-up. The magnitude of these effect may be regarded as ranging from fairly small (mean = 6% improvement) for subclinical anxiety to more clinically significant for moderate and high levels of anxiety (18% and 11%, respectively). A more recent, larger meta-analysis of 10 RCTs from Hilton and colleagues showed significant improvement in PTSD symptoms with meditation interventions [56]. Similarly, another large meta-analysis including 19 RCTs by Gallegos et al. examining both meditation and yoga for PTSD showed a smaller effect size, while a meta analysis examining yoga alone on PTSD showed inconclusive results [57, 58]. This suggests the possibility that meditation rather than yoga may have a more significant effect on PTSD symptoms.

Cognitive disorders

A recent review by Berk et al. [59] reviewed six studies investigating the effects of MBTs on cognition in older adults. The studies reported a variety of neuropsychological tests to measure global cognitive function, executive function, and memory. Three of the six reviewed studies were RCTs, with most of the studies conducted as pilot projects and more appropriately interpreted as evidence of feasibility of MBI interventions in older adults. The review concluded that MBI for older adults were feasible, but results on cognitive improvement were inconclusive due a limited number of studies, small sample sizes, and a high risk of bias [59]. A more recent longitudinal mixed-methods observational study with a 1-year follow-up period using a customized 8-week group-based mindfulness training program for older adults with MCI (n  =  14) showed significant improvements in cognitive function (p  <  0.05) and trait mindfulness (p  <  0.05) after completing the intervention in MCI participants. Those who meditated more during the 59 weeks showed greater improvements in cognitive function (p  <  0.05) and everyday activity functioning (p  <  0.05), with large effect sizes at the 1-year follow-up [60]. Similarly, another review examined nine studies which indicated that mind-body interventions improved cognitive function, everyday activity functioning, and mindfulness, as well as resulting in a moderate reduction in fall risk, depression and stress, and lower risk of dementia at 1 year [61]. Inclusion criteria included more broad interventions such as mindfulness or meditation, yoga, tai chi, and qigong on cognitive function and everyday functionality of non-hospitalized adults aged 55 years or over with MCI. Although the data is promising, the conclusions are limited by number of studies and small sample size, heterogeneity of outcome measures, lack of an active control group, and absence of long-term follow up.

A growing body of research evidence supports the use of MBTs (including meditation, yoga, tai chi, and qigong) as minimally invasive, cost-effective approaches for the management of late-life mood and cognitive disorders. In contrast to pharmacological approaches, MBTs aim to teach patients life-long skills that may continue to confer benefits long after formal training has ended. Additional research evaluating the mechanisms by which MBTs improve mental health and cognition is needed. As the majority of studies to date have focused on younger and middle-aged adults, whether the proposed mechanisms by which MBTs improve mood, sleep, and well-being generalize to geriatric populations is less well understood. Improved understanding of the neurobiological mechanisms of MBTs will lead to the development of preventive interventions oriented toward promoting well-being and resilience in this vulnerable population.

Conclusion

Despite the increasing use of CIM by individuals and growing body of research examining the efficacy of CIM for treating mental disorders, research, and scientific support for its efficacy for older adults remains limited. Overall, there is stronger and more consistent evidence about the benefits of dietary interventions and mind-body therapies for mood and cognitive disorders, while the evidence for most herbal and nutritional supplements remains mixed and inconclusive. The non-invasive nature of mind-body therapies and Mediterranean diet modifications also make these CIM interventions more favorable over supplementation use due to the variability in formulations available, as well as potential drug-drug interactions. However, studies have consistently faced limitations, such as small sample size, heterogeneity of outcome measures, lack of an active control group, and absence of long-term follow-up, particularly in older adults. Additional research is needed to determine predictors and biomarkers of response that would allow identification of individuals who are more likely to respond to CIM. Implementing CIM interventions in the communities will represent the next phase of CIM research as preventive, well-being oriented interventions for stress-diathesis disorders.