Essential vitamins, minerals, and omega–3 fatty acids are often deficient in the general population in America and other developed countries; and are exceptionally deficient in patients suffering from mental disorders . Studies have shown that daily supplements of vital nutrients often effectively reduce patients’ symptoms . Supplements that contain amino acids also reduce symptoms, because they are converted to neurotransmitters that alleviate depression and other mental disorders. Based on emerging scientific evidence, this form of nutritional supplement treatment may be appropriate for controlling major depression, bipolar disorder, schizophrenia and anxiety disorders, eating disorders, attention deficit disorder/attention deficit hyperactivity disorder (ADD/ADHD), addiction, and autism .In the last few years there have been a number of studies identifying an inverse association between diet quality and the common mental disorders, depression and anxiety, in adults , ,  and two prospective studies suggesting that diet quality influences the risk for depressive illness in adults over time , .
Mood disorders (i.e. depression, bipolar condition) are very common on acute psychiatric units . Depression has for some time now been known to be associated with deficiencies in neurotransmitters such as serotonin, dopamine, noradrenaline, and GABA [14–20]. As reported in several studies, the amino acid tryptophan, tyrosine, phenylalanine, and methionine are often helpful treating many mood disorders, including depression [21–25]. Tryptophan is a precursor to serotonin and is usually converted to serotonin when taken alone on an empty stomach. Therefore, tryptophan can induce sleep and tranquility and in cases of serotonin deficiencies, restore serotonin levels leading to diminished depression [26, 23].
Since the consumption of omega–3 fatty acids from fish and other sources has declined in most populations, the incidence of major depression has increased . Several mechanisms of action may explain how eicosapentaenoic acid (EPA) which the body converts into docosahexaenoic acid (DHA), the two omega–3 fatty acids found in fish oil, elicit antidepressant effects in humans. Most of the proposed mechanisms involve neurotransmitters and, of course, some have more supporting data than others. For example, antidepressant effects may be due to EPA being converted into prostaglandins, leukotrienes, and other chemicals the brain needs .
While psychological stress is known to increase the pro-inflammatory cytokines, the relationship appears to be bi-directional, with inflammation suggested as a direct contributor to the risk for depressive illness . Inflammation is accompanied by an accumulation of highly reactive oxygen species, and increased oxidative stress is also implicated as a factor in depressive illnesses . Consumption of diets rich in antioxidants, vitamins, minerals and fiber is associated with reduced systemic inflammation . Conversely, diets that are low in essential nutrients, such as magnesium and western type dietary patterns  are associated with increased systemic inflammation.
An important aspect of the shift in habitual diets globally is that of an increase in refined carbohydrate consumption. Hyperglycemia promotes an inflammatory state and high glycemic load (GL) diets are also associated with increased systemic inflammation . Dietary factors, such as refined sugars and saturated fats, have a detrimental impact on the expression of neurotrophic factors  that are particularly salient to depressive illness. Thus, it is plausible to speculate that, by modifying inflammatory, oxidative, and neurotrophic factors, diet quality influences the genesis and progression of depressive illnesses. These hypotheses remain to be tested . These hypotheses however remain largely untested .
The most consistent correlation found in one study that involved the ecological analysis of schizophrenia and diet concluded that increased consumption of refined sugar results in a lack of substantial improvement in patients with schizophrenia, as measured by both the number of days spent in the hospital and poor social functioning . In the study performed there was a very strong association with consumption of sugar and increased mean hospital time and worsening of social functioning based upon two calculative scores with a Pearson coefficient of 0.94 and 0.89 respectively. That study also concluded that the dietary predictors of the outcome of schizophrenia and prevalence of depression are similar to those that predict illnesses such as coronary heart disease and diabetes . There are preliminary data from RCTs suggesting that anti-inflammatory nutrients, such as omega–3 and folate-based compounds, may also be effective for other SMIs, including bipolar disorder and schizophrenia . Because inflammation is particularly elevated during onset of psychotic disorders, these adjunctive treatments may have neuroprotective effects in the early stages of illness among young people   potentially improving cognitive outcomes for some patients. However, the extent to which their effects are due specifically to their anti-inflammatory properties is not fully ascertained .
Mediterranean dietary patterns are comprised of: abundant plant foods (fruits, vegetables, breads, other forms of cereals, pulses, nuts and seeds); minimally processed, seasonally fresh and locally grown foods; fresh fruits as the typical daily dessert with sweets elaborated from nuts, olive oil and concentrated sugars or honey that are consumed during feast days; olive oil as the principal source of dietary lipids; dairy products (mainly cheese and yoghurt) consumed in low to moderate amounts; fewer than four eggs consumed per week; red meat consumed in low frequency and amounts; wine consumed in low to moderate amounts, and generally taken with meals. Such a dietary pattern assures a sufficient intake of certain nutrients that have been related in some way with a reduced risk of several chronic diseases. Various scores or indexes have been developed to assess the adherence to the Mediterranean diet pattern in the population and to link such patterns with several nutrient-related diseases .
A trial conducted in clinically depressed participants  observed large reductions in depressive symptoms from a 12-week modified Mediterranean diet with 32.3% of participants achieving remission from dietary intervention versus 8.0% in the social support control condition (p = 0.028) Subsequent RCTs have replicated these findings of the Mediterranean diet reducing symptoms in people with moderate to severe depression . As a meta-analysis of 50 studies has shown, the Mediterranean diet significantly reduces inflammatory markers in other (i.e., non-psychiatric) populations, and it is possible that the benefits in people with depression are linked to the anti-inflammatory effects.
Changing established dietary behaviors is challenging, and this is attributed to factors such an obesogenic environment  and the addictive nature of high-fat high-sugar foods .However, there is evidence that neural reward thresholds can be changed in favor of preferring healthy over unhealthy food .A Mediterranean diet not only has demonstrated health benefits but is also a highly palatable diet and thus more likely to become a sustainable part of a healthy lifestyle .
As seen above, the role of diet plays a crucial role contributing to changes in mental health. This is an aspect less addressed by researchers  and further not widely acknowledged by physicians. Thus, the aim of this study is to increase the data pool to answer the question whether dietary patterns have any effect on mental health, particularly the acute psychiatric inpatients. This study seeks to contribute to the growing school of thought that a holistic approach is required for psychiatric treatment, especially healthier diet control.
Study design and methodology:
The study was conducted on an acute inpatient psychiatric unit of an academic hospital. The study was approved by the institutional review board. 100 non-consecutive inpatients were approached by the researchers and after their verbal agreement the Eating Habits Questionnaire (Dana Fiber Institute)  was administered. The questionnaire was employed owing to its concise set of questions addressing major food groups and multiple options for recording frequency of consumption. The questionnaire also entailed some basic questions regarding demographic characteristics of the study population. Explanation was offered regarding the purpose of the study and confidentiality was ensured.
The KIDMED questionnaire was used to evaluate the adherence to a Mediterranean
diet in adolescents. It consists of 16 items, where there are 4 questions denoting a negative connotation to the Mediterranean diet (consumption of fast food, baked goods, sweets, and skipping breakfast) and 12 questions denoting a positive connotation (consumption of oil, fish, fruits, vegetables, cereals, nuts, pulses, pasta or rice, dairy products, and yoghurt). Questions denoting negative connotation are scored with −1, while positive connotation questions are scored with +1. According to the KIDMED index, a score of 0–3 reflects poor adherence to the Mediterranean diet, a score of 4–7 describes average adherence, and a score of 8–12 good adherence. However, the score was modified as “healthy” with a score of over 4 and “unhealthy” as 3 and under .
The study was conducted as a descriptive, cross sectional, correlational design, to examine the relationship between KIDMed score index (a measure of healthy dietary habits) and BMI, gender, level of education, smoking, income and exercise. The data was analyzed using SPSS. The Mediterranean diet index KIDMed was used to categorize all patients as having a healthy or an unhealthy score which corresponded to their dietary habits.