Dietary Restrictions and Depressive Symptoms: Longitudinal Results from the Constances Cohort

Bidirectional associations between dietary diversity and depressive symptoms in Chinese adult women: A retrospective cohort study

OBJECTIVE

This study aimed to examine the bidirectional associations between dietary diversity and clinical depressive symptoms in adult women, and influencing factors of clinical depressive symptoms.

METHODS

This longitudinal study included a total of 22,385 participants, each of whom underwent at least two data collections. We used convenience sampling to recruit women from a health management center of a general hospital in southern China from April 2015 to December 2021. They completed an online self-reported health questionnaire, which included demographic characteristics, lifestyle information, the Dietary Diversity Scale (DDS), and the Patient Health Questionnaire-9.

RESULTS

New-onset depressive symptoms and low dietary diversity were observed in this study among 1285 and 3223 participants, respectively. Negative associations were observed between baseline low dietary diversity and new-onset depressive symptoms (P < 0.05) and between baseline depressive symptoms and low dietary diversity (P < 0.001). Cross-lagged panel analysis indicated that dietary diversity negatively and prospectively predicted depressive symptoms, but vice versa (P < 0.05). Strong evidence of a nonlinear association between DDS scores and incident depressive symptoms was found (P nonlinear < 0.05) regardless of whether the variables were adjusted. Besides, age, menarche age, physical activity, sleep duration, longer sedentary behavior and other lifestyle factors were influencing factors of depressive symptoms (P < 0.05).

CONCLUSIONS

The present study identified bidirectional associations between dietary diversity and depressive symptoms, and the associations were found to have a non-linear pattern. Adherence to dietary diversity and a healthy lifestyle could be effective non-pharmacological preventive measures to reduce the incidence of depressive symptoms.

Metabolic syndrome and risk of death in older adults with major psychiatric disorders: Results from a 5-year prospective multicenter study

OBJECTIVES

No study has explored the association of individual components of metabolic syndrome with mortality in older patients with psychiatric disorders. In this report, we examined whether metabolic syndrome or any of its components predicted mortality in a cohort of older adults with psychiatric disorders.

METHODS

We used data from a multicenter 5-year prospective cohort, including 634 in- and out-patients with schizophrenia, bipolar or major depressive disorder. Metabolic syndrome was assessed at baseline following NCEP-ATPIII criteria. Cause of death was categorized as cardiovascular disorder (CVD) mortality, non-CVD disease-related mortality (e.g., infections), suicide and accident.

RESULTS

122 participants (44.0%) were diagnosed with metabolic syndrome at baseline. In the full sample, there was no significant association between metabolic syndrome or any of its components with all-cause, CVD and non-CVD mortality. However, for the subpopulation of older adults with major depressive disorder, metabolic syndrome was significantly associated with increased all-cause and disease-related mortality after adjustment for age, sex and smoking status (p = 0.032 and p = 0.036, respectively). There was a significant interaction between metabolic syndrome and psychiatric diagnoses indicating that in participants with major depressive disorder, metabolic syndrome had a significantly greater effect on all-cause mortality (p = 0.025) and on disease-related mortality (p = 0.008) than in participants with either bipolar disorder or schizophrenia.

CONCLUSIONS

Our findings do not support an association between metabolic syndrome and increased mortality in older patients with major psychiatric disorders. Several explanations are discussed, including a survival bias, a lack of sensitivity of the used cut-offs and a ceiling effect of metabolic syndrome on mortality in this very high-risk population. The latter hypothesis could also explain the significant association between metabolic syndrome and mortality in the depressive subgroup, where a ceiling effect is yet to be reached, given the less marked premature mortality in depressive patients compared to those with bipolar disorder or schizophrenia.

A high fat western diet attenuates phasic dopamine release

Natural rewards, such as food and social interaction, as well as drugs of abuse elicit increased mesolimbic dopamine release in the nucleus accumbens (NAc). Drugs of abuse, however, increase NAc dopamine release to a greater extent and are known to induce lasting changes on the functioning of the mesolimbic dopamine pathway. Less is known about the long-term effects of diet composition on this reward pathway. In the present study, two diets were compared: a higher-fat diet (Western Diet: WD) and a control diet (standard lab chow) on their effect on the mesolimbic dopamine system. Twenty male C57BL/6 J mice were placed on one of these diets at 7 weeks old. After twelve weeks on the diet, in vivo fixed potential amperometry was used to measure real-time stimulation-evoked dopamine release in the NAc of anesthetized mice before and after an i.p. injection of the dopamine transporter (DAT) inhibitor nomifensine. Results indicated that diet altered mesolimbic dopamine functioning. Mice that consumed the WD demonstrated a hypodopaminergic profile, specifically reduced baseline dopamine release and an attenuated dopaminergic response to DAT inhibition compared to the control diet group. Thus, diet may play a role in mediating dopamine-related behavior, disorders associated with dopamine dysfunction, and pharmacological treatments aimed at altering dopamine transmission.