The impact of cholesterol lowering on patients' mood

The pharmacological bases for repurposing statins in depression: a review of mechanistic studies

Statins are commonly prescribed medications widely investigated for their potential actions on the brain and mental health. Pre-clinical and clinical evidence suggests that statins may play a role in the treatment of depressive disorders, but only the latter has been systematically assessed. Thus, the physiopathological mechanisms underlying statins' putative antidepressant or depressogenic effects have not been established. This review aims to gather available evidence from mechanistic studies to strengthen the pharmacological basis for repurposing statins in depression. We used a broad, well-validated search strategy over three major databases (Pubmed/MEDLINE, Embase, PsychINFO) to retrieve any mechanistic study investigating statins' effects on depression. The systematic search yielded 8068 records, which were narrowed down to 77 relevant papers. The selected studies (some dealing with more than one bodily system) described several neuropsychopharmacological (44 studies), endocrine-metabolic (17 studies), cardiovascular (6 studies) and immunological (15 studies) mechanisms potentially contributing to the effects of statins on mood. Numerous articles highlighted the beneficial effect of statins on depression, particularly through positive actions on serotonergic neurotransmission, neurogenesis and neuroplasticity, hypothalamic-pituitary axis regulation and modulation of inflammation. The role of other mechanisms, especially the association between statins, lipid metabolism and worsening of depressive symptoms, appears more controversial. Overall, most mechanistic evidence supports an antidepressant activity for statins, likely mediated by a variety of intertwined processes involving several bodily systems. Further research in this area can benefit from measuring relevant biomarkers to inform the selection of patients most likely to respond to statins' antidepressant effects while also improving our understanding of the physiopathological basis of depression.

Magnesium intake was inversely associated with hostility among American young adults

Hostility is a complex personality trait associated with many cardiovascular risk factor phenotypes. Although magnesium intake has been related to mood and cardio-metabolic disease, its relation with hostility remains unclear. We hypothesize that high total magnesium intake is associated with lower levels of hostility because of its putative antidepressant mechanisms. To test the hypothesis, we prospectively analyzed data in 4,716 young adults aged 18-30 years at baseline (1985-1986) from four U.S. cities over five years of follow-up using data from the Coronary Artery Risk Development in Young Adults (CARDIA) study. Magnesium intake was estimated from a dietary history questionnaire plus supplements at baseline. Levels of hostility were assessed using the Cook-Medley scale at baseline and year 5 (1990-1991). Generalized estimating equations were applied to estimate the association of magnesium intake with hostility as repeated measures at the two time-points (baseline and year 5). General linear model was used to determine the association between magnesium intake and change in hostility over 5 years. After adjustment for socio-demographic and major lifestyle factors, a significant inverse association was observed between magnesium intake and hostility level over 5 years of follow-up. Beta coefficients (95% CI) across higher quintiles of magnesium intake were 0 (reference), -1.28 (-1.92, -0.65), -1.45 (-2.09, -0.81), -1.41 (-2.08, -0.75) and -2.16 (-2.85, -1.47), respectively (Plinear-trend<.01). The inverse association was independent of socio-demographic and major lifestyle factors, supplement use, and depression status at year 5. This prospective study provides evidence that in young adults, high magnesium intake was inversely associated with hostility level independent of socio-demographic and major lifestyle factors.

Relationship between DRD4 polymorphism and lipid metabolism: what is the role of novelty seeking?

OBJECTIVE

This study examined the association of the dopamine receptor D4 (DRD4) gene polymorphism with the temperament dimension of novelty seeking (NS) on cardiovascular heart disease risk factors [the levels of high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, and triglycerides].

METHOD

From the ongoing population-based study of 'Cardiovascular Risk in Young Finns', 125 participants were DRD4 genotyped in 1997 and responded to the NS scale of the Temperament and Character Inventory in 2001. Their cholesterol and triglyceride concentrations were assessed in 2001.

RESULTS

Having a 2- or 5-allele DRD4 polymorphism was related to high HDL cholesterol levels in men, but to low HDL cholesterol levels in women. NS was related to triglycerides in men and to LDL in women, but this was mediated by behavioral, age, and weight factors, and NS was not the underlying factor for the association between the polymorphism and lipids.

CONCLUSION

Our preliminary findings suggest that there is a link between the dopaminergic receptor gene DRD4 and lipid metabolism, but this link is dependent on gender.

Does the level of LDL cholesterol moderate a relationship between DRD4 and novelty seeking?

This study examined the role of low density lipoprotein (LDL) cholesterol level in the association between Dopamine D4 receptor (DRD4) polymorphism and temperament dimension novelty seeking. From the on-going population based study of "Cardiovascular Risk in Young Finns", 78 men and women responded to the novelty seeking scale of the temperament and character inventory [Archives of General Psychiatry 44 (1987) 573] and were apolipoprotein E (apoE) and DRD4 genotyped. DRD4 polymorphism was related to disorderliness, a component of novelty seeking, in subjects with high LDL cholesterol level but not in subjects with low LDL cholesterol level. This finding did not change after adjustment for apoE polymorphism. Our findings suggest that the genetic determination of temperament may be dependent on biological factors, such as LDL cholesterol.

The combined effects of apolipoprotein E polymorphism and low-density lipoprotein cholesterol on cognitive performance in young adults

This study examined the relations of apolipoprotein E (ApoE) genotype and the low-density lipoprotein (LDL) cholesterol level to cognitive performance of 57 randomly selected healthy young adults. From the ongoing population-based study of Cardiovascular Risk in Young Finns, 25 men and 32 women were ApoE genotyped and participated in mental arithmetic and reaction time tasks. In contrast to findings obtained from studies with elderly subjects, ApoE4 polymorphism was associated with better cognitive performance. In addition, LDL cholesterol moderated this association. In the ApoE4 genotype group, low LDL cholesterol was associated with good performance in the mental arithmetic test, whereas for those without ApoE4 genotype, low LDL cholesterol was associated with poor performance. Performance in the reaction time task did not differ between the ApoE groups. In conclusion, assessment of the influence of ApoE on cognitive performance may require taking additional physiological factors, such as the level of cholesterol, into account.

Illness representation and change in dietary habits in hypercholesterolemic patients

The association between a patient's illness representation and long-term changes in treatment adherence still needs to be clarified.

AIM

to evaluate the association between the representation of hypercholesterolemia and dietary modifications over 1-year, controlling for biopsychosocial factors.

METHODS

208 hypercholesterolemic Caucasian patients. Measures of dietary intake, illness representation, and biopsychosocial factors were collected at baseline, 3, 6, and 12 months.

RESULTS

Two multiple regressions were performed on the 1-year change in dietary habits; one with subjects with elevated fat consumption at baseline, another with individuals with low-moderate fat consumption. Higher scores on items reflecting an accurate illness representation at baseline were associated with greater dietary modification among patients of the first group. For patients with low-moderate total fat consumption, maintenance of dietary habits was associated to lower scores on the perception of stress and symptoms.

CONCLUSION

To optimize adherence, intervention on illness representation should be adjusted according to initial dietary habits.