Review Article - (2020) Volume 6, Issue 6
Adila Reddy* and Lokes Kumar Kalasapati
Department of Psychiatry, Bhaskar Medical College and Bhaskar General Hospital, Hyderabad, India
Received Date: November 11, 2020; Accepted Date: November 25, 2020; Published Date: December 02, 2020
Citation: Reddy A, Kumar KL (2020) Correlation between Levels of Serum Cholesterol and Depression in Parasuicide Patients. Clinical Psychiatry Vol.6 No. 6:76.
Background: Studies on the association of cholesterol levels with depression have yielded mixed results. Similarly, the association between suicidality and cholesterol is conflicted. The effect of statins on various mental health diseases is also widely debated.
Objective: To assess and establish a correlation between levels of cholesterol and depression in parasuicide patients.
Methods: Study Design: Cross-sectional.
Study period: June 2, 2016 to June 1, 2017.
Study area: Yenkapally, Telangana.
Sample size: 98.
Study population: Inpatients who have attempted suicide.
Exclusion criteria: Nutritional and metabolic disorders, schizophrenia, dementia, mental retardation, alcoholism, patients on antidiabetics, antidepressants or statins, etc. The exclusion criteria was extensive to exclude any cause known to influence cholesterol or depression levels.
Data collected: Demographic data, serum cholesterol level, and level of depression.
Data analysis: R Project statistical software and Social Science Statistics.
Results: The total serum cholesterol levels showed no variation in subjects from different sexes of similar age, nourishment, and built. They were consistent with the socio-economic status and the age of the individual. The level of depression among the subjects showed no discernable pattern with age, gender, and socioeconomic status. A graph plotted shows an overall picture that the total serum cholesterol and the level of depression are inversely proportional to each other. The statistical correlation established was significant (r=-0.3607, p=0.000272). Upon gender stratification the values were consistent: Female (r=-0.3452, p=0.005588), Male (r=-0.4487, p=0.010397).
Conclusion: The level of cholesterol is inversely proportional to the level of depression. This correlation has a significant impact on the clinical practice of psychiatry and the treatment of depression. It helps in the identification of individuals at high risk of developing depression.
Cholesterol; Suicide; Depression; HAM-D; Parasuicide
Suicide is defined as the intentional taking of one's own life [1]. Suicide is the third leading cause of death in 15-19-year-olds [2]. A prior suicide attempt is the single most important risk factor for suicide in the general population [2].
The association between mental disorders and suicide has been excessively documented [3-5]. The role of serotonin in mood disorders is also known [6,7]. Doctoral work of PHA Steegmans suggested that, a decrease in fatty acids, leads to a decrease in protein-bound fatty acids and protein-bound tryptophan, leading to a decrease in tryptophan hydroxylase activity which in turn leads to a fall in CNS serotonin levels, which leads to depression. [8] He further suggested that a fall in cholesterol level contributes to an increase in violent deaths, including suicide, which is also supported by other papers [8-10].
The role of cholesterol lowering drugs, statins in causing depression has been inconclusive. Some studies show that statins could lead to depression [11] and though statins are widely tolerated, in some participants, may increase the risk of serious psychiatric events and/or behavioral changes [12]. Other studies contradictorily suggest that statins be used as an adjunct drug in treatment for depression as they improve the patient’s mood [13] and lower the risk of depression [14].
The level of total serum cholesterol in patients suffering from depression has not been adequately studied. A study suggested that cholesterol levels were lower during manic and/or depressive episodes than in mixed episodes [15]. A 1998 study concluded that depressive patients showed a significant depletion in the total polyunsaturated fatty acids, particularly docosahexaenoic acid in the RBC cell membrane. Incubation of RBC from the control subjects abolished all significant differences between patients and controls [16].
Similarly, there are mixed results on association between cholesterol levels and risk of suicide. Some studies found that lower cholesterol levels were associated with increased risk of suicidal behavior [17,18] and other studies found evidence in the contrary [19,20].
In this study we aim to assess and establish a relationship between serum cholesterol level and the level of depression parasuicide patients. We also hope to assess the role of age, sex and socioeconomic status on the correlation.
A cross-sectional study was conducted at a tertiary care teaching hospital located in a rural area of Yenkapally, Hyderabad, Telangana. The study lasted from June 2, 2016 to June 1, 2017.
A total number of 121 inpatients of the hospital were chosen to take part in the study. Out of which, patients with co-morbidities, nutritional or mental disorders such as hypertension, diabetes mellitus, obesity, alcoholism, schizophrenia, dementia, mental retardation, drug dependency, and patients currently on any antidiabetic medication, antidepressants, statins, etc. were excluded. Attempt was made to exclude all causes that are known to influence the level of cholesterol and/or level of depression. The aim and procedure of the study was explained to the subjects prior to the start of the study and all questions were answered. Following which an informed consent was obtained from all participants. Some of the chosen participants did not consent to the procedure, bringing the study size to a total of 98 subjects. There were 65 female participants and 33 male participants. Ratio of female to male participants was of 2:1.
The subjects’ cholesterol levels were assessed in a sterile biochemical laboratory by using prepacked kits based on modified Roeschlau’s method. Blood sample needed for assessment was collected from the antecubital vein of arm by a trained medical professional following all aseptic precautions.
Level of depression in the subjects was evaluated using the Hamilton Rating Scale of Depression or ‘HAM-D', a gold standard scale to rate depression in clinical practice. A multiple item questionnaire was presented to every subject to assess their level of depressiveness. The answers were evaluated in accordance with the scale suggested:
0-7=Normal
8-13=Mild Depression
14-18=Moderate Depression
19-22= Severe Depression
>23=Very Severe Depression
The data obtained from the above tests was statistically evaluated using R Project software and Social Science Statistics. A correlation was established. It’s significance was assessed using Pearson's correlation and a p-value.
Table 1 shows that the total serum cholesterol levels assessed from the samples showed no variation in subjects from different genders of similar age, nourishment and built. They were consistent with the socio- economic status of the individual. A rise in the cholesterol level was seen with the rise in the patient age, which corresponds to existing data.
| Levels of cholesterol | Subjects |
|---|---|
| Low Cholesterol Level (≤150 mg/dL) | 81 subjects |
| High Cholesterol Level (≥150 mg/dL) | 17 subjects |
| Lowest recorded Cholesterol Level | 86 mg/dL |
| Highest recorded Cholesterol Level | 204 mg/dL |
| Mean | 130.01 mg/dL |
| Median | 124.5 mg/dL |
| Mode | 126 mg/dL |
Table 1: Observed cholesterol levels- cholesterol levels.
The Table 2 study sample showed a moderate level of depression.
| Levels of depression | Total |
|---|---|
| Lowest recorded HAM-D Score | 7 |
| Highest recorded HAM-D Score | 32 |
| Mean | 16.81 |
| Median | 16 |
| Mode | 14 |
Table 2: Observed depression levels-level of depression
No variation with age or gender was seen.
A graph (Figure 1) plotted using the obtained values, shows an inverse relationship between total serum cholesterol and level of depression.
Figure 1: Graph showing the inverse relationship between ‘Total Serum Cholesterol Level’ and ‘Level of Depression’.
Overall: Pearson’s correlation coefficient is -0.3607, showing a negative association. P value is 0.000272, significant.
Female: Pearson’s correlation coefficient is -0.3452, showing a negative association. P value is 0.005588, significant (Table 3).
| Phases (depending of level of depression) | |
|---|---|
| Phase I-7 to 10 | There is nominal increase in the level of total serum cholesterol from 140 mg/dL to 145 mg/dL with rising level of depression in females. |
| Phase II-10 to 26 | There is a constant fall in the blood cholesterol level from 145 mg/dL to 115 mg/dL over a significantly higher range. There is a small dip at the HAM-D score of 15. |
| Phase III-26 to 32 | With growing score of Hamilton scale of depression, there is a rise in total cholesterol from 115 mg/dL to 120 mg/dL. |
Table 3: Levels of depression female curve.
Male: Pearson’s correlation coefficient is -0.4487, showing a negative association. P value is 0.010397, significant (Table 4).
| Phases (depending of level of depression) | |
|---|---|
| Phase I-7 to 15 | There is an initial increase of cholesterol level from 100 mg/dL to 145 mg/dL with increasing levels of depression. |
| Phase II-15 to 18 | With rising depression levels, there is a dramatic fall of cholesterol from 145 mg/dL to 124 mg/dL. |
| Phase III-18 to 22 | With increasing level of depression, there is a slight increase in the cholesterol level from 124 mg/dL to 125 mg/dL. |
| Phase IV-22 to 27 | The last phase of the graph shows a constant fall from 125 mg/dL to 96 mg/dL in the cholesterol level with regards to increasing depression level. |
Table 4: Levels of depression male curve
Both genders showed a statistically significant correlation.
Female (r=-0.3452, p=0.005588), Male (r=-0.4487, p=0.010397), and Overall (r=-0.3607, p=0.000272) values are significant (n=98).
A small pilot study conducted by Ernst E, et al. showed mood changes suggestive of depression associated with the use of a fibrate-induced lowering of cholesterol concentration, which is in accordance with the results of the present study [21].
A Cleveland researcher found that unipolar depressed subjects, regardless of their subtype and relatives of the depressed subjects had significantly lower esterified cholesterol ratio than normal controls. The results of this study are similar to the current study [22]. It was hypothesized that lower esterification in serum cholesterol may constitute a vulnerability factor for depression through alterations in cell membrane micro viscosity. This may contribute to the pathophysiology leading to suicide [22].
Like our study, a meta-analysis found higher total cholesterol was associated with lower levels of depression. This association was found to be substantially larger among medication-free samples [23].
A study titled ‘Lipids, Depression and Suicide’ stated that clinical recovery from depression may be associated with a significant increase of total cholesterol. It further mentioned that decreased levels of cholesterol in plasma were observed in patients who have committed suicide when compared to others which was also found in the current study [24].
The present study is supported by a study published in The American Journal of Clinical Nutrition which postulated that adequate long-chain polyunsaturated fatty acids, particularly docosahexaenoic acid may reduce the development of depression [25].
Association between low cholesterol level and the presence of major depression in patients with panic disorder was found in a Turkish study with suggested a broader relation between cholesterol and other psychiatric illnesses [26].
A significant decrease in serum cholesterol in patients with Major Depressive Disorder was noted in both sexes and in all age groups which was similar to the current study [27].
When the blood cholesterol levels were compared between parasuicide and normal individuals, the study showed low cholesterol concentrations in the former which is in favor of the current study [28].
A Parisian study found that both low serum cholesterol concentration and declining cholesterol concentration were associated with increased risk of death from suicide in men. This differs from the current study which found no variation based on genders [29].
A study found that when risk factors such as alcohol intoxication and psychiatric histories were considered, there was little evidence remains to support the hypothesis that cholesterollowering drugs are associated with deaths due to homicides, suicides, and accidents. This is dissimilar to the results of our study [30].
In direct contrast to our study it was mentioned that in recent trials using statin treatment, there were slightly fewer deaths from accidents and suicide in the treated group compared with the placebo group [31].
Highlights
Lower cholesterol levels are associated with higher aggression, impulsivity and depression. Individuals with depression have higher chances of attempting suicide. Are individuals with low cholesterol more suspectable to depression?
Can cholesterol levels be used as an indicator to identify high risk individuals of committing suicide?
This study fails to compare data with urban population, which may show a similar or different picture.
A longitudinal study would shed better light on the long-term effect of cholesterol on the level of depression.
Data from other ethnicities was not taken. Hence, a comparison could not have been established.
Other psychiatric adverse drug reactions could not have been assessed adequately.
The study does not take different types of lipoproteins into consideration.
This study does not assess the effect of cholesterol modifying drugs on depression.
The conclusion of this study is that the level of cholesterol is inversely proportional to the level of depression. That is decrease in total serum cholesterol level causes an increase in the level of depression exhibited by the subject and vice versa.
Total serum cholesterol level 1/level of depression.
Therapy as the rate of attempting suicide in the year following an episode of deliberate self-harm is hundred times more than the population in general. It helps in determining if the patient is dangerous to himself or to people around him. It further works as a marker for suicidal depressiveness. Additionally, it helps in identifying suspected individuals with a family history of depression i.e. it acts as a prognostic test. Lastly, this goes a long way in understanding the biochemical mechanism leading to suicide.
The authors would like to thank our subjects for their participation in the research.
This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.
