LOW LEVELS OF BLOOD LACTATE DEHYDROGENASE (LDH) appear to be significantly associated with depression and suicide attempts in adults with major depression. That’s the conclusion of a new study of 300 individuals conducted by Dr. Qian Yao and colleagues in China. Today we look at a potential blood test to assess the risk for suicide.
Recent research has focused on the relationship between energy metabolism and depression. Previous studies suggested that lactate dehydrogenase (LDH) blood levels may be a biomarker for Parkinson’s, Huntington’s, and post-stroke depression.
A link between lactate metabolism and depression remains unclear. Today we look at the new study suggesting serum LDH may be a reasonable indicator of suicide risk.
“When down her weedy trophies and herself
Fell in the weeping brook. Her clothes spread wide;
And, mermaid-like, while they bore her up:
Which time she chanted snatches of old tunes;
As one incapable of her distress,
Or like a creature native and indued
Unto that element: but long it could not be
Till that, her garments, heavy with their drink,
Pull’d the poor wretch from her melodious lay
To muddy death.
— Ophelia in Shakespeare’s Hamlet
Gertrude offers two visions of Ophelia singing as she sinks into the water — the first is of someone unaware of her life-threatening danger; it seems to convey Ophelia’s actual state. The young woman has gone mad and did nothing to try and escape her watery death.
The second image of Ophelia that Gertrude proposes is as if she were “a creature native and endued unto that element” — Ophelia as a water nymph or mermaid, who fits in so well with this scene that it’s as if she belonged there as if it were her home. Ophelia continues to float on the water’s surface for a brief moment — then her clothing becomes waterlogged and pulls her under.
“Ophelia no longer belongs anywhere among the living — her father is dead, and her lover has been brutally unkind to her — it’s not clear what her future would have been had her life not ended here.”
LDH blood test and suicide risk
The study authors hypothesized that serum LDH might be a biomarker for major depression, given LDH reflects a reduced energy metabolic status in depressed individuals.
In a study published in General Hospital Psychiatry, the researchers looked at differences in serum LDH in 232 patients with major depressive disorder (MDD) and 110 healthy controls. The average age across both groups was 33 years.
They also checked to see if LDH predicted suicide attempts in the depressed cohort. The researchers also assessed depression using the 24-item Hamilton Depression Scale (HAMD-24).
Results
The serum LDH level of the depression group was much lower than the control group (178 versus 197). The depression group members also had lower cholesterol levels but no differences in the cholesterol subtypes (LDL, HDL, and triglycerides).
Here is what the researchers discovered when they examined subgroups of depression:
Serum LDH in depressed individuals who had attempted suicide was significantly lower than those without suicide attempts (170 versus 181).
Note that the LDH levels for the non-suicidal depressed patients were also lower than controls (181 versus 197). There appeared to be no significant correlation between the HAMD-24 score and suicide attempts.
Gender, blood measurements, and suicide risk
While both male ad female depressed patients had lower LDH levels (compared with controls), a correlation between total cholesterol and LDL-cholesterol seemed to be potential suicide markers for only females.
My take: A blood test and suicide risk assessment
The study is quite limited, including its retrospective nature. The researchers did not look at changes in LDH isoenzymes in depressed patients. I wonder if spinal fluid levels of LDH correlate with suicide risk.
Overall, the results link LDH, early onset, and clinical prognosis of depressive symptoms. Someday, blood tests may guide clinical intervention, including identifying suicide risk for early intervention.
The researchers disclosed no financial conflicts. The National Natural Science Foundation of China supported the research.
The information I provided in this blog is for educational purposes only and does not substitute for professional medical advice. Please consult a medical professional or healthcare provider if you seek medical advice, diagnoses, or treatment. I am not liable for risks or issues associated with using or acting upon the information in this blog.
If You Know Someone in Crisis (USA)
Call or text the 988 Suicide & Crisis Lifeline at 988 (para ayuda en español, llame al 988). The Lifeline provides 24-hour, confidential support to anyone in suicidal crisis or emotional distress. Call 911 in life-threatening situations. If you are worried about a friend’s social media updates, you can contact the safety teams at the social media company. They will reach out to connect the person with the help they need.
The Veterans Crisis Line connects Service members and Veterans in crisis, as well as their family members and friends, with qualified Department of Veteran’s Affairs (VA) responders through a confidential toll-free hotline, online chat, or text messaging service. Dial 1–800–273–8255 and Press 1 to talk to someone or text 838255 to connect with a VA responder. You can also start a confidential online chat session at Veterans Crisis Chat.
Thank you for joining me in this look at a blood test for assessing an individual’s suicide risk.
