BDNF levels were highest when cannabis use disorder and schizophrenia co-occurred compared to either condition alone | Research

The takeaway

In a small study of 80 male subjects, those with both cannabis use disorder and schizophrenia had significantly higher serum BDNF levels than those with either condition alone or tobacco-only controls.

Psychiatry researchers studying biomarkers for dual diagnosis; neuroscientists investigating BDNF in substance use and psychosis.

Dual CUD + schizophrenia showed highest BDNF levels

What the researchers found

BDNF levels differed significantly across four groups of 20 subjects each. The dual-diagnosis group (CUD + schizophrenia) had higher BDNF than the CUD-only, schizophrenia-only, or tobacco-only groups. This suggests a synergistic effect of the two conditions on neurotrophin expression.

Why it matters

BDNF plays a key role in brain plasticity and has been explored as a biomarker for psychiatric conditions. The finding that co-occurring CUD and schizophrenia elevates BDNF beyond either condition alone raises questions about what this means for brain function and treatment response.

The numbers in context

80 male subjects in 4 groups of 20. BDNF significantly different across groups. CUD + schizophrenia group highest. Tobacco-only served as the reference group.

How the study worked

Cross-sectional observational study comparing serum BDNF in four groups of 20 male subjects (aged 18-45): tobacco use disorder only (control), schizophrenia alone, CUD alone, and CUD + schizophrenia.

What this study cannot tell us

Very small sample size (20 per group). Male subjects only. Cross-sectional design. Serum BDNF may not reflect brain BDNF levels. Multiple potential confounders including medication effects, substance use severity, and illness duration. Tobacco-only control group is imperfect.

How to read the evidence

Small exploratory study with appropriate group comparisons but very limited sample size and multiple potential confounders.

When this study was published

2024 study

The bigger picture

Elevated BDNF in dual-diagnosis patients could reflect compensatory neuroplasticity, altered cannabinoid-dopamine interactions, or a distinct neurobiological state that may require different treatment approaches than either condition alone.

Questions still open

Is elevated BDNF in dual diagnosis patients protective, compensatory, or pathological? Could BDNF serve as a biomarker to guide treatment in this population?

Common questions

What is BDNF?

Brain-derived neurotrophic factor is a protein that supports the growth, survival, and plasticity of brain cells. It is involved in learning, memory, and mood regulation, and its levels are altered in many psychiatric conditions.

Is higher BDNF good or bad?

Context matters. While BDNF generally supports brain health, abnormally elevated levels in specific conditions could indicate a compensatory response to ongoing brain stress or altered signaling that is not necessarily beneficial.

Read the original research

Serum brain-derived neurotrophic factor level and its relation with cannabis use disorder and schizophrenia: A cross-sectional exploratory study in patients at a tertiary care hospital.

Indian journal of pharmacology, 56(2), 91-96

View on PubMed ↗Publisher’s paper ↗

Citation

George, Aishwariya Brigit; Gupta, Abhishek; Jain, Raka; Sood, Mamta; Sarkar, Siddharth. (2024). Serum brain-derived neurotrophic factor level and its relation with cannabis use disorder and schizophrenia: A cross-sectional exploratory study in patients at a tertiary care hospital.. Indian journal of pharmacology, 56(2), 91-96. https://doi.org/10.4103/ijp.ijp_771_22