About this Research Topic
As long recognized, depression and addiction are common chronic, relapsing psychiatric disorders with high co-morbidity.
For a long-lasting drug abuser, abstinence arouses a negative emotional state in the seeker.
Conversely, a depressive individual is more likely to seek for euphoric effects promoted by the psychoactive substances’ consumption and is more likely to be prone to addiction risk. Given that both psychiatric diseases implicate maladaptive responses to stress, they might share a common neural circuitry and similar molecular mechanisms may occur in the brain.
Accumulating evidence has shown that Lateral Habenula (LHb) regulates dopamine and serotonin systems and has reciprocal projections with the Ventral Tegmental Area (VTA). VTA is well known as the initial target of most addictive drugs, suggesting its significant role in encoding rewarding and aversive behaviors.
Earlier research reported that inhibition of translocation of the serotonin transporter resulted in resilience to stress-induced, depression-like, and drug-seeking behaviors. A myriad of studies reported opioid receptors play a significant role in motivational processes that relate to reward and mood regulation, thus might be a potential molecular target linking depression and addiction. In addition, drug abuse might cause permanent epigenetic modifications which might implicate an increased vulnerability to depression.
In conclusion, depression and addiction as two major psychiatric diseases seem to have common physiopathological mechanisms at the neural circuitry level, common molecular targets, and epigenetic basis.
Investigating the distinct and shared mechanisms will contribute to deepening our understanding of the comorbidity and seeking implications. This might help for dual diagnosis treatment of depression and addiction.
This Research Topic aims to collect the latest research advances in preclinical and clinical investigations focusing on the neurophysiology and pathological mechanisms underlying depression and addiction circuits. We welcome authors to submit their works with an eye of regards to the investigation of the neural circuitry, molecular and cellular mechanisms, epigenetic regulation, and therapeutic advances in depression and addiction.
Keywords: Depression, Addiction, Behavior, Neural plasticity, Neural Circuits
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