This is a map of repetition among all symptoms in the DSM-5.
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These findings are from a descriptive study published in Psychological Medicine which mapped the repetition among the 1419 symptoms described in 202 diagnoses of adult psychopathology in section II of the DSM-5. 2/10 cambridge.org/core/journals/…
The first stage of coding aimed to distil the constituent symptoms of the diagnoses in chapters 1–19 of section II of the DSM-5. The resulting list of symptoms was then coded for content overlap using both qualitative content coding and natural language processing. 3/10
In total, 202 diagnoses were represented, including 135 primary disorders and 76 specifiers or other specified disorders with additional symptoms. While repetition appeared to be pervasive, the majority (63.2%) of the 628 distinct symptoms were unique to a single diagnosis. 4/10
Overall, of the 202 diagnoses represented, 140 (69.3%) had at least one symptom that repeated in another diagnosis – 118 (58.4%) in a diagnosis in another chapter. 5/10
A noteworthy finding was that the symptoms in the DSM-5 that repeat most frequently, and that repeat across most chapters, are dominated by symptoms of major depressive disorder (MDD). 6/10
Specifically, 10 of the top 15 most non-specific symptoms in the DSM-5 appeared in the diagnostic criteria for MDD. 7/10
Perhaps MDD symptoms are psychological responses to stress, similar to how fever – a symptom that also cuts across numerous diagnostic categories – reflects an inflammatory response to cell damage or stress. 8/10
The pervasiveness of MDD symptoms throughout the DSM-5 likely hampers diagnostic accuracy through misattribution of symptoms in other diagnoses to MDD, and inflation of the rates of comorbidity due to symptom overlap with other diagnoses. 9/10
Ultimately, more empirical work on fine-grained clinical phenomena promises to improve on the reliability and validity of the DSM-5 constructs that frame much research and practice. 10/10
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Screen time is associated with depressive symptoms - likely mediated by shorter sleep & worse white matter organization.
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These findings are from a study in @JAMAPsych which aimed to identify the association between screen time during late childhood and depressive symptoms in early adolescence. 2/8 jamanetwork.com/journals/jamap…
During adolescence, major sleep-circadian changes contribute to a delayed sleep phase; this makes adolescents vulnerable to external influences, such as screen time, which can result in insufficient sleep and poor sleep quality. 3/8
Depression may be contagious through a dysfunctional mirror neuron system.
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This discussion is from a review article in @ElsevierConnect which describes the theory of ‘contagious depression’, whereby depression can be induced or triggered by our social environment. 2/11 sciencedirect.com/science/articl…
Emotions can spread like an infectious disease across social networks in a phenomenon called emotional contagion, which can be defined as a tendency to acquire affective states from our social contacts. 3/11
Light can travel through the head, guided by cerebrospinal fluid & tissue geometry.
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These findings are from a study in @spietweets which explored the physical limits of photon transport in the head in the extreme case wherein the source and detector were diametrically opposite. 2/10 spiedigitallibrary.org/journals/neuro…
Optical modalities for noninvasive imaging of the human brain hold promise to fill the technology gap between cheap and portable devices such as electroencephalography (EEG) and expensive high-resolution instruments such as functional magnetic resonance imaging (fMRI). 3/10
These findings are from a study in @PhysRevE which employs cavity quantum electrodynamics to explore entangled biphoton generation through cascade emission as a potential source for the synchronized activity of neurons. 2/13 journals.aps.org/pre/abstract/1…
Quantum entanglement is the phenomenon of a group of particles being generated, interacting, or sharing spatial proximity in such a way that the quantum state of each particle of the group cannot be described independently of the state of the others. 3/13
These findings are from a paper in @scisignal which describes how sleep deprivation increases resting energy expenditure, leading to the development of a negative energy balance in highly active cells like neurons. 2/8 science.org/doi/10.1126/sc…
Sleep loss dysregulates cellular metabolism and energy homeostasis. 3/8
A history of heavy cannabis use is associated with lower brain activation during a working memory task.
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These findings are from a study in @JAMANetworkOpen which examined the association of lifetime history of heavy cannabis use and recent cannabis use with brain activation across a range of brain functions in a large sample of young adults in the US. 2/9 jamanetwork.com/journals/jaman…
Given the cognitive effects of cannabis and the disruption of the endogenous cannabinoid system by tetrahydrocannabinol (THC), it may be that brain regions with high cannabinoid 1 (CB1) receptor density might be altered by cannabis. 3/9