The way depression is diagnosed and treated needs a major overhaul, say authors of a new review article in the scientific journal Brain, Behavior, and Immunity.
The way depression is diagnosed and treated needs a major overhaul, say authors of a new review article in the scientific journal Brain, Behavior, and Immunity.
This is because current treatment of depression is ineffective and lacks a plausible, coherent theoretical basis, they claim.
A new theory for depression and its treatment is proposed in the article “Depression subtyping based on evolutionary psychiatry: Proximate mechanisms and ultimate functions,” authored by Markus J. Rantala, from University of Turku in Finland; Severi Luoto, from the University of Auckland in New Zealand; Indrikis Krams from the University of Tartu in Estonia and University of Latvia; and Hasse Karlsson from the University of Turku.
“We argue that depression is not a single disease; it is a heterogeneous syndrome, with patients differing remarkably in symptom profile, pathophysiology and treatment responsiveness,” says Severi Luoto, a PhD candidate in evolutionary psychology at the University of Auckland.
The review article classifies depressive episodes into 12 subtypes based on evolutionary psychiatry.
The 12 subtypes are induced by:
- infection, in which sickness behaviour to combat pathogens and parasites may lead to symptoms such as loss of appetite, sleep disturbances, anhedonia, impaired concentration;
- long-term stress which is known to activate the immune system, causing an increase in proinflammatory cytokine levels that influence mood;
- loneliness;
- traumatic experience;
- hierarchy conflict where events such as unemployment, exclusion from a social group, bullying at school or professional hierarchy conflicts may trigger a depressive episode;
- grief;
- romantic rejection;
- postpartum events which lead to depression in 10-15% of women;
- the season, where Seasonal Affective Disorder (SAD) affects the individual at the same time each year;
- chemicals such as alcohol and cocaine;
- somatic diseases such as Alzheimer’s, Parkinson’s, migraine, epilepsy, stroke and traumatic brain injury; and
- starvation which is known to reduce mood and, when prolonged, can lead to apathy and social withdrawal.
