Download presentation
Presentation is loading. Please wait.
Published byHartanti Budiman Modified over 6 years ago
1
Mood Disorders Biological explanations Genetics
Neurochemical abnormalities
2
Mood Disorders – Genetic
Zubenko et al (2001) Family history – 50% of FD relatives, 25% of SD relatives also had mood disorder Relatives had increased risk of suicide & liver disease McGuffin et al (1996) MZ 46%, DZ 20% MZ concordances substantially inflated in more serious cases
3
Mood Disorders – Genetic
Depression tends to run in families The closer the relationship with a sufferer, the more likely a person will have a mood disorder Genetic evidence is strongest for most severe forms of the disorder Concordance rates also indicate a substantial environmental contribution
4
Mood Disorders - Neurochemical
Abnormality in neurochemicals Too much or too little of some chemicals e.g. serotonin affects the functioning of the brain – this might have an effect on emotion regulation
5
Mood Disorders - Neurochemical
6
Mood Disorders - Neurochemical
Noradrenanaline (NA) Too little leads to depression, too much to mania (catecholamine hypothesis) Serotonin (5-HT) Regulates NA activity, so too little allows abnormal fluctuations in NA (permissive amine hypothesis) Dopamine (DA) Involved in reinforcement, so too little results in anhedonia (dopamine hypothesis)
7
Mood Disorders - Neurochemical
Some evidence (but not all) suggests that mood disorder patients have abnormal levels of NA & 5-HT Might be sensitivity to neurotransmitters that matters, not raw levels in brain Interactions between neurotransmitters are poorly understood – likely to be complex Problems with direction of causality
8
Mood Disorders - Neurochemical
Drugs that alter brain levels of NA & 5-HT are effective in treating depression in about 60% of cases So what about the non-responsive patients? Relapse when drugs are discontinued? Treatment-aetiology fallacy?
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.