It appears that SSRIs can actually "reboot" the brain and leads to increased neurogenesis/neuroplasticity in the hippocampus

The sample was made up of 42161 twins.  That is a pretty large sample size!  Male twins had a concordance rate of MZ 31% and DZ 11%, whereas women had a concordance rate of MZ 44% and DZ 16%.

The serotonin transporter protein (5-HTT/SLC6A4) transports the neurotransmitter serotonin from synapses to presynaptic neurons. A polymorphism of this gene was the focus of Caspi et al's study of depression.

Caspi found that those people who had two short alleles of the 5-HTT gene and had three or more stressful life events were more likely to develop MDD.  The study did not do personality testing.

Most research in genetics is correlational.  Ecological validity is not a concern as the studies are not done under highly controlled conditions and there is no manipulation of the environment by the researchers.  Twins studies do not necessarily represent the general population, so population validity is low.  There is little to no control over extraneous variables, so internal validity is low.

We cannot directly measure the level of serotonin in one's brain. All of our measures are indirect.  All of the other statements are true.

The cortisol hypothesis argues that an over-active stress response may be the cause of depression.

Cortisol leads to increased levels of MAO-A, an enzyme which breaks down serotonin.  It also affects the prefrontal cortex and the hippocampus, leading to impairment of decision-making and memory.  Finally, when cortisol levels are high in the evening, this disturbs circadian rhythms, making it difficult to fall asleep.

Personalization. This is Anna's inability to differentiate between feedback that is meant for those in the class that are not doing good work - and her own performance.  She internalizes the feedback from the teacher and feels that she has failed, even though she has positive feedback.

The study was a natural experiment.  The researchers used a pre-test/post-test design, but they did not manipulate any variables. The IV is the individual's thinking style, but it is naturally occurring.

The triad does not specifically identify personal relationships as one of the key negative filters.

Beck's original theory is based on hours and hours of documented clinical interviews with depressed patients.

Nolen-Hoeksema's Response Styles Theory argues that women ruminate more.  Nolen-Hoeksema has found that ruminators are more uncertain about solutions they come up with to their problems than non-ruminators.  This uncertainty may keep ruminators analyzing everything that happens to them or over-interpreting what others say.

Self-blame schema. A cognitive schema in which an individual attributes the occurrence of a negative event to oneself, even though there is no reason to do so. The direction of blame often has implications for individuals' emotions and behaviours during and following stressful situations.

Meany's research showed that neglect led to a lack of genetic expression of the GR gene which regulates the stress response.  This means that there is a higher level of cortisol over time which leads to hippocampal impairment.  This hippocampal impairment led to memory loss in rats - but we also know that it is linked to depression in humans.  The hippocampus also plays a role in emotional regulation.

The study only took a single measure from the participants at a single time.  There was no follow-up to this study to see if there was change over time.  Therefore, the study is cross-sectional. The study was correlational (not experimental) and the results showed a positive correlation between the number of ACEs and the likelihood of depression.

Kirmayer argued that there is a "symptom pool" that determines how individuals in different cultural groups develop their symptoms.  The theory is interesting in that it explains why, perhaps, Jewish women in Freud's Austria had difficulty moving their arms, whereas today this symptom is not linked to any major mental illness.  However, the way that this actually "works," is unclear.

A key problem with the research is that we are not sure whether people who are prone to depression spend more time on social media, or whether social media actually leads to depression. There are many correlational studies that show a link between depression and social media use - and this evidence is cross-cultural.  The studies are also representative of social media users and are naturalistic, so external validity is high.

There is no such thing as "lifetime incidence."  Incidence is defined as the number of new cases diagnosed in a certain period of time within a population.  Point prevalence is the proportion of a population that has a disorder at a specific point in time.  Lifetime prevalence is the proportion of the population who at some point in life has ever had the disorder.

Bolton used an emic approach to diagnosis - that is, he sought the advice of local healers to develop a method for diagnosing poor mental health.