PSYX 340 Psychological Disorders · Unit 2: Mood, suicide, body and addiction · on Exam 2
2.1 Depressive disorders
Study notes for Depressive disorders in PSYX 340 Psychological Disorders at Montana State University: the big ideas, a worked example, common mistakes and an exam tip. The same topic has endless practice questions and flashcards in Mathub.
Big ideas
- A major depressive episode needs 5 or more of 9 symptoms over the same 2 weeks, including depressed mood or loss of interest (anhedonia). The others are weight or appetite change, sleep change, psychomotor agitation or slowing, fatigue, worthlessness or guilt, poor concentration, and thoughts of death or suicide.
- Persistent depressive disorder (dysthymia) is depressed mood most days for at least 2 years (1 year in children and teens). Also in the chapter: premenstrual dysphoric disorder and disruptive mood dysregulation disorder in children.
- Biological explanations: genetic risk, low activity of serotonin and norepinephrine (the classic monoamine hypothesis, now seen as incomplete), cortisol and the HPA axis, and brain circuits including the prefrontal cortex, hippocampus and amygdala.
- Psychological explanations: Freud’s symbolic loss; Lewinsohn’s behavioral theory of fewer rewards; Beck’s cognitive triad (negative views of self, world and future) and errors in thinking; learned helplessness (Seligman) and the attribution version (internal, global, stable explanations for failures); rumination.
- Treatments: antidepressants (SSRIs such as fluoxetine; SNRIs; older tricyclics and MAO inhibitors), CBT and behavioral activation, interpersonal psychotherapy, ECT for severe or treatment-resistant cases, and newer options such as transcranial magnetic stimulation and ketamine-based treatment.
Worked example
For the past three weeks Chris has felt down nearly every day, lost interest in gaming and friends, slept 11 hours a day, gained weight and felt worthless. He can still concentrate and has no thoughts of death. Does this meet criteria for a major depressive episode?
Show the solution
Yes. Five symptoms are present for at least two weeks: depressed mood, anhedonia, sleep change (hypersomnia), appetite or weight change, and worthlessness. At least one of the five is depressed mood or anhedonia (he has both). Concentration and thoughts of death are not required.
Common mistakes
- Counting 2 weeks for persistent depressive disorder. It is 2 years (1 year in youth); major depression is 2 weeks.
- Forgetting that one of the five symptoms must be depressed mood or loss of interest.
- Treating the “chemical imbalance” as settled fact. The monoamine hypothesis is part of the story, not the whole of it.
- Saying ECT is outdated. It is still one of the most effective treatments for severe depression, now given under anesthesia.
Exam tipLearn the cognitive theories by author: Beck (triad and errors), Seligman (learned helplessness), Abramson (attributions), Nolen-Hoeksema (rumination). Matching names to theories is a common exam item.
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