Unipolar Depression

Assessing the presence of shared genetic architecture between Alzheimer’s disease and major depressive disorder using genome-wide association data

“…AD PRS were tested for association with early-onset and late-onset MDD, where early- and late-onset were defined firstly by using the first and last quartiles of AOO, and secondly using subsets of MDD cases experiencing their first depressive episode before or after the age of 40 years. While not ideal for isolating ‘late-onset' cases, this age threshold has previously been used, 50, 51 and is certainly above the typical onset age for depression. 49 In this instance, it also maximized the number of late-onset cases; using a later cutoff, for example, over 60 years, while more likely to reflect true late-onset depression, reduced the number of late-onset cases (GS:SFHS N =22, UKB N =132) below that required for adequately powered analysis.…”

Epidemiology and Heritability of Major Depressive Disorder, Stratified by Age of Onset, Sex, and Illness Course in Generation Scotland: Scottish Family Health Study (GS:SFHS)

“…To estimate the genetic and shared environment correlations between age-of-onset (AOO) of MDD in our sample, we classified participants by status and AOO into 'absent', 'earlier onset', and 'later onset' with age 40 as the cut-off between earlier and later AOO. We used age 40 as the cut-off on the basis of initial definitions of onset subtypes [ 36 – 38 ] and because it helped maximize the sample size of the two age of onset subgroups. We could not use a later age of onset, for example of 60 years old, because our sample size of MDD cases at that threshold was not sufficient to have a well-powered analysis (n AOO ≥ 60 = 24).…”

Acute phase cognitive therapy for recurrent major depressive disorder: Who drops out and how much do patient skills influence response?

“…In addition, the evaluator assessed current and lifetime DSM-IV comorbid diagnoses, current diagnosis of double depression (major depressive disorder with dysthymia), DSM-IV melancholia, Research Diagnostic Criteria (RDC; Spitzer, Endicott, & Robins, 1978) for endogenous definite subtype, primary versus secondary depression diagnosis, and family history (Winkour, 1979; Winkour, Behar, van Valkenberg, & Lowry, 1978). In these analyses, family history was coded positive when the patient reported that a family member suffered from significant symptoms of a mood disorder, alcohol or drug abuse, or sociopathy.…”