One shouldn’t complicate things for the pleasure of complicating, but one should also never simplify or pretend to be sure of such simplicity where there is none. If things were simple, word would have gotten around. - Jacques Derrida
Depression assessment scales come in two basic forms - interviewer/clinician rated and sufferer/patient rated. As stated in the background information on the IDS/QIDS questionnaires (see below) "There are several accepted clinician rated and patient self report measures of depressive symptoms. The most commonly used clinician rated scales are the 17, 21, 24, 28, and 31 item versions of the Hamilton Rating Scale for Depression (HRSD) (Hamilton 1960, 1967), and the 10-item Montgomery-Asberg Scale (Montgomery and Asberg 1979). The most frequently used self-reports include the 13, and 21 item version of the Beck Depression Inventory (BDI) (Beck et al. 1961), the BDI-II (Beck et al. 1996), the Zung Depression Rating Scale (Zung 1965), the Carroll Rating Scale (CRS) (Carroll et al. 1981), and the Patient Health Questionnaire - 9 (PHQ-9) (Kroenke et al. 2001)." There are problems with many of the older scales - either because the scales themselves are flawed - like the Hamilton - or because they are expensive - like the Hospital Anxiety and Depression Scale (HADS) and the Beck Depression Inventory - or both. Happily there are several good, free, quick scales currently available to choose from. Unfortunately different scales may not agree as much as one would want on, for example, the severity of someone's depression. Good clinical judgement is also required.
Combined PHQ-9, GAD-7 & phobia measures - the UK Increasing Access to Psychological Therapies (IAPT) initiative recommends routine use of a combination of questionnaires, the PHQ-9 for depression, GAD-7 for anxiety, and three IAPT phobia scales (social, agoraphobia, and specific phobia). Here is a downloadable version of this combined measure. Click for a 7 page PDF giving more background information about the PHQ-9 and GAD-7, including helpful scoring information. If one only wants to measure depression, or if one is using a specific anxiety measure (e.g. the SPIN, IES-R, etc) and so don't need the more general GAD-7, here is the PHQ-9 downloadable on its own as a Word doc and as a PDF file.
Two Question Screening for Depresson - this is a two question primary care screen - with a possible further four questions for to clarify likely diagnosis further.
Inventory of Depressive Symptomatology (IDS) and Quick Inventory of Depressive Symptomatology (QIDS) - the IDS is a 30 item scale while the QIDS contains 16 items. Both are available in both clinician-rated and patient-rated forms (e.g. QIDS-SR16 & background) . They are also available in, at least, a couple of dozen languages. These are very well researched and widely used scales - for example in the huge US STAR*D research studies.
Clinically Useful Depression Outcome Scale (CUDOS) - this is an 18 item patient rated scale. In some ways it is easier/quicker to score than the QIDS (but less researched & less widely used). The CUDOS also contains questions on function & life quality. It is free to use in its paper version or can be linked to a subscription when patients can score it via the internet and the clinician can access these scores - with a chart showing change in scores across time, and a linked patient appointment reminder system. The website provides scoring information and the related Clinically Useful Anxiety Outcome Scale (CUXOS).
Depression Happiness Scale, full 25 item scale (DHS) & shortened 6 item scale (SDHS) - these scales - both long and short forms -are of particular interest in allowing assessment of movement into happiness & wellbeing (as well as monitoring of depression).
Geriatric Depression Scale, full 15 item scale & shortened 5 item scale - a number of research studies have documented the value of these simple questionnaires - both the fuller version & the shorter version - for detecting and monitoring depression in the elderly.
Mood Disorder Questionnaire (MDQ) - a good screening scale for detecting bipolar spectrum disorders (mania & hypomania) that can improve patient care in primary care, psychiatric service and possibly too general community settings. I sometimes use an unvalidated weekly adaptation to monitor progress.
Dysfunctional Thoughts Record - here's a classic thought monitoring record. The success of simple behavioural activation in comparative trials with the fuller cognitive behavioural package means that I now rarely use this type of record sheet. This is further reinforced by the way mindfulness based cognitive therapy and ACT teach taking a different stance to the process of thinking itself rather than disputing the content of thought.
Rumination Record - here's a simple 4 question rumination scale assessing frequency, interference caused, sense of uncontrollability, and associated distress. Rumination is a major problem in depression, so it can be helpful to target it.
Intrusive Memories Record - distressing memories may be clinically important in the onset/maintenance of depression - see for example encouraging initial research - so appropriate methods of tracking such memories make good sense.
Self-Discrepancies Questionnaire - mismatches between "actual self" and "ideal self" judgements are associated with increased depression risk. There has been considerable research in this area and it can suggest possible therapeutic intervention targets.
Depressive Beliefs Questionnaire - a "home grown" questionnaire to highlight beliefs that might be used, for example, as targets for behavioural experiments.