Depression and affective illness

SEED group 10th November, 2009

Outline

• Definitions

• Aetiology and burden

• Special populations

• Measurement– Gold standard interview schedules– Clinician interview schedules– Self-reported screening instruments

• Example from MCS

Definitions: DSM-IV• Adjustment Disorders • Anxiety Disorders • Dissociative Disorders • Eating Disorders • Impulse-Control Disorders • Mood Disorders

– Bipolar Disorder – Cyclothymic Disorder – Dysthymic Disorder – Major Depressive Disorder

• Sexual Disorders • Sleep Disorders • Psychotic Disorders • Sexual Dysfunctions • Somatoform Disorders • Substance Disorders • Personality Disorders • See also International Classification of Diseases, Injuries and causes of death (ICD-

10) and Research Diagnostic Criteria (RDC) for alternative classification systems

Source: DSM-IV

Definitions

• Depression is a syndrome

• Identification is based on report of symptoms

• DSM-IV defines on symptoms, not etiology

Definitions: Mood disorders• Persistent mood disorders – years, decades

– Dysthymia: persistent low mood, very distressing– Cyclothymia: cyclic fluctuation mild depression /

hypomania• Depression (unipolar) – disturbed sleep, low

mood (unchanged by setting), low energy, weight changes, lowered self-esteem & self-confidence, guilt, worthlessness, hopelessness, agitation– Mild: 2-3 sx, distressing but copes most situations– Moderate: 4+ sx, difficulty coping– Severe: nearly all sx, suicidal– With psychotic features: severe, + hallucinations

Sources: ICD-10, DSM-IV

Definitions: Mood disorders (2)

• Mania – Hypomania: mild euphoria, agitation, talkative,

irritability, lack of sleep– Mania: excitement, distraction, uninhibited,

risk taking– Mania with psychotic features: as mania +

grandiose delusions, hallucinations, non-communicative

• Bipolar – repeated episodes of depression and mania

Sources: ICD-10, DSM-IV

Prevalence and burden: Major depression

• 4-10% of people worldwide will have a major depressive episode in their lifetime

• Point prevalence in UK: 2.8% depressive episode, 11.4% mixed depression and anxiety (DSM-IV)

• Average, 1st episode mid-20’s, many experience 1st episode in adolescence. Often reactive, initial symptoms vary widely from somatic anxiety

• 50% people have a 2nd episode, risk of relapse after 2nd episode 70%, after 3rd 90%

Source: NICE guidance CG90

Prevalence and burden: Major depression (2)

• By 2020 will be the 2nd highest cause of disability-adjusted life years lost

• Dose-response on QoL and disability, severely impacts work

• 4 to 20 times risk of suicide, problems in family functioning, children

• Socio-economic factors associated with depression prevalence; unemployed, social class 4 or below, no formal educational qualifications, live in urban area, moved 3 times in last 2 years. Also gender; women more susceptible

Source: NICE guidance CG90

Aetiology: Major depression

• Huge amount of literature!• Combination of social, psychological, genetic factors

– Cause, correlate or consequence?

• Theory may be embedded in treatment e.g. medication, cognitive therapy, psychodynamic therapy

• Patient’s theory important as it rationalises treatment choice– e.g. medication will be useful to correct this biochemical

imbalance; CBT will be useful to help me stop seeing things in a depressive way; psychodynamic therapy will be useful to help me come to terms with what has happened to me in the past

– Reasons for Depression Questionnaire (RFD), 48 items for which strength of belief for cause is rated on 4-point Likert.

Sources: 1999. Mental Health: A Report of the Surgeon General. Leykin et al 2007: Cogn Ther Res. 31:437-449

Special populations

• Comorbidity – Panic disorder + depression in GP population, RR for suicidal

ideation (15.4, 7.0 to 34.2), depression alone (RR 5.3, 2.5 to 11.0) (Goodwin 2001)

– Anxiety– High levels in chronic medical illness

• Perinatal and postnatal women– PND ~ 10% (Cooper 1997, Reck 2008, Chaudron 2004)– Higher rates of relapse than general population (Nielsen Forman

2000)

• Past history of depression– Higher risk of having more episodes

Davis (2008) Curr Opin Psychiatry 21(1):14-8. Goodwin (2001) Depress Anxiety 14:244-246 Cooper (1997) Arch Dis Child 77(2): 97-9. Reck (2008) Acta Psychiatr Scand 118(6):459-68. Chaudron (2004) Pediatrics 113(3 Pt 1): 551-8. Nielsen Forman (2000) Bjog 107(10): 1210-7. Berkman (2000) Ch.9. 1999. Mental Health: A Report of the Surgeon General.

Special populations (2)

• Substance abusing populations (dual diagnosis)– 1/3 of patients presenting for depression have

concurrent substance abuse problem (Davis 2008)– Homeless highly at risk for substance abuse

• Ethnic minorities• Elderly

– US, prevalence 8 – 20% of older adults in the community, up to 37% GP population (Surgeon General 1999)

• Children

Screening for depression: individuals and populations

• Population screening– Brief, easily administered– Lower prevalence rates than GP and specialty care– Can’t confirm true positives

• Case-finding in GP population– SR of RCTs using routine screening instruments with results fed back to

GPs (or not) found little effect on depression recognition (6 studies, RR 1.0, 0.89 to 1.13, I2 23%, 0 to 69%)

– Why? Imprecise cut-off scores, lack of management education for GPs, extra work for minimal gain

• Case-finding in high-risk populations– Same SR found that feeding back positive scores to GPs for high-risk

patients improved depression recognition (3 studies, RR 2.66, 1.78 to 3.96, I2 0%, 0 to 73%)

– Little evidence for changes in treatment rates and improved outcomes

Source: Gilbody (2005) Cochrane CD002792.

Psychometric properties of depression scales

• Validity, does it measure what it is supposed to measure?– Self-administered depression scales may

measure affect well, but may also measure somatic features that are independent of depression (e.g. chronic fatigue, symptoms of CHD)

• Test-retest reliability– Difficult in depression; poor follow-up rates,

fluctuating course of illnessSource: McDowell (1996) Measuring Health: Ch 6. Oxford University Press.

Psychometric properties of depression scales (2)

• Cut-point– Highest specificity (true negatives) and sensitivity (true

positives), = threshold cut-point for classifying a case– E.g.

• ≥15 (case) <15 (non-case)• 14/15 (threshold is between these two numbers)

– Clearly does not allow for the continuum of depression, hence false-negatives and true-positives are likely

– Often find a different cut-points for slightly different populations when checked against a gold standard

• best to check literature (and do sensitivity around cut-points) before assigning a cut-point from a dataset where gold standard has not been used in a sub-sample to verify

Sources: McDowell (1996) Measuring Health: Ch 6. Oxford University Press.

Gold Standard interview schedules• Diagnostic tools, that is they exclude differential

diagnoses• Usually a lengthy structured interview

administered by a psychiatric professional. Clinical judgement may be required for some schedules. Expensive, burdensome and impractical for research unless testing the validity of a measure or confirming cases identified by a rapid screen.

• DSM-IV Structured clinical interview (SCID)– Clinical judgement required. 1 to 1.5 hours.

Sources: McDowell (1996) Measuring Health: Ch 6. Oxford University Press. Hewitt et al. Health Technol Assess. 2009 Jul;13(36)

Gold Standard interviews (2)• Present state examination (PSE)

– Based on ICD classification. Psychiatric Assessment Schedule (PAS) derived from it, uses the RDC classification. Clinical judgement required.

• Others– Schedule for Affective Disorders and Schizophrenia,

SADS [RDC]– Standardised Psychiatric Interview, SPI [RDC]– Diagnostic Interview Schedule, DIS [DSM] (no clinical

judgement)– Composite International Diagnostic Interview, CIDI

[ICD or DSM]– Mini International Neuropsychatric Interview, MINI

[DSM-IV or ICD-10]Sources: McDowell (1996) Measuring Health: Ch 6. Oxford University Press. Hewitt et al. Health Technol Assess. 2009 Jul;13(36)

Clinician interview schedules

• Designed to be administered by a clinician / observer but without clinical judgement. Usually brief and easy to administer. Primary use is case-finding and assessment of change in clinical practice.

• Raskin Depression rating scale (RDRS)• Montgomery –Asberg Depression Rating Scale

(MADRS)• Hamilton Depression Rating Scale (HDRS)

– Very widely used– NOT a screening instrument, but assesses severity of

depression in a diagnosed person– 17 or 31 items– Designed to be rated by two people

Source: Hewitt et al. Health Technol Assess. 2009 Jul;13(36)

Self-reported screening instruments• Most widely used of all instruments. They do not differentially

diagnose, that is exclude other reasons for depression. Some categorise into mild, moderate, severe depression, others do not. Regardless of reason for development, most have been used for all purposes; population screens, case-finding, research, assessment of change. Obvious problems with less literate populations.

• Beck Depression Inventory (BDI)– 7, 13 or 21 items.

• Carroll Rating Scale– 12 or 52 items. Self administered Hamilton Rating Scale. Screening and

severity of diagnosed depression.• Centre for Epidemiologic Studies Depression Scale (CES-D) ()

– Can also be administered in interview. 20 items. Noted to generate high false-positives.

• General Health Questionnaire (GHQ)– 12, 28 or 30 items

Sources: Andrews (2001) Aust N Z J Public Health 25: 494-7. McDowell (1996) Measuring Health: Ch 6. Oxford University Press. Hewitt (2009) Health Technol Assess Jul;13(36). Ware (?) SF-36 Health Survey Update. Kessler (2003) Archives of General Psychiatry. 60(2), 184-189

Self-reported screening instruments (2)

• Hospital Anxiety and Depression Scale (HADS)– 14 items. Anxiety and depression.

• Hopkins Symptom Check-List (HSCL)– 13 or 25 items

• Kessler Psychological Distress Scale (K6, K10)– 6 or 10 items. Screening, potential for clinical use. Claims to

discriminate cases of serious mental illness from non-cases. Not depression specific.

• Subscales and component scores of Mosby SF-xx– 4/8 subscales (Vitality, Social Functioning, Role Emotional, Mental

Health) cluster to form Mental Component dimension. Both Mental Health subscale and Mental Health Component have been used to screen for depression and assess change.

• Zung’s Self-rating Depression Scale (SDS or Z-SDS) ()– 20 items. Lower specificity and sensitivity than other measures.

Sources: Andrews (2001) Aust N Z J Public Health 25: 494-7. McDowell (1996) Measuring Health: Ch 6. Oxford University Press. Hewitt (2009) Health Technol Assess Jul;13(36). Ware (?) SF-36 Health Survey Update. Kessler (2003) Archives of General Psychiatry. 60(2), 184-189

Special populations: screening tools

• Comorbidity with medical illness– QOF, GPs screen for depression for patients with

CHD and diabetes

• Peri- and postnatal women– Edinburgh Post Natal Depression Scale (EPDS)– NICE guidelines 2+1 questions; Whooley et al. Not

validated!

• Ethnic minorities– Many instruments re-validated in other languages,

variously testing language, comprehension. Cut-points may differ with same measure in different language

McDowell (1996) Measuring Health: Ch 6. Oxford University Press.

Special populations: screening tools (2)• Elderly

– Self-reported: Geriatric Depression Scale (GDS) 4 or 15 items. Not reliable for individuals with cognitive impairment

• Dementia– Interviewer administered: Cornell Scale for

Depression in Dementia (CSDD) • Children

– 7-17 years: Self-administered Children’s Depression Inventory (CDI), modelled on Beck Depression Inventory . Also parent and teacher forms.

– Adolescents: Center for Epidemiologic Studies Depression Scale (CES-D), Reynolds Adolescent Depression Scale (RADS)

McDowell (1996) Measuring Health: Ch 6. Oxford University Press.

Example from MCS• Post-natal depression. LOSA used as a proxy

for EPDS due to space constraints (although EPDS does not contain such a question)– Interviewer administered– Sweeps 1, 2, 3 and 4 of natural mothers, asked

sweep 2-4 if there was a new baby since cohort baby– Since (cohort/last) baby born, ever been a time low

for 2 wks or more? Y/N • Doctor diagnosed depression. DEAN Has a

Dr ever told you that you suffer depression or serious anxiety? Y/N (If yes) TRDE are you currently being treated for this Y/N – Interviewer administered– Sweeps 1,2,3 and 4, asked 3-4 only if negative

previous response to DEAN

Example from MCS (2)

• SF-8. In past 4 weeks, SFEM how much bothered by emotional problems? Scale, and, SFEP how much did personal or emotional problems keep you from usual activities? Scale. Also forms Mental Component Scale with SFEN, how much energy did you have and SFPE, how much did physical/emotional problems limit social activities – Interviewer administered as part of entire SF-8 QoL – SFEM sweep 3 only, SFEP sweeps 3 and 4 only.

• Psychological distress. Kessler K6 self-administered (in last 30 days…) PHDE, PHHO, PHRF, PHEE, PHWO, PHNE Scale – Self-CAPI– Sweeps 2, 3 and 4, mother and partner

Count %

LOSASweep

1     

Refusal 0 0

Don't Know 11 0.1

Not applicable 53 0.3

Yes 6328 34.1

No 12160 65.5

Total 18552 100

    White Mixed Indian

Pakistani & Bangladeshi

Black or Black British

Other Ethnic

 

LOSA S1  

  Count % Count % Count % Count % Count % Count %

Yes 5354 34.5 74 38.7 159 33.5 394 31.3 240 35.5 94 27.2No 10154 65.5 117 61.3 315 66.5 866 68.7 437 64.5 251 72.8

Total 15508 100 191 100 474 100 1260 100 677 100 345 100

LOSA, sweep 1

High rate of PND across all ethnicities– true finding, recall bias, unvalidated question or ?

Sweep 1 Sweep 3Count % Count %

DEAN     

Refusal 0 0 7 0

Don't Know 2 0 4 0

Not applicable 23 0.1 ? ?

Yes TRDE 4552 24.5 5964 (cum) 39.1 (cum)No 13975 75.3 9271 60.8

Total 18552 100 15246 100

   

White 

Mixed 

Indian 

Pakistani and Bangladeshi

Black or Black British

Other Ethnic group

 DEAN S 1  

  Count % Count % Count % Count % Count % Count %

Yes 4161 26.8 45 23.6 52 10.9 172 13.6 79 11.6 36 10.4No 11375 73.2 146 76.4 427 89.1 1091 86.4 600 88.4 310 89.6

Total 15536 100 191 100 479 100 1263 100 679 100 346 100

DEAN (ever dx)

• High rate of ever dx• Lower rate of ever dx in EM (12% vs 27%)

Sweep 1 Sweep 3

Count % Count %

TRDE Yes 1668 36.6 1269 21.5

  No 2883 63.0 4625 78.5

  Total 4552 100 5894 100

White  Mixed Indian

Pakistani and Bangladeshi

Black or Black British

Other Ethnic group

TRDE S 1

Yes 1528 36.7 10 22.2 23 45.1 61 35.5 32 40.5 13 36.1No 2633 63.3 35 77.8 28 54.9 111 64.5 47 59.5 23 63.9

Total 4161 100 45 100 51 100 172 100 79 100 36 100

point prev

Yes 1528 9.8 10 5.2 23 4.8 61 4.8 32 4.7 13 3.8Total 15536 191 479 1263 679 346

TRDE (current tx)

•1/3 of ever dx are in current episode (all ethnicities)•Current tx rates ½ EM vs whites, related to lack of dx rather than poor treatment uptake

SF-8• Hmmmm.• 1st item should read (General Health)

– Overall, how would you rate your health during the past 4 weeks?1. Excellent2. Very good3. Good4. Fair5. Poor6. Very poor

• It reads: I would now like to ask about your health. How would you describe your health generally. Would you say it is...

1 ... excellent,2 very good,3 good,4 fair,5 or poor?

• Scoring algorithms are 16 not 15….

The following questions ask about how you have been feeling during the past 30 days. For each question, please circle the number that best describes how often you had this feeling.

Q1. During the past 30 days, All of Most of Some of A little of None of about how often did you feel … the time the time the time the time the time a. …nervous? 1 2 3 4 5 b. …hopeless? 1 2 3 4 5 c. …restless or fidgety? 1 2 3 4 5 d. …so depressed that nothing 1 2 3 4 5

could cheer you up? e. …that everything was an effort? 1 2 3 4 5 f. …worthless? 1 2 3 4 5

Kessler K6

© 2005 Harvard School of Medicine

Kessler K6 distribution, mothers, Sweep 3

Kessler K6, mothers, sweep 3• Using alternate 1-5 scoring scheme, cut-point on the K6 for ‘severe’ is 19+• What is cut-point for K6 in ethnic minority populations? … calibration apparently underway

(small numbers)

  N %

Below 19 699 5.1

19+ 13080 94.9

Total 13779 100

   White 

Mixed 

Indian 

Pakistani and Bangladeshi

Black or Black British

Other Ethnic group

 

Kessler K6

Sweep 3  

  Count % Count % Count % Count % Count %Coun

t %

Below 19 570 4.7 10 8.5 23 7.9 46 9.8 27 7.8 16 10.1

19+ 11642 95.3 108 91.5 268 92.1 424 90.2 319 92.2 143 89.9

Total 12212 100.0 118 100.0 291 100.0 470 100.0 346 100.0 159 100.0