Reply (Per Bech)
Per Bech’s reply to Donald Klein’s response to his and Martin Katz’s reply to Klein’s comment on his Clinical Psychometrics
Two very important issues are raised by Donald F Klein in our dialogue based on my Clinical Psychometrics, namely the recognition of sub-syndromes in major depression and the dimension of severity on which the clinical effect is measured in trials of antidepressants.
The research question concerning sub-syndromes is: “On what basis may the experienced psychiatrist say that this person has a type of depressive illness for which a specific treatment is needed?” The research question about the measurement of clinical effect is: “Which symptoms may the experienced psychiatrist assemble when making a global assessment of depression severity?”
We have previously answered the second question (Bech, Gram et al. 1975) and identified the following Hamilton items used by experienced psychiatrists: Depressed mood, work and interest, general somatics (fatigability), psychic anxiety, guilt feelings, and psychomotor retardation (HAM-D6). Using Rasch analysis we showed that this rank order was maintained from week to week in trials of antidepressants (Bech, Allerup et al. 1984, Licht, Qvitzau et al. 2005, Bech, Allerup et al. 2014).
In our re-analysis of the STAR*D study we showed that the remission rate for Level 1 on citalopram with the HAM-D6 was 45% (HAM-D6 < 4) versus 36% on the HAM-D17(HAM-D17< 7) P < 0.01 [Ostergaard, Bech et al. 2014]. On Level 2 in the STAR*D study, using HAM-D6 but not using HAM-D17, we showed that bupropion was significantly superior to buspirone as citalopram augmentation in non-responders from Level 1 (Bech, Fava et al. 2011). When demonstrating dose-response relationship of antidepressants we found HAM-D6 superior to HAM-D17(Bech 2010).
Concerning the other research question on sub-syndromes, use of factor analysis is appropriate to classify the sub-types without any basic measurement operation. Thus, the universe of symptoms behind DSM-5 major depression can indeed be combined in many different ways (Ostergaard, Jensen et al. Dec 2011). Sub-syndromes such as atypical depression (hyperphagia and hypersomnia), apathetic depression (tiredness, lack of interests, concentration problems, insomnia) have been identified by principal component analyses. In such sub-syndromes the Rasch model’s requirement of rank ordering or item difficulty is beyond the scope of the psychometric analysis. Here it is the confirmative validity of the items that is in focus.
Bech P. Is the antidepressive effect of second-generation antidepressants a myth? Psychological medicine 2010; 40: 181-186.
Bech P, Allerup P, Larsen ER, Csillag C, Licht RW. The Hamilton Depression Scale (HAM-D) and the Montgomery-Asberg Depression Scale (MADRS). A psychometric re-analysis of the European Genome-Based Therapeutic Drugs for Depression Study using Rasch analysis. Psychiatry research 2014 doi : 10.1016/j.psychres.2014.03.024.
Bech P, Allerup P, Reisby N, Gram LF. Assessment of symptom change from improvement curves on the Hamilton depression scale in trials with antidepressants. Psychopharmacology 1984; 84: 276-81.
Bech P, Fava M, Trivedi MH, Wisniewski SR, Rush AJ. Outcomes on the pharmacopsychometric triangle in bupropion-SR vs. buspirone augmentation of citalopram in the STAR*D trial. Acta Psychiatrica Scandinavica 2011; 125: 342-8.
Bech P, Gram LF, Dein E, Jacobsen O, Vitger J, Bolwig TG. Quantitative rating of depressive states. Acta Psychiatrica Scandinavica 1975; 51: 161-70.
Licht RW, Qvitzau S, Allerup P, Bech P. Validation of the Bech-Rafaelsen Melancholia Scale and the Hamilton Depression Scale in patients with major depression; is the total score a valid measure of illness severity? Acta Psychiatrica Scandinavica, 2005; 111: 144-9.
Ostergaard SD, Jensen SOW, Bech P. The heterogeneity of the depressive syndrome: When numbers get serious. Acta Psychiatrica Scandinavica 2011; 124: 495-6.
Ostergaard SD, Bech P, Trivedi M, Wisniewski S, Rush J. Fava M. 2014. Brief unidimensional melancholia rating scales are highly sensitive to the effect of citalopram and may have biological validity: Implications for the Research Domain Criteria (RDoC). Journal of Affective Disorders 2014; 163: 18-24.
May 29, 2014