Reliability and Validity of the Mental Health Quotient (MHQ)
Authors: Newson Jennifer , Pastukh Vladyslav , Thiagarajan Tara 
Published: October 2021

Background: The MHQ is an assessment of mental health and wellbeing that comprehensively covers symptoms across 10 major psychiatric disorders as defined by the DSM-5, in addition to constructs defined by RDoC and positive dimensions of mental function using a novel life-impact scale. An overall measure of mental wellbeing, the Mental Health Quotient or MHQ, is computed based on these elements using a nonlinear transformation of the scale followed by a rescaling. The MHQ has been deployed as part of the Mental Health Million Project as a freely available anonymous online assessment that, on completion, provides a score to the individual that places them on a spectrum from Distressed to Thriving along with a personal report spanning their various dimensions of mental wellbeing with strategies for improvement. Since its launch in April 2020 over 200,000 people have taken the MHQ. Here we provide various demonstrations of the reliability and validity of the MHQ.Objective: This paper outlines the reliability and validity of the Mental Health Quotient (MHQ), including construct validity of the life impact scale, sample and test-retest reliability of the assessment and criterion validation of the MHQ with respect to productivity loss and clinical burden.Methods: To assess sample reliability, random demographically matched samples of 11,033 people were compared from within the same 6-month period. Test retest reliability was determined using the subset of individuals who had taken the assessment twice at least 3 days apart (N=1907). In addition, a subset of respondents (N=4,247 or 7,625) were asked additional questions (along with the standard MHQ questions) on symptom frequency and severity for an example symptom (Feelings of Sadness, Distress or Hopelessness), days of work missed in the past month, and days with reduced productivity. In addition, elements with high negative life impact considered to meet the threshold to be considered a ‘symptom’ were mapped to the criteria for each of 10 major DSM-5 based mental health disorders to calculate the clinical burden (N=174,618).Results: Distinct samples collected during the same period had indistinguishable MHQ distributions and average ratings for each of the 47 elements, demonstrating the reliability of the assessment and MHQ scores were correlated with r=0.84 between retakes. The life impact rating was correlated with both frequency and severity of symptoms and mean values had a clear linear relationship with an R2&gt;0.99. Furthermore, aggregate MHQ scores were systematically related to both productivity and clinical burden. At one end of the scale, those in the Distressed category had an average productivity loss of 15.2±0.5 days per month with 89.08% (8,986/10,087) mapping to 1 or more DSM-5 based clinical disorders. In contrast those at the other end of the scale, in the Thriving category, had an average productivity loss of 1.3±0.1 and 0.00% (1/24,365) had any DSM-5 based clinical disorder.Conclusions: The MHQ is a valid and reliable assessment of mental wellbeing when delivered anonymously online