Authors' Responses to the Comments on "Pattern and Correlates of Depression among Medical Students: An 18-Month Follow-Up Study".

Dear Sir,

We would like to thank the authors of the letter for the interest shown in our study and the comments. This was a study with three assessments for mental health measures overtime on medical students. The Patient Health Questionnaire (PHQ)-9 was employed as a cross-sectional measure of depression at each of the three assessments. Recently, investigators have employed the PHQ in a similar manner in medical students,[12] though there has been no effort to validate its repeated use.

The limitations due to attrition or non- response to specific scales at the follow-up assessments are already mentioned in the study.[3] Following your comments, we re-examined the data. On multivariate analysis, students lost to follow-up or who did not complete the PHQ were more likely to be from the government college (P < 0.001, OR = 7.14[2.86–20]) and of the male gender (P = 0.006, OR = 2.01[1.22–3.22]) at the second (8 months) and third (18 months) follow-ups, respectively. Otherwise, the two groups were comparable across baseline variables such as religion, personal choice of course, initial depression status, level of perceived support, and presence of alcohol intake. The variation in the number followed up between the colleges (government vs. private) may be explained by the gaps in the data collection. The implication of data from males being more likely to be missing in the third assessment may be viewed as possibly significant, though the nature of this significance is open to conjecture.

We agree that cannabis use has risen significantly in the state and may have mental health implications, as mentioned in the letter. However, the focus of the study was mental health measures (depression, burnout, and empathy [unpublished]) and the study was envisaged in 2012. At the time, there was no clear evidence of significant cannabis use among young medical students in Kerala, with studies having been published mainly from northern states in India.[45]

It would have been interesting to enquire about a family history of mental health issues, particularly depression, in view of the focus of this publication.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.