An exploration of the misuse of Over the Counter (OTC) and Prescription Only Medication (POM) by people accessing substance misuse treatment services

Roz Gittins, Humankind


There is a growing concern about the role of over the counter (OTC) and prescription only medication (POM) in the mental health condition substance dependence. Medications which are licenced for mental health conditions, such as ADHD, anxiety, depression, insomnia and schizophrenia, including benzodiazepines, gabapentinoids, stimulants, antidepressants and antipsychotics have been implicated. There is increasing awareness of this issue, and the impact on drug interactions, mental health, overdoses and drug-related deaths. However, actual prevalence, demographic characteristics and the impact on the mental health and substance use of those accessing treatment from specialist substance misuse services (SMS) remains unknown due to the lack of appropriate monitoring systems. Mental health and SMS providers such as Humankind, have a significant role in managing POM and OTC misuse, especially when it impacts on other mental health or substance misuse issues.

Aims and objectives

The overall aim is to explore the misuse of OTCs and POMs by people accessing specialist SMS, including the extent of the issue, which medicines are misused, their associated experiences and how it impacts their mental health and use of other substances.

  • Complete a systematic review of the existing literature (registered on PROSPERO)
  • Identify the prevalence of the misuse of different OTC and POMs amongst those accessing SMS
  • Explore the relationship with ‘other’ substance use, mental health, negative and positive experiences and key demographics including gender, ethnicity and age
  • Identify the needs of people accessing and working in SMSs
  • Propose service development recommendations.


After completing a systematic review of the existing literature, at least 600 patients will be asked to complete an anonymised survey across 3 of Humankind’s SMS (in the South West, North East and West of England). The relationship between the prevalence of the misuse of different types of medicines, other drug use, mental health and associated demographic data (including gender, ethnicity and age) will be identified using regression analysis.  In addition, patients across these Humankind sites will be interviewed to gain a better understanding of their use, including positive and negative experiences, the relationship with ‘other’ substance use and their mental health.  Staff across the sites will also be interviewed to better understand their experience of supporting individuals. Using a modified grounded theory approach, semi-structured interviews will be conducted until data saturation is reached. All interviews will cover the needs of those requiring treatment and what they think services should be doing to help. Key themes will be identified using a framework approach.    

How the results of the research will be used

Service developments need to be informed about the nature of the problem and associated treatment needs. The findings will be shared to inform service developments, so that the extent of the current problem can be reduced, effective treatment can be offered and steps can be taken to prevent further occurrence. The results will be published in peer reviewed journals and shared at external forums, including the CMHP conference, so that other services and as many patients as possible may benefit.

This project is running from November 2019 and is due to finish in August 2021