The use of nalmefene, a biochemical treatment, is believed by Grant et al. (2008) to help reduce the urge to gamble. To test its effectiveness, participants were assessed to ensure they were suitable to participate. They were then randomly allocated to either a group receiving nalmefene or to a group receiving a placebo.

Mark scheme

Marking points from the official mark scheme (May/June 2020). The mark or mark type is shown in brackets.

1. [1] A placebo is a substance, such as a pill or injection (sugar or saline), given to a participant that has no therapeutic effect,
2. [1] but is where the participant responds as if they have received active ingredients.
3. [2] (b) 'studies enrolled only individuals with DSM-IV PG; psychiatric comorbidity was assessed using the Structured Clinical Interview for DSM-IV. A semi-structured, rater-administered questionnaire was used to collect clinical information.
4. [2] Gambling severity was assessed with the Yale Brown Obsessive Compulsive Scale Modified for Pathological Gambling [PG-YBOCS]. The first five items of the PG-YBOCS comprise the gambling urge/thought subscale and the final five comprise the gambling behaviour subscale.'
5. [2] (c) infrequent gambling (i.e. less than one time per week) that did not meet DSM-IV criteria for PG; / unstable medical illness or clinically significant abnormalities on laboratory tests, EKG, physical examination at screening visit;
6. [2] current pregnancy or lactation, or inadequate contraception in women of childbearing potential; / a need for medication other than nalmefene or naltrexone with possible psychotropic effects or medications with unfavorable interactions with nalmefene or naltrexone (e.g., narcotics); / lifetime history of bipolar disorder type I or II, dementia, schizophrenia, or any psychotic disorder; / current DSM-IV substance abuse or dependence with possible exception of nicotine dependence; / positive urine drug screen at screening; / initiation of psychotherapy or behavior therapy within 3 months prior to study baseline; / previous treatment with nalmefene or naltrexone; / clinically significant suicidality; / treatment with investigational medication or depot neuroleptics within 3 months, with fluoxetine within 4 weeks, or with other psychotropics within 2 weeks prior to study baseline.
7. [1] (d) Advantages: Biochemicals easy to take; swallowing a pill. / Biochemicals mean the gambler is passive in their treatment (an advantage for many people). / Biochemicals prevent production of endorphins and other neurochemicals associated with arousal/pleasure
8. [1] Disadvantages: biochemicals are addictive and the aim is to treat an addictive behaviour. / biochemicals may not be taken as prescribed (non-adherence). / biochemicals ignore the role of alternative reasons why a gambler might be addicted.
9. [1] Conclusion: any appropriate conclusion drawn from the discussion that has been presented. A conclusion is a 'decision reached by reasoning' and so a summary of points already made scores 0 marks.