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Dual diagnosis: psychiatric illness and addiction

Patients with both a psychiatric illness and an addiction may have complex problems, but GPs can help them manage their condition, explains psychiatrist Dr Ash Kahn

Patients with both a psychiatric illness and an addiction may have complex problems, but GPs can help them manage their condition, explains psychiatrist Dr Ash Kahn

It is now estimated that a third of patients in mental health services have a substance misuse problem and half of patients in drug and alcohol services have a mental health issue.

In Britain, about 30% of people with serious mental illness also misuse drugs or alcohol. Factor in the multitude of patients such as depressed executives or housewives who are dependent on SSRIs and/or alcohol and prevalence rates increase even more.

There are complex connections between the issues: sustained substance misuse can exacerbate mental illness, and debilitating mental illness clearly increases inappropriate use of substances.Illnesses that may predispose to the development of an addictive disorder include depression, post-traumatic stress disorder, bipolar disorder and anxiety disorders which, if left untreated, increase the chronicity of both the addiction and the illness.

Substance misusers with a psychiatric disorder have an increased rate of rehospitalisation even when they take their medication, and substance misuse contributes to deterioration of psychotic illnesses.

Blaming the addiction
People with acute psychiatric illnesses usually know something is seriously wrong before they are diagnosed, but those who are dependent on alcohol or drugs try to blame their psychological symptoms on their addiction, not a second problem.

The problem does not disappear post-diagnosis. For example, patients with schizophrenia tend to self-medicate with drugs. Conventional medications either don't alleviate many of the symptoms, or carry unacceptable side-effects.

Haloperidol, for example, may make patients with schizophrenia feel sedated, so they may use amphetamines or crack cocaine to increase their feeling of well-being.A significant number of patients may present with a mental illness they have been attempting to self-treat. If the patient is in an acute state their concentration and insight will be poor.

Typically patients will use any substance for general relief of distress, rather than specific substances for specific symptom relief.It is important to elicit a thorough history of recent alcohol and/or drug use to differentiate symptoms of substance misuse from those of mental illness; however, symptoms can only be fully discussed when the patient is not under the influence.

History-taking at the initial consultation can be difficult and frustrating because misusers may be defensive, hostile, frightened and in denial, determined not to admit their addiction, or anything else, including psychiatric symptoms.

Corroborative information from family members or other agencies may be useful.

GPs must be aware of the process and intensity of addiction and assess patients for cross-addictions. Many presenting alcoholics will also be dependent on hypnotics or benzodiazepines, but consider their second addiction a minor point, so won't mention it.

There are also growing numbers of patients presenting with multi-impulsive disorders who have an eating disorder and an addiction.

Intervention saves lives
The morbidity and mortality rates for misusers are higher than for any other mental illness, yet patients are often written off, when effective and appropriate interventions can save lives, families and careers.

The development of an addictive disorder is influenced by a wide range of biopsychosocial factors, rather than a lack of moral fibre. It is essential to address the individual patient rather than attempting to determine and treat one issue.

Most symptoms and presenting problems in dual-diagnosis patients may be misattributed to either substance misuse or mental illness alone, and it may be almost impossible to determine which comes first. Hallucinations may present in alcohol abuse as part of a withdrawal state, which may be hard to distinguish from hallucinations that are part of a psychotic illness, and depression as a result of alcohol abuse may be impossible to distinguish from a mood disorder.

Both the psychiatric illness and the addiction need to be addressed – failure to treat one will result in the eventual failure of treatment of the other. This is a major issue in public sector service delivery, where community drug and alcohol teams, which offer brief interventions, are separate from community mental health teams, and where service provision for the severely addicted is lacking.

Research has demonstrated that community alcohol teams are confident when dealing with patients with alcohol-related problems but feel de-skilled when having to help patients with mental health problems as well. The same is true in reverse for community mental health teams.

Overall, the best outcomes for addiction (up to 70% recovery) are achieved when patients undergo an inpatient, abstinence-based, 12-step treatment programme and continue to attend fellowship meetings after their discharge. Patients with dual diagnosis disorders can be extremely challenging.

Lateness, rudeness and demanding behaviour are common during the initial consultation, yet a therapeutic alliance can be forged. They need an empathetic approach that honestly reflects the complexity of a dual diagnosis, identifies the challenges of treatment, and reiterates the GP's commitment to continued support. It may be beneficial to agree a consensus on treatment.

If patients accept and understand their illnesses, they can learn to manage and live with them. Patients with long-term conditions such as depression and bipolar disorder achieve better outcomes when they work in partnership with a practitioner. But generally outcomes are worse than for either psychiatric illnesses or addictions that present on their own.

Although speed of access is important, there is no quick fix for dual-diagnosis patients. GPs will have to view treatment as continuing, rather than finite. Since relapse rates for both addictions and mental illness are high, a staged approach that rewards incremental progress may be helpful.

Patients can go a long way to prolong the time to further episodes of illness through cognitive behaviour therapy, psychotherapy and working through emotional issues, but they must also acknowledge the importance of long-term medication. If patients discontinue their medication the underlying condition will recur and the patient may revert to substance abuse.

Education is the key: in some cases, it might be necessary to allow the patient to stop medication to prove the point.

Key indicators
• History of violence
• History of attempted suicide
• Contact with criminal justice system
• Relapse into substance abuse and psychiatric treatment
• Homelessness

Common outcomes
• Social problems/homelessness
• Dependence on multifaceted public services
• Worse psychiatric symptoms than patients with mental illness alone
• Poor physical health
• Prescribing problems caused by drug interactions with prescribed medication
• Non-compliance

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