Screening for alcohol use and depression​

Clinical challenges with concurrent alcohol use and major depression

Concurrent alcohol use and major depression pose various clinical challenges:

• identifying alcohol use disorders in patients with symptoms of major depression
• knowing when and to what extent symptoms of major depression are alcohol induced
• managing concurrent alcohol use and major depression with the goal of achieving remission in both
• managing relapses in both disorders over the patient's lifetime.

Alcohol-induced major depression

Identifying alcohol-induced depression is important because depression caused by drinking has a different prognosis and is treated much differently from major depressive episodes that are not related to alcohol use.

Major depression is suggested by a constellation of symptoms that are elicited from a patient's description. These symptoms can occur in states that may be either:

• non-pathological (e.g., grief), pathological (e.g., major depressive disorder) or
• completely unrelated to a mood disorder (e.g., hypothyroidism).

Consequently, a diagnosis of major depressive disorder cannot be confirmed until potential mimics are ruled out. One such mimic is an alcohol-induced major depressive episode (Schuckit et al., 2013).

Beyond the many acute psychoactive effects of alcohol, the most common mental health presentations seen in primary care settings relate to alcohol's depression- and anxiety-inducing effects.

An alcohol use disorder can result in emotional, cognitive and behavioural changes that are indistinguishable from those of idiopathic major depression (often referred to as independent major depressive episode).

In patients with active alcohol use disorders and comorbid symptoms of major depression, major depressive episodes are most likely to be alcohol induced and to resolve completely with abstinence. More than 80 per cent of patients who meet criteria for major depressive episode have an alcohol-induced episode that resolves with abstinence (Brown et al., 1995; Davidson, 1995).

Up to four weeks of abstinence from alcohol is required to resolve alcohol-related changes and to determine whether the major depressive episode is alcohol induced.

In a significant proportion of people with alcohol-induced major depressive episodes, symptoms begin to show marked improvement after just one week of abstinence. Only 15 to 20 per cent continue to have clinically significant symptoms after four weeks of abstinence (Brown et al., 1995).

Influence of alcohol on major depression

Consuming alcohol at levels constituting an alcohol use disorder and, for some people, even at levels within the low-risk drinking guidelines, has many negative impacts on major depression (Castaneda et al., 1996; Centers for Disease Control and Prevention, 2009; Davis, 2008; Hashimoto, 2015; Hasin et al., 1996; Ishikawa, 2015). These include:

• increased suicide risk
• increased irritability and aggressiveness
• intensified hopelessness
• progressively exacerbated symptoms over time
• acutely intensified subset of symptoms
• poorer treatment adherence
• reduced or unsuccessful treatment efficacy
• increased risk of relapse or recurrence
• increased risk of chronic treatment-refractory major depression
• limited treatment options (e.g., sedative-hypnotics and bupropion are relatively contraindicated).

Influence of major depression on alcohol use

Patients with major depressive disorder or bipolar disorder have increased lifetime rates of alcohol use disorder.

Major depression may increase relapse risk in people with an alcohol use disorder.

• A Swiss study (Suter et al., 2011) that followed patients for one year following discharge from residential alcohol treatment found that patients with clinically significant depressive symptoms relapsed sooner and were less likely to maintain abstinence than patients without depression. They also had elevated alcohol use disorder indices and used psychiatric treatment services more often.
• Interestingly, several studies have found contradictory results, suggesting that a depressive episode, whether treated or untreated, does not influence the development of an alcohol use disorder (Curry et al., 2012; Schuckit et al., 2013).

Independent of the causal relationship, depressive symptoms in people being treated for alcohol use disorder have been associated with worse outcomes in the alcohol use disorder and on other measures of health and functioning (Samet et al., 2013; Sanchez et al., 2014).

Screening tools for concurrent alcohol use and major depression

Separate screening tests are required for alcohol use and major depression. There is no single screening test for concurrent alcohol use and major depression.

No screening test can distinguish between alcohol-induced depressive symptoms and idiopathic major depression.

Tools for identifying major depression

Useful self-administered screening tools for major depression include the freely available Patient Health Questionnaire (PHQ-9) and Hamilton Rating Scale for Depression (HAMD-7), as well as the Beck Depression Inventory.

Numerous replicated studies have found that structured instruments help to identify major depression and track treatment response in primary care settings (Trivedi, 2009).

Identifying hidden concurrent disorders

The likelihood of missing a disorder in screening varies:

• hidden major depression in the case of an identified alcohol use disorder (least likely to miss)
• hidden alcohol use disorder in the case of identified symptoms of major depression (most likely to miss)
• both disorders hidden when concurrent; that is, when these disorders co-occur, neither one presents in an obvious manner (does not happen).

If you suspect major depression, screen for alcohol use throughout treatment. This is especially important in cases of treatment failure, frequent deterioration or "brittle" control of depressive symptoms.

If you identify an alcohol use disorder, screen for major depression, especially in:

• women
• people who drink in a binge pattern
• people whose alcohol use disorder begins after age 30.