HIV is a highly stigmatized, chronic disease with a substantial co-occurrence of mental health problems . On the one hand, patients with mental health problems are at increased risk of contracting HIV. On the other hand, HIV-infected patients are at increased risk of developing mental health problems compared with the general population . Mental health problems in HIV-infected patients have a negative influence on the treatment, adherence to treatment, and prognosis of the HIV-infection [3, 4]. Similar effects have been determined for other chronic diseases, such as diabetes and chronic obstructive pulmonary disease (COPD) [5, 6]. However, there are some important differences between HIV and other chronic diseases. First, HIV-infected patients suffer more from shame, stigma, and discrimination, which can also cause mental health problems [7, 8]. Second, mental health problems in HIV-infected patients can affect public health. Psychopathology like depression and substance abuse can increase hazardous sexual behaviour and, with it, the chance of spreading HIV [9, 10].
The most common mental disorders among HIV-infected patients are depression and depressive symptoms. The chance of developing a depressive disorder is two times higher in HIV-infected patients than in HIV-negative comparison subjects . Depressive symptoms are even more common: 54% of HIV-infected patients reported depressive symptoms in the past week . Although it has a high prevalence, only fewer than 50% of the cases are recognized clinically . Apart from the HIV-infection, stigma and discrimination are associated with an increase in depressive symptoms among HIV-infected patients . In addition, the risk of suicide and suicide attempts is higher among HIV-infected patients compared with the general population and compared with patients with other chronic diseases .
Conversely, several mental health problems have been identified as risk factors for contracting HIV [16, 17]. For example, depressive symptoms and the use of alcohol or drugs, such as amphetamine, cannabis and cocaine, are associated with increased sexually risky behaviour and an increased risk of contracting HIV, particularly among men who have sex with men(MSM) [18–20]. Certain personality traits of the Five-Factor Module of Personality  are also associated with an increased risk. High scores on neuroticism (chronic emotional distress, e.g. anxiety, depression, impulsiveness) and low scores on agreeableness (altruism, modesty, trust) and conscientiousness are associated with HIV risk behaviours .
Mental health problems can arise and increase during different stages of HIV, such as for example, immediately after testing HIV-positive or after many years of living with HIV . Despite the fact that mental health problems are poorly recognized by clinicians , some of the HIV-infected patients with mental health problems will seek help at an institution for mental health. To develop an optimal treatment plan for this group of patients, it is important to determine the demographic characteristics, psychiatric diagnoses and severity of the psychopathology.
In the Netherlands there is a database available that includes demographic data of almost all HIV-positive patients (ATHENA) . We are interested in knowing whether the mental health treatment seeking HIV-infected population in Amsterdam differs from the general HIV-infected population in Amsterdam on demographic and medical characteristics.
The majority of HIV-infected patients in the Netherlands are homosexual men. In 2010, 7532 men (58%) of the infected HIV population (13.035) were men who have sex with men (MSM) . It is interesting, therefore, to compare them with homosexual HIV-negative men.
It is unknown whether the presence of HIV has an effect on the severity of psychiatric symptoms of patients with mental health problems. We hypothesize that HIV may cause more severe symptoms and is associated with more co-morbid substance use among patients with a depressive or dysthymic disorder. Furthermore, HIV-infected patients with mental health problems probably show a different pattern in personality traits like neuroticism, agreeableness and conscientiousness, compared with non-infected patients with the same mental health problems.
If treatable mental health problems, such as depressive symptoms, alcohol and drug abuse and, to a lesser extent, personality traits are recognised and assessed, the prognosis of the HIV-infection might be improved and the risk of spreading HIV diminished. The present study had two main objectives. First, we described the clinical and demographic characteristics of patients with HIV who seek treatment for their mental health problems in a specialized outpatient clinic for HIV and mental health. We subsequently compared these patients with the general population of HIV-positive patients in the Netherlands. Second, we tested whether HIV-infected homosexual patients and non-infected homosexual patients with a lifetime depressive or dysthymic disorder differed on 1) depressive symptoms, 2) co-morbid use of alcohol and drugs, and 3) personality traits.
The chance of developing psychopathology is higher in HIV-infected patients than in HIV-negative comparison subjects . However, we also expect that these symptoms are more severe, due to the influence of a lifelong disease, exacerbated by stigma and discrimination.